/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */

import {
  AnimationTriggerNames,
  BoundTarget,
  compileClassDebugInfo,
  compileComponentClassMetadata,
  compileComponentDeclareClassMetadata,
  compileComponentFromMetadata,
  compileDeclareComponentFromMetadata,
  compileDeferResolverFunction,
  ConstantPool,
  CssSelector,
  DeclarationListEmitMode,
  DeclareComponentTemplateInfo,
  DEFAULT_INTERPOLATION_CONFIG,
  DeferBlockDepsEmitMode,
  DomElementSchemaRegistry,
  ExternalExpr,
  FactoryTarget,
  makeBindingParser,
  outputAst as o,
  R3ComponentDeferMetadata,
  R3ComponentMetadata,
  R3DeferPerComponentDependency,
  R3DirectiveDependencyMetadata,
  R3NgModuleDependencyMetadata,
  R3PipeDependencyMetadata,
  R3TargetBinder,
  R3TemplateDependency,
  R3TemplateDependencyKind,
  R3TemplateDependencyMetadata,
  SchemaMetadata,
  SelectorMatcher,
  TmplAstDeferredBlock,
  ViewEncapsulation,
} from '@angular/compiler';
import ts from 'typescript';

import {Cycle, CycleAnalyzer, CycleHandlingStrategy} from '../../../cycles';
import {
  ErrorCode,
  FatalDiagnosticError,
  makeDiagnostic,
  makeRelatedInformation,
} from '../../../diagnostics';
import {absoluteFrom, relative} from '../../../file_system';
import {
  assertSuccessfulReferenceEmit,
  DeferredSymbolTracker,
  ImportedFile,
  ImportedSymbolsTracker,
  LocalCompilationExtraImportsTracker,
  ModuleResolver,
  Reference,
  ReferenceEmitter,
} from '../../../imports';
import {DependencyTracker} from '../../../incremental/api';
import {
  extractSemanticTypeParameters,
  SemanticDepGraphUpdater,
} from '../../../incremental/semantic_graph';
import {IndexingContext} from '../../../indexer';
import {
  DirectiveMeta,
  extractDirectiveTypeCheckMeta,
  HostDirectivesResolver,
  MatchSource,
  MetadataReader,
  MetadataRegistry,
  MetaKind,
  NgModuleMeta,
  PipeMeta,
  ResourceRegistry,
} from '../../../metadata';
import {PartialEvaluator} from '../../../partial_evaluator';
import {PerfEvent, PerfRecorder} from '../../../perf';
import {
  ClassDeclaration,
  DeclarationNode,
  Decorator,
  Import,
  isNamedClassDeclaration,
  ReflectionHost,
  reflectObjectLiteral,
} from '../../../reflection';
import {
  ComponentScopeKind,
  ComponentScopeReader,
  DtsModuleScopeResolver,
  LocalModuleScope,
  LocalModuleScopeRegistry,
  makeNotStandaloneDiagnostic,
  makeUnknownComponentImportDiagnostic,
  StandaloneScope,
  TypeCheckScopeRegistry,
} from '../../../scope';
import {
  getDiagnosticNode,
  makeUnknownComponentDeferredImportDiagnostic,
} from '../../../scope/src/util';
import {
  AnalysisOutput,
  CompilationMode,
  CompileResult,
  DecoratorHandler,
  DetectResult,
  HandlerPrecedence,
  ResolveResult,
} from '../../../transform';
import {TemplateId, TypeCheckableDirectiveMeta, TypeCheckContext} from '../../../typecheck/api';
import {ExtendedTemplateChecker} from '../../../typecheck/extended/api';
import {TemplateSemanticsChecker} from '../../../typecheck/template_semantics/api/api';
import {getSourceFile} from '../../../util/src/typescript';
import {Xi18nContext} from '../../../xi18n';
import {
  combineResolvers,
  compileDeclareFactory,
  compileInputTransformFields,
  compileNgFactoryDefField,
  compileResults,
  extractClassDebugInfo,
  extractClassMetadata,
  extractSchemas,
  findAngularDecorator,
  forwardRefResolver,
  getDirectiveDiagnostics,
  getProviderDiagnostics,
  InjectableClassRegistry,
  isExpressionForwardReference,
  readBaseClass,
  ReferencesRegistry,
  removeIdentifierReferences,
  resolveEncapsulationEnumValueLocally,
  resolveEnumValue,
  resolveImportedFile,
  resolveLiteral,
  resolveProvidersRequiringFactory,
  ResourceLoader,
  toFactoryMetadata,
  tryUnwrapForwardRef,
  validateHostDirectives,
  wrapFunctionExpressionsInParens,
} from '../../common';
import {extractDirectiveMetadata, parseDirectiveStyles} from '../../directive';
import {createModuleWithProvidersResolver, NgModuleSymbol} from '../../ng_module';

import {checkCustomElementSelectorForErrors, makeCyclicImportInfo} from './diagnostics';
import {
  ComponentAnalysisData,
  ComponentResolutionData,
  DeferredComponentDependency,
} from './metadata';
import {
  _extractTemplateStyleUrls,
  extractComponentStyleUrls,
  extractInlineStyleResources,
  extractTemplate,
  makeResourceNotFoundError,
  ParsedTemplateWithSource,
  parseTemplateDeclaration,
  preloadAndParseTemplate,
  ResourceTypeForDiagnostics,
  StyleUrlMeta,
  transformDecoratorResources,
} from './resources';
import {ComponentSymbol} from './symbol';
import {
  animationTriggerResolver,
  collectAnimationNames,
  validateAndFlattenComponentImports,
} from './util';
import {getTemplateDiagnostics} from '../../../typecheck';
import {JitDeclarationRegistry} from '../../common/src/jit_declaration_registry';

const EMPTY_ARRAY: any[] = [];

type UsedDirective = R3DirectiveDependencyMetadata & {
  ref: Reference<ClassDeclaration>;
  importedFile: ImportedFile;
};

type UsedPipe = R3PipeDependencyMetadata & {
  ref: Reference<ClassDeclaration>;
  importedFile: ImportedFile;
};

type UsedNgModule = R3NgModuleDependencyMetadata & {
  importedFile: ImportedFile;
};

type AnyUsedType = UsedPipe | UsedDirective | UsedNgModule;

type ComponentTemplate = R3ComponentMetadata<R3TemplateDependency>['template'];

const isUsedDirective = (decl: AnyUsedType): decl is UsedDirective =>
  decl.kind === R3TemplateDependencyKind.Directive;

const isUsedPipe = (decl: AnyUsedType): decl is UsedPipe =>
  decl.kind === R3TemplateDependencyKind.Pipe;

/**
 * `DecoratorHandler` which handles the `@Component` annotation.
 */
export class ComponentDecoratorHandler
  implements
    DecoratorHandler<Decorator, ComponentAnalysisData, ComponentSymbol, ComponentResolutionData>
{
  constructor(
    private reflector: ReflectionHost,
    private evaluator: PartialEvaluator,
    private metaRegistry: MetadataRegistry,
    private metaReader: MetadataReader,
    private scopeReader: ComponentScopeReader,
    private dtsScopeReader: DtsModuleScopeResolver,
    private scopeRegistry: LocalModuleScopeRegistry,
    private typeCheckScopeRegistry: TypeCheckScopeRegistry,
    private resourceRegistry: ResourceRegistry,
    private isCore: boolean,
    private strictCtorDeps: boolean,
    private resourceLoader: ResourceLoader,
    private rootDirs: ReadonlyArray<string>,
    private defaultPreserveWhitespaces: boolean,
    private i18nUseExternalIds: boolean,
    private enableI18nLegacyMessageIdFormat: boolean,
    private usePoisonedData: boolean,
    private i18nNormalizeLineEndingsInICUs: boolean,
    private moduleResolver: ModuleResolver,
    private cycleAnalyzer: CycleAnalyzer,
    private cycleHandlingStrategy: CycleHandlingStrategy,
    private refEmitter: ReferenceEmitter,
    private referencesRegistry: ReferencesRegistry,
    private depTracker: DependencyTracker | null,
    private injectableRegistry: InjectableClassRegistry,
    private semanticDepGraphUpdater: SemanticDepGraphUpdater | null,
    private annotateForClosureCompiler: boolean,
    private perf: PerfRecorder,
    private hostDirectivesResolver: HostDirectivesResolver,
    private importTracker: ImportedSymbolsTracker,
    private includeClassMetadata: boolean,
    private readonly compilationMode: CompilationMode,
    private readonly deferredSymbolTracker: DeferredSymbolTracker,
    private readonly forbidOrphanRendering: boolean,
    private readonly enableBlockSyntax: boolean,
    private readonly enableLetSyntax: boolean,
    private readonly localCompilationExtraImportsTracker: LocalCompilationExtraImportsTracker | null,
    private readonly jitDeclarationRegistry: JitDeclarationRegistry,
    private readonly i18nPreserveSignificantWhitespace: boolean,
  ) {
    this.extractTemplateOptions = {
      enableI18nLegacyMessageIdFormat: this.enableI18nLegacyMessageIdFormat,
      i18nNormalizeLineEndingsInICUs: this.i18nNormalizeLineEndingsInICUs,
      usePoisonedData: this.usePoisonedData,
      enableBlockSyntax: this.enableBlockSyntax,
      enableLetSyntax: this.enableLetSyntax,
      preserveSignificantWhitespace: this.i18nPreserveSignificantWhitespace,
    };
  }

  private literalCache = new Map<Decorator, ts.ObjectLiteralExpression>();
  private elementSchemaRegistry = new DomElementSchemaRegistry();

