<script setup lang="ts">
import { ref, onMounted, onUnmounted, computed } from 'vue'

const currentTime = ref(new Date())
const selectedDate = ref(new Date())

let timer: ReturnType<typeof setInterval>

onMounted(() => {
  timer = setInterval(() => {
    currentTime.value = new Date()
  }, 1000)
})

onUnmounted(() => {
  clearInterval(timer)
})

const timeString = computed(() => {
  const hours = currentTime.value.getHours().toString().padStart(2, '0')
  const minutes = currentTime.value.getMinutes().toString().padStart(2, '0')
  const seconds = currentTime.value.getSeconds().toString().padStart(2, '0')
  return `${hours}:${minutes}:${seconds}`
})

const dateString = computed(() => {
  const year = currentTime.value.getFullYear()
  const month = (currentTime.value.getMonth() + 1).toString().padStart(2, '0')
  const day = currentTime.value.getDate().toString().padStart(2, '0')
  const weekDays = ['星期日', '星期一', '星期二', '星期三', '星期四', '星期五', '星期六']
  const weekDay = weekDays[currentTime.value.getDay()]
  return `${year}年${month}月${day}日 ${weekDay}`
})

const currentYear = computed(() => selectedDate.value.getFullYear())
const currentMonth = computed(() => selectedDate.value.getMonth())

const monthNames = [
  '一月', '二月', '三月', '四月', '五月', '六月',
  '七月', '八月', '九月', '十月', '十一月', '十二月'
]

const weekDayNames = ['日', '一', '二', '三', '四', '五', '六']

const daysInMonth = computed(() => {
  return new Date(currentYear.value, currentMonth.value + 1, 0).getDate()
})

const firstDayOfMonth = computed(() => {
  return new Date(currentYear.value, currentMonth.value, 1).getDay()
})

const calendarDays = computed(() => {
  const days = []
  
  for (let i = 0; i < firstDayOfMonth.value; i++) {
    days.push(null)
  }
  
  for (let i = 1; i <= daysInMonth.value; i++) {
    days.push(i)
  }
  
  return days
})

function prevMonth() {
  selectedDate.value = new Date(currentYear.value, currentMonth.value - 1, 1)
}

function nextMonth() {
  selectedDate.value = new Date(currentYear.value, currentMonth.value + 1, 1)
}

function isToday(day: number | null) {
  if (!day) return false
  return (
    day === currentTime.value.getDate() &&
    currentMonth.value === currentTime.value.getMonth() &&
    currentYear.value === currentTime.value.getFullYear()
  )
}
</script>

<template>
  <div class="calendar">
    <div class="calendar-header">
      <div class="time">{{ timeString }}</div>
      <div class="date">{{ dateString }}</div>
    </div>
    
    <div class="calendar-body">
      <div class="month-nav">
        <button class="nav-btn" @click="prevMonth">‹</button>
        <span class="month-title">{{ monthNames[currentMonth] }} {{ currentYear }}</span>
        <button class="nav-btn" @click="nextMonth">›</button>
      </div>
      
      <div class="weekdays">
        <div v-for="day in weekDayNames" :key="day" class="weekday">{{ day }}</div>
      </div>
      
      <div class="calendar-grid">
        <div
          v-for="(day, index) in calendarDays"
          :key="index"
          class="calendar-day"
          :class="{ 'calendar-day-today': isToday(day), 'calendar-day-empty': !day }"
        >
          {{ day }}
        </div>
      </div>
    </div>
  </div>
</template>

<style scoped>
.calendar {
  color: white;
  height: 100%;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.calendar-header {
  text-align: center;
  padding-bottom: 10px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  margin-bottom: 10px;
  flex-shrink: 0;
}

.time {
  font-size: 28px;
  font-weight: 200;
  letter-spacing: 2px;
  font-family: 'SF Pro Display', -apple-system, BlinkMacSystemFont, sans-serif;
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
  margin-bottom: 2px;
}

.date {
  font-size: 12px;
  opacity: 0.8;
  font-weight: 400;
}

.calendar-body {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-height: 0;
  overflow: hidden;
}

.month-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 8px;
  flex-shrink: 0;
}

.nav-btn {
  background: rgba(255, 255, 255, 0.1);
  border: none;
  color: white;
  width: 24px;
  height: 24px;
  border-radius: 4px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  transition: all 0.2s ease;
}

.nav-btn:hover {
  background: rgba(255, 255, 255, 0.2);
}

.month-title {
  font-size: 13px;
  font-weight: 600;
}

.weekdays {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 2px;
  margin-bottom: 4px;
  flex-shrink: 0;
}

.weekday {
  text-align: center;
  font-size: 11px;
  font-weight: 600;
  opacity: 0.6;
  padding: 2px 0;
}

.calendar-grid {
  flex: 1;
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 2px;
  min-height: 0;
}

.calendar-day {
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  border-radius: 4px;
  transition: all 0.2s ease;
  cursor: pointer;
  background: rgba(255, 255, 255, 0.05);
  min-height: 0;
  flex: 1;
}

.calendar-day:hover:not(.calendar-day-empty) {
  background: rgba(255, 255, 255, 0.15);
}

.calendar-day-today {
  background: rgba(0, 122, 255, 0.4);
  font-weight: 600;
  color: white;
}

.calendar-day-empty {
  background: transparent;
  cursor: default;
}
</style>
