<template>
  <div>
    <span 
        :sendSync="sendSync" 
        :autoStart="autoStart" 
        :defaultVal="defaultVal"
    >{{countString}}</span>
  </div>
</template>
<script>
export default {
  data() {
    return {
      isStart: false,
      globalTimer: null,//获取setInterval对象值
      countString: '0秒', //用来显示时间
      day: 0,
      hour: 0,
      minute: 0,
      second: 0,
      millisecond: 0,
      countVal: this.defaultVal, //获取初始值
      pauseTime: 0,
    }
  },
  watch: {
    'countString': {
      deep: true,
      handler: function(val, oldVal) {
        var vm = this
        if (vm.needSendSunc) {
          vm.passToParent(val)
        }
      }
    },
    'needSendSunc': {
      deep: true,
      handler: function(val) {
        var vm = this
        if (val) {
          vm.passToParent(vm.countString)
        }
      }
    }
  },
  props: {
    sendSync: {
      type: Boolean,
      default: false,
    },
    autoStart: {
      type: Boolean,
      default: false,
    },
    defaultVal: {
      type: Number,
      default: 0,
    }
  },
  mounted() {
    var vm = this
    if (vm.autoStart) {
      vm.startCountFn()
    }
  },
  computed: {
    needSendSunc: function() {
      return this.sendSync
    }
  },
  created: function() {
    this.$on('startCount', function() {
      this.startCountFn()
    });
    this.$on('stopCount', function() {
      this.stopCountFn()
    });
  },
  components: {},
  methods: {
    counterFn: function(counterTime) {
      var vm = this
      var nowDate = new Date().getTime()
      if(vm.pauseTime == 0){
        var num = nowDate - counterTime //计算时间毫秒差
      }else{
        vm.pauseTime = vm.pauseTime +10
        var num = vm.pauseTime - counterTime //计算时间毫秒差
      }
      var leave1 = num % (24 * 3600 * 1000)    //计算天数后剩余的毫秒数
      var leave2 = leave1 % (3600 * 1000)        //计算小时数后剩余的毫秒数
      var leave3 = leave2 % (60 * 1000)      //计算分钟数后剩余的毫秒数
      vm.day = Math.floor(num / (24 * 3600 * 1000)) //计算相差天数
      vm.hour = Math.floor(leave1 / (3600 * 1000))//计算相差小时
      vm.minute = Math.floor(leave2 / (60 * 1000))//计算相差分钟
      vm.second = Math.round(leave3 / 1000) //计算相差秒
      if (vm.day > 0) {
        vm.countString = `${vm.day}天 ${vm.hour}小时 ${vm.minute}分 ${vm.second}秒`;
      } else if (vm.hour > 0) {
        vm.countString = `${vm.hour}小时 ${vm.minute}分 ${vm.second}秒`;
      } else if (vm.minute > 0) {
        vm.countString = `${vm.minute}分 ${vm.second}秒`;
      } else {
        vm.countString = `${vm.second}秒`;
      }
    },
    startCountFn: function() {
      var vm = this
      if (!vm.isStart) {
        vm.countVal = vm.countVal ? vm.countVal : new Date().getTime()
        var timer = setInterval(function() {
          vm.counterFn(vm.countVal)
        }, 10)
        vm.globalTimer = timer
        vm.isStart = true
      }
    },
    stopCountFn: function() {
      var vm = this
      if (vm.isStart) {
        window.clearInterval(vm.globalTimer)
        vm.globalTimer = null;
        vm.isStart = false
        vm.pauseTime = new Date().getTime()
      }
    },
    passToParent: function(data) {
      var vm = this
      this.$emit("getDataFromChild", data)
    },
  }
}
</script>
<style>

</style>