import download from '../../utils/download'
import fs from 'fs'
import path from 'path'
import music from '../../utils/music'
import { getMusicType } from '../../utils/music/utils'

// state
const state = {
  list: [],
  waitingList: [],
  downloadStatus: {
    RUN: 'run',
    WAITING: 'waiting',
    PAUSE: 'pause',
    ERROR: 'error',
    COMPLETED: 'completed',
  },
}


const dls = {}
const tryNum = {}

// getters
const getters = {
  list: state => state.list || [],
  dls: () => dls || {},
  downloadStatus: state => state.downloadStatus,
}

const checkPath = path => {
  try {
    if (!fs.existsSync(path)) fs.mkdirSync(path, { recursive: true })
  } catch (error) {
    return error.message
  }
  return false
}

const getExt = type => {
  switch (type) {
    case '128k':
    case '192k':
    case '320k':
      return 'mp3'
    case 'ape':
      return 'ape'
    case 'flac':
      return 'flac'
  }
}

const checkList = (list, musicInfo, type) => list.some(s => s.musicInfo.songmid === musicInfo.songmid && s.type === type)

const getStartTask = (list, downloadStatus, maxDownloadNum) => {
  let downloadCount = 0
  const waitList = list.filter(item => item.status == downloadStatus.WAITING ? true : (item.status === downloadStatus.RUN && ++downloadCount && false))
  // console.log(downloadCount, waitList)
  return downloadCount < maxDownloadNum && waitList.length > 0 && waitList.shift()
}

const addTask = (list, type, store) => {
  window.requestAnimationFrame(() => {
    let item = list.shift()
    store.dispatch('download/createDownload', {
      musicInfo: item,
      type: getMusicType(item, type),
    })
    if (list.length) addTask(list, type, store)
  })
}

const refreshUrl = downloadInfo => {
  return music[downloadInfo.musicInfo.source].getMusicUrl(downloadInfo.musicInfo, downloadInfo.type).promise
}

// actions
const actions = {
  createDownload({ state, rootState, commit }, { musicInfo, type }) {
    if (checkList(state.list, musicInfo, type)) return
    let ext = getExt(type)
    const downloadInfo = {
      isComplate: false,
      status: state.downloadStatus.WAITING,
      statusText: '待下载',
      url: null,
      fileName: `${rootState.setting.download.fileName
        .replace('歌名', musicInfo.name)
        .replace('歌手', musicInfo.singer)}.${ext}`,
      progress: {
        downloaded: 0,
        total: 0,
        progress: 0,
      },
      type,
      ext,
      musicInfo,
      key: `${musicInfo.songmid}${ext}`,
    }
    downloadInfo.filePath = path.join(rootState.setting.download.savePath, downloadInfo.fileName)
    commit('addTask', downloadInfo)
    if (dls[downloadInfo.key]) {
      dls[downloadInfo.key].stop().finally(() => {
        delete dls[downloadInfo.key]
        this.dispatch('download/startTask', downloadInfo)
      })
    } else {
      // console.log(downloadInfo)
      this.dispatch('download/startTask', downloadInfo)
    }
  },
  createDownloadMultiple({ state, rootState }, { list, type }) {
    addTask([...list], type, this)
  },
  startTask({ commit, state, rootState }, downloadInfo) {
    // 检查是否可以开始任务
    if (downloadInfo && downloadInfo != state.downloadStatus.WAITING) commit('setStatus', { downloadInfo, status: state.downloadStatus.WAITING })
    let result = getStartTask(state.list, state.downloadStatus, rootState.setting.download.maxDownloadNum)
    if (!result) return downloadInfo && commit('setStatus', { downloadInfo, status: state.downloadStatus.WAITING })
    if (!downloadInfo) downloadInfo = result

