import {
  startCase
} from 'lodash';
import * as Bluebird from 'bluebird';
import { exec, ExecOptions } from 'child_process';
import * as cmdExists from 'command-exists';
import { Blueprint, ui, spinner, unwrap } from '../../lib';

const run = Bluebird.promisify<string, string, ExecOptions>(exec);
const commandExists = Bluebird.promisify<boolean, string>(cmdExists);
const ONE_KB = 1024;
const maxBuffer = 400 * ONE_KB;

/**
 * Creates a new app, initializes git and installs dependencies.
 *
 * @package blueprints
 */
export default class AppBlueprint extends Blueprint {

  /* tslint:disable:completed-docs typedef */
  static blueprintName = 'app';
  static description = 'Creates a new app, initializes git and installs dependencies';
  static longDescription = unwrap`
    Usage: denali generate app <name> [options]

    Scaffolds a new app. Sets up the correct directory structure, initializes a git repo, and
    installs the necessary dependencies.

    Guides: http://denalijs.org/master/guides/overview/app-structure/
  `;

  static params = '<name>';

  static flags = {
    skipDeps: {
      description: 'Do not install dependencies on new app',
      defaultValue: false,
      type: <any>'boolean'
    },
    'skip-git': {
      description: 'Do not initialize git in the new app',
      defaultValue: false,
      type: <any>'boolean'
    },
    useNpm: {
      description: 'Use npm to install dependencies, even if yarn is available',
      defaultValue: false,
      type: <any>'boolean'
    }
  };

  locals(argv: any) {
    let name = argv.name;
    return {
      name,
      className: startCase(name).replace(/\s/g, ''),
      humanizedName: startCase(name)
    };
  }

  async postInstall(argv: any) {
    let name = argv.name;
    if (!argv.skipDeps) {
      try {
        let yarnExists = await commandExists('yarn');
        if (yarnExists && !argv.useNpm) {
          await spinner.start('Installing dependencies with yarn');
          await run('yarn install --mutex network', { cwd: name, maxBuffer });
        } else {
          await spinner.start('Installing dependencies with npm');
          await run('npm install --loglevel=error', { cwd: name, maxBuffer });
        }
        await spinner.succeed('Dependencies installed');
      } catch (error) {
        ui.error('Denali encountered a problem while trying to install the dependencies for your new app:');
        ui.error(error.stack || error.message || error);
      }
    }

    if (!argv.skipGit) {
      await spinner.start('Setting up git repo');
      try {
        await run('git init', { cwd: name, maxBuffer });
        await run('git add .', { cwd: name, maxBuffer });
        await run('git commit -am "Initial denali project scaffold"', { cwd: name, maxBuffer });
        await spinner.succeed('Git repo initialized');
      } catch (e) {
        await spinner.fail('Unable to initialize git repo:');
        ui.error(e.stack);
      }
    }

    ui.info(`📦  ${name} created!`);
    ui.info('');
    ui.info('To launch your application, just run:');
    ui.info('');
    ui.info(`  $ cd ${name} && denali server`);
    ui.info('');
  }

}