/**
 * @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 {
  BuilderContext,
  BuilderOutput,
  createBuilder,
  targetFromTargetString,
} from '@angular-devkit/architect';
import { JsonObject, normalize, resolve } from '@angular-devkit/core';
import { NodeJsSyncHost } from '@angular-devkit/core/node';
import * as fs from 'fs';
import * as path from 'path';
import { BrowserBuilderOutput } from '../browser';
import { Schema as BrowserBuilderSchema } from '../browser/schema';
import { ServerBuilderOutput } from '../server';
import { augmentAppWithServiceWorker } from '../utils/service-worker';
import { Schema as BuildWebpackAppShellSchema } from './schema';

async function _renderUniversal(
  options: BuildWebpackAppShellSchema,
  context: BuilderContext,
  browserResult: BrowserBuilderOutput,
  serverResult: ServerBuilderOutput,
): Promise<BrowserBuilderOutput> {
  // Get browser target options.
  const browserTarget = targetFromTargetString(options.browserTarget);
  const rawBrowserOptions = await context.getTargetOptions(browserTarget);
  const browserBuilderName = await context.getBuilderNameForTarget(browserTarget);
  const browserOptions = await context.validateOptions<JsonObject & BrowserBuilderSchema>(
    rawBrowserOptions,
    browserBuilderName,
  );

  // Initialize zone.js
  const root = context.workspaceRoot;
  const zonePackage = require.resolve('zone.js', { paths: [root] });
  await import(zonePackage);

  const host = new NodeJsSyncHost();
  const projectName = context.target && context.target.project;
  if (!projectName) {
    throw new Error('The builder requires a target.');
  }

  const projectMetadata = await context.getProjectMetadata(projectName);
  const projectRoot = resolve(
    normalize(root),
    normalize((projectMetadata.root as string) || ''),
  );

  for (const outputPath of browserResult.outputPaths) {
    const localeDirectory = path.relative(browserResult.baseOutputPath, outputPath);
    const browserIndexOutputPath = path.join(outputPath, 'index.html');
    const indexHtml = fs.readFileSync(browserIndexOutputPath, 'utf8');
    const serverBundlePath = await _getServerModuleBundlePath(options, context, serverResult, localeDirectory);

    const {
      AppServerModule,
      AppServerModuleNgFactory,
      renderModule,
      renderModuleFactory,
    } = await import(serverBundlePath);

    let renderModuleFn: (module: unknown, options: {}) => Promise<string>;
    let AppServerModuleDef: unknown;

    if (renderModuleFactory && AppServerModuleNgFactory) {
      renderModuleFn = renderModuleFactory;
      AppServerModuleDef = AppServerModuleNgFactory;
    } else if (renderModule && AppServerModule) {
      renderModuleFn = renderModule;
      AppServerModuleDef = AppServerModule;
    } else {
      throw new Error(`renderModule method and/or AppServerModule were not exported from: ${serverBundlePath}.`);
    }

    // Load platform server module renderer
    const renderOpts = {
      document: indexHtml,
      url: options.route,
    };

    const html = await renderModuleFn(AppServerModuleDef, renderOpts);
    // Overwrite the client index file.
    const outputIndexPath = options.outputIndexPath
      ? path.join(root, options.outputIndexPath)
      : browserIndexOutputPath;

    fs.writeFileSync(outputIndexPath, html);

    if (browserOptions.serviceWorker) {
      await augmentAppWithServiceWorker(
        host,
        normalize(root),
        projectRoot,
        normalize(outputPath),
        browserOptions.baseHref || '/',
        browserOptions.ngswConfigPath,
      );
    }
  }

  return browserResult;
}

async function _getServerModuleBundlePath(
  options: BuildWebpackAppShellSchema,
  context: BuilderContext,
  serverResult: ServerBuilderOutput,
  browserLocaleDirectory: string,
) {
  if (options.appModuleBundle) {
    return path.join(context.workspaceRoot, options.appModuleBundle);
  } else {
    const { baseOutputPath = '' } = serverResult;
    const outputPath = path.join(baseOutputPath, browserLocaleDirectory);

    if (!fs.existsSync(outputPath)) {
      throw new Error(`Could not find server output directory: ${outputPath}.`);
    }

    const files = fs.readdirSync(outputPath, 'utf8');
    const re = /^main\.(?:[a-zA-Z0-9]{20}\.)?(?:bundle\.)?js$/;
    const maybeMain = files.filter(x => re.test(x))[0];

    if (!maybeMain) {
      throw new Error('Could not find the main bundle.');
    } else {
      return path.join(outputPath, maybeMain);
    }
  }
}

async function _appShellBuilder(
  options: JsonObject & BuildWebpackAppShellSchema,
  context: BuilderContext,
): Promise<BuilderOutput> {
  const browserTarget = targetFromTargetString(options.browserTarget);
  const serverTarget = targetFromTargetString(options.serverTarget);

  // Never run the browser target in watch mode.
  // If service worker is needed, it will be added in _renderUniversal();
  const browserTargetRun = await context.scheduleTarget(browserTarget, {
    watch: false,
    serviceWorker: false,
  });
  const serverTargetRun = await context.scheduleTarget(serverTarget, {
    watch: false,
  });

  try {
    const [browserResult, serverResult] = await Promise.all([
      browserTargetRun.result as unknown as BrowserBuilderOutput,
      serverTargetRun.result as unknown as ServerBuilderOutput,
    ]);

    if (browserResult.success === false || browserResult.baseOutputPath === undefined) {
      return browserResult;
    } else if (serverResult.success === false) {
      return serverResult;
    }

    return await _renderUniversal(options, context, browserResult, serverResult);
  } catch (err) {
    return { success: false, error: err.message };
  } finally {
    // Just be good citizens and stop those jobs.
    await Promise.all([browserTargetRun.stop(), serverTargetRun.stop()]);
  }
}

export default createBuilder(_appShellBuilder);