    // 开始任务
    commit('setStatusText', { downloadInfo, text: '任务初始化中' })
    commit('onDownload', downloadInfo)
    let msg = checkPath(rootState.setting.download.savePath)
    if (msg) return commit('setStatusText', '检查下载目录出错: ' + msg)
    const _this = this
    const options = {
      url: downloadInfo.url,
      path: rootState.setting.download.savePath,
      fileName: downloadInfo.fileName,
      method: 'get',
      override: true,
      onEnd() {
        commit('onEnd', downloadInfo)
        _this.dispatch('download/startTask')
        console.log('on complate')
      },
      onError(err) {
        console.log(err.message)
        commit('onError', downloadInfo)
        // console.log(tryNum[downloadInfo.key])
        if (++tryNum[downloadInfo.key] > 5) return
        let code
        if (err.message.includes('Response status was')) {
          code = err.message.replace(/Response status was (\d+)$/, '$1')
        } if (err.code === 'ETIMEDOUT') {
          code = 'ETIMEDOUT'
        } else {
          console.log('Download failed, Attempting Retry')
          dls[downloadInfo.key].resume()
          commit('setStatusText', { downloadInfo, text: '正在重试' })
          return
        }
        switch (code) {
          case '401':
          case '403':
          case '410':
          case 'ETIMEDOUT':
            commit('setStatusText', { downloadInfo, text: '链接失效，正在刷新链接' })
            refreshUrl(downloadInfo).then(result => {
              commit('updateUrl', { downloadInfo, url: result.url })
              commit('setStatusText', { downloadInfo, text: '链接刷新成功' })
              dls[downloadInfo.key].url = dls[downloadInfo.key].requestURL = result.url
              dls[downloadInfo.key].__initProtocol(result.url)
              dls[downloadInfo.key].resume()
            }).catch(err => {
              console.log(err)
              _this.dispatch('download/startTask')
            })
            return
        }
        _this.dispatch('download/startTask')
      },
      // onStateChanged(state) {
      //   console.log(state)
      // },
      onDownload() {
        commit('onDownload', downloadInfo)
        console.log('on download')
      },
      onProgress(status) {
        commit('onProgress', { downloadInfo, status })
        console.log(status)
      },
      onPause() {
        commit('pauseTask', downloadInfo)
        _this.dispatch('download/startTask')
      },
      onResume() {
        commit('resumeTask', downloadInfo)
      },
    }
    commit('setStatusText', { downloadInfo, text: '获取URL中...' })
    let p = options.url ? Promise.resolve() : refreshUrl(downloadInfo).then(result => {
      commit('updateUrl', { downloadInfo, url: result.url })
      if (!result.url) return Promise.reject(new Error('获取URL失败'))
      options.url = result.url
    })
    p.then(() => {
      tryNum[downloadInfo.key] = 0
      dls[downloadInfo.key] = download(options)
    }).catch(err => {
      // console.log(err.message)
      commit('onError', downloadInfo)
      commit('setStatusText', { downloadInfo, text: err.message })
      this.dispatch('download/startTask')
    })
  },
  // startTaskMultiple({ state, rootState }, list) {

  // },
  removeTask({ commit, state }, index) {
    let info = state.list[index]
    if (state.list[index].status == state.downloadStatus.RUN) {
      if (dls[info.key]) {
        dls[info.key].stop().finally(() => {
          delete dls[info.key]
        })
      }
    }
    commit('removeTask', index)
    if (dls[info.key]) delete dls[info.key]
    this.dispatch('download/startTask')
  },
  removeTaskMultiple({ commit, rootState, state }, list) {
    list.forEach(item => {
      let index = state.list.indexOf(item)
      if (index < 0) return
      // this.dispatch('download/removeTask', index)
      if (state.list[index].status == state.downloadStatus.RUN) {
        if (dls[item.key]) {
          dls[item.key].stop().finally(() => {
            delete dls[item.key]
          })
        }
      }
      commit('removeTask', index)
      if (dls[item.key]) delete dls[item.key]
    })
    let result = getStartTask(state.list, state.downloadStatus, rootState.setting.download.maxDownloadNum)
    while (result) {
      this.dispatch('download/startTask', result)
      result = getStartTask(state.list, state.downloadStatus, rootState.setting.download.maxDownloadNum)
    }
  },
}

// mitations
const mutations = {
  addTask(state, downloadInfo) {
    state.list.push(downloadInfo)
  },
  removeTask(state, index) {
    state.list.splice(index, 1)
  },
  pauseTask(state, downloadInfo) {
    downloadInfo.status = state.downloadStatus.PAUSE
    downloadInfo.statusText = '暂停下载'
  },
  resumeTask(state, downloadInfo) {
    downloadInfo.statusText = '开始下载'
  },
  setStatusText(state, { downloadInfo, index, text }) { // 设置状态文本
    if (downloadInfo) {
      downloadInfo.statusText = text
    } else {
      state.list[index].statusText = text
    }
  },
  setStatus(state, { downloadInfo, index, status }) { // 设置状态及状态文本
    let text
    switch (status) {
      case state.downloadStatus.RUN:
        text = '正在下载'
        break
      case state.downloadStatus.WAITING:
        text = '等待下载'
        break
      case state.downloadStatus.PAUSE:
        text = '暂停下载'
        break
      case state.downloadStatus.ERROR:
        text = '任务出错'
        break
      case state.downloadStatus.COMPLETED:
        text = '下载完成'
        break
    }
    if (downloadInfo) {
      downloadInfo.statusText = text
      downloadInfo.status = status
    } else {
      state.list[index].statusText = text
      state.list[index].status = status
    }
  },
  onEnd(state, downloadInfo) {
    downloadInfo.isComplate = true
    downloadInfo.status = state.downloadStatus.COMPLETED
    downloadInfo.statusText = '下载完成'
  },
  onError(state, downloadInfo) {
    downloadInfo.status = state.downloadStatus.ERROR
    downloadInfo.statusText = '任务出错'
  },
  onDownload(state, downloadInfo) {
    downloadInfo.status = state.downloadStatus.RUN
    downloadInfo.statusText = '正在下载'
  },
  onProgress(state, { downloadInfo, status }) {
    downloadInfo.progress.progress = status.progress
    downloadInfo.progress.downloaded = status.downloaded
    downloadInfo.progress.total = status.total
  },
  setTotal(state, { order, downloadInfo }) {
    downloadInfo.order = order
  },
  updateDownloadList(state, list) {
    state.list = list
  },
  updateUrl(state, { downloadInfo, url }) {
    downloadInfo.url = url
  },
}

export default {
  namespaced: true,
  state,
  getters,
  actions,
  mutations,
}