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

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

type FavoritesTab = 'favorites' | 'downloads';

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

type DownloadRow = {
    id: string;
    worksheetId: string;
    path: string;
    title: string;
    metaLine: string;
    stars: number;
    time: string;
    status: string;
    statusHighlight: boolean;
    thumb?: string;
    placeholder?: 'draw';
};

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

/** 跳转路径仅以云库 worksheets.path 为准 */
function getWorksheetNavPath(
    ws: FavoriteRecord['worksheet'] | DownloadLogRecord['worksheet'],
): string {
    const path = ws?.path?.trim();
    return path && path.startsWith('/') ? path : '';
}

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

    return {
        id: record._id,
        worksheetId: record.worksheetId,
        path: getWorksheetNavPath(ws),
        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();

    // 按日历天数计算差值
    const todayStart = new Date(
        now.getFullYear(),
        now.getMonth(),
        now.getDate(),
    ).getTime();
    const dateStart = new Date(
        date.getFullYear(),
        date.getMonth(),
        date.getDate(),
    ).getTime();
    const days = Math.round((todayStart - dateStart) / (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;
        const category = ws?.category || '';
        const categoryName = getCategoryName(category);
        const ageRange = ws ? `${ws.ageMin}-${ws.ageMax}岁` : '';
        const metaLine =
            [categoryName, ageRange].filter(Boolean).join(' · ') + ' · ';
        const difficulty = ws?.difficulty || 0;
        groups[key].items.push({
            id: record._id,
            worksheetId: record.worksheetId,
            path: getWorksheetNavPath(ws),
            title: ws?.title || '未知题型',
            metaLine,
            stars: Math.min(difficulty, 3),
            time: `${String(date.getHours()).padStart(2, '0')}:${String(date.getMinutes()).padStart(2, '0')}`,
            status: '已保存到相册',
            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[],
        favLoading: false,
        dlLoading: 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.setData({ favoriteList: [], downloadSections: [] });
        this.loadActiveTab();
    },

    loadActiveTab() {
        const tab = this.data.activeTab;
        if (tab === 'favorites' && this.data.favoriteList.length === 0) {
            this.loadFavorites();
        } else if (
            tab === 'downloads' &&
            this.data.downloadSections.length === 0
        ) {
            this.loadDownloads();
        }
    },

    onTabSwitch(e: WechatMiniprogram.TouchEvent) {
        const tab = e.currentTarget.dataset.tab as FavoritesTab;
        if (tab !== 'favorites' && tab !== 'downloads') return;
        if (tab === this.data.activeTab) return;
        this.setData({ activeTab: tab });
        // 只在数据为空时才请求
        if (tab === 'favorites' && this.data.favoriteList.length === 0) {
            this.loadFavorites();
        } else if (
            tab === 'downloads' &&
            this.data.downloadSections.length === 0
        ) {
            this.loadDownloads();
        }
    },

    async loadFavorites() {
        this.setData({ favLoading: true });
        try {
            const records = await getFavoriteList();
            this.setData({
                favoriteList: records.map((r) => mapFavoriteToItem(r)),
            });
        } finally {
            this.setData({ favLoading: false });
        }
    },

    async loadDownloads() {
        this.setData({ dlLoading: true });
        try {
            const records = await getDownloadLogs(1, DOWNLOAD_HISTORY_MAX);
            this.setData({ downloadSections: groupDownloadsByDate(records) });
        } finally {
            this.setData({ dlLoading: false });
        }
    },

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

    onCardTap(e: WechatMiniprogram.TouchEvent) {
        const path = e.currentTarget.dataset.path as string | undefined;
        if (!path) {
            wx.showToast({ title: '该练习已下架', icon: 'none' });
            return;
        }
        wx.navigateTo({ url: path });
    },

    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;

        try {
            await removeFavorite(item.worksheetId);
            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: 'success' });
        } catch {
            wx.showToast({ title: '操作失败，请重试', icon: 'none' });
        }
    },

    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' });
            },
        });
    },
});