import {
  killAllProcesses,
  waitForAnyProcessOutputToMatch,
  execAndWaitForOutputToMatch,
} from '../../utils/process';
import {writeFile, prependToFile, appendToFile} from '../../utils/fs';


const doneRe =
  /: Compiled successfully.|: Failed to compile./;
const errorRe = /Error/;


export default function() {
  // TODO(architect): Delete this test. It is now in devkit/build-angular.

  if (process.platform.startsWith('win')) {
    return Promise.resolve();
  }

  return Promise.resolve()
    // Create and import files.
    .then(() => writeFile('src/funky2.ts', `
      export function funky2(value: string): string {
        return value + 'hello';
      }
    `))
    .then(() => writeFile('src/funky.ts', `
      export * from './funky2';
    `))
    .then(() => prependToFile('src/main.ts', `
      import { funky2 } from './funky';
    `))
    .then(() => appendToFile('src/main.ts', `
      console.log(funky2('town'));
    `))
    // Should trigger a rebuild, no error expected.
    .then(() => execAndWaitForOutputToMatch('ng', ['serve'], doneRe))
    // Make an invalid version of the file.
    // Should trigger a rebuild, this time an error is expected.
    .then(() => Promise.all([
      waitForAnyProcessOutputToMatch(errorRe, 20000),
      writeFile('src/funky2.ts', `
        export function funky2(value: number): number {
          return value + 1;
        }
      `)
    ]))
    .then((results) => {
      const stderr = results[0].stderr;
      if (!/Error: (.*src\/)?main\.ts/.test(stderr)) {
        throw new Error('Expected an error but none happened.');
      }
    })
    // Change an UNRELATED file and the error should still happen.
    // Should trigger a rebuild, this time an error is also expected.
    .then(() => Promise.all([
      waitForAnyProcessOutputToMatch(errorRe, 20000),
      appendToFile('src/app/app.module.ts', `
        function anything(): number { return 1; }
      `)
    ]))
    .then((results) => {
      const stderr = results[0].stderr;
      if (!/Error: (.*src\/)?main\.ts/.test(stderr)) {
        throw new Error('Expected an error to still be there but none was.');
      }
    })
    // Fix the error!
    .then(() => Promise.all([
      waitForAnyProcessOutputToMatch(doneRe, 20000),
      writeFile('src/funky2.ts', `
        export function funky2(value: string): string {
          return value + 'hello';
        }
      `)
    ]))
    .then((results) => {
      const stderr = results[0].stderr;
      if (/Error: (.*src\/)?main\.ts/.test(stderr)) {
        throw new Error('Expected no error but an error was shown.');
      }
    })
    .then(() => killAllProcesses(), (err: any) => {
      killAllProcesses();
      throw err;
    });
}
