<template>
  <div class="count-down">
    <slot>
      {{content}}
    </slot>
  </div>
</template>

<script>
  export default {
    data() {
      return {
        content: '',
      }
    },
    props: {
      endTime: {
        type: Number,
        default: 0
      },
      endText: {
        type: String,
        default: ''
      },
      callback: {
        type: Function,
        default: null
      }
    },
    mounted() {
      this.countdowm(this.endTime)
    },
    methods: {
      countdowm(timestamp) {
        let self = this;
        let timer = setInterval(function () {
          let nowTime = new Date();
          let endTime = new Date(timestamp * 1000);
          let t = endTime.getTime() - nowTime.getTime();
          if (t > 0) {
            let day = Math.floor(t / 86400000);
            let hour = Math.floor((t / 3600000) % 24);
            let min = Math.floor((t / 60000) % 60);
            let sec = Math.floor((t / 1000) % 60);
            hour = hour < 10 ? "0" + hour : hour;
            min = min < 10 ? "0" + min : min;
            sec = sec < 10 ? "0" + sec : sec;
            let format = '';
            if (day > 0) {
              format = `${day}天${hour}小时${min}分${sec}秒`;
            }
            if (day <= 0 && hour > 0) {
              format = `${hour}小时${min}分${sec}秒`;
            }
            if (day <= 0 && hour <= 0) {
              format = `${min}分${sec}秒`;
            }
            self.content =  self.endText + ' ' + format;
          } else {
            clearInterval(timer);
            self.content = '';
            self._callback();
          }
        }, 1000);
      },
      _callback() {
        if (this.callback && this.callback instanceof Function) {
          this.callback(...this);
        }
      }
    }
  }
</script>

<style lang="scss" rel="stylesheet/scss" scoped>
  .count-down {
    margin: 10px;
    color: $red;
  }
</style>
