/**
 * @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.dev/license
 */
import {leadingComment} from '@angular/compiler';
import ts from 'typescript';

import {TypeScriptAstFactory} from '../src/typescript_ast_factory';

describe('TypeScriptAstFactory', () => {
  let factory: TypeScriptAstFactory;
  beforeEach(() => (factory = new TypeScriptAstFactory(/* annotateForClosureCompiler */ false)));

  describe('attachComments()', () => {
    it('should add the comments to the given statement', () => {
      const {
        items: [stmt],
        generate,
      } = setupStatements('x = 10;');
      factory.attachComments(stmt, [
        leadingComment('comment 1', true),
        leadingComment('comment 2', false),
      ]);

      expect(generate(stmt)).toEqual(['/* comment 1 */', '//comment 2', 'x = 10;'].join('\n'));
    });

    it('should add the comments to the given expression', () => {
      const {
        items: [expr],
        generate,
      } = setupExpressions('x + 10');
      factory.attachComments(expr, [
        leadingComment('comment 1', true),
        leadingComment('comment 2', false),
      ]);

      expect(generate(expr)).toEqual(['/* comment 1 */', '//comment 2', 'x + 10'].join('\n'));
    });
  });

  describe('createArrayLiteral()', () => {
    it('should create an array node containing the provided expressions', () => {
      const {
        items: [expr1, expr2],
        generate,
      } = setupExpressions(`42`, '"moo"');
      const array = factory.createArrayLiteral([expr1, expr2]);
      expect(generate(array)).toEqual('[42, "moo"]');
    });
  });

  describe('createAssignment()', () => {
    it('should create an assignment node using the target and value expressions', () => {
      const {
        items: [target, value],
        generate,
      } = setupExpressions(`x`, `42`);
      const assignment = factory.createAssignment(target, '=', value);
      expect(generate(assignment)).toEqual('x = 42');
    });
  });

  describe('createBinaryExpression()', () => {
    it('should create a binary operation node using the left and right expressions', () => {
      const {
        items: [left, right],
        generate,
      } = setupExpressions(`17`, `42`);
      const assignment = factory.createBinaryExpression(left, '+', right);
      expect(generate(assignment)).toEqual('17 + 42');
    });

    it('should create a binary operation node for exponentiation', () => {
      const {
        items: [left, right],
        generate,
      } = setupExpressions(`2`, `3`);
      const assignment = factory.createBinaryExpression(left, '**', right);
      expect(generate(assignment)).toEqual('2 ** 3');
    });
  });

  describe('createDynamicImport()', () => {
    it('should create a dynamic import expression from a string URL', () => {
      const {generate} = setupExpressions(``);
      const url = './some/path';
      const assignment = factory.createDynamicImport(url);
      expect(generate(assignment)).toEqual(`import("${url}")`);
    });

    it('should create a dynamic import expression from an expression URL', () => {
      const {items, generate} = setupExpressions(`'/' + 'abc' + '/'`);
      const assignment = factory.createDynamicImport(items[0]);
      expect(generate(assignment)).toEqual(`import('/' + 'abc' + '/')`);
    });
  });

  describe('createBlock()', () => {
    it('should create a block statement containing the given statements', () => {
      const {items: stmts, generate} = setupStatements('x = 10; y = 20;');
      const block = factory.createBlock(stmts);
      expect(generate(block)).toEqual(['{', '    x = 10;', '    y = 20;', '}'].join('\n'));
    });
  });

  describe('createCallExpression()', () => {
    it('should create a call on the `callee` with the given `args`', () => {
      const {
        items: [callee, arg1, arg2],
        generate,
      } = setupExpressions('foo', '42', '"moo"');
      const call = factory.createCallExpression(callee, [arg1, arg2], false);
      expect(generate(call)).toEqual('foo(42, "moo")');
    });