  /**
   * During the asynchronous preanalyze phase, it's necessary to parse the template to extract
   * any potential <link> tags which might need to be loaded. This cache ensures that work is not
   * thrown away, and the parsed template is reused during the analyze phase.
   */
  private preanalyzeTemplateCache = new Map<DeclarationNode, ParsedTemplateWithSource>();
  private preanalyzeStylesCache = new Map<DeclarationNode, string[] | null>();

  private extractTemplateOptions: {
    enableI18nLegacyMessageIdFormat: boolean;
    i18nNormalizeLineEndingsInICUs: boolean;
    usePoisonedData: boolean;
    enableBlockSyntax: boolean;
    enableLetSyntax: boolean;
    preserveSignificantWhitespace?: boolean;
  };

  readonly precedence = HandlerPrecedence.PRIMARY;
  readonly name = 'ComponentDecoratorHandler';

  detect(
    node: ClassDeclaration,
    decorators: Decorator[] | null,
  ): DetectResult<Decorator> | undefined {
    if (!decorators) {
      return undefined;
    }
    const decorator = findAngularDecorator(decorators, 'Component', this.isCore);
    if (decorator !== undefined) {
      return {
        trigger: decorator.node,
        decorator,
        metadata: decorator,
      };
    } else {
      return undefined;
    }
  }

  preanalyze(node: ClassDeclaration, decorator: Readonly<Decorator>): Promise<void> | undefined {
    // In preanalyze, resource URLs associated with the component are asynchronously preloaded via
    // the resourceLoader. This is the only time async operations are allowed for a component.
    // These resources are:
    //
    // - the templateUrl, if there is one
    // - any styleUrls if present
    // - any stylesheets referenced from <link> tags in the template itself
    //
    // As a result of the last one, the template must be parsed as part of preanalysis to extract
    // <link> tags, which may involve waiting for the templateUrl to be resolved first.

    // If preloading isn't possible, then skip this step.
    if (!this.resourceLoader.canPreload) {
      return undefined;
    }

    const meta = resolveLiteral(decorator, this.literalCache);
    const component = reflectObjectLiteral(meta);
    const containingFile = node.getSourceFile().fileName;

    const resolveStyleUrl = (styleUrl: string): Promise<void> | undefined => {
      try {
        const resourceUrl = this.resourceLoader.resolve(styleUrl, containingFile);
        return this.resourceLoader.preload(resourceUrl, {type: 'style', containingFile});
      } catch {
        // Don't worry about failures to preload. We can handle this problem during analysis by
        // producing a diagnostic.
        return undefined;
      }
    };

    // A Promise that waits for the template and all <link>ed styles within it to be preloaded.
    const templateAndTemplateStyleResources = preloadAndParseTemplate(
      this.evaluator,
      this.resourceLoader,
      this.depTracker,
      this.preanalyzeTemplateCache,
      node,
      decorator,
      component,
      containingFile,
      this.defaultPreserveWhitespaces,
      this.extractTemplateOptions,
      this.compilationMode,
    ).then(
      (template): {templateUrl?: string; templateStyles: string[]; templateStyleUrls: string[]} => {
        if (template === null) {
          return {templateStyles: [], templateStyleUrls: []};
        }

        let templateUrl;
        if (template.sourceMapping.type === 'external') {
          templateUrl = template.sourceMapping.templateUrl;
        }

        return {
          templateUrl,
          templateStyles: template.styles,
          templateStyleUrls: template.styleUrls,
        };
      },
    );

    // Extract all the styleUrls in the decorator.
    const componentStyleUrls = extractComponentStyleUrls(this.evaluator, component);

    return templateAndTemplateStyleResources.then(async (templateInfo) => {
      // Extract inline styles, process, and cache for use in synchronous analyze phase
      let styles: string[] | null = null;
      const rawStyles = parseDirectiveStyles(component, this.evaluator, this.compilationMode);
      if (rawStyles?.length) {
        styles = await Promise.all(
          rawStyles.map((style) =>
            this.resourceLoader.preprocessInline(style, {type: 'style', containingFile}),
          ),
        );
      }
      if (templateInfo.templateStyles) {
        styles ??= [];
        styles.push(
          ...(await Promise.all(
            templateInfo.templateStyles.map((style) =>
              this.resourceLoader.preprocessInline(style, {
                type: 'style',
                containingFile: templateInfo.templateUrl ?? containingFile,
              }),
            ),
          )),
        );
      }

      this.preanalyzeStylesCache.set(node, styles);

      // Wait for both the template and all styleUrl resources to resolve.
      await Promise.all([
        ...componentStyleUrls.map((styleUrl) => resolveStyleUrl(styleUrl.url)),
        ...templateInfo.templateStyleUrls.map((url) => resolveStyleUrl(url)),
      ]);
    });
  }

  analyze(
    node: ClassDeclaration,
    decorator: Readonly<Decorator>,
  ): AnalysisOutput<ComponentAnalysisData> {
    this.perf.eventCount(PerfEvent.AnalyzeComponent);
    const containingFile = node.getSourceFile().fileName;
    this.literalCache.delete(decorator);

    let diagnostics: ts.Diagnostic[] | undefined;
    let isPoisoned = false;
    // @Component inherits @Directive, so begin by extracting the @Directive metadata and building
    // on it.
    const directiveResult = extractDirectiveMetadata(
      node,
      decorator,
      this.reflector,
      this.importTracker,
      this.evaluator,
      this.refEmitter,
      this.referencesRegistry,
      this.isCore,
      this.annotateForClosureCompiler,
      this.compilationMode,
      this.elementSchemaRegistry.getDefaultComponentElementName(),
    );
    // `extractDirectiveMetadata` returns `jitForced = true` when the `@Component` has
    // set `jit: true`. In this case, compilation of the decorator is skipped. Returning
    // an empty object signifies that no analysis was produced.
    if (directiveResult.jitForced) {
      this.jitDeclarationRegistry.jitDeclarations.add(node);
      return {};
    }

    // Next, read the `@Component`-specific fields.
    const {
      decorator: component,
      metadata,
      inputs,
      outputs,
      hostDirectives,
      rawHostDirectives,
    } = directiveResult;
    const encapsulation: number =
      (this.compilationMode !== CompilationMode.LOCAL
        ? resolveEnumValue(this.evaluator, component, 'encapsulation', 'ViewEncapsulation')
        : resolveEncapsulationEnumValueLocally(component.get('encapsulation'))) ??
      ViewEncapsulation.Emulated;

    let changeDetection: number | o.Expression | null = null;
    if (this.compilationMode !== CompilationMode.LOCAL) {
      changeDetection = resolveEnumValue(
        this.evaluator,
        component,
        'changeDetection',
        'ChangeDetectionStrategy',
      );
    } else if (component.has('changeDetection')) {
      changeDetection = new o.WrappedNodeExpr(component.get('changeDetection')!);
    }

    let animations: o.Expression | null = null;
    let animationTriggerNames: AnimationTriggerNames | null = null;
    if (component.has('animations')) {
      const animationExpression = component.get('animations')!;
      animations = new o.WrappedNodeExpr(animationExpression);
      const animationsValue = this.evaluator.evaluate(
        animationExpression,
        animationTriggerResolver,
      );
      animationTriggerNames = {includesDynamicAnimations: false, staticTriggerNames: []};
      collectAnimationNames(animationsValue, animationTriggerNames);
    }

    // Go through the root directories for this project, and select the one with the smallest
    // relative path representation.
    const relativeContextFilePath = this.rootDirs.reduce<string | undefined>(
      (previous, rootDir) => {
        const candidate = relative(absoluteFrom(rootDir), absoluteFrom(containingFile));
        if (previous === undefined || candidate.length < previous.length) {
          return candidate;
        } else {
          return previous;
        }
      },
      undefined,
    )!;

    // Note that we could technically combine the `viewProvidersRequiringFactory` and
    // `providersRequiringFactory` into a single set, but we keep the separate so that
    // we can distinguish where an error is coming from when logging the diagnostics in `resolve`.
    let viewProvidersRequiringFactory: Set<Reference<ClassDeclaration>> | null = null;
    let providersRequiringFactory: Set<Reference<ClassDeclaration>> | null = null;
    let wrappedViewProviders: o.Expression | null = null;

    if (component.has('viewProviders')) {
      const viewProviders = component.get('viewProviders')!;
      viewProvidersRequiringFactory = resolveProvidersRequiringFactory(
        viewProviders,
        this.reflector,
        this.evaluator,
      );
      wrappedViewProviders = new o.WrappedNodeExpr(
        this.annotateForClosureCompiler
          ? wrapFunctionExpressionsInParens(viewProviders)
          : viewProviders,
      );
    }

    if (component.has('providers')) {
      providersRequiringFactory = resolveProvidersRequiringFactory(
        component.get('providers')!,
        this.reflector,
        this.evaluator,
      );
    }

    let resolvedImports: Reference<ClassDeclaration>[] | null = null;
    let resolvedDeferredImports: Reference<ClassDeclaration>[] | null = null;

    let rawImports: ts.Expression | null = component.get('imports') ?? null;
    let rawDeferredImports: ts.Expression | null = component.get('deferredImports') ?? null;

