/**
 * @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 {ParseLocation, ParseSourceFile, ParseSourceSpan} from '@angular/compiler';
import {EmitterVisitorContext} from '@angular/compiler/src/output/abstract_emitter';

import {originalPositionFor} from './source_map_util';

describe('AbstractEmitter', () => {
  describe('EmitterVisitorContext', () => {
    const fileA = new ParseSourceFile('a0a1a2a3a4a5a6a7a8a9', 'a.js');
    const fileB = new ParseSourceFile('b0b1b2b3b4b5b6b7b8b9', 'b.js');
    let ctx: EmitterVisitorContext;

    beforeEach(() => {
      ctx = EmitterVisitorContext.createRoot();
    });

    it('should add source files to the source map', () => {
      ctx.print(createSourceSpan(fileA, 0), 'o0');
      ctx.print(createSourceSpan(fileA, 1), 'o1');
      ctx.print(createSourceSpan(fileB, 0), 'o2');
      ctx.print(createSourceSpan(fileB, 1), 'o3');
      const sm = ctx.toSourceMapGenerator('o.ts').toJSON()!;
      expect(sm.sources).toEqual([fileA.url, fileB.url]);
      expect(sm.sourcesContent).toEqual([fileA.content, fileB.content]);
    });

    it('should generate a valid mapping', () => {
      ctx.print(createSourceSpan(fileA, 0), 'fileA-0');
      ctx.println(createSourceSpan(fileB, 1), 'fileB-1');
      ctx.print(createSourceSpan(fileA, 2), 'fileA-2');

      expectMap(ctx, 0, 0, 'a.js', 0, 0);
      expectMap(ctx, 0, 7, 'b.js', 0, 2);
      expectMap(ctx, 1, 0, 'a.js', 0, 4);
    });

    it('should be able to shift the content', async () => {
      ctx.print(createSourceSpan(fileA, 0), 'fileA-0');

      const sm = ctx.toSourceMapGenerator('o.ts', 10).toJSON()!;
      expect(await originalPositionFor(sm, {line: 11, column: 0})).toEqual({
        line: 1,
        column: 0,
        source: 'a.js',
      });
    });

    it('should use the default source file for the first character', () => {
      ctx.print(null, 'fileA-0');
      expectMap(ctx, 0, 0, 'o.ts', 0, 0);
    });

    it('should use an explicit mapping for the first character', () => {
      ctx.print(createSourceSpan(fileA, 0), 'fileA-0');
      expectMap(ctx, 0, 0, 'a.js', 0, 0);
    });

    it('should map leading segment without span', () => {
      ctx.print(null, '....');
      ctx.print(createSourceSpan(fileA, 0), 'fileA-0');

      expectMap(ctx, 0, 0, 'o.ts', 0, 0);
      expectMap(ctx, 0, 4, 'a.js', 0, 0);
      expect(nbSegmentsPerLine(ctx)).toEqual([2]);
    });

    it('should handle indent', () => {
      ctx.incIndent();
      ctx.println(createSourceSpan(fileA, 0), 'fileA-0');
      ctx.incIndent();
      ctx.println(createSourceSpan(fileA, 1), 'fileA-1');
      ctx.decIndent();
      ctx.println(createSourceSpan(fileA, 2), 'fileA-2');

      expectMap(ctx, 0, 0, 'o.ts', 0, 0);
      expectMap(ctx, 0, 2, 'a.js', 0, 0);
      expectMap(ctx, 1, 0);
      expectMap(ctx, 1, 2);
      expectMap(ctx, 1, 4, 'a.js', 0, 2);
      expectMap(ctx, 2, 0);
      expectMap(ctx, 2, 2, 'a.js', 0, 4);

      expect(nbSegmentsPerLine(ctx)).toEqual([2, 1, 1]);
    });

    it('should coalesce identical span', () => {
      const span = createSourceSpan(fileA, 0);
      ctx.print(span, 'fileA-0');
      ctx.print(null, '...');
      ctx.print(span, 'fileA-0');
      ctx.print(createSourceSpan(fileB, 0), 'fileB-0');

      expectMap(ctx, 0, 0, 'a.js', 0, 0);
      expectMap(ctx, 0, 7, 'a.js', 0, 0);
      expectMap(ctx, 0, 10, 'a.js', 0, 0);
      expectMap(ctx, 0, 17, 'b.js', 0, 0);

      expect(nbSegmentsPerLine(ctx)).toEqual([2]);
    });
  });
});

// All lines / columns indexes are 0-based
// Note: source-map line indexes are 1-based, column 0-based
async function expectMap(
  ctx: EmitterVisitorContext,
  genLine: number,
  genCol: number,
  source: string | null = null,
  srcLine: number | null = null,
  srcCol: number | null = null,
) {
  const sm = ctx.toSourceMapGenerator('o.ts').toJSON()!;
  const genPosition = {line: genLine + 1, column: genCol};
  const origPosition = await originalPositionFor(sm, genPosition);
  expect(origPosition.source).toEqual(source);
  expect(origPosition.line).toEqual(srcLine === null ? null : srcLine + 1);
  expect(origPosition.column).toEqual(srcCol);
}

// returns the number of segments per line
function nbSegmentsPerLine(ctx: EmitterVisitorContext) {
  const sm = ctx.toSourceMapGenerator('o.ts').toJSON()!;
  const lines = sm.mappings.split(';');
  return lines.map((l) => {
    const m = l.match(/,/g);
    return m === null ? 1 : m.length + 1;
  });
}

function createSourceSpan(file: ParseSourceFile, idx: number) {
  const col = 2 * idx;
  const start = new ParseLocation(file, col, 0, col);
  const end = new ParseLocation(file, col + 2, 0, col + 2);
  const sourceSpan = new ParseSourceSpan(start, end);
  return {sourceSpan};
}
