<template>
  <el-dialog :visible.sync="dialogFormVisible" :title="titleText" append-to-body>
    <div>
      <el-row :gutter="20">
        <el-col :span="6">
          <el-row>
            <div class="avatar">
              <el-image
                :src="photo!==''?photo:defaultPhoto"
                fit="cover"
                style="width: 130px; height: 175px"/>
            </div>
          </el-row>
          <el-row>
            <el-upload
              ref="upload"
              :before-upload="handleBeforeUpload"
              :http-request="uploadFile"
              :show-file-list="false"
              class="avatar-uploader"
              action="string"
              accept=".jpg,.jpeg,.png,.bmp">
              <el-button type="primary" class="face-btn">点击上传照片</el-button>
            </el-upload>
          </el-row>
          <el-row>
            <el-button v-if="!canSnap" type="primary" plain class="face-btn" @click="openCamera">打开摄像头</el-button>
            <el-button v-else type="primary" plain class="face-btn" @click="setImage">摄像头拍照</el-button>
          </el-row>
        </el-col>

        <el-col :span="18">
          <div class="camera_outer">
            <video
              id="videoCamera"
              :width="videoWidth"
              :height="videoHeight"
              autoplay
            />
            <canvas
              id="canvasCamera"
              :width="videoWidth"
              :height="videoHeight"
              style="display: none"
            />
          </div>
        </el-col>
      </el-row>
    </div>
    <div slot="footer" class="dialog-footer">
      <el-button v-show="canSave" type="primary" @click="saveData">保存</el-button>
      <el-button @click="cancel">取消</el-button>
    </div>
  </el-dialog>
</template>

<script>
import { regFace } from '@/api/system/user'
export default {
  name: 'RegFace',
  data() {
    return {
      userId: '', // 用户id
      userName: '', // 用户名称
      dialogFormVisible: false, // 对话框是否显示
      defaultProps: {
        label: 'name',
        children: 'children'
      },
      videoWidth: 396,
      videoHeight: 297,
      thisCancas: null,
      thisContext: null,
      thisVideo: null,
      canSnap: false, // 是否显示拍照按钮
      canSave: false, // 是否可以提交
      photo: '', // 图片路径
      defaultPhoto: require('@/assets/global_images/photo.png'), // 默认图片路径
      btnLoading: false // 保存按钮的加载中状态
    }
  },
  computed: {
    titleText: function() {
      return this.userName + ''
    }
  },
  methods: {
    // 初始化对话框
    initDialog: function(dialogFormVisible, row) {
      this.loading = true
      this.userId = row.id
      this.userName = row.name
      this.dialogFormVisible = dialogFormVisible
    },
    // 图片上传
    uploadFile(file) {
      console.log('uploadFile:' + file.file.name)
      // 转base64
      this.getBase64(file.file).then(resBase64 => {
        this.photo = 'data:image/png;base64,' + resBase64.split(',')[1] // 直接拿到base64信息
        this.canSave = true
      })
    },
    getBase64(file) {
      return new Promise((resolve, reject) => {
        const reader = new FileReader()
        let fileResult = ''
        reader.readAsDataURL(file)
        // 开始转
        reader.onload = function() {
          fileResult = reader.result
        }
        // 转 失败
        reader.onerror = function(error) {
          reject(error)
        }
        // 转 结束  咱就 resolve 出去
        reader.onloadend = function() {
          resolve(fileResult)
        }
      })
    },
    // 上传前判断文件格式及大小
    handleBeforeUpload(file) {
      const isJPG = (file.type === 'image/jpeg') || (file.type === 'image/png') || (file.type === 'image/bmp')
      let res = true
      console.log(file.size)
      const isLt2M = file.size / 1024 < 200
      if (!isJPG) {
        this.$message.error('上传图片只能是 JPG 或 PNG 或 BMP 格式!')
        res = false
      }
      if (!isLt2M) {
        this.$message.error('上传图片大小不能超过 200KB!')
        res = false
      }
      return res
    },
    openCamera() {
      // 打开摄像头
      const _this = this
      this.thisCancas = document.getElementById('canvasCamera')
      this.thisContext = this.thisCancas.getContext('2d')
      this.thisVideo = document.getElementById('videoCamera')
      // 旧版本浏览器可能根本不支持mediaDevices，我们首先设置一个空对象
      if (navigator.mediaDevices === undefined) {
        navigator.mediaDevices = {}
      }
      // 一些浏览器实现了部分mediaDevices，我们不能只分配一个对象
      // 使用getUserMedia，因为它会覆盖现有的属性。
      // 这里，如果缺少getUserMedia属性，就添加它。
      if (navigator.mediaDevices.getUserMedia === undefined) {
        navigator.mediaDevices.getUserMedia = function(constraints) {
          // 首先获取现存的getUserMedia(如果存在)
          const getUserMedia =
            navigator.webkitGetUserMedia ||
            navigator.mozGetUserMedia ||
            navigator.getUserMedia
          // 有些浏览器不支持，会返回错误信息
          // 保持接口一致
          if (!getUserMedia) {
            return Promise.reject(
              new Error('getUserMedia is not implemented in this browser')
            )
          }
          // 否则，使用Promise将调用包装到旧的navigator.getUserMedia
          return new Promise(function(resolve, reject) {
            getUserMedia.call(navigator, constraints, resolve, reject)
          })
        }
      }
      const constraints = {
        audio: false,
        video: {
          width: this.videoWidth,
          height: this.videoHeight
        }
      }
      navigator.mediaDevices
        .getUserMedia(constraints)
        .then(function(stream) {
          // 旧的浏览器可能没有srcObject
          if ('srcObject' in _this.thisVideo) {
            _this.thisVideo.srcObject = stream
          } else {
            // 避免在新的浏览器中使用它，因为它正在被弃用。
            _this.thisVideo.src = window.URL.createObjectURL(stream)
          }
          _this.thisVideo.onloadedmetadata = function(e) {
            _this.thisVideo.play()
          }
        })
        .catch((err) => {
          console.log(err)
        })