    if ((rawImports || rawDeferredImports) && !metadata.isStandalone) {
      if (diagnostics === undefined) {
        diagnostics = [];
      }
      const importsField = rawImports ? 'imports' : 'deferredImports';
      diagnostics.push(
        makeDiagnostic(
          ErrorCode.COMPONENT_NOT_STANDALONE,
          component.get(importsField)!,
          `'${importsField}' is only valid on a component that is standalone.`,
          [
            makeRelatedInformation(
              node.name,
              `Did you forget to add 'standalone: true' to this @Component?`,
            ),
          ],
        ),
      );
      // Poison the component so that we don't spam further template type-checking errors that
      // result from misconfigured imports.
      isPoisoned = true;
    } else if (
      this.compilationMode !== CompilationMode.LOCAL &&
      (rawImports || rawDeferredImports)
    ) {
      const importResolvers = combineResolvers([
        createModuleWithProvidersResolver(this.reflector, this.isCore),
        forwardRefResolver,
      ]);

      const importDiagnostics: ts.Diagnostic[] = [];

      if (rawImports) {
        const expr = rawImports;
        const imported = this.evaluator.evaluate(expr, importResolvers);
        const {imports: flattened, diagnostics} = validateAndFlattenComponentImports(
          imported,
          expr,
          false /* isDeferred */,
        );
        importDiagnostics.push(...diagnostics);
        resolvedImports = flattened;
        rawImports = expr;
      }

      if (rawDeferredImports) {
        const expr = rawDeferredImports;
        const imported = this.evaluator.evaluate(expr, importResolvers);
        const {imports: flattened, diagnostics} = validateAndFlattenComponentImports(
          imported,
          expr,
          true /* isDeferred */,
        );
        importDiagnostics.push(...diagnostics);
        resolvedDeferredImports = flattened;
        rawDeferredImports = expr;
      }

      if (importDiagnostics.length > 0) {
        isPoisoned = true;
        if (diagnostics === undefined) {
          diagnostics = [];
        }
        diagnostics.push(...importDiagnostics);
      }
    }

    let schemas: SchemaMetadata[] | null = null;
    if (component.has('schemas') && !metadata.isStandalone) {
      if (diagnostics === undefined) {
        diagnostics = [];
      }
      diagnostics.push(
        makeDiagnostic(
          ErrorCode.COMPONENT_NOT_STANDALONE,
          component.get('schemas')!,
          `'schemas' is only valid on a component that is standalone.`,
        ),
      );
    } else if (this.compilationMode !== CompilationMode.LOCAL && component.has('schemas')) {
      schemas = extractSchemas(component.get('schemas')!, this.evaluator, 'Component');
    } else if (metadata.isStandalone) {
      schemas = [];
    }

    // Parse the template.
    // If a preanalyze phase was executed, the template may already exist in parsed form, so check
    // the preanalyzeTemplateCache.
    // Extract a closure of the template parsing code so that it can be reparsed with different
    // options if needed, like in the indexing pipeline.
    let template: ParsedTemplateWithSource;
    if (this.preanalyzeTemplateCache.has(node)) {
      // The template was parsed in preanalyze. Use it and delete it to save memory.
      const preanalyzed = this.preanalyzeTemplateCache.get(node)!;
      this.preanalyzeTemplateCache.delete(node);

      template = preanalyzed;
    } else {
      const templateDecl = parseTemplateDeclaration(
        node,
        decorator,
        component,
        containingFile,
        this.evaluator,
        this.depTracker,
        this.resourceLoader,
        this.defaultPreserveWhitespaces,
      );
      template = extractTemplate(
        node,
        templateDecl,
        this.evaluator,
        this.depTracker,
        this.resourceLoader,
        {
          enableI18nLegacyMessageIdFormat: this.enableI18nLegacyMessageIdFormat,
          i18nNormalizeLineEndingsInICUs: this.i18nNormalizeLineEndingsInICUs,
          usePoisonedData: this.usePoisonedData,
          enableBlockSyntax: this.enableBlockSyntax,
          enableLetSyntax: this.enableLetSyntax,
          preserveSignificantWhitespace: this.i18nPreserveSignificantWhitespace,
        },
        this.compilationMode,
      );

      if (
        this.compilationMode === CompilationMode.LOCAL &&
        template.errors &&
        template.errors.length > 0
      ) {
        // Template errors are handled at the type check phase. But we skip this phase in local compilation mode. As a result we need to handle the errors now and add them to the diagnostics.
        if (diagnostics === undefined) {
          diagnostics = [];
        }

        diagnostics.push(
          ...getTemplateDiagnostics(
            template.errors,
            '' as TemplateId, // Template ID is required as part of the template type check, mainly for mapping the template to its component class. But here we are generating the diagnostic outside of the type check context, and so we skip the template ID.
            template.sourceMapping,
          ),
        );
      }
    }
    const templateResource = template.declaration.isInline
      ? {path: null, expression: component.get('template')!}
      : {
          path: absoluteFrom(template.declaration.resolvedTemplateUrl),
          expression: template.sourceMapping.node,
        };

    // Figure out the set of styles. The ordering here is important: external resources (styleUrls)
    // precede inline styles, and styles defined in the template override styles defined in the
    // component.
    let styles: string[] = [];

    const styleResources = extractInlineStyleResources(component);
    const styleUrls: StyleUrlMeta[] = [
      ...extractComponentStyleUrls(this.evaluator, component),
      ..._extractTemplateStyleUrls(template),
    ];

    for (const styleUrl of styleUrls) {
      try {
        const resourceUrl = this.resourceLoader.resolve(styleUrl.url, containingFile);
        if (
          styleUrl.source === ResourceTypeForDiagnostics.StylesheetFromDecorator &&
          ts.isStringLiteralLike(styleUrl.expression)
        ) {
          // Only string literal values from the decorator are considered style resources
          styleResources.add({
            path: absoluteFrom(resourceUrl),
            expression: styleUrl.expression,
          });
        }
        const resourceStr = this.resourceLoader.load(resourceUrl);
        styles.push(resourceStr);
        if (this.depTracker !== null) {
          this.depTracker.addResourceDependency(node.getSourceFile(), absoluteFrom(resourceUrl));
        }
      } catch {
        if (this.depTracker !== null) {
          // The analysis of this file cannot be re-used if one of the style URLs could
          // not be resolved or loaded. Future builds should re-analyze and re-attempt
          // resolution/loading.
          this.depTracker.recordDependencyAnalysisFailure(node.getSourceFile());
        }

        if (diagnostics === undefined) {
          diagnostics = [];
        }
        const resourceType =
          styleUrl.source === ResourceTypeForDiagnostics.StylesheetFromDecorator
            ? ResourceTypeForDiagnostics.StylesheetFromDecorator
            : ResourceTypeForDiagnostics.StylesheetFromTemplate;
        diagnostics.push(
          makeResourceNotFoundError(styleUrl.url, styleUrl.expression, resourceType).toDiagnostic(),
        );
      }
    }

    if (encapsulation === ViewEncapsulation.ShadowDom && metadata.selector !== null) {
      const selectorError = checkCustomElementSelectorForErrors(metadata.selector);
      if (selectorError !== null) {
        if (diagnostics === undefined) {
          diagnostics = [];
        }
        diagnostics.push(
          makeDiagnostic(
            ErrorCode.COMPONENT_INVALID_SHADOW_DOM_SELECTOR,
            component.get('selector')!,
            selectorError,
          ),
        );
      }
    }

    // If inline styles were preprocessed use those
    let inlineStyles: string[] | null = null;
    if (this.preanalyzeStylesCache.has(node)) {
      inlineStyles = this.preanalyzeStylesCache.get(node)!;
      this.preanalyzeStylesCache.delete(node);
      if (inlineStyles !== null) {
        styles.push(...inlineStyles);
      }
    } else {
      // Preprocessing is only supported asynchronously
      // If no style cache entry is present asynchronous preanalyze was not executed.
      // This protects against accidental differences in resource contents when preanalysis
      // is not used with a provided transformResource hook on the ResourceHost.
      if (this.resourceLoader.canPreprocess) {
        throw new Error('Inline resource processing requires asynchronous preanalyze.');
      }

      if (component.has('styles')) {
        const litStyles = parseDirectiveStyles(component, this.evaluator, this.compilationMode);
        if (litStyles !== null) {
          inlineStyles = [...litStyles];
          styles.push(...litStyles);
        }
      }

      if (template.styles.length > 0) {
        styles.push(...template.styles);
      }
    }

    // Collect all explicitly deferred symbols from the `@Component.deferredImports` field
    // (if it exists) and populate the `DeferredSymbolTracker` state. These operations are safe
    // for the local compilation mode, since they don't require accessing/resolving symbols
    // outside of the current source file.
    let explicitlyDeferredTypes: R3DeferPerComponentDependency[] | null = null;
    if (metadata.isStandalone && rawDeferredImports !== null) {
      const deferredTypes = this.collectExplicitlyDeferredSymbols(rawDeferredImports);
      for (const [deferredType, importDetails] of deferredTypes) {
        explicitlyDeferredTypes ??= [];
        explicitlyDeferredTypes.push({
          symbolName: importDetails.name,
          importPath: importDetails.from,
          isDefaultImport: isDefaultImport(importDetails.node),
        });
        this.deferredSymbolTracker.markAsDeferrableCandidate(
          deferredType,
          importDetails.node,
          node,
          true /* isExplicitlyDeferred */,
        );
      }
    }

    const output: AnalysisOutput<ComponentAnalysisData> = {
      analysis: {
        baseClass: readBaseClass(node, this.reflector, this.evaluator),
        inputs,
        inputFieldNamesFromMetadataArray: directiveResult.inputFieldNamesFromMetadataArray,
        outputs,
        hostDirectives,
        rawHostDirectives,
        meta: {
          ...metadata,
          template,
          encapsulation,
          changeDetection,
          interpolation: template.interpolationConfig ?? DEFAULT_INTERPOLATION_CONFIG,
          styles,

