const chalk = require('chalk')
const debug = require('debug')
const execa = require('execa')
const resolve = require('resolve')
const inquirer = require('inquirer')
const Generator = require('./Generator')
const cloneDeep = require('lodash.clonedeep')
const sortObject = require('./util/sortObject')
const getVersions = require('./util/getVersions')
const installDeps = require('./util/installDeps')
const clearConsole = require('./util/clearConsole')
const PromptModuleAPI = require('./PromptModuleAPI')
const writeFileTree = require('./util/writeFileTree')
const formatFeatures = require('./util/formatFeatures')
const setupDevProject = require('./util/setupDevProject')

const {
  defaults,
  saveOptions,
  loadOptions,
  savePreset,
  validatePreset
} = require('./options')

const {
  log,
  error,
  hasGit,
  hasYarn,
  logWithSpinner,
  stopSpinner
} = require('@vue/cli-shared-utils')

const isManualMode = answers => answers.preset === '__manual__'

module.exports = class Creator {
  constructor (name, context, promptModules) {
    this.name = name
    this.context = process.env.VUE_CLI_CONTEXT = context
    const { presetPrompt, featurePrompt } = this.resolveIntroPrompts()
    this.presetPrompt = presetPrompt
    this.featurePrompt = featurePrompt
    this.outroPrompts = this.resolveOutroPrompts()
    this.injectedPrompts = []
    this.promptCompleteCbs = []
    this.createCompleteCbs = []

    const promptAPI = new PromptModuleAPI(this)
    promptModules.forEach(m => m(promptAPI))
  }

  async create (cliOptions = {}) {
    const isTestOrDebug = process.env.VUE_CLI_TEST || process.env.VUE_CLI_DEBUG
    const { name, context, createCompleteCbs } = this
    const run = (command, args) => {
      if (!args) { [command, ...args] = command.split(/\s+/) }
      return execa(command, args, { cwd: context })
    }

    let preset
    if (cliOptions.preset) {
      // vue create foo --preset bar
      preset = this.resolvePreset(cliOptions.preset)
    } else if (cliOptions.default) {
      // vue create foo --default
      preset = defaults.presets.default
    } else if (cliOptions.inlinePreset) {
      // vue create foo --inlinePreset {...}
      try {
        preset = JSON.parse(cliOptions.inlinePreset)
      } catch (e) {
        error(`CLI inline preset is not valid JSON: ${cliOptions.inlinePreset}`)
        process.exit(1)
      }
    } else {
      preset = await this.promptAndResolvePreset()
    }

    // clone before mutating
    preset = cloneDeep(preset)
    // inject core service
    preset.plugins['@vue/cli-service'] = Object.assign({
      projectName: name
    }, preset)

    const packageManager = (
      cliOptions.packageManager ||
      loadOptions().packageManager ||
      (hasYarn() ? 'yarn' : 'npm')
    )

    await clearConsole()
    logWithSpinner(`✨`, `Creating project in ${chalk.yellow(context)}.`)

    // get latest CLI version
    const { latest } = await getVersions()
    // generate package.json with plugin dependencies
    const pkg = {
      name,
      version: '0.1.0',
      private: true,
      devDependencies: {}
    }
    const deps = Object.keys(preset.plugins)
    deps.forEach(dep => {
      pkg.devDependencies[dep] = `^${latest}`
    })
    // write package.json
    await writeFileTree(context, {
      'package.json': JSON.stringify(pkg, null, 2)
    })

    // intilaize git repository before installing deps
    // so that vue-cli-service can setup git hooks.
    if (hasGit()) {
      logWithSpinner(`🗃`, `Initializing git repository...`)
      await run('git init')
    }

    // install plugins
    stopSpinner()
    log(`⚙  Installing CLI plugins. This might take a while...`)
    log()
    if (isTestOrDebug) {
      // in development, avoid installation process
      await setupDevProject(context)
    } else {
      await installDeps(context, packageManager, cliOptions.registry)
    }

    // run generator
    log()
    log(`🚀  Invoking generators...`)
    const plugins = this.resolvePlugins(preset.plugins)
    const generator = new Generator(
      context,
      pkg,
      plugins,
      createCompleteCbs
    )
    await generator.generate({
      extractConfigFiles: preset.useConfigFiles
    })

    // install additional deps (injected by generators)
    log(`📦  Installing additional dependencies...`)
    log()
    if (!isTestOrDebug) {
      await installDeps(context, packageManager, cliOptions.registry)
    }

    // run complete cbs if any (injected by generators)
    log()
    logWithSpinner('⚓', `Running completion hooks...`)
    for (const cb of createCompleteCbs) {
      await cb()
    }

    // commit initial state
    if (hasGit()) {
      await run('git add -A')
      if (isTestOrDebug) {
        await run('git', ['config', 'user.name', 'test'])
        await run('git', ['config', 'user.email', 'test@test.com'])
      }
      await run(`git commit -m init`)
    }

