// components/calendar/index.ts

interface DayInfo {
	date: string; // YYYY-MM-DD
	year: number;
	month: number;
	day: number;
	isCurrentMonth: boolean;
	hasJournal: boolean;
	isToday: boolean;
}

interface MonthInfo {
	year: number;
	month: number;
	days: DayInfo[];
}

interface CalendarData {
	currentYear: number;
	months: MonthInfo[];
	scrollIntoView: string; // 滚动到的元素 id
}

Component({
	properties: {
		// 日记数据，key 为日期 YYYY-MM-DD，value 为日记 id 数组
		journalMap: {
			type: Object,
			value: {}
		}
	},

	data: <CalendarData>{
		currentYear: 0,
		months: [],
		scrollIntoView: ''
	},

	lifetimes: {
		attached() {
			this.initCalendar();
		}
	},

	observers: {
		'journalMap.**'(journalMap: Record<string, number[]>) {
			// 日记数据更新时重新生成所有月份的日期
			if (this.data.months.length > 0) {
				this.updateAllMonthsDays(journalMap);
			}
		}
	},

	methods: {
		/** 初始化日历 */
		initCalendar() {
			const now = new Date();
			const currentYear = now.getFullYear();
			const currentMonth = now.getMonth() + 1;

			this.setData({
				currentYear,
				months: this.generateYearMonths(currentYear)
			});

			// 滚动到当前月份
			this.scrollToMonth(currentMonth);
		},

		/** 生成指定年份的 12 个月 */
		generateYearMonths(year: number): MonthInfo[] {
			const months: MonthInfo[] = [];
			const today = new Date();
			const todayStr = `${today.getFullYear()}-${String(today.getMonth() + 1).padStart(2, '0')}-${String(today.getDate()).padStart(2, '0')}`;

			for (let month = 1; month <= 12; month++) {
				months.push({
					year,
					month,
					days: this.generateDaysForMonth(year, month, this.data.journalMap || {}, todayStr)
				});
			}

			return months;
		},

		/** 更新所有月份的日期数据 */
		updateAllMonthsDays(journalMap: Record<string, number[]>) {
			const { months } = this.data;
			const today = new Date();
			const todayStr = `${today.getFullYear()}-${String(today.getMonth() + 1).padStart(2, '0')}-${String(today.getDate()).padStart(2, '0')}`;

			const updatedMonths = months.map(monthInfo => ({
				...monthInfo,
				days: this.generateDaysForMonth(monthInfo.year, monthInfo.month, journalMap, todayStr)
			}));

			this.setData({ months: updatedMonths });
		},

		/** 生成指定月份的日期数据 */
		generateDaysForMonth(year: number, month: number, journalMap: Record<string, number[]>, todayStr: string): DayInfo[] {
			const days: DayInfo[] = [];
			// 当前月第一天
			const firstDay = new Date(year, month - 1, 1);
			const firstDayWeek = firstDay.getDay();

			// 当前月最后一天
			const lastDay = new Date(year, month, 0);
			const lastDate = lastDay.getDate();

			// 上个月需要显示的日期
			const prevMonthLastDay = new Date(year, month - 1, 0);
			const prevMonthLastDate = prevMonthLastDay.getDate();
			for (let i = firstDayWeek - 1; i >= 0; i--) {
				const day = prevMonthLastDate - i;
				const prevMonth = month === 1 ? 12 : month - 1;
				const prevYear = month === 1 ? year - 1 : year;
				const dateKey = `${prevYear}-${String(prevMonth).padStart(2, '0')}-${String(day).padStart(2, '0')}`;
				days.push({
					date: dateKey,
					year: prevYear,
					month: prevMonth,
					day,
					isCurrentMonth: false,
					hasJournal: !!journalMap[dateKey],
					isToday: dateKey === todayStr
				});
			}

			// 当前月的日期
			for (let day = 1; day <= lastDate; day++) {
				const dateKey = `${year}-${String(month).padStart(2, '0')}-${String(day).padStart(2, '0')}`;
				days.push({
					date: dateKey,
					year,
					month,
					day,
					isCurrentMonth: true,
					hasJournal: !!journalMap[dateKey],
					isToday: dateKey === todayStr
				});
			}

			// 下个月需要显示的日期（补齐到 35 个格子，6 行）
			const remainingDays = 35 - days.length;
			for (let day = 1; day <= remainingDays; day++) {
				const nextMonth = month === 12 ? 1 : month + 1;
				const nextYear = month === 12 ? year + 1 : year;
				const dateKey = `${nextYear}-${String(nextMonth).padStart(2, '0')}-${String(day).padStart(2, '0')}`;
				days.push({
					date: dateKey,
					year: nextYear,
					month: nextMonth,
					day,
					isCurrentMonth: false,
					hasJournal: !!journalMap[dateKey],
					isToday: dateKey === todayStr
				});
			}

			return days;
		},

		/** 切换年份 */
		changeYear(delta: number) {
			const newYear = this.data.currentYear + delta;
			this.setData({
				currentYear: newYear,
				months: this.generateYearMonths(newYear)
			});

			// 滚动到第一个月
			this.scrollToMonth(1);
		},

		/** 上一年 */
		prevYear() {
			this.changeYear(-1);
		},

		/** 下一年 */
		nextYear() {
			this.changeYear(1);
		},

		/** 滚动到指定月份 */
		scrollToMonth(month: number) {
			// 先清空，然后设置，触发滚动
			this.setData({ scrollIntoView: '' });
			wx.nextTick(() => {
				this.setData({ scrollIntoView: `month-${month}` });
			});
		},

		/** 点击日期 */
		onDayTap(e: WechatMiniprogram.BaseEvent) {
			const { date, year, month, day } = e.currentTarget.dataset;

			// 触发自定义事件，传递选中的日期信息
			this.triggerEvent('dateselect', {
				date,
				year,
				month,
				day
			});
		}
	}
});