          // These will be replaced during the compilation step, after all `NgModule`s have been
          // analyzed and the full compilation scope for the component can be realized.
          animations,
          viewProviders: wrappedViewProviders,
          i18nUseExternalIds: this.i18nUseExternalIds,
          relativeContextFilePath,
          rawImports: rawImports !== null ? new o.WrappedNodeExpr(rawImports) : undefined,
        },
        typeCheckMeta: extractDirectiveTypeCheckMeta(node, inputs, this.reflector),
        classMetadata: this.includeClassMetadata
          ? extractClassMetadata(
              node,
              this.reflector,
              this.isCore,
              this.annotateForClosureCompiler,
              (dec) => transformDecoratorResources(dec, component, styles, template),
            )
          : null,
        classDebugInfo: extractClassDebugInfo(
          node,
          this.reflector,
          this.rootDirs,
          /* forbidOrphanRenderering */ this.forbidOrphanRendering,
        ),
        template,
        providersRequiringFactory,
        viewProvidersRequiringFactory,
        inlineStyles,
        styleUrls,
        resources: {
          styles: styleResources,
          template: templateResource,
        },
        isPoisoned,
        animationTriggerNames,
        rawImports,
        resolvedImports,
        rawDeferredImports,
        resolvedDeferredImports,
        explicitlyDeferredTypes,
        schemas,
        decorator: (decorator?.node as ts.Decorator | null) ?? null,
      },
      diagnostics,
    };

    return output;
  }

  symbol(node: ClassDeclaration, analysis: Readonly<ComponentAnalysisData>): ComponentSymbol {
    const typeParameters = extractSemanticTypeParameters(node);

    return new ComponentSymbol(
      node,
      analysis.meta.selector,
      analysis.inputs,
      analysis.outputs,
      analysis.meta.exportAs,
      analysis.typeCheckMeta,
      typeParameters,
    );
  }

  register(node: ClassDeclaration, analysis: ComponentAnalysisData): void {
    // Register this component's information with the `MetadataRegistry`. This ensures that
    // the information about the component is available during the compile() phase.
    const ref = new Reference(node);
    this.metaRegistry.registerDirectiveMetadata({
      kind: MetaKind.Directive,
      matchSource: MatchSource.Selector,
      ref,
      name: node.name.text,
      selector: analysis.meta.selector,
      exportAs: analysis.meta.exportAs,
      inputs: analysis.inputs,
      inputFieldNamesFromMetadataArray: analysis.inputFieldNamesFromMetadataArray,
      outputs: analysis.outputs,
      queries: analysis.meta.queries.map((query) => query.propertyName),
      isComponent: true,
      baseClass: analysis.baseClass,
      hostDirectives: analysis.hostDirectives,
      ...analysis.typeCheckMeta,
      isPoisoned: analysis.isPoisoned,
      isStructural: false,
      isStandalone: analysis.meta.isStandalone,
      isSignal: analysis.meta.isSignal,
      imports: analysis.resolvedImports,
      rawImports: analysis.rawImports,
      deferredImports: analysis.resolvedDeferredImports,
      animationTriggerNames: analysis.animationTriggerNames,
      schemas: analysis.schemas,
      decorator: analysis.decorator,
      assumedToExportProviders: false,
      ngContentSelectors: analysis.template.ngContentSelectors,
      preserveWhitespaces: analysis.template.preserveWhitespaces ?? false,
      isExplicitlyDeferred: false,
    });

    this.resourceRegistry.registerResources(analysis.resources, node);
    this.injectableRegistry.registerInjectable(node, {
      ctorDeps: analysis.meta.deps,
    });
  }

  index(
    context: IndexingContext,
    node: ClassDeclaration,
    analysis: Readonly<ComponentAnalysisData>,
  ) {
    if (analysis.isPoisoned && !this.usePoisonedData) {
      return null;
    }
    const scope = this.scopeReader.getScopeForComponent(node);
    const selector = analysis.meta.selector;
    const matcher = new SelectorMatcher<DirectiveMeta[]>();
    if (scope !== null) {
      let {dependencies, isPoisoned} =
        scope.kind === ComponentScopeKind.NgModule ? scope.compilation : scope;
      if (
        (isPoisoned || (scope.kind === ComponentScopeKind.NgModule && scope.exported.isPoisoned)) &&
        !this.usePoisonedData
      ) {
        // Don't bother indexing components which had erroneous scopes, unless specifically
        // requested.
        return null;
      }

      for (const dep of dependencies) {
        if (dep.kind === MetaKind.Directive && dep.selector !== null) {
          matcher.addSelectables(CssSelector.parse(dep.selector), [
            ...this.hostDirectivesResolver.resolve(dep),
            dep,
          ]);
        }
      }
    }
    const binder = new R3TargetBinder(matcher);
    const boundTemplate = binder.bind({template: analysis.template.diagNodes});

    context.addComponent({
      declaration: node,
      selector,
      boundTemplate,
      templateMeta: {
        isInline: analysis.template.declaration.isInline,
        file: analysis.template.file,
      },
    });
    return null;
  }

  typeCheck(
    ctx: TypeCheckContext,
    node: ClassDeclaration,
    meta: Readonly<ComponentAnalysisData>,
  ): void {
    if (this.typeCheckScopeRegistry === null || !ts.isClassDeclaration(node)) {
      return;
    }

    if (meta.isPoisoned && !this.usePoisonedData) {
      return;
    }
    const scope = this.typeCheckScopeRegistry.getTypeCheckScope(node);
    if (scope.isPoisoned && !this.usePoisonedData) {
      // Don't type-check components that had errors in their scopes, unless requested.
      return;
    }

    const binder = new R3TargetBinder<TypeCheckableDirectiveMeta>(scope.matcher);
    ctx.addTemplate(
      new Reference(node),
      binder,
      meta.template.diagNodes,
      scope.pipes,
      scope.schemas,
      meta.template.sourceMapping,
      meta.template.file,
      meta.template.errors,
      meta.meta.isStandalone,
      meta.meta.template.preserveWhitespaces ?? false,
    );
  }

  extendedTemplateCheck(
    component: ts.ClassDeclaration,
    extendedTemplateChecker: ExtendedTemplateChecker,
  ): ts.Diagnostic[] {
    return extendedTemplateChecker.getDiagnosticsForComponent(component);
  }

  templateSemanticsCheck(
    component: ts.ClassDeclaration,
    templateSemanticsChecker: TemplateSemanticsChecker,
  ): ts.Diagnostic[] {
    return templateSemanticsChecker.getDiagnosticsForComponent(component);
  }

  resolve(
    node: ClassDeclaration,
    analysis: Readonly<ComponentAnalysisData>,
    symbol: ComponentSymbol,
  ): ResolveResult<ComponentResolutionData> {
    const metadata = analysis.meta as Readonly<R3ComponentMetadata<R3TemplateDependencyMetadata>>;
    const diagnostics: ts.Diagnostic[] = [];
    const context = getSourceFile(node);

    // Check if there are some import declarations that contain symbols used within
    // the `@Component.deferredImports` field, but those imports contain other symbols
    // and thus the declaration can not be removed. This diagnostics is shared between local and
    // global compilation modes.
    const nonRemovableImports = this.deferredSymbolTracker.getNonRemovableDeferredImports(
      context,
      node,
    );
    if (nonRemovableImports.length > 0) {
      for (const importDecl of nonRemovableImports) {
        const diagnostic = makeDiagnostic(
          ErrorCode.DEFERRED_DEPENDENCY_IMPORTED_EAGERLY,
          importDecl,
          `This import contains symbols that are used both inside and outside of the ` +
            `\`@Component.deferredImports\` fields in the file. This renders all these ` +
            `defer imports useless as this import remains and its module is eagerly loaded. ` +
            `To fix this, make sure that all symbols from the import are *only* used within ` +
            `\`@Component.deferredImports\` arrays and there are no other references to those ` +
            `symbols present in this file.`,
        );
        diagnostics.push(diagnostic);
      }
      return {diagnostics};
    }

    let data: ComponentResolutionData;

    if (this.compilationMode === CompilationMode.LOCAL) {
      // Initial value in local compilation mode.
      data = {
        declarations: EMPTY_ARRAY,
        declarationListEmitMode:
          !analysis.meta.isStandalone || analysis.rawImports !== null
            ? DeclarationListEmitMode.RuntimeResolved
            : DeclarationListEmitMode.Direct,
        deferPerBlockDependencies: this.locateDeferBlocksWithoutScope(analysis.template),
        deferBlockDepsEmitMode: DeferBlockDepsEmitMode.PerComponent,
        deferrableDeclToImportDecl: new Map(),
        deferPerComponentDependencies: analysis.explicitlyDeferredTypes ?? [],
      };

      if (this.localCompilationExtraImportsTracker === null) {
        // In local compilation mode the resolve phase is only needed for generating extra imports.
        // Otherwise we can skip it.
        return {data};
      }
    } else {
      // Initial value in global compilation mode.
      data = {
        declarations: EMPTY_ARRAY,
        declarationListEmitMode: DeclarationListEmitMode.Direct,
        deferPerBlockDependencies: new Map(),
        deferBlockDepsEmitMode: DeferBlockDepsEmitMode.PerBlock,
        deferrableDeclToImportDecl: new Map(),
        deferPerComponentDependencies: [],
      };
    }

    if (this.semanticDepGraphUpdater !== null && analysis.baseClass instanceof Reference) {
      symbol.baseClass = this.semanticDepGraphUpdater.getSymbol(analysis.baseClass.node);
    }

    if (analysis.isPoisoned && !this.usePoisonedData) {
      return {};
    }

    const scope = this.scopeReader.getScopeForComponent(node);
    if (scope !== null) {
      // Replace the empty components and directives from the analyze() step with a fully expanded
      // scope. This is possible now because during resolve() the whole compilation unit has been
      // fully analyzed.
      //
      // First it needs to be determined if actually importing the directives/pipes used in the
      // template would create a cycle. Currently ngtsc refuses to generate cycles, so an option
      // known as "remote scoping" is used if a cycle would be created. In remote scoping, the
      // module file sets the directives/pipes on the ɵcmp of the component, without
      // requiring new imports (but also in a way that breaks tree shaking).
      //
      // Determining this is challenging, because the TemplateDefinitionBuilder is responsible for
      // matching directives and pipes in the template; however, that doesn't run until the actual
      // compile() step. It's not possible to run template compilation sooner as it requires the
      // ConstantPool for the overall file being compiled (which isn't available until the
      // transform step).
      //
      // Instead, directives/pipes are matched independently here, using the R3TargetBinder. This
      // is an alternative implementation of template matching which is used for template
      // type-checking and will eventually replace matching in the TemplateDefinitionBuilder.

