import * as path from 'path'
import * as fs from 'fs-extra'
import * as inquirer from 'inquirer'
import * as semver from 'semver'
import {
  DEFAULT_TEMPLATE_SRC,
  TARO_CONFIG_FLODER,
  TARO_BASE_CONFIG,
  getUserHomeDir,
  chalk,
  SOURCE_DIR
} from '@tarojs/helper'
import { isArray } from '@tarojs/shared'

import { createApp } from './init'
import fetchTemplate from './fetchTemplate'
import Creator from './creator'

import type { ITemplates } from './fetchTemplate'

export interface IProjectConf {
  projectName: string;
  projectDir: string;
  templateSource: string;
  clone?: boolean;
  template: string;
  description?: string;
  typescript?: boolean;
  css: 'none' | 'sass' | 'stylus' | 'less';
  date?: string;
  src?: string;
  sourceRoot?: string;
  env?: string;
  autoInstall?: boolean,
  framework: 'nerv' | 'react' | 'vue' | 'vue3'
}

interface AskMethods {
  (conf: IProjectConf, prompts: object[], choices?: ITemplates[]): void;
}

export default class Project extends Creator {
  public rootPath: string
  public conf: IProjectConf

  constructor (options: IProjectConf) {
    super(options.sourceRoot)
    const unSupportedVer = semver.lt(process.version, 'v7.6.0')
    if (unSupportedVer) {
      throw new Error('Node.js 版本过低，推荐升级 Node.js 至 v8.0.0+')
    }
    this.rootPath = this._rootPath

    this.conf = Object.assign(
      {
        projectName: '',
        projectDir: '',
        template: '',
        description: ''
      },
      options
    )
  }

  init () {
    console.log(chalk.green('Taro即将创建一个新项目!'))
    console.log('Need help? Go and open issue: https://github.com/NervJS/taro/issues/new')
    console.log()
  }

  create () {
    this.fetchTemplates()
      .then((templateChoices: ITemplates[]) => {
        return this.ask(templateChoices)
      })
      .then(answers => {
        const date = new Date()
        this.conf = Object.assign(this.conf, answers)
        this.conf.date = `${date.getFullYear()}-${date.getMonth() + 1}-${date.getDate()}`
        this.write()
      })
      .catch(err => console.log(chalk.red('创建项目失败: ', err)))
  }

  async fetchTemplates (): Promise<ITemplates[]> {
    const conf = this.conf
    // 使用默认模版
    if (conf.template && conf.template === 'default') {
      return Promise.resolve([])
    }

    // 处理模版源取值
    if (!conf.templateSource) {
      const homedir = getUserHomeDir()
      if (!homedir) {
        chalk.yellow('找不到用户根目录，使用默认模版源！')
        conf.templateSource = DEFAULT_TEMPLATE_SRC
      }

      const taroConfigPath = path.join(homedir, TARO_CONFIG_FLODER)
      const taroConfig = path.join(taroConfigPath, TARO_BASE_CONFIG)

      if (fs.existsSync(taroConfig)) {
        const config = await fs.readJSON(taroConfig)
        conf.templateSource = config && config.templateSource ? config.templateSource : DEFAULT_TEMPLATE_SRC
      } else {
        await fs.createFile(taroConfig)
        await fs.writeJSON(taroConfig, { templateSource: DEFAULT_TEMPLATE_SRC })
        conf.templateSource = DEFAULT_TEMPLATE_SRC
      }
    }

    // 从模板源下载模板
    return fetchTemplate(this.conf.templateSource, this.templatePath(''), this.conf.clone)
  }

  ask (templateChoices: ITemplates[]) {
    const prompts: object[] = []
    const templateChoicesPrompts: object[] = []
    const conf = this.conf

    this.askProjectName(conf, prompts)
    this.askDescription(conf, prompts)
    this.askFramework(conf, prompts)
    this.askTypescript(conf, prompts)
    this.askCSS(conf, prompts)

    return inquirer.prompt(prompts).then(answers => {
      const newTemplateChoices: ITemplates[] = templateChoices
        .filter(templateChoice => {
          const { platforms } = templateChoice
          if (typeof platforms === 'string') {
            return answers.framework === templateChoice.platforms
          } else if (isArray(platforms)) {
            return templateChoice.platforms?.includes(answers.framework)
          } else {
            return true
          }
        })
      this.askTemplate(conf, templateChoicesPrompts, newTemplateChoices)
      return inquirer.prompt(templateChoicesPrompts)
        .then(templateChoiceAnswer => {
          return {
            ...answers,
            ...templateChoiceAnswer
          }
        })
    })
  }

  askProjectName: AskMethods = function (conf, prompts) {
    if ((typeof conf.projectName as string | undefined) !== 'string') {
      prompts.push({
        type: 'input',
        name: 'projectName',
        message: '请输入项目名称！',
        validate (input) {
          if (!input) {
            return '项目名不能为空！'
          }
          if (fs.existsSync(input)) {
            return '当前目录已经存在同名项目，请换一个项目名！'
          }
          return true
        }
      })
    } else if (fs.existsSync(conf.projectName)) {
      prompts.push({
        type: 'input',
        name: 'projectName',
        message: '当前目录已经存在同名项目，请换一个项目名！',
        validate (input) {
          if (!input) {
            return '项目名不能为空！'
          }
          if (fs.existsSync(input)) {
            return '项目名依然重复！'
          }
          return true
        }
      })
    }
  }

  askDescription: AskMethods = function (conf, prompts) {
    if (typeof conf.description !== 'string') {
      prompts.push({
        type: 'input',
        name: 'description',
        message: '请输入项目介绍！'
      })
    }
  }

  askTypescript: AskMethods = function (conf, prompts) {
    if (typeof conf.typescript !== 'boolean') {
      prompts.push({
        type: 'confirm',
        name: 'typescript',
        message: '是否需要使用 TypeScript ？'
      })
    }
  }

  askCSS: AskMethods = function (conf, prompts) {
    const cssChoices = [
      {
        name: 'Sass',
        value: 'sass'
      },
      {
        name: 'Less',
        value: 'less'
      },
      {
        name: 'Stylus',
        value: 'stylus'
      },
      {
        name: '无',
        value: 'none'
      }
    ]

    if ((typeof conf.css as string | undefined) !== 'string') {
      prompts.push({
        type: 'list',
        name: 'css',
        message: '请选择 CSS 预处理器（Sass/Less/Stylus）',
        choices: cssChoices
      })
    }
  }

  askFramework: AskMethods = function (conf, prompts) {
    const frameworks = [
      {
        name: 'React',
        value: 'react'
      },
      {
        name: 'Nerv',
        value: 'nerv'
      },
      {
        name: 'Vue',
        value: 'vue'
      },
      {
        name: 'Vue3',
        value: 'vue3'
      }
    ]

    if ((typeof conf.framework as string | undefined) !== 'string') {
      prompts.push({
        type: 'list',
        name: 'framework',
        message: '请选择框架',
        choices: frameworks
      })
    }
  }

  askTemplate: AskMethods = function (conf, prompts, list = []) {
    const choices = [
      {
        name: '默认模板',
        value: 'default'
      },
      ...list.map(item => ({
        name: item.desc ? `${item.name}（${item.desc}）` : item.name,
        value: item.name
      }))
    ]

    if ((typeof conf.template as 'string' | undefined) !== 'string') {
      prompts.push({
        type: 'list',
        name: 'template',
        message: '请选择模板',
        choices
      })
    }
  }

  write (cb?: () => void) {
    this.conf.src = SOURCE_DIR
    createApp(this, this.conf, cb).catch(err => console.log(err))
  }
}