    it('should create a call marked with a PURE comment if `pure` is true', () => {
      const {
        items: [callee, arg1, arg2],
        generate,
      } = setupExpressions(`foo`, `42`, `"moo"`);
      const call = factory.createCallExpression(callee, [arg1, arg2], true);
      expect(generate(call)).toEqual('/*@__PURE__*/ foo(42, "moo")');
    });

    it('should create a call marked with a closure-style pure comment if `pure` is true', () => {
      factory = new TypeScriptAstFactory(/* annotateForClosureCompiler */ true);

      const {
        items: [callee, arg1, arg2],
        generate,
      } = setupExpressions(`foo`, `42`, `"moo"`);
      const call = factory.createCallExpression(callee, [arg1, arg2], true);
      expect(generate(call)).toEqual('/** @pureOrBreakMyCode */ foo(42, "moo")');
    });
  });

  describe('createConditional()', () => {
    it('should create a condition expression', () => {
      const {
        items: [test, thenExpr, elseExpr],
        generate,
      } = setupExpressions(`!test`, `42`, `"moo"`);
      const conditional = factory.createConditional(test, thenExpr, elseExpr);
      expect(generate(conditional)).toEqual('!test ? 42 : "moo"');
    });
  });

  describe('createElementAccess()', () => {
    it('should create an expression accessing the element of an array/object', () => {
      const {
        items: [expr, element],
        generate,
      } = setupExpressions(`obj`, `"moo"`);
      const access = factory.createElementAccess(expr, element);
      expect(generate(access)).toEqual('obj["moo"]');
    });
  });

  describe('createExpressionStatement()', () => {
    it('should create a statement node from the given expression', () => {
      const {
        items: [expr],
        generate,
      } = setupExpressions(`x = 10`);
      const stmt = factory.createExpressionStatement(expr);
      expect(ts.isExpressionStatement(stmt)).toBe(true);
      expect(generate(stmt)).toEqual('x = 10;');
    });
  });

  describe('createFunctionDeclaration()', () => {
    it('should create a function declaration node with the given name, parameters and body statements', () => {
      const {
        items: [body],
        generate,
      } = setupStatements('{x = 10; y = 20;}');
      const fn = factory.createFunctionDeclaration(
        'foo',
        [
          {name: 'arg1', type: null},
          {name: 'arg2', type: factory.createBuiltInType('number')},
        ],
        body,
      );
      expect(generate(fn)).toEqual('function foo(arg1, arg2: number) { x = 10; y = 20; }');
    });
  });

  describe('createFunctionExpression()', () => {
    it('should create a function expression node with the given name, parameters and body statements', () => {
      const {
        items: [body],
        generate,
      } = setupStatements('{x = 10; y = 20;}');
      const fn = factory.createFunctionExpression(
        'foo',
        [
          {name: 'arg1', type: null},
          {name: 'arg2', type: factory.createBuiltInType('number')},
        ],
        body,
      );
      expect(ts.isExpressionStatement(fn)).toBe(false);
      expect(generate(fn)).toEqual('function foo(arg1, arg2: number) { x = 10; y = 20; }');
    });

    it('should create an anonymous function expression node if the name is null', () => {
      const {
        items: [body],
        generate,
      } = setupStatements('{x = 10; y = 20;}');
      const fn = factory.createFunctionExpression(
        null,
        [
          {name: 'arg1', type: null},
          {name: 'arg2', type: factory.createBuiltInType('number')},
        ],
        body,
      );
      expect(generate(fn)).toEqual('function (arg1, arg2: number) { x = 10; y = 20; }');
    });
  });

  describe('createIdentifier()', () => {
    it('should create an identifier with the given name', () => {
      const id = factory.createIdentifier('someId') as ts.Identifier;
      expect(ts.isIdentifier(id)).toBe(true);
      expect(id.text).toEqual('someId');
    });
  });