      const isModuleScope = scope.kind === ComponentScopeKind.NgModule;
      // Dependencies coming from the regular `imports` field.
      const dependencies = isModuleScope ? scope.compilation.dependencies : scope.dependencies;
      // Dependencies from the `@Component.deferredImports` field.
      const explicitlyDeferredDependencies = getExplicitlyDeferredDeps(scope);

      // Mark the component is an NgModule-based component with its NgModule in a different file
      // then mark this file for extra import generation
      if (isModuleScope && context.fileName !== getSourceFile(scope.ngModule).fileName) {
        this.localCompilationExtraImportsTracker?.markFileForExtraImportGeneration(context);
      }

      // Make sure that `@Component.imports` and `@Component.deferredImports` do not have
      // the same dependencies.
      if (
        metadata.isStandalone &&
        analysis.rawDeferredImports !== null &&
        explicitlyDeferredDependencies.length > 0
      ) {
        const diagnostic = validateNoImportOverlap(
          dependencies,
          explicitlyDeferredDependencies,
          analysis.rawDeferredImports,
        );
        if (diagnostic !== null) {
          diagnostics.push(diagnostic);
        }
      }

      // Set up the R3TargetBinder, as well as a 'directives' array and a 'pipes' map that are
      // later fed to the TemplateDefinitionBuilder.
      const binder = createTargetBinder(dependencies);
      const pipes = extractPipes(dependencies);

      let allDependencies = dependencies;
      let deferBlockBinder = binder;

      // If there are any explicitly deferred dependencies (via `@Component.deferredImports`),
      // re-compute the list of dependencies and create a new binder for defer blocks.
      if (explicitlyDeferredDependencies.length > 0) {
        allDependencies = [...explicitlyDeferredDependencies, ...dependencies];
        deferBlockBinder = createTargetBinder(allDependencies);
      }

      // Next, the component template AST is bound using the R3TargetBinder. This produces a
      // BoundTarget, which is similar to a ts.TypeChecker.
      const bound = binder.bind({template: metadata.template.nodes});

      // Find all defer blocks used in the template and for each block
      // bind its own scope.
      const deferBlocks = new Map<TmplAstDeferredBlock, BoundTarget<DirectiveMeta>>();
      for (const deferBlock of bound.getDeferBlocks()) {
        deferBlocks.set(deferBlock, deferBlockBinder.bind({template: deferBlock.children}));
      }

      // Register all Directives and Pipes used at the top level (outside
      // of any defer blocks), which would be eagerly referenced.
      const eagerlyUsed = new Set<ClassDeclaration>();
      for (const dir of bound.getEagerlyUsedDirectives()) {
        eagerlyUsed.add(dir.ref.node);
      }
      for (const name of bound.getEagerlyUsedPipes()) {
        if (!pipes.has(name)) {
          continue;
        }
        eagerlyUsed.add(pipes.get(name)!.ref.node);
      }

      // Set of Directives and Pipes used across the entire template,
      // including all defer blocks.
      const wholeTemplateUsed = new Set<ClassDeclaration>(eagerlyUsed);
      for (const bound of deferBlocks.values()) {
        for (const dir of bound.getEagerlyUsedDirectives()) {
          wholeTemplateUsed.add(dir.ref.node);
        }
        for (const name of bound.getEagerlyUsedPipes()) {
          if (!pipes.has(name)) {
            continue;
          }
          wholeTemplateUsed.add(pipes.get(name)!.ref.node);
        }
      }

      const declarations = new Map<ClassDeclaration, UsedPipe | UsedDirective | UsedNgModule>();

      // Transform the dependencies list, filtering out unused dependencies.
      for (const dep of allDependencies) {
        // Only emit references to each dependency once.
        if (declarations.has(dep.ref.node)) {
          continue;
        }

        switch (dep.kind) {
          case MetaKind.Directive:
            if (!wholeTemplateUsed.has(dep.ref.node) || dep.matchSource !== MatchSource.Selector) {
              continue;
            }
            const dirType = this.refEmitter.emit(dep.ref, context);
            assertSuccessfulReferenceEmit(
              dirType,
              node.name,
              dep.isComponent ? 'component' : 'directive',
            );

            declarations.set(dep.ref.node, {
              kind: R3TemplateDependencyKind.Directive,
              ref: dep.ref,
              type: dirType.expression,
              importedFile: dirType.importedFile,
              selector: dep.selector!,
              inputs: dep.inputs.propertyNames,
              outputs: dep.outputs.propertyNames,
              exportAs: dep.exportAs,
              isComponent: dep.isComponent,
            });
            break;
          case MetaKind.Pipe:
            if (!wholeTemplateUsed.has(dep.ref.node)) {
              continue;
            }

            const pipeType = this.refEmitter.emit(dep.ref, context);
            assertSuccessfulReferenceEmit(pipeType, node.name, 'pipe');

            declarations.set(dep.ref.node, {
              kind: R3TemplateDependencyKind.Pipe,
              type: pipeType.expression,
              name: dep.name,
              ref: dep.ref,
              importedFile: pipeType.importedFile,
            });
            break;
          case MetaKind.NgModule:
            const ngModuleType = this.refEmitter.emit(dep.ref, context);
            assertSuccessfulReferenceEmit(ngModuleType, node.name, 'NgModule');

            declarations.set(dep.ref.node, {
              kind: R3TemplateDependencyKind.NgModule,
              type: ngModuleType.expression,
              importedFile: ngModuleType.importedFile,
            });
            break;
        }
      }

      const getSemanticReference = (decl: UsedDirective | UsedPipe) =>
        this.semanticDepGraphUpdater!.getSemanticReference(decl.ref.node, decl.type);

      if (this.semanticDepGraphUpdater !== null) {
        symbol.usedDirectives = Array.from(declarations.values())
          .filter(isUsedDirective)
          .map(getSemanticReference);
        symbol.usedPipes = Array.from(declarations.values())
          .filter(isUsedPipe)
          .map(getSemanticReference);
      }

      const eagerDeclarations = Array.from(declarations.values()).filter(
        (decl) => decl.kind === R3TemplateDependencyKind.NgModule || eagerlyUsed.has(decl.ref.node),
      );

      // Process information related to defer blocks
      if (this.compilationMode !== CompilationMode.LOCAL) {
        this.resolveDeferBlocks(node, deferBlocks, declarations, data, analysis, eagerlyUsed);
      }

      const cyclesFromDirectives = new Map<UsedDirective, Cycle>();
      const cyclesFromPipes = new Map<UsedPipe, Cycle>();

      // Scan through the directives/pipes actually used in the template and check whether any
      // import which needs to be generated would create a cycle. This check is skipped for
      // standalone components as the dependencies of a standalone component have already been
      // imported directly by the user, so Angular won't introduce any imports that aren't already
      // in the user's program.
      if (!metadata.isStandalone) {
        for (const usedDep of eagerDeclarations) {
          const cycle = this._checkForCyclicImport(usedDep.importedFile, usedDep.type, context);
          if (cycle !== null) {
            switch (usedDep.kind) {
              case R3TemplateDependencyKind.Directive:
                cyclesFromDirectives.set(usedDep, cycle);
                break;
              case R3TemplateDependencyKind.Pipe:
                cyclesFromPipes.set(usedDep, cycle);
                break;
            }
          }
        }
      }
      // Check whether any usages of standalone components in imports requires the dependencies
      // array to be wrapped in a closure. This check is technically a heuristic as there's no
      // direct way to check whether a `Reference` came from a `forwardRef`. Instead, we check if
      // the reference is `synthetic`, implying it came from _any_ foreign function resolver,
      // including the `forwardRef` resolver.
      const standaloneImportMayBeForwardDeclared =
        analysis.resolvedImports !== null && analysis.resolvedImports.some((ref) => ref.synthetic);

      const cycleDetected = cyclesFromDirectives.size !== 0 || cyclesFromPipes.size !== 0;
      if (!cycleDetected) {
        // No cycle was detected. Record the imports that need to be created in the cycle detector
        // so that future cyclic import checks consider their production.
        for (const {type, importedFile} of eagerDeclarations) {
          this.maybeRecordSyntheticImport(importedFile, type, context);
        }

