// 文件上传

const fs = require('fs')
const config = require('../config')

/**
 * 文件上传
 * post: /upload
 */
module.exports = async ctx => {
  const body = ctx.request.body
  // 存储路径
  const saveDir = config.upload
  // 文件名不含扩展名
  const fn = body.fn
  // 文件路径不含斜杠
  const fp = body.fp
  const files = ctx.request.files
  if (files) {
    // 文件（客户端表单名为：file）
    const file = files.file
    // 文件原来路径
    const oldPath = file.path
    // 文件名称（当前含扩展名，后面不再含扩展名）
    let name = file.name
    const dot = name.lastIndexOf('.')
    // 文件扩展名（带.）
    const ext = name.substring(dot).toLowerCase()
    if (dot < 0) { ctx.body = { code: 2, message: '文件无扩展名' } }
    else if (fn && /;|\.|#|\\|\/|,/.test(fn)) { ctx.body = { code: 4, message: '文件名参数含非法字符' } }
    else if (fp && /;|\.|#|\\|\/|,/.test(fp)) { ctx.body = { code: 6, message: '文件路径参数含非法字符' } }
    else if ('.htm.html.js.php.asp.aspx'.includes(ext)) { ctx.body = { code: 5, message: '文件扩展名受限' } }
    else {
      let newPath = saveDir
      let url = ''
      // 已经指定名称（固定文件夹必须事先手工创建）
      if (fn) {
        if (fn.startsWith('crm_')) { url = 'crm/' + fn.substring(4) + '_' + Math.random().toString().slice(-8) }
        else if (fn.startsWith('face_')) { url = 'image/face/' + fn.substring(5) }
        else if ('.xls.xlsx'.includes(ext)) { url = 'excel/' + fn }
        else if ('.png.jpg.gif.jpeg.bmp.ico.svg'.includes(ext)) { url = 'image/' + fn }
        else if ('.pdf'.includes(ext)) { url = 'pdf/' + fn }
        else if ('.doc.docx'.includes(ext)) { url = 'word/' + fn }
        else if ('.txt'.includes(ext)) { url = 'txt/' + fn }
        else { url = 'other/' + fn }
        name = url
      } else {
        // 根据系统时间命名
        const now = new Date()
        const time = {
          y: now.getFullYear(),
          m: ('0' + (now.getMonth() + 1)).slice(-2),
          d: ('0' + now.getDate()).slice(-2),
          hh: ('0' + now.getHours()).slice(-2),
          mm: ('0' + now.getMinutes()).slice(-2),
          ss: ('0' + now.getSeconds()).slice(-2)
        }
        // 创建文件夹
        newPath = saveDir + '/' + time.y
        if (!fs.existsSync(newPath)) { fs.mkdirSync(newPath) }
        newPath = saveDir + '/' + time.y + '/' + time.m
        if (!fs.existsSync(newPath)) { fs.mkdirSync(newPath) }
        newPath = saveDir + '/' + time.y + '/' + time.m + '/' + time.d
        if (!fs.existsSync(newPath)) { fs.mkdirSync(newPath) }
        // 新文件名称（不含扩展名）
        name = time.hh + time.mm + time.ss + String(Math.random()).slice(-2)
        // 文件路径（不含主机名）
        url = time.y + '/' + time.m + '/' + time.d + '/' + name + ext
      }

      // 保存
      try {
        const chunkTotal = body.totalChunks
        const data = fs.readFileSync(oldPath)
        fs.unlinkSync(oldPath)
        if (chunkTotal > 1) {
          // 分片上传
          const chunkNumber = body.chunkNumber
          const totalSize = body.totalSize
          fs.writeFileSync(newPath + '/' + totalSize + '_' + chunkNumber + ext, data)
          // 最后一个时合并文件
          if (chunkNumber === chunkTotal) {
            const wrStream = fs.createWriteStream(newPath + '/' + name + ext)
            const merge = i => {
              const chunkPath = newPath + '/' + totalSize + '_' + i + ext
              const reStream = fs.createReadStream(chunkPath)
              reStream.pipe(wrStream, { end: false })
              reStream.once('end', () => {
                fs.unlinkSync(chunkPath)
                i < chunkTotal && merge(i + 1)
              })
            }
            merge(1)
          }
        } else {
          // 单文件上传
          fs.writeFileSync(newPath + '/' + name + ext, data)
        }
        ctx.body = { code: 0, data: url }
      }
      catch (err) { ctx.body = { code: 3, message: '文件转存出错' } }
    }
  } else { ctx.body = { code: 1, message: '没有检测到上传数据' } }
}