import { appSharePageMethods } from '../../base/pageMixin';
import { takePendingCategoryTabId } from '../../utils/index';
import tracker from '../../utils/tracker';
import { ApiRequestError } from '../../services/api-request';
import {
    getWorksheet,
    listAllWorksheets,
    listCategories,
} from '../../services/content-api';
import {
    BASE_TABS,
    buildCategoryDataset,
    getCategoryItems,
    type CategoryDataset,
    type CategoryItem,
} from './category.model';

const TAB_BAR_PATHS = new Set([
    '/pages/home/home',
    '/pages/category/category',
    '/pages/age/age',
    '/pages/favorites/favorites',
    '/pages/profile/profile',
]);
const SKELETON_ITEMS: CategoryItem[] = Array.from(
    { length: 6 },
    (_, index) => ({
        id: `skeleton-${index}`,
        title: '\u00a0',
        subtitle: '\u00a0',
        icon: '',
        previewImg: '',
        ageBand: '',
        difficultyLabel: '',
        path: '',
        available: false,
        likes: '',
        downloads: '',
        date: '',
        updatedAt: '',
        skeleton: true,
    }),
);

Page({
    data: {
        searchPlaceholder: '搜索练习纸...',
        searchKeyword: '',
        sidebarTabs: BASE_TABS,
        activeCategoryId: 'all',
        displayItems: SKELETON_ITEMS,
        scrollIntoViewId: '',
        loading: true,
        errorMessage: '',
    },

    _defaultCategoryId: 'all',
    _categoryData: null as CategoryDataset | null,
    _loadVersion: 0,
    _opening: false,

    onLoad(options: Record<string, string>) {
        tracker.reportPageView('pages/category/category');
        if (options.id && options.id !== 'all') {
            this._defaultCategoryId = options.id;
            this.setData({ activeCategoryId: options.id });
        }
    },

    onShow() {
        void this.loadWorksheets(takePendingCategoryTabId() ?? undefined);
    },

    onHide() {
        this._loadVersion++;
    },

    onUnload() {
        this._loadVersion++;
    },

    /** 每次进入重新读取公开目录与完整分页；失败清空内容，不回退静态数据或旧云服务。 */
    async loadWorksheets(overrideCategoryId?: string) {
        const version = ++this._loadVersion;
        this._categoryData = null;
        this.setData({
            displayItems: SKELETON_ITEMS,
            sidebarTabs: BASE_TABS,
            loading: true,
            errorMessage: '',
        });
        try {
            const [categories, worksheets] = await Promise.all([
                listCategories(),
                listAllWorksheets(),
            ]);
            if (version !== this._loadVersion) return;
            const dataset = buildCategoryDataset(categories, worksheets);
            const desiredId =
                overrideCategoryId ||
                this.data.activeCategoryId ||
                this._defaultCategoryId;
            const activeId = dataset.sidebarTabs.some(
                (tab) => tab.id === desiredId,
            )
                ? desiredId
                : 'all';
            this._categoryData = dataset;
            this.setData({
                loading: false,
                sidebarTabs: dataset.sidebarTabs,
                activeCategoryId: activeId,
                displayItems: getCategoryItems(
                    dataset,
                    activeId,
                    this.data.searchKeyword,
                ),
                scrollIntoViewId: '',
                errorMessage: '',
            });
        } catch (error) {
            if (version !== this._loadVersion) return;
            this._categoryData = null;
            this.setData({
                loading: false,
                displayItems: [],
                sidebarTabs: BASE_TABS,
                errorMessage:
                    error instanceof Error
                        ? error.message
                        : '加载失败，请稍后重试',
            });
        }
    },

    onRetry() {
        void this.loadWorksheets();
    },

    onTapCategory(e: WechatMiniprogram.TouchEvent) {
        const id = e.currentTarget.dataset.id as string;
        if (
            !this._categoryData ||
            this.data.loading ||
            !id ||
            id === this.data.activeCategoryId ||
            !this._categoryData.sidebarTabs.some((tab) => tab.id === id)
        )
            return;
        this.setData({
            activeCategoryId: id,
            displayItems: getCategoryItems(
                this._categoryData,
                id,
                this.data.searchKeyword,
            ),
            scrollIntoViewId: '',
        });
        tracker.report('category_select', 'pages/category/category', {
            category_id: id,
        });
    },

    onSearchInput(e: WechatMiniprogram.Input) {
        const keyword = (e.detail.value ?? '').trim();
        this.setData({
            searchKeyword: keyword,
            displayItems: getCategoryItems(
                this._categoryData,
                this.data.activeCategoryId,
                keyword,
            ),
        });
    },

    onClearSearch() {
        this.setData({
            searchKeyword: '',
            displayItems: getCategoryItems(
                this._categoryData,
                this.data.activeCategoryId,
            ),
        });
    },

    /** 点击时重新检查详情，已下架或网络不可用时不进入内置生成页。 */
    async onTapItem(e: WechatMiniprogram.TouchEvent) {
        const id = e.currentTarget.dataset.id as string;
        if (
            this._opening ||
            this.data.loading ||
            !id ||
            !this.data.displayItems.some(
                (item) => item.id === id && item.available,
            )
        )
            return;
        this._opening = true;
        const version = this._loadVersion;
        try {
            const row = await getWorksheet(id);
            if (version !== this._loadVersion) return;
            if (!row.path) throw new Error('内容暂不可用');
            tracker.reportWorksheetClick('pages/category/category', {
                worksheet_id: row.id,
                worksheet_title: row.title,
                category_id: this.data.activeCategoryId,
                source: 'category_list',
            });
            const fail = () =>
                wx.showToast({ title: '暂时无法打开该内容', icon: 'none' });
            if (TAB_BAR_PATHS.has(row.path))
                wx.switchTab({ url: row.path, fail });
            else wx.navigateTo({ url: row.path, fail });
        } catch (error) {
            if (version !== this._loadVersion) return;
            wx.showToast({
                title:
                    error instanceof Error
                        ? error.message
                        : '暂时无法打开，请稍后重试',
                icon: 'none',
            });
            if (error instanceof ApiRequestError && error.statusCode === 404)
                void this.loadWorksheets();
        } finally {
            this._opening = false;
        }
    },

    ...appSharePageMethods,
});