        // Check whether the dependencies arrays in ɵcmp need to be wrapped in a closure.
        // This is required if any dependency reference is to a declaration in the same file
        // but declared after this component.
        const declarationIsForwardDeclared = eagerDeclarations.some((decl) =>
          isExpressionForwardReference(decl.type, node.name, context),
        );

        if (
          this.compilationMode !== CompilationMode.LOCAL &&
          (declarationIsForwardDeclared || standaloneImportMayBeForwardDeclared)
        ) {
          data.declarationListEmitMode = DeclarationListEmitMode.Closure;
        }

        data.declarations = eagerDeclarations;

        // Register extra local imports.
        if (
          this.compilationMode === CompilationMode.LOCAL &&
          this.localCompilationExtraImportsTracker !== null
        ) {
          // In global compilation mode `eagerDeclarations` contains "all" the component
          // dependencies, whose import statements will be added to the file. In local compilation
          // mode `eagerDeclarations` only includes the "local" dependencies, meaning those that are
          // declared inside this compilation unit.Here the import info of these local dependencies
          // are added to the tracker so that we can generate extra imports representing these local
          // dependencies. For non-local dependencies we use another technique of adding some
          // best-guess extra imports globally to all files using
          // `localCompilationExtraImportsTracker.addGlobalImportFromIdentifier`.
          for (const {type} of eagerDeclarations) {
            if (type instanceof ExternalExpr && type.value.moduleName) {
              this.localCompilationExtraImportsTracker.addImportForFile(
                context,
                type.value.moduleName,
              );
            }
          }
        }
      } else {
        if (this.cycleHandlingStrategy === CycleHandlingStrategy.UseRemoteScoping) {
          // Declaring the directiveDefs/pipeDefs arrays directly would require imports that would
          // create a cycle. Instead, mark this component as requiring remote scoping, so that the
          // NgModule file will take care of setting the directives for the component.
          this.scopeRegistry.setComponentRemoteScope(
            node,
            eagerDeclarations.filter(isUsedDirective).map((dir) => dir.ref),
            eagerDeclarations.filter(isUsedPipe).map((pipe) => pipe.ref),
          );
          symbol.isRemotelyScoped = true;

          // If a semantic graph is being tracked, record the fact that this component is remotely
          // scoped with the declaring NgModule symbol as the NgModule's emit becomes dependent on
          // the directive/pipe usages of this component.
          if (
            this.semanticDepGraphUpdater !== null &&
            scope.kind === ComponentScopeKind.NgModule &&
            scope.ngModule !== null
          ) {
            const moduleSymbol = this.semanticDepGraphUpdater.getSymbol(scope.ngModule);
            if (!(moduleSymbol instanceof NgModuleSymbol)) {
              throw new Error(
                `AssertionError: Expected ${scope.ngModule.name} to be an NgModuleSymbol.`,
              );
            }

            moduleSymbol.addRemotelyScopedComponent(
              symbol,
              symbol.usedDirectives,
              symbol.usedPipes,
            );
          }
        } else {
          // We are not able to handle this cycle so throw an error.
          const relatedMessages: ts.DiagnosticRelatedInformation[] = [];
          for (const [dir, cycle] of cyclesFromDirectives) {
            relatedMessages.push(
              makeCyclicImportInfo(dir.ref, dir.isComponent ? 'component' : 'directive', cycle),
            );
          }
          for (const [pipe, cycle] of cyclesFromPipes) {
            relatedMessages.push(makeCyclicImportInfo(pipe.ref, 'pipe', cycle));
          }
          throw new FatalDiagnosticError(
            ErrorCode.IMPORT_CYCLE_DETECTED,
            node,
            'One or more import cycles would need to be created to compile this component, ' +
              'which is not supported by the current compiler configuration.',
            relatedMessages,
          );
        }
      }
    } else {
      // If there is no scope, we can still use the binder to retrieve *some* information about the
      // deferred blocks.
      data.deferPerBlockDependencies = this.locateDeferBlocksWithoutScope(metadata.template);
    }

    // Run diagnostics only in global mode.
    if (this.compilationMode !== CompilationMode.LOCAL) {
      // Validate `@Component.imports` and `@Component.deferredImports` fields.
      if (analysis.resolvedImports !== null && analysis.rawImports !== null) {
        const importDiagnostics = validateStandaloneImports(
          analysis.resolvedImports,
          analysis.rawImports,
          this.metaReader,
          this.scopeReader,
          false /* isDeferredImport */,
        );
        diagnostics.push(...importDiagnostics);
      }
      if (analysis.resolvedDeferredImports !== null && analysis.rawDeferredImports !== null) {
        const importDiagnostics = validateStandaloneImports(
          analysis.resolvedDeferredImports,
          analysis.rawDeferredImports,
          this.metaReader,
          this.scopeReader,
          true /* isDeferredImport */,
        );
        diagnostics.push(...importDiagnostics);
      }

      if (
        analysis.providersRequiringFactory !== null &&
        analysis.meta.providers instanceof o.WrappedNodeExpr
      ) {
        const providerDiagnostics = getProviderDiagnostics(
          analysis.providersRequiringFactory,
          analysis.meta.providers!.node,
          this.injectableRegistry,
        );
        diagnostics.push(...providerDiagnostics);
      }

      if (
        analysis.viewProvidersRequiringFactory !== null &&
        analysis.meta.viewProviders instanceof o.WrappedNodeExpr
      ) {
        const viewProviderDiagnostics = getProviderDiagnostics(
          analysis.viewProvidersRequiringFactory,
          analysis.meta.viewProviders!.node,
          this.injectableRegistry,
        );
        diagnostics.push(...viewProviderDiagnostics);
      }

      const directiveDiagnostics = getDirectiveDiagnostics(
        node,
        this.injectableRegistry,
        this.evaluator,
        this.reflector,
        this.scopeRegistry,
        this.strictCtorDeps,
        'Component',
      );
      if (directiveDiagnostics !== null) {
        diagnostics.push(...directiveDiagnostics);
      }

      const hostDirectivesDiagnostics =
        analysis.hostDirectives && analysis.rawHostDirectives
          ? validateHostDirectives(
              analysis.rawHostDirectives,
              analysis.hostDirectives,
              this.metaReader,
            )
          : null;
      if (hostDirectivesDiagnostics !== null) {
        diagnostics.push(...hostDirectivesDiagnostics);
      }
    }

    if (diagnostics.length > 0) {
      return {diagnostics};
    }

    return {data};
  }

  xi18n(
    ctx: Xi18nContext,
    node: ClassDeclaration,
    analysis: Readonly<ComponentAnalysisData>,
  ): void {
    ctx.updateFromTemplate(
      analysis.template.content,
      analysis.template.declaration.resolvedTemplateUrl,
      analysis.template.interpolationConfig ?? DEFAULT_INTERPOLATION_CONFIG,
    );
  }

  updateResources(node: ClassDeclaration, analysis: ComponentAnalysisData): void {
    const containingFile = node.getSourceFile().fileName;

    // If the template is external, re-parse it.
    const templateDecl = analysis.template.declaration;
    if (!templateDecl.isInline) {
      analysis.template = extractTemplate(
        node,
        templateDecl,
        this.evaluator,
        this.depTracker,
        this.resourceLoader,
        this.extractTemplateOptions,
        this.compilationMode,
      );
    }

    // Update any external stylesheets and rebuild the combined 'styles' list.
    // TODO(alxhub): write tests for styles when the primary compiler uses the updateResources
    // path
    let styles: string[] = [];
    if (analysis.styleUrls !== null) {
      for (const styleUrl of analysis.styleUrls) {
        try {
          const resolvedStyleUrl = this.resourceLoader.resolve(styleUrl.url, containingFile);
          const styleText = this.resourceLoader.load(resolvedStyleUrl);
          styles.push(styleText);
        } catch (e) {
          // Resource resolve failures should already be in the diagnostics list from the analyze
          // stage. We do not need to do anything with them when updating resources.
        }
      }
    }
    if (analysis.inlineStyles !== null) {
      for (const styleText of analysis.inlineStyles) {
        styles.push(styleText);
      }
    }
    for (const styleText of analysis.template.styles) {
      styles.push(styleText);
    }

    analysis.meta.styles = styles.filter((s) => s.trim().length > 0);
  }

  compileFull(
    node: ClassDeclaration,
    analysis: Readonly<ComponentAnalysisData>,
    resolution: Readonly<ComponentResolutionData>,
    pool: ConstantPool,
  ): CompileResult[] {
    if (analysis.template.errors !== null && analysis.template.errors.length > 0) {
      return [];
    }

    const perComponentDeferredDeps = this.resolveAllDeferredDependencies(resolution);
    const meta: R3ComponentMetadata<R3TemplateDependency> = {
      ...analysis.meta,
      ...resolution,
      defer: this.compileDeferBlocks(resolution),
    };
    const fac = compileNgFactoryDefField(toFactoryMetadata(meta, FactoryTarget.Component));

    removeDeferrableTypesFromComponentDecorator(analysis, perComponentDeferredDeps);

    const def = compileComponentFromMetadata(meta, pool, makeBindingParser());
    const inputTransformFields = compileInputTransformFields(analysis.inputs);
    const classMetadata =
      analysis.classMetadata !== null
        ? compileComponentClassMetadata(analysis.classMetadata, perComponentDeferredDeps).toStmt()
        : null;
    const debugInfo =
      analysis.classDebugInfo !== null
        ? compileClassDebugInfo(analysis.classDebugInfo).toStmt()
        : null;
    const deferrableImports = this.deferredSymbolTracker.getDeferrableImportDecls();
    return compileResults(
      fac,
      def,
      classMetadata,
      'ɵcmp',
      inputTransformFields,
      deferrableImports,
      debugInfo,
    );
  }

