<script setup lang="ts">
const currentDate = new Date();
const currentMonth = currentDate.getMonth();
const currentYear = currentDate.getFullYear();

// 获取指定月份信息的基础函数
const getFirstDayOfMonth = (year: number, month: number): number => {
  return new Date(year, month, 1).getDay();
};

const getDaysInMonth = (year: number, month: number): number => {
  return new Date(year, month + 1, 0).getDate();
};

// 优化后的日历生成函数
const generateCalendarData = (
    year: number,
    month: number
): Array<Array<{ day: number; isCurrentMonth: boolean; isCurrentDay: boolean }>> => {
  const weeks: Array<Array<{ day: number; isCurrentMonth: boolean; isCurrentDay: boolean }>> = [];
  const daysInMonth = getDaysInMonth(year, month);
  const firstDayIndex = getFirstDayOfMonth(year, month);

  // 获取当前日期的日部分
  const currentDay = currentDate.getDate();

  // 计算前后月信息
  const prevMonth = month === 0 ? 11 : month - 1;
  const nextMonth = month === 11 ? 0 : month + 1;
  const prevYear = month === 0 ? year - 1 : year;
  const nextYear = month === 11 ? year + 1 : year;

  const daysInPrevMonth = getDaysInMonth(prevYear, prevMonth);
  const daysInNextMonth = getDaysInMonth(nextYear, nextMonth);

  let dayCounter = 1;
  let nextMonthDayCounter = 1;

  for (let week = 0; week < 5; week++) {
    const weekDays = [];

    for (let day = 0; day < 7; day++) {
      const isFirstWeek = week === 0;
      const position = week * 7 + day;

      // 当前月日期
      if ((isFirstWeek && day >= firstDayIndex) || (!isFirstWeek && dayCounter <= daysInMonth)) {
        const isToday = dayCounter === currentDay && month === currentMonth && year === currentYear;
        weekDays.push({day: dayCounter, isCurrentMonth: true, isCurrentDay: isToday});
        dayCounter++;
      }
      // 前月日期
      else if (isFirstWeek) {
        const prevDay = daysInPrevMonth - firstDayIndex + day + 1;
        weekDays.push({day: prevDay, isCurrentMonth: false, isCurrentDay: false});
      }
      // 下月日期
      else {
        weekDays.push({day: nextMonthDayCounter, isCurrentMonth: false, isCurrentDay: false});
        nextMonthDayCounter++;
      }
    }

    weeks.push(weekDays);
  }

  return weeks;
};

// 使用示例
const calendarData = generateCalendarData(currentYear, currentMonth);

</script>

<template>
  <div class="calendar-wrapper">
    <span class="current">{{ currentYear }}年{{ currentMonth + 1 }}月</span>
    <div class="row">
      <div class="item">
        <span class="tip">日</span>
      </div>
      <div class="item">
        <span class="tip">一</span>
      </div>
      <div class="item">
        <span class="tip">二</span>
      </div>
      <div class="item">
        <span class="tip">三</span>
      </div>
      <div class="item">
        <span class="tip">四</span>
      </div>
      <div class="item">
        <span class="tip">五</span>
      </div>
      <div class="item">
        <span class="tip">六</span>
      </div>
    </div>
    <div v-for="item in calendarData" class="row">
      <div class="item" v-for="subItem in item">
          <span :class="subItem.isCurrentDay ? 'currentDay' : subItem.isCurrentMonth ? '' : 'otherMonth'">
        {{ subItem.isCurrentDay ? "今" : subItem.day }}
      </span>
      </div>
    </div>
  </div>

</template>

<style scoped lang="scss">
.calendar-wrapper {
  width: 100%;
  height: 100%;
  box-sizing: border-box;
  padding:0 20px 20px;
  background-color: #FFF;
  border-radius: 0 0 8px 8px;
  display: flex;
  flex-direction: column;
  .current{
    font-weight: 500;
    font-size: 18px;
    color: #333333;
    font-style: normal;
    margin-bottom: 8px;
  }
  .row {
    flex: 1;
    width: 100%;
    background: #F9FAFC ;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-weight: 500;
    font-size: 14px;
    color: #999999;
    font-style: normal;
    .item {
      width: 100%;
      height: 100%;
      display: flex;
      justify-content: center;
      align-items: center;
      span {
        margin: auto;
        height: 34px;
        width: 34px;
        display: flex;
        justify-content: center;
        align-items: center;
        font-weight: bold;
        font-size: 16px;
        color: #666666;
        font-style: normal;
        border-radius:17px;
      }
      .currentDay {
        background: #1677FE;
        color: #fff;
      }
      .otherMonth{
        color: #999;
      }
    }
  }
}
</style>