/**
 * @license
 * Copyright Google Inc. 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 * as ts from 'typescript';

import {createLanguageService} from '../src/language_service';
import {TypeScriptServiceHost} from '../src/typescript_host';

import {MockTypescriptHost} from './test_utils';

describe('completions', () => {
  let mockHost = new MockTypescriptHost(['/app/main.ts', '/app/parsing-cases.ts']);
  let service = ts.createLanguageService(mockHost);
  let ngHost = new TypeScriptServiceHost(mockHost, service);
  let ngService = createLanguageService(ngHost);

  beforeEach(() => { mockHost.reset(); });

  it('should be able to get entity completions',
     () => { expectContains('/app/test.ng', 'entity-amp', '&', '>', '<', 'ι'); });

  it('should be able to return html elements', () => {
    let htmlTags = ['h1', 'h2', 'div', 'span'];
    let locations = ['empty', 'start-tag-h1', 'h1-content', 'start-tag', 'start-tag-after-h'];
    for (let location of locations) {
      expectContains('/app/test.ng', location, ...htmlTags);
    }
  });

  it('should be able to return element diretives',
     () => { expectContains('/app/test.ng', 'empty', 'my-app'); });

  it('should be able to return h1 attributes',
     () => { expectContains('/app/test.ng', 'h1-after-space', 'id', 'dir', 'lang', 'onclick'); });

  it('should be able to find common angular attributes',
     () => { expectContains('/app/test.ng', 'div-attributes', '(click)', '[ngClass]'); });

  it('should be able to get completions in some random garbage', () => {
    const fileName = '/app/test.ng';
    mockHost.override(fileName, ' > {{tle<\n  {{retl  ><bel/beled}}di>\n   la</b  </d    &a  ');
    expect(() => ngService.getCompletionsAt(fileName, 31)).not.toThrow();
  });

  it('should be able to infer the type of a ngForOf', () => {
    const fileName = mockHost.addCode(`
      interface Person {
        name: string,
        street: string
      }

      @Component({template: '<div *ngFor="let person of people">{{person.~{name}name}}</div'})
      export class MyComponent {
        people: Person[]
      }`);
    expectContains(fileName, 'name', 'name', 'street');
  });

  it('should be able to infer the type of a ngForOf with an async pipe', () => {
    const fileName = mockHost.addCode(`
      interface Person {
        name: string,
        street: string
      }

      @Component({template: '<div *ngFor="let person of people | async">{{person.~{name}name}}</div>'})
      export class MyComponent {
        people: Promise<Person[]>;
      }`);
    expectContains(fileName, 'name', 'name', 'street');
  });

  it('should be able to complete every character in the file', () => {
    const fileName = '/app/test.ng';

    expect(() => {
      let chance = 0.05;
      function tryCompletionsAt(position: number) {
        try {
          if (Math.random() < chance) {
            ngService.getCompletionsAt(fileName, position);
          }
        } catch (e) {
          // Emit enough diagnostic information to reproduce the error.
          console.error(
              `Position: ${position}\nContent: "${mockHost.getFileContent(fileName)}"\nStack:\n${e.stack}`);
          throw e;
        }
      }

      const originalContent = mockHost.getFileContent(fileName) !;

      // For each character in the file, add it to the file and request a completion after it.
      for (let index = 0, len = originalContent.length; index < len; index++) {
        const content = originalContent.substr(0, index);
        mockHost.override(fileName, content);
        tryCompletionsAt(index);
      }

      // For the complete file, try to get a completion at every character.
      mockHost.override(fileName, originalContent);
      for (let index = 0, len = originalContent.length; index < len; index++) {
        tryCompletionsAt(index);
      }

      // Delete random characters in the file until we get an empty file.
      let content = originalContent;
      while (content.length > 0) {
        const deleteIndex = Math.floor(Math.random() * content.length);
        content = content.slice(0, deleteIndex - 1) + content.slice(deleteIndex + 1);
        mockHost.override(fileName, content);

        const requestIndex = Math.floor(Math.random() * content.length);
        tryCompletionsAt(requestIndex);
      }