  compilePartial(
    node: ClassDeclaration,
    analysis: Readonly<ComponentAnalysisData>,
    resolution: Readonly<ComponentResolutionData>,
  ): CompileResult[] {
    if (analysis.template.errors !== null && analysis.template.errors.length > 0) {
      return [];
    }
    const templateInfo: DeclareComponentTemplateInfo = {
      content: analysis.template.content,
      sourceUrl: analysis.template.declaration.resolvedTemplateUrl,
      isInline: analysis.template.declaration.isInline,
      inlineTemplateLiteralExpression:
        analysis.template.sourceMapping.type === 'direct'
          ? new o.WrappedNodeExpr(analysis.template.sourceMapping.node)
          : null,
    };

    const perComponentDeferredDeps = this.resolveAllDeferredDependencies(resolution);
    const meta: R3ComponentMetadata<R3TemplateDependencyMetadata> = {
      ...analysis.meta,
      ...resolution,
      defer: this.compileDeferBlocks(resolution),
    };
    const fac = compileDeclareFactory(toFactoryMetadata(meta, FactoryTarget.Component));
    const inputTransformFields = compileInputTransformFields(analysis.inputs);
    const def = compileDeclareComponentFromMetadata(meta, analysis.template, templateInfo);
    const classMetadata =
      analysis.classMetadata !== null
        ? compileComponentDeclareClassMetadata(
            analysis.classMetadata,
            perComponentDeferredDeps,
          ).toStmt()
        : null;
    const deferrableImports = this.deferredSymbolTracker.getDeferrableImportDecls();
    return compileResults(fac, def, classMetadata, 'ɵcmp', inputTransformFields, deferrableImports);
  }

  compileLocal(
    node: ClassDeclaration,
    analysis: Readonly<ComponentAnalysisData>,
    resolution: Readonly<Partial<ComponentResolutionData>>,
    pool: ConstantPool,
  ): CompileResult[] {
    // In the local compilation mode we can only rely on the information available
    // within the `@Component.deferredImports` array, because in this mode compiler
    // doesn't have information on which dependencies belong to which defer blocks.
    const deferrableTypes = analysis.explicitlyDeferredTypes;

    const meta = {
      ...analysis.meta,
      ...resolution,
      defer: this.compileDeferBlocks(resolution),
    } as R3ComponentMetadata<R3TemplateDependency>;

    if (analysis.explicitlyDeferredTypes !== null) {
      removeDeferrableTypesFromComponentDecorator(analysis, analysis.explicitlyDeferredTypes);
    }

    const fac = compileNgFactoryDefField(toFactoryMetadata(meta, FactoryTarget.Component));
    const def = compileComponentFromMetadata(meta, pool, makeBindingParser());
    const inputTransformFields = compileInputTransformFields(analysis.inputs);
    const classMetadata =
      analysis.classMetadata !== null
        ? compileComponentClassMetadata(analysis.classMetadata, deferrableTypes).toStmt()
        : null;
    const debugInfo =
      analysis.classDebugInfo !== null
        ? compileClassDebugInfo(analysis.classDebugInfo).toStmt()
        : null;
    const deferrableImports = this.deferredSymbolTracker.getDeferrableImportDecls();
    return compileResults(
      fac,
      def,
      classMetadata,
      'ɵcmp',
      inputTransformFields,
      deferrableImports,
      debugInfo,
    );
  }

  /**
   * Locates defer blocks in case scope information is not available.
   * For example, this happens in the local compilation mode.
   */
  private locateDeferBlocksWithoutScope(
    template: ComponentTemplate,
  ): Map<TmplAstDeferredBlock, DeferredComponentDependency[]> {
    const deferBlocks = new Map<TmplAstDeferredBlock, DeferredComponentDependency[]>();
    const directivelessBinder = new R3TargetBinder<DirectiveMeta>(new SelectorMatcher());
    const bound = directivelessBinder.bind({template: template.nodes});
    const deferredBlocks = bound.getDeferBlocks();

    for (const block of deferredBlocks) {
      // We can't determine the dependencies without a scope so we leave them empty.
      deferBlocks.set(block, []);
    }
    return deferBlocks;
  }

  /**
   * Computes a list of deferrable symbols based on dependencies from
   * the `@Component.imports` field and their usage in `@defer` blocks.
   */
  private resolveAllDeferredDependencies(
    resolution: Readonly<ComponentResolutionData>,
  ): R3DeferPerComponentDependency[] {
    const deferrableTypes: R3DeferPerComponentDependency[] = [];
    // Go over all dependencies of all defer blocks and update the value of
    // the `isDeferrable` flag and the `importPath` to reflect the current
    // state after visiting all components during the `resolve` phase.
    for (const [_, deps] of resolution.deferPerBlockDependencies) {
      for (const deferBlockDep of deps) {
        const importDecl =
          resolution.deferrableDeclToImportDecl.get(deferBlockDep.declaration.node) ?? null;
        if (importDecl !== null && this.deferredSymbolTracker.canDefer(importDecl)) {
          deferBlockDep.isDeferrable = true;
          deferBlockDep.importPath = (importDecl.moduleSpecifier as ts.StringLiteral).text;
          deferBlockDep.isDefaultImport = isDefaultImport(importDecl);
          deferrableTypes.push(deferBlockDep as R3DeferPerComponentDependency);
        }
      }
    }
    return deferrableTypes;
  }

  /**
   * Collects deferrable symbols from the `@Component.deferredImports` field.
   */
  private collectExplicitlyDeferredSymbols(
    rawDeferredImports: ts.Expression,
  ): Map<ts.Identifier, Import> {
    const deferredTypes = new Map<ts.Identifier, Import>();
    if (!ts.isArrayLiteralExpression(rawDeferredImports)) {
      return deferredTypes;
    }

    for (const element of rawDeferredImports.elements) {
      const node = tryUnwrapForwardRef(element, this.reflector) || element;

      if (!ts.isIdentifier(node)) {
        // Can't defer-load non-literal references.
        continue;
      }

      const imp = this.reflector.getImportOfIdentifier(node);
      if (imp !== null) {
        deferredTypes.set(node, imp);
      }
    }
    return deferredTypes;
  }

  /**
   * Check whether adding an import from `origin` to the source-file corresponding to `expr` would
   * create a cyclic import.
   *
   * @returns a `Cycle` object if a cycle would be created, otherwise `null`.
   */
  private _checkForCyclicImport(
    importedFile: ImportedFile,
    expr: o.Expression,
    origin: ts.SourceFile,
  ): Cycle | null {
    const imported = resolveImportedFile(this.moduleResolver, importedFile, expr, origin);
    if (imported === null) {
      return null;
    }
    // Check whether the import is legal.
    return this.cycleAnalyzer.wouldCreateCycle(origin, imported);
  }

  private maybeRecordSyntheticImport(
    importedFile: ImportedFile,
    expr: o.Expression,
    origin: ts.SourceFile,
  ): void {
    const imported = resolveImportedFile(this.moduleResolver, importedFile, expr, origin);
    if (imported === null) {
      return;
    }

    this.cycleAnalyzer.recordSyntheticImport(origin, imported);
  }

  /**
   * Resolves information about defer blocks dependencies to make it
   * available for the final `compile` step.
   */
  private resolveDeferBlocks(
    componentClassDecl: ClassDeclaration,
    deferBlocks: Map<TmplAstDeferredBlock, BoundTarget<DirectiveMeta>>,
    deferrableDecls: Map<ClassDeclaration, AnyUsedType>,
    resolutionData: ComponentResolutionData,
    analysisData: Readonly<ComponentAnalysisData>,
    eagerlyUsedDecls: Set<ClassDeclaration>,
  ) {
    // Collect all deferred decls from all defer blocks from the entire template
    // to intersect with the information from the `imports` field of a particular
    // Component.
    const allDeferredDecls = new Set<ClassDeclaration>();

    for (const [deferBlock, bound] of deferBlocks) {
      const usedDirectives = new Set(bound.getEagerlyUsedDirectives().map((d) => d.ref.node));
      const usedPipes = new Set(bound.getEagerlyUsedPipes());
      let deps: DeferredComponentDependency[];

      if (resolutionData.deferPerBlockDependencies.has(deferBlock)) {
        deps = resolutionData.deferPerBlockDependencies.get(deferBlock)!;
      } else {
        deps = [];
        resolutionData.deferPerBlockDependencies.set(deferBlock, deps);
      }

      for (const decl of Array.from(deferrableDecls.values())) {
        if (decl.kind === R3TemplateDependencyKind.NgModule) {
          continue;
        }
        if (
          decl.kind === R3TemplateDependencyKind.Directive &&
          !usedDirectives.has(decl.ref.node)
        ) {
          continue;
        }
        if (decl.kind === R3TemplateDependencyKind.Pipe && !usedPipes.has(decl.name)) {
          continue;
        }
        // Collect initial information about this dependency.
        // `isDeferrable`, `importPath` and `isDefaultImport` will be
        // added later during the `compile` step.
        deps.push({
          typeReference: decl.type,
          symbolName: decl.ref.node.name.text,
          isDeferrable: false,
          importPath: null,
          isDefaultImport: false,
          declaration: decl.ref,
        });
        allDeferredDecls.add(decl.ref.node);
      }
    }

