import { NAV_INNER_PX } from '../../utils/navMetrics';
import { getFavoriteList, removeFavorite } from '../../utils/favorites';
import { getDownloadLogs } from '../../utils/downloadLogs';
import type { FavoriteRecord } from '../../utils/favorites';
import type { DownloadLogRecord } from '../../utils/downloadLogs';

const { statusBarHeight } = wx.getWindowInfo();
const NAV_BLOCK_HEIGHT = statusBarHeight + NAV_INNER_PX;

type FavoritesTab = 'favorites' | 'downloads';

type FavoriteItem = {
    id: string;
    worksheetId: string;
    variant: 'standard';
    title: string;
    metaLine: string;
    stars: number;
    timeBadge: string;
    thumb: string;
};

type DownloadRow = {
    id: string;
    title: string;
    time: string;
    status: string;
    statusHighlight: boolean;
    thumb?: string;
    placeholder?: 'draw';
};

type DownloadSection = {
    key: string;
    label: string;
    items: DownloadRow[];
};

function mapFavoriteToItem(record: FavoriteRecord): FavoriteItem {
    const ws = record.worksheet;
    const title = ws?.title || '未知题型';
    const category = ws?.category || '';
    const ageRange = ws ? `${ws.ageMin}-${ws.ageMax}岁` : '';
    const metaLine = [category, ageRange].filter(Boolean).join(' · ') + ' · ';
    const difficulty = ws?.difficulty || 0;
    const timeBadge = formatTimeBadge(record.createdAt);

    return {
        id: record._id,
        worksheetId: record.worksheetId,
        variant: 'standard',
        title,
        metaLine,
        stars: Math.min(difficulty, 3),
        timeBadge,
        thumb: ws?.previewImg || '',
    };
}

function formatTimeBadge(dateStr: string): string {
    const date = new Date(dateStr);
    const now = new Date();
    const diff = now.getTime() - date.getTime();
    const days = Math.floor(diff / (1000 * 60 * 60 * 24));

    if (days === 0) return '收藏于今天';
    if (days === 1) return '收藏于昨天';
    if (days < 7) return `收藏于 ${days} 天前`;
    if (days < 30) return `收藏于 ${Math.floor(days / 7)} 周前`;
    return `收藏于 ${Math.floor(days / 30)} 个月前`;
}

function groupDownloadsByDate(records: DownloadLogRecord[]): DownloadSection[] {
    const now = new Date();
    const todayStr = formatDateKey(now);
    const yesterday = new Date(now.getTime() - 24 * 60 * 60 * 1000);
    const yesterdayStr = formatDateKey(yesterday);

    const groups: Record<string, { label: string; items: DownloadRow[] }> = {};

    for (const record of records) {
        const date = new Date(record.createdAt);
        const key = formatDateKey(date);
        let label: string;

        if (key === todayStr) {
            label = '今天';
        } else if (key === yesterdayStr) {
            label = '昨天';
        } else {
            label = `${date.getMonth() + 1}月${date.getDate()}日`;
        }

        if (!groups[key]) {
            groups[key] = { label, items: [] };
        }

        const ws = record.worksheet;
        groups[key].items.push({
            id: record._id,
            title: ws?.title || '未知题型',
            time: `${String(date.getHours()).padStart(2, '0')}:${String(date.getMinutes()).padStart(2, '0')}`,
            status: '已保存相册',
            statusHighlight: true,
            thumb: ws?.previewImg,
        });
    }

    return Object.keys(groups).map((key) => ({
        key,
        label: groups[key].label,
        items: groups[key].items,
    }));
}

function formatDateKey(date: Date): string {
    return `${date.getFullYear()}-${date.getMonth() + 1}-${date.getDate()}`;
}

Page({
    data: {
        favScrollHeight: 0,
        activeTab: 'favorites' as FavoritesTab,
        favoriteList: [] as FavoriteItem[],
        downloadSections: [] as DownloadSection[],
        loading: false,
    },

    onLoad() {
        const win = wx.getWindowInfo();
        this.setData({
            favScrollHeight: win.windowHeight - NAV_BLOCK_HEIGHT,
        });
    },

    onShow() {
        const tab = wx.getStorageSync('favorites_active_tab') as FavoritesTab;
        if (tab === 'downloads' || tab === 'favorites') {
            this.setData({ activeTab: tab });
            wx.removeStorageSync('favorites_active_tab');
        }
        this.loadData();
    },

    onTabSwitch(e: WechatMiniprogram.TouchEvent) {
        const tab = e.currentTarget.dataset.tab as FavoritesTab;
        if (tab !== 'favorites' && tab !== 'downloads') return;
        this.setData({ activeTab: tab });
    },

    async loadData() {
        this.setData({ loading: true });
        await Promise.all([this.loadFavorites(), this.loadDownloads()]);
        this.setData({ loading: false });
    },

    async loadFavorites() {
        const records = await getFavoriteList();
        const list = records.map((r) => mapFavoriteToItem(r));
        this.setData({ favoriteList: list });
    },

    async loadDownloads() {
        const records = await getDownloadLogs();
        const sections = groupDownloadsByDate(records);
        this.setData({ downloadSections: sections });
    },

    onDiscoverTap() {
        wx.switchTab({ url: '/pages/home/home' });
    },

    onSearchTap() {
        wx.showToast({ title: '搜索功能开发中', icon: 'none' });
    },

    async onRemoveFavorite(e: WechatMiniprogram.TouchEvent) {
        const id = e.currentTarget.dataset.id as string | undefined;
        if (!id) return;

        const item = (this.data.favoriteList as FavoriteItem[]).find(
            (i) => i.id === id,
        );
        if (!item) return;

        // 乐观更新 UI
        const list = (this.data.favoriteList as FavoriteItem[]).filter(
            (i) => i.id !== id,
        );
        this.setData({ favoriteList: list });
        wx.showToast({ title: '已取消收藏', icon: 'none' });

        // 调用云端
        await removeFavorite(item.worksheetId);
    },

    onClearHistory() {
        wx.showModal({
            title: '清空下载历史',
            content: '确定清空本地展示的历史记录吗？',
            success: (res) => {
                if (!res.confirm) return;
                this.setData({ downloadSections: [] });
                wx.showToast({ title: '已清空', icon: 'none' });
            },
        });
    },

    onDownloadMore(e: WechatMiniprogram.TouchEvent) {
        const id = e.currentTarget.dataset.id as string | undefined;
        wx.showToast({
            title: id ? `更多操作：${id}` : '更多',
            icon: 'none',
        });
    },
});