  describe('createIfStatement()', () => {
    it('should create an if-else statement', () => {
      const {
        items: [testStmt, thenStmt, elseStmt],
        generate,
      } = setupStatements('!test;x = 10;x = 42;');
      const test = (testStmt as ts.ExpressionStatement).expression;
      const ifStmt = factory.createIfStatement(test, thenStmt, elseStmt);
      expect(generate(ifStmt)).toEqual(
        ['if (!test)', '    x = 10;', 'else', '    x = 42;'].join('\n'),
      );
    });

    it('should create an if statement if the else expression is null', () => {
      const {
        items: [testStmt, thenStmt],
        generate,
      } = setupStatements('!test;x = 10;');
      const test = (testStmt as ts.ExpressionStatement).expression;
      const ifStmt = factory.createIfStatement(test, thenStmt, null);
      expect(generate(ifStmt)).toEqual(['if (!test)', '    x = 10;'].join('\n'));
    });
  });

  describe('createArrowFunctionExpression()', () => {
    it('should create an arrow function with an implicit return if a single statement is provided', () => {
      const {
        items: [body],
        generate,
      } = setupExpressions('arg2 + arg1');
      const fn = factory.createArrowFunctionExpression(
        [
          {name: 'arg1', type: null},
          {name: 'arg2', type: factory.createBuiltInType('number')},
        ],
        body,
      );
      expect(generate(fn)).toEqual('(arg1, arg2: number) => arg2 + arg1');
    });

    it('should create an arrow function with an implicit return object literal', () => {
      const {
        items: [body],
        generate,
      } = setupExpressions('{a: 1, b: 2}');
      const fn = factory.createArrowFunctionExpression([], body);
      expect(generate(fn)).toEqual('() => ({ a: 1, b: 2 })');
    });

    it('should create an arrow function with a body when an array of statements is provided', () => {
      const {
        items: [body],
        generate,
      } = setupStatements('{x = 10; y = 20; return x + y;}');
      const fn = factory.createArrowFunctionExpression(
        [
          {name: 'arg1', type: null},
          {name: 'arg2', type: factory.createBuiltInType('number')},
        ],
        body,
      );
      expect(generate(fn)).toEqual('(arg1, arg2: number) => { x = 10; y = 20; return x + y; }');
    });
  });

  describe('createLiteral()', () => {
    it('should create a string literal', () => {
      const {generate} = setupStatements();
      const literal = factory.createLiteral('moo');
      expect(ts.isStringLiteral(literal)).toBe(true);
      expect(generate(literal)).toEqual('"moo"');
    });

    it('should create a number literal', () => {
      const {generate} = setupStatements();
      const literal = factory.createLiteral(42);
      expect(ts.isNumericLiteral(literal)).toBe(true);
      expect(generate(literal)).toEqual('42');
    });

    it('should create a negative number literal', () => {
      const {generate} = setupStatements();
      const literal = factory.createLiteral(-42);
      expect(ts.isPrefixUnaryExpression(literal)).toBe(true);
      expect(generate(literal)).toEqual('-42');
    });

    it('should create a number literal for `NaN`', () => {
      const {generate} = setupStatements();
      const literal = factory.createLiteral(NaN);
      expect(ts.isNumericLiteral(literal)).toBe(true);
      expect(generate(literal)).toEqual('NaN');
    });

    it('should create a boolean literal', () => {
      const {generate} = setupStatements();
      const literal = factory.createLiteral(true);
      expect(ts.isToken(literal)).toBe(true);
      expect(generate(literal)).toEqual('true');
    });

    it('should create an `undefined` literal', () => {
      const {generate} = setupStatements();
      const literal = factory.createLiteral(undefined);
      expect(ts.isIdentifier(literal)).toBe(true);
      expect(generate(literal)).toEqual('undefined');
    });

    it('should create a `null` literal', () => {
      const {generate} = setupStatements();
      const literal = factory.createLiteral(null);
      expect(ts.isToken(literal)).toBe(true);
      expect(generate(literal)).toEqual('null');
    });
  });

