import {
  AppJSONConfig,
  ExpoConfig,
  getConfig,
  getProjectConfigDescriptionWithPaths,
  ProjectConfig,
} from '@expo/config';
import chalk from 'chalk';

import * as Log from '../../../log';
import { env } from '../../../utils/env';
import { getPlatformBundlers } from '../../server/platformBundlers';
import { PrerequisiteCommandError, ProjectPrerequisite } from '../Prerequisite';
import { ensureDependenciesAsync } from '../dependencies/ensureDependenciesAsync';
import { ResolvedPackage } from '../dependencies/getMissingPackages';

const debug = require('debug')('expo:doctor:webSupport') as typeof console.log;

/** Ensure the project has the required web support settings. */
export class WebSupportProjectPrerequisite extends ProjectPrerequisite {
  /** Ensure a project that hasn't explicitly disabled web support has all the required packages for running in the browser. */
  async assertImplementation(): Promise<void> {
    if (env.EXPO_NO_WEB_SETUP) {
      Log.warn('Skipping web setup: EXPO_NO_WEB_SETUP is enabled.');
      return;
    }
    debug('Ensuring web support is setup');

    const result = await this._shouldSetupWebSupportAsync();

    // Ensure web packages are installed
    await this._ensureWebDependenciesInstalledAsync({ exp: result.exp });
  }

  /** Exposed for testing. */
  async _shouldSetupWebSupportAsync(): Promise<ProjectConfig> {
    const config = getConfig(this.projectRoot);

    // Detect if the 'web' string is purposefully missing from the platforms array.
    if (isWebPlatformExcluded(config.rootConfig)) {
      // Get exact config description with paths.
      const configName = getProjectConfigDescriptionWithPaths(this.projectRoot, config);
      throw new PrerequisiteCommandError(
        'WEB_SUPPORT',
        chalk`Skipping web setup: {bold "web"} is not included in the project ${configName} {bold "platforms"} array.`
      );
    }

    return config;
  }

  /** Exposed for testing. */
  async _ensureWebDependenciesInstalledAsync({ exp }: { exp: ExpoConfig }): Promise<boolean> {
    const requiredPackages: ResolvedPackage[] = [
      // use react-native-web/package.json to skip node module cache issues when the user installs
      // the package and attempts to resolve the module in the same process.
      { file: 'react-native-web/package.json', pkg: 'react-native-web' },
      { file: 'react-dom/package.json', pkg: 'react-dom' },
    ];

    const bundler = getPlatformBundlers(exp).web;
    // Only include webpack-config if bundler is webpack.
    if (bundler === 'webpack') {
      requiredPackages.push(
        // `webpack` and `webpack-dev-server` should be installed in the `@expo/webpack-config`
        {
          file: '@expo/webpack-config/package.json',
          pkg: '@expo/webpack-config',
          dev: true,
        }
      );
    }

    try {
      return await ensureDependenciesAsync(this.projectRoot, {
        // This never seems to work when prompting, installing, and running -- instead just inform the user to run the install command and try again.
        skipPrompt: true,
        isProjectMutable: false,
        exp,
        installMessage: `It looks like you're trying to use web support but don't have the required dependencies installed.`,
        warningMessage: chalk`If you're not using web, please ensure you remove the {bold "web"} string from the platforms array in the project Expo config.`,
        requiredPackages,
      });
    } catch (error) {
      // Reset the cached check so we can re-run the check if the user re-runs the command by pressing 'w' in the Terminal UI.
      this.resetAssertion();
      throw error;
    }
  }
}

/** Return `true` if the `web` platform is purposefully excluded from the project Expo config. */
export function isWebPlatformExcluded(rootConfig: AppJSONConfig): boolean {
  // Detect if the 'web' string is purposefully missing from the platforms array.
  const isWebExcluded =
    Array.isArray(rootConfig.expo?.platforms) &&
    !!rootConfig.expo?.platforms.length &&
    !rootConfig.expo?.platforms.includes('web');
  return isWebExcluded;
}