<template>
  <div class="camera_outer">
    <video
      id="videoCamera"
      :width="videoWidth"
      :height="videoHeight"
      autoplay
    />
    <canvas
      id="canvasCamera"
      :width="videoWidth"
      :height="videoHeight"
      style="display: none"
    />
  </div>
</template>

<script>
import { faceLogin } from '@/api/login'
import { setToken } from '@/utils/auth'
export default {
  name: 'FaceLogin',
  data() {
    return {
      videoWidth: 414,
      videoHeight: 736,
      thisCancas: null,
      thisContext: null,
      thisVideo: null,
      faceList: [],
      tryFaceLogin: true, // 尝试人脸登录
      tryCount: 0
    }
  },
  mounted() {
    this.videoWidth = document.body.clientWidth
    this.videoHeight = document.body.clientHeight
    this.getCompetence()
  },
  methods: {
    // 调用权限（打开摄像头功能）
    getCompetence() {
      const _this = this
      this.thisCancas = document.getElementById('canvasCamera')
      this.thisContext = this.thisCancas.getContext('2d')
      this.thisVideo = document.getElementById('videoCamera')
      this.videoHeight = _this.thisVideo.clientHeight
      this.videoWidth = _this.thisVideo.clientWidth
      // 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) {
            alert('error')
            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()
            // _this.$emit('cameraReady')
            _this.setImage()
          }
        })
        .catch((err) => {
          alert(err)
          console.log(err)
        })
    },
    //  绘制图片（拍照功能）
    setImage() {
      const _this = this
      // 点击，canvas画图
      _this.thisContext.drawImage(
        _this.thisVideo,
        0,
        0,
        _this.videoWidth,
        _this.videoHeight
      )
      debugger
      // 获取图片base64链接
      const image = this.thisCancas.toDataURL('image/png')
      // this.$emit('captured', image)
      this.handleFaceCaptured(image)
    },
    handleFaceCaptured(image) {
      console.log(image)
      this.faceList.push(image)
      console.log(this.faceList.length)

      if (this.tryFaceLogin === false) {
        return ''
      }

      if (this.tryCount < 5) {
        // 如果拍到照片，调用接口进行登录，同时停止拍照
        if (this.faceList.length > this.tryCount) {
          faceLogin({
            image: this.faceList[this.tryCount] // 取一张图进行尝试
          }).then(response => {
            console.log(response)
            if (response.code === 200) {
              if (response.success === true) {
                // 设置token
                const data = response.data
                setToken(data.token)
                this.$store.commit('SET_TOKEN', data.token)

                // 关闭摄像头
                this.stopNavigator()

                // 跳转页面
                this.$message.success('登录成功')
                this.$router.push({ path: '/' })
              } else {
                // 登录失败，重新触发拍照并识别
                if (response.message === '') {
                  response.message = '人脸匹配失败'
                }
                this.$message.warning(response.message + '，已尝试' + this.tryCount + '次')
                const that = this
                setTimeout(function() {
                  that.setImage()
                }, 1000)
              }
            }
          })
          this.tryCount++
        }
      } else {
        this.$message.error('人脸登录失败，请重试或联系管理员')
        // this.$router.push('/applogin')
      }
    },
    // 关闭摄像头
    stopNavigator() {
      if (this.thisVideo != null && this.thisVideo.srcObject !== null) {
        this.thisVideo.srcObject.getTracks()[0].stop()
      }
    }
  }
}
</script>

<style lang="scss" scoped>
  .camera_outer {
    width: 100%;
    height: 100%;
    overflow: hidden;
    background-size: 100%;
  }
</style>