  describe('createNewExpression()', () => {
    it('should create a `new` operation on the constructor `expression` with the given `args`', () => {
      const {
        items: [expr, arg1, arg2],
        generate,
      } = setupExpressions('Foo', '42', '"moo"');
      const call = factory.createNewExpression(expr, [arg1, arg2]);
      expect(generate(call)).toEqual('new Foo(42, "moo")');
    });
  });

  describe('createObjectLiteral()', () => {
    it('should create an object literal node, with the given properties', () => {
      const {
        items: [prop1, prop2, prop3],
        generate,
      } = setupExpressions('42', '"moo"', 'foo');
      const obj = factory.createObjectLiteral([
        {propertyName: 'prop1', value: prop1, kind: 'property', quoted: false},
        {propertyName: 'prop2', value: prop2, kind: 'property', quoted: true},
        {expression: prop3, kind: 'spread'},
      ]);
      expect(generate(obj)).toEqual('{ prop1: 42, "prop2": "moo", ...foo }');
    });
  });

  describe('createParenthesizedExpression()', () => {
    it('should add parentheses around the given expression', () => {
      const {
        items: [expr],
        generate,
      } = setupExpressions(`a + b`);
      const paren = factory.createParenthesizedExpression(expr);
      expect(generate(paren)).toEqual('(a + b)');
    });
  });

  describe('createPropertyAccess()', () => {
    it('should create a property access expression node', () => {
      const {
        items: [expr],
        generate,
      } = setupExpressions(`obj`);
      const access = factory.createPropertyAccess(expr, 'moo');
      expect(generate(access)).toEqual('obj.moo');
    });
  });

  describe('createReturnStatement()', () => {
    it('should create a return statement returning the given expression', () => {
      const {
        items: [expr],
        generate,
      } = setupExpressions(`42`);
      const returnStmt = factory.createReturnStatement(expr);
      expect(generate(returnStmt)).toEqual('return 42;');
    });

    it('should create a void return statement if the expression is null', () => {
      const {generate} = setupStatements();
      const returnStmt = factory.createReturnStatement(null);
      expect(generate(returnStmt)).toEqual('return;');
    });
  });

  describe('createTaggedTemplate()', () => {
    it('should create a tagged template node from the tag, elements and expressions', () => {
      const elements = [
        {raw: 'raw\\n1', cooked: 'raw\n1', range: null},
        {raw: 'raw\\n2', cooked: 'raw\n2', range: null},
        {raw: 'raw\\n3', cooked: 'raw\n3', range: null},
      ];
      const {
        items: [tag, ...expressions],
        generate,
      } = setupExpressions('tagFn', '42', '"moo"');
      const template = factory.createTaggedTemplate(tag, {elements, expressions});
      expect(generate(template)).toEqual('tagFn `raw\\n1${42}raw\\n2${"moo"}raw\\n3`');
    });
  });

  describe('createThrowStatement()', () => {
    it('should create a throw statement, throwing the given expression', () => {
      const {
        items: [expr],
        generate,
      } = setupExpressions(`new Error("bad")`);
      const throwStmt = factory.createThrowStatement(expr);
      expect(generate(throwStmt)).toEqual('throw new Error("bad");');
    });
  });

  describe('createTypeOfExpression()', () => {
    it('should create a typeof expression node', () => {
      const {
        items: [expr],
        generate,
      } = setupExpressions(`42`);
      const typeofExpr = factory.createTypeOfExpression(expr);
      expect(generate(typeofExpr)).toEqual('typeof 42');
    });
  });

  describe('createVoidExpression()', () => {
    it('should create a void expression node', () => {
      const {
        items: [expr],
        generate,
      } = setupExpressions(`42`);
      const voidExpr = factory.createVoidExpression(expr);
      expect(generate(voidExpr)).toEqual('void 42');
    });
  });

