<template>
  <div class="home">
    這是首頁
    <img alt="Vue logo" src="@/assets/logo.png">
  </div>
  <hr/>
  <button @click="getCameras">掃碼</button>  ====  <button @click="stop">取消掃碼</button>
  <div style="height: 100%; width: 100%">
    <MyHeader :name="'調用攝像頭掃碼'" left="arrow-left" @goBackEv="$emit('goBack')" />
    <div class="qrcode">
      <div id="reader"></div>
    </div>
  </div>
</template>
<script lang="ts">
  import { defineComponent } from 'vue'
  import { Html5Qrcode } from "html5-qrcode"
  export default defineComponent({
    name: 'Home',
    components: {
    },
    setup(){
      let html5QrCode:any = null
      const start = () => {
        html5QrCode.start(
          // environment后置攝像頭 user前置攝像頭
          { facingMode: "environment" },
          {
            fps: 2, // 可選，每秒幀掃描二維碼
            qrbox: { width: 250, height: 250 } // 可選，如果你想要有界框UI
            // aspectRatio: 1.777778 // 可選，視頻饋送需要的縱橫比，(4:3--1.333334, 16:9--1.777778, 1:1--1.0)傳遞錯誤的縱橫比會導致視頻不顯示
          },
          (decodedText: any, decodedResult: any) => {
            // do something when code is read
            console.log('decodedText', decodedText)
            console.log('decodedResult', decodedResult)
            // this.$emit("goBack", decodedText)
          }
        )
          .catch((err: any) => {
            console.log('掃碼錯誤信息', err)
            // 錯誤信息處理僅供參考，具體情況看輸出?。?！
            if (typeof err == 'string') {
              // this.$toast(err)
            } else {
              // if (err.name == 'NotAllowedError') return this.$toast("您需要授予相機訪問權限")
              // if (err.name == 'NotFoundError') return this.$toast('這個設備上沒有攝像頭')
              // if (err.name == 'NotSupportedError') return this.$toast('攝像頭訪問只支持在安全的上下文中，如https或localhost')
              // if (err.name == 'NotReadableError') return this.$toast('相機被占用')
              // if (err.name == 'OverconstrainedError') return this.$toast('安裝攝像頭不合適')
              // if (err.name == 'StreamApiNotSupportedError') return this.$toast('此瀏覽器不支持流API')
            }
          })
      }
      const getCameras = () => {
        Html5Qrcode.getCameras()
          .then((devices) => {
            if (devices && devices.length) {
              html5QrCode = new Html5Qrcode("reader")
              start()
            }
          })
          .catch((err:any) => {
            // handle err
            html5QrCode = new Html5Qrcode("reader")
            // this.$toast('您需要授予相機訪問權限')
          })
      }
      const stop = () => {
        html5QrCode.stop().then((ignore:any) => {
          // QR Code scanning is stopped.
          console.log("QR Code scanning stopped.")
        })
          .catch((err:any) => {
            // Stop failed, handle it.
            console.log("Unable to stop scanning.")
          })
      }
      return {
        getCameras,
        stop
      }
    }
  })
</script>