<template>
  <div id="calendar">
    <!-- 年份 月份 -->
    <div class="title">
      <div class="label">活动日历</div>
      <div class="total">当前活动 {{ list.length }} 场</div>
    </div>
    <div class="content">
      <ul class="month">
        <!--点击会触发pickpre函数，重新刷新当前日期 @click(vue v-on:click缩写) -->
        <li class="arrow">
          <span
            @click="pickPre(currentYear, currentMonth, 'year')"
            style="margin-right: 20px"
            >❮❮</span
          >
          <span @click="pickPre(currentYear, currentMonth, 'month')">❮</span>
        </li>
        <li class="year-month">
          <span class="choose-year">{{ currentYear }}年</span>
          <span class="choose-month">{{ currentMonth }}月</span>
        </li>
        <li class="arrow">
          <span @click="pickNext(currentYear, currentMonth, 'month')">❯</span>
          <span
            @click="pickNext(currentYear, currentMonth, 'year')"
            style="margin-left: 20px"
            >❯❯</span
          >
        </li>
      </ul>
      <!-- 星期 -->
      <ul class="weekdays">
        <li>一</li>
        <li>二</li>
        <li>三</li>
        <li>四</li>
        <li>五</li>
        <li>六</li>
        <li>日</li>
      </ul>
      <!-- 日期 -->
      <ul class="days">
        <!-- 核心 v-for循环 每一次循环用<li>标签创建一天 -->
        <li v-for="(item, index) in days" :key="index">
          <!--本月-->
          <!--如果不是本月  改变类名加灰色-->

          <span
            v-if="item.month != currentMonth"
            class="other-month"
            @click="clickOtherItem(item)"
            >{{ +item.date }}</span
          >

          <!--如果是本月  还需要判断是不是这一天-->
          <span v-else>
            <!--今天  同年同月同日-->
            <span
              class="current-month"
              @click="clickItem(item)"
              :class="{
                'current-day':
                  item.day.getFullYear() == new Date().getFullYear() &&
                  item.day.getMonth() == new Date().getMonth() &&
                  item.day.getDate() == new Date().getDate(),
                active: item.value === activeTime,
                'not-allow': !item.hasActivity,
                'has-activity': item.hasActivity,
              }"
              >{{ +item.date }}</span
            >
          </span>
        </li>
      </ul>
    </div>
  </div>
</template>

<script>
export default {
  name: "",
  components: {},
  mixins: [],
  props: {},
  computed: {},
  watch: {},
  data() {
    return {
      currentDay: 1,
      currentMonth: 1,
      currentYear: 1970,
      currentWeek: 1,
      days: [],
      activeTime: "2023-09-21",
      list: ["2023-09-20", "2023-09-21", "2023-09-11"],
    };
  },
  created() {
    this.initData(null);
  },
  mounted() {},
  methods: {
    // 点击其他月份的 判断
    clickOtherItem(item) {
      if (item.month < this.currentMonth) {
        this.pickPre(this.currentYear, this.currentMonth, "month");
      } else {
        this.pickNext(this.currentYear, this.currentMonth, "month");
      }
    },
    clickItem(item) {
      if (!item.hasActivity) return;
      this.activeTime = item.value;
    },
    initData: function (cur) {
      var date;
      console.log(cur);
      if (cur) {
        date = new Date(cur);
      } else {
        var now = new Date();
        var d = new Date(this.formatDate(now.getFullYear(), now.getMonth(), 1));
        d.setDate(35);
        date = new Date(this.formatDate(d.getFullYear(), d.getMonth() + 1, 1));
      }
      this.currentDay = date.getDate();
      this.currentYear = date.getFullYear();
      this.currentMonth = date.getMonth() + 1;

      this.currentWeek = date.getDay(); // 1...6,0
      if (this.currentWeek == 0) {
        this.currentWeek = 7;
      }
      var str = this.formatDate(
        this.currentYear,
        this.currentMonth,
        this.currentDay
      );
      this.days.length = 0;
      // 今天是周日，放在第一行第7个位置，前面6个
      //初始化本周
      console.log(this.currentWeek, "this.currentWeek");
      for (let i = this.currentWeek - 1; i >= 0; i--) {
        const d = new Date(str);
        d.setDate(d.getDate() - i);
        const day = d;
        const year = d.getFullYear();
        const month =
          d.getMonth() + 1 < 10 ? `0${d.getMonth() + 1}` : d.getMonth() + 1;
        const date = d.getDate() < 10 ? `0${d.getDate()}` : d.getDate();
        const value = `${year}-${month}-${date}`;
        const dayobject = {
          year,
          month,
          date,
          value,
          day,
        };
        this.days.push(dayobject); // 将日期放入data 中的days数组 供页面渲染使用
      }
      //其他周
      for (var i = 1; i <= 35 - this.currentWeek; i++) {
        var d = new Date(str);
        d.setDate(d.getDate() + i);
        const day = d;
        const year = d.getFullYear();
        const month =
          d.getMonth() + 1 < 10 ? "0" + (d.getMonth() + 1) : d.getMonth() + 1;
        const date = d.getDate() < 10 ? "0" + d.getDate() : d.getDate();
        const value = year + "-" + month + "-" + date;
        var dayobject = {
          year,
          month,
          date,
          value,
          day,
          hasActivity: false, // 是否有活动数据
        };
        this.days.push(dayobject);
      }
      // 拿到日历数组后 根据返回的有活动的列表进行过滤
      this.days = this.days.map((item) => {
        if (this.list.indexOf(item.value) !== -1) {
          this.$set(item, "hasActivity", true);
        }
        return item;
      });
    },
    pickPre: function (year, month, type) {
      if (type === "month") {
        const preMonth = month - 1 <= 0 ? 12 : month - 1;
        const preYear = month - 1 <= 0 ? year - 1 : year;
        this.initData(this.formatDate(preYear, preMonth, 1));
      } else {
        this.initData(this.formatDate(year - 1, month, 1));
      }
    },
    pickNext: function (year, month, type) {
      if (type === "month") {
        const nextMonth = month + 1 > 12 ? 1 : month + 1;
        const nextYear = month + 1 > 12 ? year + 1 : year;
        this.initData(this.formatDate(nextYear, nextMonth, 1));
      } else {
        this.initData(this.formatDate(year + 1, month, 1));
      }
    },

