<template> 
  <div>
    <el-upload 
      :data="dataObj" 
      :file-list="fileList" 
      :before-upload="beforeUpload" 
      :on-remove="handleRemove" 
      :on-success="handleUploadSuccess"
      :on-preview="handlePreview" 
      :limit="maxCount" 
      :on-exceed="handleExceed" 
      action="http://yjlive160322.oss-cn-beijing.aliyuncs.com"
      list-type="picture">
      <el-button size="small">点击上传</el-button>
      <div slot="tip" class="el-upload__tip color">{{ tips }}</div>
    </el-upload>
    <el-dialog :visible.sync="dialogVisible">
      <img :src="dialogImageUrl" width="100%" alt="">
    </el-dialog>
  </div>
</template>
<script>
import {
  policy
} from '@/api/oss'

export default {
  name: 'multiUpload',
  props: {
    //图片属性数组
    tips: {
      type: String,
      default: '支付扩展名:.rar .zip .doc .docx .pdf .jpg...'
    },
    value: {
      type: Array,
      default() {
        return []
      }
    },
    //最大上传图片数量
    maxCount: {
      type: Number,
      default: 5
    }
  },
  data() {
    return {
      dataObj: {
        policy: '',
        signature: '',
        key: '',
        ossaccessKeyId: '',
        dir: '',
        host: ''
      },
      dialogVisible: false,
      dialogImageUrl: null
    }
  },
  computed: {
    fileList() {
      let fileList = []
      for (let i = 0; i < this.value.length; i++) {
        fileList.push({
          url: this.value[i]
        })
      }
      return fileList
    }
  },
  methods: {
    emitInput(fileList) {
      let value = []
      for (let i = 0; i < fileList.length; i++) {
        value.push(fileList[i].url)
      }
      this.$emit('input', value)
    },
    handleRemove(file, fileList) {
      this.emitInput(fileList)
    },
    handlePreview(file) {
      this.dialogVisible = true
      this.dialogImageUrl = file.url
    },
    beforeUpload(file) {
      let _self = this
      return new Promise((resolve, reject) => {
        policy().then(response => {
          _self.dataObj.policy = response.data.policy
          _self.dataObj.signature = response.data.signature
          _self.dataObj.ossaccessKeyId = response.data.accessKeyId
          _self.dataObj.key = response.data.dir + '/${filename}'
          _self.dataObj.dir = response.data.dir
          _self.dataObj.host = response.data.host
          resolve(true)
        }).catch(err => {
          console.log(err)
          reject(false)
        })
      })
    },
    handleUploadSuccess(res, file) {
      this.fileList.push({
        url: file.name,
        url: this.dataObj.host + '/' + this.dataObj.dir + '/' + file.name
      })
      this.emitInput(this.fileList)
    },
    handleExceed(files, fileList) {
      this.$message({
        message: '最多只能上传' + this.maxCount + '张图片',
        type: 'warning',
        duration: 1000
      })
    }
  }
}
</script>
<style scoped>
 .color{
 color:#CCCCCC
 }
</style>
