<template>
  <div class="page-scan">
    <!--返回-->
    <!-- <van-nav-bar
      title="扫描二维码/条形码"
      fixed
      @click-left="clickIndexLeft()"
      class="scan-index-bar">
      <template #left>
        <van-icon name="arrow-left" size="18" color="#fff"/>
        <span style="color: #fff">取消</span>
      </template>
    </van-nav-bar> -->
    <!-- 扫码区域 -->
    <div class="QrCode">
      <video ref="video" height="100%" width="100%" id="video" autoplay></video>
    </div>
    <!-- 扫码样式一 -->
    <!-- <div class="Qr_scanner">
      <div class="box">
        <div class="line_row">
          <div class="line"></div>
        </div>
        <div class="angle"></div>
      </div>
    </div> -->
    <!-- 扫码样式二 -->
    <div class="qr-scanner">
      <div class="box">
        <div class="line"></div>
        <div class="angle"></div>
      </div>
      <div class="back-arrow" @click="clickIndexLeft">
        <van-icon name="arrow-left" color="#fff" />
      </div>
    </div>
  </div>
</template>
 
<script>
// WebRTC适配器 只需要引入就ok
import 'webrtc-adapter';
import { BrowserMultiFormatReader } from '@zxing/library'
export default {
  name: 'scanCodePage',
  data() {
    return {
      codeReader: null,
    }
  },
  mounted() {
    this.codeReader = new BrowserMultiFormatReader()
    this.openScan()
  },
  beforeUnmount() {
    this.codeReader && this.codeReader.reset()
  },
  methods: {
    async openScan() {
      // this.codeReader.listVideoInputDevices().then(videoInputDevices => {
      //   // 默认获取第一个摄像头设备id
      //   videoInputDevices.forEach((device) =>
      //     alert(`${device.label}, ${device.deviceId}`)
      //   )
      //   let firstDeviceId = videoInputDevices[0].deviceId
      //   this.codeReader && this.codeReader.reset() // 重置
      //   this.decodeFromInputVideoFunc(firstDeviceId)
      // })

      // this.codeReader.getVideoInputDevices().then((videoInputDevices) => {
      this.codeReader.listVideoInputDevices().then((videoInputDevices) => {
        // 默认获取第一个摄像头设备id
        let firstDeviceId = videoInputDevices[0].deviceId
        // 获取第一个摄像头设备的名称
        const videoInputDeviceslablestr = JSON.stringify(videoInputDevices[0].label)
        if (videoInputDevices.length > 1) {
          // 判断是否后置摄像头
          if (videoInputDeviceslablestr.indexOf('back') > -1) {
            firstDeviceId = videoInputDevices[0].deviceId
          } else {
            firstDeviceId = videoInputDevices[1].deviceId
          }
        }
        this.codeReader && this.codeReader.reset() // 重置
        this.decodeFromInputVideoFunc(firstDeviceId)
      }).catch(err => {
        console.error(err)
      })
    },
    decodeFromInputVideoFunc(firstDeviceId) {
      this.codeReader.decodeFromInputVideoDeviceContinuously(firstDeviceId, 'video', (result, err) => {
        if (result) {
          console.log('扫描结果', result)
          if (result.text) {
            this.clickIndexLeft(result.text)
          }
        }
        if (err && !(err)) {
          console.error(err)
        }
      })
    },
    // 返回上一页
    clickIndexLeft(result) {
      this.codeReader && this.codeReader.reset()
      this.codeReader = null
      this.$route.params.result = result
      this.$router.back()
    }
  }
}
</script>
 
<style lang="scss" scope>
// #region

// .scan-index-bar{
//   background-image: linear-gradient( -45deg, #42a5ff ,#59cfff);
// }
// .van-nav-bar__title{
//   color: #fff !important;
// }

// #endregion

/** 
  扫码样式一
*/
.QrCode {
  width: 100vw;
  height: 100vh;
  position: relative;
  #video {
    width: 100%;
    height: 100%;
    object-fit: cover;
  }
}
// #region