      // Build up the string from zero asking for a completion after every char
      buildUp(originalContent, (text, position) => {
        mockHost.override(fileName, text);
        tryCompletionsAt(position);
      });
    }).not.toThrow();
  });

  describe('with regression tests', () => {
    it('should not crash with an incomplete component', () => {
      expect(() => {
        const fileName = mockHost.addCode(`
          @Component({
            template: '~{inside-template}'
          })
          export class MyComponent {

          }`);

        expectContains(fileName, 'inside-template', 'h1');
      }).not.toThrow();
    });

    it('should hot crash with an incomplete class', () => {
      expect(() => {
        mockHost.addCode('\nexport class');
        ngHost.getAnalyzedModules();
      }).not.toThrow();
    });

  });

  it('should respect paths configuration', () => {
    mockHost.overrideOptions(options => {
      options.baseUrl = '/app';
      options.paths = {'bar/*': ['foo/bar/*']};
      return options;
    });
    mockHost.addScript('/app/foo/bar/shared.ts', `
      export interface Node {
        children: Node[];
      }
    `);
    mockHost.addScript('/app/my.component.ts', `
      import { Component } from '@angular/core';
      import { Node } from 'bar/shared';

      @Component({
        selector: 'my-component',
        template: '{{tree.~{tree} }}'
      })
      export class MyComponent {
        tree: Node;
      }
    `);
    ngHost.getAnalyzedModules();
    expectContains('/app/my.component.ts', 'tree', 'children');
  });

  it('should work with input and output', () => {
    const fileName = mockHost.addCode(`
      @Component({
        selector: 'foo-component',
        template: \`
          <div string-model ~{stringMarker}="text"></div>
          <div number-model ~{numberMarker}="value"></div>
        \`,
      })
      export class FooComponent {
        text: string;
        value: number;
      }
    `);
    expectContains(fileName, 'stringMarker', '[model]', '(model)');
    expectContains(fileName, 'numberMarker', '[inputAlias]', '(outputAlias)');
  });

  function expectContains(fileName: string, locationMarker: string, ...names: string[]) {
    let location = mockHost.getMarkerLocations(fileName) ![locationMarker];
    if (location == null) {
      throw new Error(`No marker ${locationMarker} found.`);
    }
    expectEntries(locationMarker, ngService.getCompletionsAt(fileName, location), ...names);
  }
});


function expectEntries(
    locationMarker: string, completion: ts.CompletionInfo | undefined, ...names: string[]) {
  let entries: {[name: string]: boolean} = {};
  if (!completion) {
    throw new Error(
        `Expected result from ${locationMarker} to include ${names.join(', ')} but no result provided`);
  }
  if (!completion.entries.length) {
    throw new Error(
        `Expected result from ${locationMarker} to include ${names.join(', ')} an empty result provided`);
  }
  for (const entry of completion.entries) {
    entries[entry.name] = true;
  }
  let missing = names.filter(name => !entries[name]);
  if (missing.length) {
    throw new Error(
        `Expected result from ${locationMarker} to include at least one of the following, ${missing.join(', ')}, in the list of entries ${completion.entries.map(entry => entry.name).join(', ')}`);
  }
}

function buildUp(originalText: string, cb: (text: string, position: number) => void) {
  let count = originalText.length;

  let inString: boolean[] = (new Array(count)).fill(false);
  let unused: number[] = (new Array(count)).fill(1).map((v, i) => i);

  function getText() {
    return new Array(count)
        .fill(1)
        .map((v, i) => i)
        .filter(i => inString[i])
        .map(i => originalText[i])
        .join('');
  }

  function randomUnusedIndex() { return Math.floor(Math.random() * unused.length); }

  while (unused.length > 0) {
    let unusedIndex = randomUnusedIndex();
    let index = unused[unusedIndex];
    if (index == null) throw new Error('Internal test buildup error');
    if (inString[index]) throw new Error('Internal test buildup error');
    inString[index] = true;
    unused.splice(unusedIndex, 1);
    let text = getText();
    let position = inString.filter((_, i) => i <= index)
                       .map(v => v ? 1 : 0)
                       .reduce((p: number, v) => p + v, 0);
    cb(text, position);
  }
}