      this.canSnap = true
    },
    //  绘制图片（拍照功能）
    setImage() {
      const _this = this
      // 点击，canvas画图
      _this.thisContext.drawImage(
        _this.thisVideo,
        0,
        0,
        _this.videoWidth,
        _this.videoHeight
      )
      // 获取图片base64链接
      const image = this.thisCancas.toDataURL('image/png')
      this.photo = image
      this.canSave = true

      // 关闭摄像头并将按钮复位
      this.canSnap = false
      this.stopNavigator()
    },
    // 关闭摄像头
    stopNavigator() {
      this.thisVideo.srcObject.getTracks()[0].stop()
    },
    // 保存数据
    saveData: function() {
      this.btnLoading = true
      regFace({
        userId: this.userId,
        image: this.photo
      }).then(response => {
        console.log(response)
        if (response.code === 200) {
          this.$message.success('人脸注册成功')
          this.btnLoading = false
          this.$emit('watchChild')
          this.dialogFormVisible = false
        }
      })
    },
    // 点击取消
    cancel() {
      this.dialogFormVisible = false
      this.$emit('watchChild')
    }
  }
}
</script>

<style lang="scss" scoped>
  .camera_outer {
    position: relative;
    overflow: hidden;
    background-size: 100%;
    border: 2px solid #007eff;
    width: 400px;
    height: 301px;
  }

  .avatar-uploader .el-upload {
    margin-left: 12px;
    margin-top: 10px;
    cursor: pointer;
    position: relative;
    overflow: hidden;
  }
  .avatar-uploader .el-upload:hover {
    border-color: #409EFF;
  }
  .avatar-uploader-icon {
    font-size: 28px;
    color: #8c939d;
    width: 178px;
    height: 238px;
    line-height: 238px;
    text-align: center;
  }
  .avatar {
    margin: 0px 10px;
    display: block;
  }
  .face-btn {
    width:126px;
    margin-left: 10px;
    margin-top: 20px;
  }
</style>