    // For standalone components with the `imports` and `deferredImports` fields -
    // inspect the list of referenced symbols and mark the ones used in defer blocks
    // as potential candidates for defer loading.
    if (analysisData.meta.isStandalone) {
      if (analysisData.rawImports !== null) {
        this.registerDeferrableCandidates(
          componentClassDecl,
          analysisData.rawImports,
          false /* isDeferredImport */,
          allDeferredDecls,
          eagerlyUsedDecls,
          resolutionData,
        );
      }
      if (analysisData.rawDeferredImports !== null) {
        this.registerDeferrableCandidates(
          componentClassDecl,
          analysisData.rawDeferredImports,
          true /* isDeferredImport */,
          allDeferredDecls,
          eagerlyUsedDecls,
          resolutionData,
        );
      }
    }
  }

  /**
   * Inspects provided imports expression (either `@Component.imports` or
   * `@Component.deferredImports`) and registers imported types as deferrable
   * candidates.
   */
  private registerDeferrableCandidates(
    componentClassDecl: ClassDeclaration,
    importsExpr: ts.Expression,
    isDeferredImport: boolean,
    allDeferredDecls: Set<ClassDeclaration>,
    eagerlyUsedDecls: Set<ClassDeclaration>,
    resolutionData: ComponentResolutionData,
  ) {
    if (!ts.isArrayLiteralExpression(importsExpr)) {
      return;
    }

    for (const element of importsExpr.elements) {
      const node = tryUnwrapForwardRef(element, this.reflector) || element;

      if (!ts.isIdentifier(node)) {
        // Can't defer-load non-literal references.
        continue;
      }

      const imp = this.reflector.getImportOfIdentifier(node);
      if (imp === null) {
        // Can't defer-load symbols which aren't imported.
        continue;
      }

      const decl = this.reflector.getDeclarationOfIdentifier(node);
      if (decl === null) {
        // Can't defer-load symbols which don't exist.
        continue;
      }

      if (!isNamedClassDeclaration(decl.node)) {
        // Can't defer-load symbols which aren't classes.
        continue;
      }

      // Are we even trying to defer-load this symbol?
      if (!allDeferredDecls.has(decl.node)) {
        continue;
      }

      if (eagerlyUsedDecls.has(decl.node)) {
        // Can't defer-load symbols that are eagerly referenced as a dependency
        // in a template outside of a defer block.
        continue;
      }

      // Is it a standalone directive/component?
      const dirMeta = this.metaReader.getDirectiveMetadata(new Reference(decl.node));
      if (dirMeta !== null && !dirMeta.isStandalone) {
        continue;
      }

      // Is it a standalone pipe?
      const pipeMeta = this.metaReader.getPipeMetadata(new Reference(decl.node));
      if (pipeMeta !== null && !pipeMeta.isStandalone) {
        continue;
      }

      if (dirMeta === null && pipeMeta === null) {
        // This is not a directive or a pipe.
        continue;
      }

      // Keep track of how this class made it into the current source file
      // (which ts.ImportDeclaration was used for this symbol).
      resolutionData.deferrableDeclToImportDecl.set(decl.node, imp.node);

      this.deferredSymbolTracker.markAsDeferrableCandidate(
        node,
        imp.node,
        componentClassDecl,
        isDeferredImport,
      );
    }
  }

  private compileDeferBlocks(
    resolution: Readonly<Partial<ComponentResolutionData>>,
  ): R3ComponentDeferMetadata {
    const {
      deferBlockDepsEmitMode: mode,
      deferPerBlockDependencies: perBlockDeps,
      deferPerComponentDependencies: perComponentDeps,
    } = resolution;

    if (mode === DeferBlockDepsEmitMode.PerBlock) {
      if (!perBlockDeps) {
        throw new Error(
          'Internal error: deferPerBlockDependencies must be present when compiling in PerBlock mode',
        );
      }

      const blocks = new Map<TmplAstDeferredBlock, o.Expression | null>();
      for (const [block, dependencies] of perBlockDeps) {
        blocks.set(
          block,
          dependencies.length === 0 ? null : compileDeferResolverFunction({mode, dependencies}),
        );
      }

      return {mode, blocks};
    }

    if (mode === DeferBlockDepsEmitMode.PerComponent) {
      if (!perComponentDeps) {
        throw new Error(
          'Internal error: deferPerComponentDependencies must be present in PerComponent mode',
        );
      }
      return {
        mode,
        dependenciesFn:
          perComponentDeps.length === 0
            ? null
            : compileDeferResolverFunction({mode, dependencies: perComponentDeps}),
      };
    }

    throw new Error(`Invalid deferBlockDepsEmitMode. Cannot compile deferred block metadata.`);
  }
}

/**
 * Creates an instance of a target binder based on provided dependencies.
 */
function createTargetBinder(dependencies: Array<PipeMeta | DirectiveMeta | NgModuleMeta>) {
  const matcher = new SelectorMatcher<DirectiveMeta[]>();
  for (const dep of dependencies) {
    if (dep.kind === MetaKind.Directive && dep.selector !== null) {
      matcher.addSelectables(CssSelector.parse(dep.selector), [dep]);
    }
  }
  return new R3TargetBinder(matcher);
}

/**
 * Returns the list of dependencies from `@Component.deferredImports` if provided.
 */
function getExplicitlyDeferredDeps(scope: LocalModuleScope | StandaloneScope) {
  return scope.kind === ComponentScopeKind.NgModule
    ? []
    : (scope as StandaloneScope).deferredDependencies;
}

function extractPipes(
  dependencies: Array<PipeMeta | DirectiveMeta | NgModuleMeta>,
): Map<string, PipeMeta> {
  const pipes = new Map<string, PipeMeta>();
  for (const dep of dependencies) {
    if (dep.kind === MetaKind.Pipe) {
      pipes.set(dep.name, dep);
    }
  }
  return pipes;
}

/**
 * Drop references to existing imports for deferrable symbols that should be present
 * in the `setClassMetadataAsync` call. Otherwise, an import declaration gets retained.
 */
function removeDeferrableTypesFromComponentDecorator(
  analysis: Readonly<ComponentAnalysisData>,
  deferrableTypes: R3DeferPerComponentDependency[],
) {
  if (analysis.classMetadata) {
    const deferrableSymbols = new Set(deferrableTypes.map((t) => t.symbolName));
    const rewrittenDecoratorsNode = removeIdentifierReferences(
      (analysis.classMetadata.decorators as o.WrappedNodeExpr<ts.Node>).node,
      deferrableSymbols,
    );
    analysis.classMetadata.decorators = new o.WrappedNodeExpr(rewrittenDecoratorsNode);
  }
}

/**
 * Validates that `@Component.imports` and `@Component.deferredImports` do not have
 * overlapping dependencies.
 */
function validateNoImportOverlap(
  eagerDeps: Array<PipeMeta | DirectiveMeta | NgModuleMeta>,
  deferredDeps: Array<PipeMeta | DirectiveMeta | NgModuleMeta>,
  rawDeferredImports: ts.Expression,
) {
  let diagnostic: ts.Diagnostic | null = null;
  const eagerDepsSet = new Set();
  for (const eagerDep of eagerDeps) {
    eagerDepsSet.add(eagerDep.ref.node);
  }
  for (const deferredDep of deferredDeps) {
    if (eagerDepsSet.has(deferredDep.ref.node)) {
      const classInfo = deferredDep.ref.debugName
        ? `The \`${deferredDep.ref.debugName}\``
        : 'One of the dependencies';
      diagnostic = makeDiagnostic(
        ErrorCode.DEFERRED_DEPENDENCY_IMPORTED_EAGERLY,
        getDiagnosticNode(deferredDep.ref, rawDeferredImports),
        `\`${classInfo}\` is imported via both \`@Component.imports\` and ` +
          `\`@Component.deferredImports\`. To fix this, make sure that ` +
          `dependencies are imported only once.`,
      );
      break;
    }
  }
  return diagnostic;
}

function validateStandaloneImports(
  importRefs: Reference<ClassDeclaration>[],
  importExpr: ts.Expression,
  metaReader: MetadataReader,
  scopeReader: ComponentScopeReader,
  isDeferredImport: boolean,
): ts.Diagnostic[] {
  const diagnostics: ts.Diagnostic[] = [];
  for (const ref of importRefs) {
    const dirMeta = metaReader.getDirectiveMetadata(ref);
    if (dirMeta !== null) {
      if (!dirMeta.isStandalone) {
        // Directly importing a directive that's not standalone is an error.
        diagnostics.push(
          makeNotStandaloneDiagnostic(
            scopeReader,
            ref,
            importExpr,
            dirMeta.isComponent ? 'component' : 'directive',
          ),
        );
      }
      continue;
    }

    const pipeMeta = metaReader.getPipeMetadata(ref);
    if (pipeMeta !== null) {
      if (!pipeMeta.isStandalone) {
        diagnostics.push(makeNotStandaloneDiagnostic(scopeReader, ref, importExpr, 'pipe'));
      }
      continue;
    }

    const ngModuleMeta = metaReader.getNgModuleMetadata(ref);
    if (!isDeferredImport && ngModuleMeta !== null) {
      // Importing NgModules is always legal in `@Component.imports`,
      // but not supported in `@Component.deferredImports`.
      continue;
    }

    // Make an error?
    const error = isDeferredImport
      ? makeUnknownComponentDeferredImportDiagnostic(ref, importExpr)
      : makeUnknownComponentImportDiagnostic(ref, importExpr);
    diagnostics.push(error);
  }

  return diagnostics;
}

/** Returns whether an ImportDeclaration is a default import. */
function isDefaultImport(node: ts.ImportDeclaration): boolean {
  return node.importClause !== undefined && node.importClause.namedBindings === undefined;
}