  describe('createUnaryExpression()', () => {
    it('should create a unary expression with the operator and operand', () => {
      const {
        items: [expr],
        generate,
      } = setupExpressions(`value`);
      const unaryExpr = factory.createUnaryExpression('!', expr);
      expect(generate(unaryExpr)).toEqual('!value');
    });
  });

  describe('createVariableDeclaration()', () => {
    it('should create a variable declaration statement node for the given variable name and initializer', () => {
      const {
        items: [initializer],
        generate,
      } = setupExpressions(`42`);
      const varDecl = factory.createVariableDeclaration('foo', initializer, 'let', null);
      expect(generate(varDecl)).toEqual('let foo = 42;');
    });

    it('should create a constant declaration statement node for the given variable name and initializer', () => {
      const {
        items: [initializer],
        generate,
      } = setupExpressions(`42`);
      const varDecl = factory.createVariableDeclaration('foo', initializer, 'const', null);
      expect(generate(varDecl)).toEqual('const foo = 42;');
    });

    it('should create a downleveled declaration statement node for the given variable name and initializer', () => {
      const {
        items: [initializer],
        generate,
      } = setupExpressions(`42`);
      const varDecl = factory.createVariableDeclaration('foo', initializer, 'var', null);
      expect(generate(varDecl)).toEqual('var foo = 42;');
    });

    it('should create an uninitialized variable declaration statement node for the given variable name and a null initializer', () => {
      const {generate} = setupStatements();
      const varDecl = factory.createVariableDeclaration('foo', null, 'let', null);
      expect(generate(varDecl)).toEqual('let foo;');
    });

    it('should create a variable declaration with a type', () => {
      const {
        items: [initializer],
        generate,
      } = setupExpressions(`42`);
      const varDecl = factory.createVariableDeclaration(
        'foo',
        initializer,
        'let',
        factory.createBuiltInType('number'),
      );
      expect(generate(varDecl)).toEqual('let foo: number = 42;');
    });
  });

  describe('createRegularExpressionLiteral()', () => {
    it('should create a regular expressions without flags', () => {
      const {generate} = setupStatements();
      const regex = factory.createRegularExpressionLiteral('^\\d+-foo$', null);
      expect(generate(regex)).toEqual('/^\\d+-foo$/');
    });

    it('should create a regular expressions with flags', () => {
      const {generate} = setupStatements();
      const regex = factory.createRegularExpressionLiteral('^\\d+-foo$', 'gi');
      expect(generate(regex)).toEqual('/^\\d+-foo$/gi');
    });
  });

  describe('createSpreadElement()', () => {
    it('should create a spread element in an array', () => {
      const {generate} = setupStatements();
      const before = factory.createIdentifier('a');
      const spread = factory.createSpreadElement(factory.createIdentifier('b'));
      const array = factory.createArrayLiteral([before, spread]);
      expect(generate(array)).toEqual('[a, ...b]');
    });

    it('should create a spread in a call expression', () => {
      const {generate} = setupStatements();
      const fn = factory.createIdentifier('fn');
      const before = factory.createIdentifier('a');
      const spread = factory.createSpreadElement(factory.createIdentifier('b'));
      const call = factory.createCallExpression(fn, [before, spread], false);
      expect(generate(call)).toEqual('fn(a, ...b)');
    });
  });

  describe('createBuiltInType()', () => {
    it('should create keyword type nodes for simple types', () => {
      const {generate} = setupStatements();
      expect(generate(factory.createBuiltInType('any'))).toEqual('any');
      expect(generate(factory.createBuiltInType('boolean'))).toEqual('boolean');
      expect(generate(factory.createBuiltInType('number'))).toEqual('number');
      expect(generate(factory.createBuiltInType('string'))).toEqual('string');
      expect(generate(factory.createBuiltInType('never'))).toEqual('never');
      expect(generate(factory.createBuiltInType('unknown'))).toEqual('unknown');
    });