// .Qr_scanner {
//   position: fixed;
//   top: 0;
//   left: 0;
//   right: 0;
//   bottom: 0;
//   z-index: 9;
//   width: 100%;
//   height: 100%;
//   background-color: rgba(0, 0, 0, 0.5);
// }
// .Qr_scanner .box {
//   width: 75vw;
//   height: 75vw;
//   max-height: 75vh;
//   max-width: 75vh;
//   position: relative;
//   left: 50%;
//   top: 50%;
//   transform: translate(-50%, -50%);
//   border: 1px solid rgb(43, 113, 254);
//   .line_row {
//     width: 100%;
//     overflow: hidden;
//     background-image: linear-gradient(
//         0deg,
//         transparent 24%,
//         rgba(136, 176, 255, 0.1) 25%,
//         rgba(136, 176, 255, 0.1) 26%,
//         transparent 27%,
//         transparent 74%,
//         rgba(136, 176, 255, 0.1) 75%,
//         rgba(136, 176, 255, 0.1) 76%,
//         transparent 77%,
//         transparent
//       ),
//       linear-gradient(
//         90deg,
//         transparent 24%,
//         rgba(136, 176, 255, 0.1) 25%,
//         rgba(136, 176, 255, 0.1) 26%,
//         transparent 27%,
//         transparent 74%,
//         rgba(136, 176, 255, 0.1) 75%,
//         rgba(136, 176, 255, 0.1) 76%,
//         transparent 77%,
//         transparent
//       );
//     background-size: 3rem 3rem;
//     background-position: -1rem -1rem;
//     animation: Heightchange 2s infinite;
//     animation-timing-function: cubic-bezier(0.53, 0, 0.43, 0.99);
//     animation-delay: 1.4s;
//     border-bottom: 1px solid rgba(136, 176, 255, 0.1);
//     display: flex;
//     justify-content: center;
//     align-items: flex-end;
//   }
// }
// .Qr_scanner .line {
//   width: 100%;
//   height: 3px;
//   background: #2b71fe;
//   // opacity: 0.58;
//   filter: blur(4px);
// }
// .Qr_scanner .box:after,
// .Qr_scanner .box:before,
// .Qr_scanner .angle:after,
// .Qr_scanner .angle:before {
//   content: "";
//   display: block;
//   position: absolute;
//   width: 78px;
//   height: 78px;
//   border: 0.3rem solid transparent;
// }
// .Qr_scanner .box:after,
// .Qr_scanner .box:before {
//   top: -7px;
//   border-top-color: #2b71fe;
// }
// .Qr_scanner .angle:after,
// .Qr_scanner .angle:before {
//   bottom: -7px;
//   border-bottom-color: #2b71fe;
// }
// .Qr_scanner .box:before,
// .Qr_scanner .angle:before {
//   left: -7px;
//   border-left-color: #2b71fe;
// }
// .Qr_scanner .box:after,
// .Qr_scanner .angle:after {
//   right: -7px;
//   border-right-color: #2b71fe;
// }
// @keyframes radar-beam {
//   0% {
//     transform: translateY(-100%);
//   }
//   100% {
//     transform: translateY(0);
//   }
// }
// @keyframes Heightchange {
//   0% {
//     height: 0;
//   }
//   100% {
//     height: 100%;
//   }
// }

// #endregion

/**
  扫码样式二
*/
.qr-scanner {
  background-image:
    linear-gradient(0deg,
    transparent 24%,
    rgba(32, 255, 77, 0.1) 25%,
    rgba(32, 255, 77, 0.1) 26%,
    transparent 27%,
    transparent 74%,
    rgba(32, 255, 77, 0.1) 75%,
    rgba(32, 255, 77, 0.1) 76%,
    transparent 77%,
    transparent),
    linear-gradient(90deg,
    transparent 24%,
    rgba(32, 255, 77, 0.1) 25%,
    rgba(32, 255, 77, 0.1) 26%,
    transparent 27%,
    transparent 74%,
    rgba(32, 255, 77, 0.1) 75%,
    rgba(32, 255, 77, 0.1) 76%,
    transparent 77%,
    transparent);
  background-size: 3rem 3rem;
  background-position: -1rem -1rem;
  // width: 100%;
  // height: 100%;
  // position: relative;
  // background-color: #111;

  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 9;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.5);
}
.qr-scanner .box {
  width: 75vw;
  height: 75vw;
  max-height: 75vh;
  max-width: 75vh;
  position: relative;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  overflow: hidden;
  border: 0.1rem solid rgba(0, 255, 51, 0.2);
}
.qr-scanner .line {
  height: calc(100% - 2px);
  width: 100%;
  background: linear-gradient(180deg, rgba(0, 255, 51, 0) 43%, #00ff33 211%);
  border-bottom: 3px solid #00ff33;
  transform: translateY(-100%);
  animation: radar-beam 2s infinite;
  animation-timing-function: cubic-bezier(0.53, 0, 0.43, 0.99);
  animation-delay: 1.4s;
}
.qr-scanner .box:after,
.qr-scanner .box:before,
.qr-scanner .angle:after,
.qr-scanner .angle:before {
  content: '';
  display: block;
  position: absolute;
  width: 3vw;
  height: 3vw;
  border: 0.2rem solid transparent;
}
.qr-scanner .box:after,
.qr-scanner .box:before {
  top: 0;
  border-top-color: #00ff33;
}
.qr-scanner .angle:after,
.qr-scanner .angle:before {
  bottom: 0;
  border-bottom-color: #00ff33;
}
.qr-scanner .box:before,
.qr-scanner .angle:before {
  left: 0;
  border-left-color: #00ff33;
}
.qr-scanner .box:after,
.qr-scanner .angle:after {
  right: 0;
  border-right-color: #00ff33;
}
@keyframes radar-beam {
  0% {
    transform: translateY(-100%);
  }
  100% {
    transform: translateY(0);
  }
}

.qr-scanner .back-arrow {
  position: fixed;
  top: 20px;
  left: 20px;
  width: 30px;
  height: 30px;
  border-radius: 100%;
  background-color: rgba(0, 0, 0, 0.3);
  z-index: 999;

  display: flex;
  justify-content: center;
  align-items: center;
}
</style>