import fs from 'fs';
import inquirer from 'inquirer';
import path from 'path';
import yeoman from 'yeoman-environment';
import { install } from '../../shared/npm';

const loadGenerator = (root: string, rootPkg: string) => {
  return new Promise<any>((resolve, reject) => {
    fs.readFile(rootPkg, 'utf8', (err, data) => {
      if (err) {
        reject(err);
      } else {
        const json = JSON.parse(data);
        const deps = json.dependencies || json.devDependencies || {};
        const generators = Object.keys(deps)
          .filter((name) => {
            if (!/^generator-|^@[^/]+\/generator-/.test(name)) {
              return false;
            }
            const generatorPath = path.join(root, 'node_modules', name);
            return fs.existsSync(generatorPath);
          })
          .map((name) => {
            const generatorPkgPath = path.join(
              root,
              'node_modules',
              name,
              'package.json'
            );
            const generatorPkgData = fs.readFileSync(generatorPkgPath, 'utf8');
            const generatorPkgJson = JSON.parse(generatorPkgData);
            const desc = generatorPkgJson.description;

            return { name, desc };
          });
        resolve(generators);
      }
    });
  });
};

const run = (ctx: any, name: string) => {
  const root = ctx.root;
  const yeomanEnv = yeoman.createEnv();
  let generatorEntry = path.join(root, 'node_modules', name, 'app/index.js');

  if (!fs.existsSync(generatorEntry)) {
    generatorEntry = path.join(
      root,
      'node_modules',
      name,
      'generators',
      'app/index.js'
    );
  }
  yeomanEnv.register(require.resolve(generatorEntry), name);
  yeomanEnv.run(name, ctx, (err) => {
    ctx.reporter && ctx.reporter.reportInitResult()
    if (err) {
      ctx.logger.error(err);
    } else {
      ctx.logger.debug('create project success!');
    }
  });
};

module.exports = (ctx: any) => {
  ctx.commander.register('init', 'Create a new project', () => {
    const { root, rootPkg, args } = ctx;
    const { generator } = args;
    loadGenerator(root, rootPkg).then(async (generators: any) => {
      // feflow init 简化逻辑直接安装并使用脚手架
      if (generator && /^generator-|^@[^/]+\/generator-/.test(generator)) {
        const isGeneratorInstalled = generators.some((item: any) => {
          return item.name === generator
        });
        if (generators.length && isGeneratorInstalled) {
          run(ctx, generator);
          return;
        } else {
          const askIfInstallGenerator = [
            {
              type: 'confirm',
              name: 'ifInstall',
              message: `You have not installed the generator ${generator}，if you want to install and use ?`,
              default: true
            }
          ];
          const answer = await inquirer.prompt(askIfInstallGenerator);
          if (answer.ifInstall) {
            const packageManager = ctx.config && ctx.config.packageManager;
            install(
              packageManager,
              ctx.root,
              'install',
              generator,
              false,
              true
            ).then(() => {
              ctx.logger.info(`install success`);
              run(ctx, generator);
            });
            return;
          }
        }
      }
      const options = generators.map((item: any) => {
        return item.desc;
      });
      if (generators.length) {
        inquirer
          .prompt([
            {
              type: 'list',
              name: 'desc',
              message: '您想要创建哪种类型的工程?',
              choices: options
            }
          ])
          .then((answer: any) => {
            let name;
            generators.map((item: any) => {
              if (item.desc === answer.desc) {
                name = item.name;
              }
            });
            ctx.reporter.report('init', name)
            name && run(ctx, name);
          });
      } else {
        ctx.logger.warn(
          'You have not installed a template yet, ' +
          ' please use install command. Guide: https://github.com/Tencent/feflow'
        );
      }
    });
  });
};