    // log instructions
    stopSpinner()
    log()
    log(`🎉  Successfully created project ${chalk.yellow(name)}.`)
    log(
      `👉  Get started with the following commands:\n\n` +
      chalk.cyan(` ${chalk.gray('$')} cd ${name}\n`) +
      chalk.cyan(` ${chalk.gray('$')} ${packageManager === 'yarn' ? 'yarn serve' : 'npm run serve'}`)
    )
    log()
  }

  async promptAndResolvePreset () {
    // prompt
    await clearConsole(true)
    const answers = await inquirer.prompt(this.resolveFinalPrompts())
    debug('vue-cli:answers')(answers)

    if (answers.packageManager) {
      saveOptions({
        packageManager: answers.packageManager
      })
    }

    let preset
    if (answers.preset && answers.preset !== '__manual__') {
      preset = this.resolvePreset(answers.preset)
    } else {
      // manual
      preset = {
        useConfigFiles: answers.useConfigFiles === 'files',
        plugins: {}
      }
      answers.features = answers.features || []
      // run cb registered by prompt modules to finalize the preset
      this.promptCompleteCbs.forEach(cb => cb(answers, preset))
    }

    // validate
    validatePreset(preset)

    // save preset
    if (answers.save && answers.saveName) {
      savePreset(answers.saveName, preset)
    }

    debug('vue-cli:preset')(preset)
    return preset
  }

  resolvePreset (name) {
    const savedPresets = loadOptions().presets || {}
    let preset = savedPresets[name]
    // use default preset if user has not overwritten it
    if (name === 'default' && !preset) {
      preset = defaults.presets.default
    }
    if (!preset) {
      error(`preset "${name}" not found.`)
      const presets = Object.keys(savedPresets)
      if (presets.length) {
        log()
        log(`available presets:\n${presets.join(`\n`)}`)
      } else {
        log(`you don't seem to have any saved preset.`)
        log(`run vue-cli in manual mode to create a preset.`)
      }
      process.exit(1)
    }
    return preset
  }

  // { id: options } => [{ id, apply, options }]
  resolvePlugins (rawPlugins) {
    // ensure cli-service is invoked first
    rawPlugins = sortObject(rawPlugins, ['@vue/cli-service'])
    return Object.keys(rawPlugins).map(id => {
      const module = resolve.sync(`${id}/generator`, { basedir: this.context })
      return {
        id,
        apply: require(module),
        options: rawPlugins[id]
      }
    })
  }

  resolveIntroPrompts () {
    const savedOptions = loadOptions()
    const presets = Object.assign({}, savedOptions.presets, defaults.presets)
    const presetChoices = Object.keys(presets).map(name => {
      return {
        name: `${name} (${formatFeatures(presets[name])})`,
        value: name
      }
    })
    const presetPrompt = {
      name: 'preset',
      type: 'list',
      message: `Please pick a preset:`,
      choices: [
        ...presetChoices,
        {
          name: 'Manually select features',
          value: '__manual__'
        }
      ]
    }
    const featurePrompt = {
      name: 'features',
      when: isManualMode,
      type: 'checkbox',
      message: 'Check the features needed for your project:',
      choices: [],
      pageSize: 8
    }
    return {
      presetPrompt,
      featurePrompt
    }
  }

  resolveOutroPrompts () {
    const outroPrompts = [
      {
        name: 'useConfigFiles',
        when: isManualMode,
        type: 'list',
        message: 'Where do you prefer placing config for Babel, PostCSS, ESLint, etc.?',
        choices: [
          {
            name: 'In dedicated config files',
            value: 'files'
          },
          {
            name: 'In package.json',
            value: 'pkg'
          }
        ]
      },
      {
        name: 'save',
        when: isManualMode,
        type: 'confirm',
        message: 'Save this as a preset for future projects?'
      },
      {
        name: 'saveName',
        when: answers => answers.save,
        type: 'input',
        message: 'Save preset as:'
      }
    ]

    // ask for packageManager once
    const savedOptions = loadOptions()
    if (!savedOptions.packageManager && hasYarn()) {
      outroPrompts.push({
        name: 'packageManager',
        type: 'list',
        message: 'Pick the package manager to use when installing dependencies:',
        choices: [
          {
            name: 'Use Yarn',
            value: 'yarn',
            short: 'Yarn'
          },
          {
            name: 'Use NPM',
            value: 'npm',
            short: 'NPM'
          }
        ]
      })
    }

    return outroPrompts
  }

  resolveFinalPrompts () {
    // patch generator-injected prompts to only show in manual mode
    this.injectedPrompts.forEach(prompt => {
      const originalWhen = prompt.when || (() => true)
      prompt.when = answers => {
        return isManualMode(answers) && originalWhen(answers)
      }
    })
    const prompts = [
      this.presetPrompt,
      this.featurePrompt,
      ...this.injectedPrompts,
      ...this.outroPrompts
    ]
    debug('vue-cli:prompts')(prompts)
    return prompts
  }
}