    // 返回 类似 2016-01-02 格式的字符串
    formatDate: function (year, month, day) {
      var y = year;
      var m = month;
      if (m < 10) m = "0" + m;
      var d = day;
      if (d < 10) d = "0" + d;
      return y + "-" + m + "-" + d;
    },
  },
};
</script>
<style lang="less" scoped>
* {
  box-sizing: border-box;
}
ul,
li {
  list-style: none;
  margin: 0;
  padding: 0;
}
body {
  font-family: Verdana, sans-serif;
  background: #e8f0f3;
}
#calendar {
  width: 440px;
  height: 400px;
  display: flex;
  flex-direction: column;
  padding: 20px;
  margin: 0 auto;
  box-shadow: 0 2px 2px 0 rgba(0, 0, 0, 0.14), 0 3px 1px -2px rgba(0, 0, 0, 0.1),
    0 1px 5px 0 rgba(0, 0, 0, 0.12);
}
.title {
  height: 28px;
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  .label {
    color: #000;
    font-family: PingFang SC;
    font-size: 16px;
    font-style: normal;
    font-weight: 600;
  }
  .total {
    height: 28px;
    padding: 8px 15px;
    border-radius: 32px;
    background: rgba(0, 91, 255, 0.1);
    display: flex;
    align-items: center;
    color: #005bff;
    font-family: PingFang SC;
    font-size: 14px;
    font-style: normal;
    font-weight: 400;
  }
}
.content {
  display: flex;
  flex: 1;
  height: 0;
  flex-direction: column;
  .month {
    height: 40.25px;
    display: flex;
    justify-content: space-between;
    padding: 0 10px;
    align-items: center;
    .year-month {
      color: rgba(0, 0, 0, 0.85);
      text-align: center;
      font-family: PingFang SC;
      font-size: 16px;
      font-style: normal;
      font-weight: 600;
      .choose-year {
        margin-right: 12px;
      }
    }
    .arrow {
      span:hover {
        cursor: pointer;
        color: #005bff;
      }
    }
  }
  .weekdays {
    height: 40.25px;
    display: flex;
    li {
      cursor: default;
      display: flex;
      align-items: center;
      justify-content: center;
      width: calc(100% / 7);
      height: 40px;
      color: rgba(0, 0, 0, 0.85);
      text-align: center;
      font-family: PingFang SC;
      font-size: 14px;
      font-style: normal;
      font-weight: 400;
    }
  }
  .days {
    flex: 1;
    height: 0;
    display: flex;
    flex-wrap: wrap;
    li {
      display: flex;
      align-items: center;
      justify-content: center;
      width: calc(100% / 7);
      height: 40px;
      color: rgba(0, 0, 0, 0.85);
      text-align: center;
      font-family: PingFang SC;
      font-size: 14px;
      font-style: normal;
      font-weight: 400;
      span {
        width: 34px;
        height: 34px;
        line-height: 34px;
      }
      .has-activity {
        display: inline-block;
        width: 34px;
        height: 34px;
        position: relative;
      }
      .current-day {
        color: #005bff;
      }
      .active {
        color: #fff;
        display: inline-block;
        width: 34px;
        height: 34px;
        background: #005bff;
        border-radius: 50%;
        position: relative;
      }
      .other-month {
        color: rgba(0, 0, 0, 0.45);
        cursor: default;
      }
      .current-month:hover {
        width: 34px;
        height: 34px;
        display: inline-block;
        cursor: pointer;
        background: #f2f2f2;
        color: rgba(0, 0, 0, 0.85);
        border-radius: 50%;
      }
      .active:hover {
        cursor: pointer;
        color: #fff;
        display: inline-block;
        width: 34px;
        height: 34px;
        background: #005bff;
        border-radius: 50%;
      }
      .not-allow:hover {
        cursor: not-allowed;
        background-color: white;
      }
      .has-activity::after {
        content: "";
        position: absolute;
        width: 4px;
        height: 4px;
        border-radius: 50%;
        background-color: #005bff;
        left: 50%;
        bottom: 2px;
        margin-left: -2px;
      }
      .active::after {
        content: "";
        position: absolute;
        width: 4px;
        height: 4px;
        border-radius: 50%;
        background-color: white;
        left: 50%;
        bottom: 2px;
        margin-left: -2px;
      }
    }
  }
}
</style>