    it('should create a type reference for "function"', () => {
      const {generate} = setupStatements();
      expect(generate(factory.createBuiltInType('function'))).toEqual('Function');
    });
  });

  describe('createExpressionType()', () => {
    it('should create a type reference for an identifier', () => {
      const {items, generate} = setupExpressions('MyType');
      const type = factory.createExpressionType(items[0], null);
      expect(generate(type)).toEqual('MyType');
    });

    it('should create a type reference for a property access', () => {
      const {items, generate} = setupExpressions('ns.MyType');
      const type = factory.createExpressionType(items[0], null);
      expect(generate(type)).toEqual('ns.MyType');
    });

    it('should create a type reference with type parameters', () => {
      const {items, generate} = setupExpressions('MyType');
      const typeParam = factory.createBuiltInType('string');
      const type = factory.createExpressionType(items[0], [typeParam]);
      expect(generate(type)).toEqual('MyType<string>');
    });
  });

  describe('createArrayType()', () => {
    it('should create an array type node', () => {
      const {generate} = setupStatements();
      const elementType = factory.createBuiltInType('string');
      const type = factory.createArrayType(elementType);
      expect(generate(type)).toEqual('string[]');
    });
  });

  describe('createMapType()', () => {
    it('should create a type literal with an index signature', () => {
      const {generate} = setupStatements();
      const valueType = factory.createBuiltInType('number');
      const type = factory.createMapType(valueType);
      expect(generate(type)).toEqual('{\n    [key: string]: number;\n}');
    });
  });

  describe('setSourceMapRange()', () => {
    it('should attach the `sourceMapRange` to the given `node`', () => {
      const {
        items: [expr],
      } = setupExpressions(`42`);

      factory.setSourceMapRange(expr, {
        start: {line: 0, column: 1, offset: 1},
        end: {line: 2, column: 3, offset: 15},
        content: '-****\n*****\n****',
        url: 'original.ts',
      });

      const range = ts.getSourceMapRange(expr);
      expect(range.pos).toEqual(1);
      expect(range.end).toEqual(15);
      expect(range.source?.getLineAndCharacterOfPosition(range.pos)).toEqual({
        line: 0,
        character: 1,
      });
      expect(range.source?.getLineAndCharacterOfPosition(range.end)).toEqual({
        line: 2,
        character: 3,
      });
    });
  });
});

/**
 * Setup some statements to use in a test, along with a generate function to print the created nodes
 * out.
 *
 * The TypeScript printer requires access to the original source of non-synthesized nodes.
 * It uses the source content to output things like text between parts of nodes, which it doesn't
 * store in the AST node itself.
 *
 * So this helper (and its sister `setupExpressions()`) capture the original source file used to
 * provide the original statements/expressions that are used in the tests so that the printing will
 * work via the returned `generate()` function.
 */
function setupStatements(stmts: string = ''): SetupResult<ts.Statement> {
  const printer = ts.createPrinter({newLine: ts.NewLineKind.LineFeed});
  const sf = ts.createSourceFile('test.ts', stmts, ts.ScriptTarget.ES2015, true);
  return {
    items: Array.from(sf.statements),
    generate: (node: ts.Node) => printer.printNode(ts.EmitHint.Unspecified, node, sf),
  };
}

/**
 * Setup some statements to use in a test, along with a generate function to print the created nodes
 * out.
 *
 * See `setupStatements()` for more information about this helper function.
 */
function setupExpressions(...exprs: string[]): SetupResult<ts.Expression> {
  const {
    items: [arrayStmt],
    generate,
  } = setupStatements(`[${exprs.join(',')}];`);
  const expressions = Array.from(
    ((arrayStmt as ts.ExpressionStatement).expression as ts.ArrayLiteralExpression).elements,
  );
  return {items: expressions, generate};
}

interface SetupResult<TNode extends ts.Node> {
  items: TNode[];
  generate(node: ts.Node): string;
}
