import type { PaperType } from '../config/worksheets/papers';
import { apiRequest } from './api-request';

/** 小程序使用的公开接口字段，不复用旧云集合的 _id 和管理配置。 */
export interface ApiCategory {
    id: string;
    name: string;
    icon: string;
    parentId: string | null;
    status: 'active';
}

export interface ApiWorksheet {
    rendering?: { rendererKey: 'paper-sheet'; paperType: PaperType };
    id: string;
    title: string;
    subtitle: string;
    category: string;
    path: string;
    ageMin: number;
    ageMax: number;
    difficulty: 1 | 2 | 3 | 4;
    previewImg: string | null;
    likes: string;
    downloads: string;
    createdAt: string;
    updatedAt: string;
    contentUpdatedAt: string | null;
}

interface WorksheetPage {
    items: ApiWorksheet[];
    total: number;
    page: number;
    pageSize: number;
    hasNext: boolean;
}

/** 分类直接由服务端发布状态决定，不用本地目录补齐或恢复下架分类。 */
export async function listCategories(): Promise<ApiCategory[]> {
    const rows = await apiRequest<ApiCategory[]>('/categories', {
        auth: 'none',
    });
    if (
        !Array.isArray(rows) ||
        rows.some(
            (row) =>
                !row ||
                typeof row.id !== 'string' ||
                !row.id ||
                typeof row.name !== 'string' ||
                typeof row.icon !== 'string' ||
                row.status !== 'active',
        )
    ) {
        throw new Error('分类数据异常，请稍后重试');
    }
    return rows;
}

/** 展示计数保持十进制字符串，不转换 Number 或重复叠加展示种子。 */
function validateWorksheet(row: ApiWorksheet): void {
    if (
        !row ||
        !row.id ||
        typeof row.id !== 'string' ||
        typeof row.title !== 'string' ||
        typeof row.subtitle !== 'string' ||
        typeof row.category !== 'string' ||
        typeof row.path !== 'string' ||
        !Number.isInteger(row.ageMin) ||
        !Number.isInteger(row.ageMax) ||
        row.ageMin < 0 ||
        row.ageMax < row.ageMin ||
        ![1, 2, 3, 4].includes(row.difficulty) ||
        typeof row.downloads !== 'string' ||
        !/^\d+$/.test(row.downloads) ||
        typeof row.likes !== 'string' ||
        !/^\d+$/.test(row.likes) ||
        (row.previewImg !== null && typeof row.previewImg !== 'string')
    ) {
        throw new Error('题型数据异常，请稍后重试');
    }
}

/** 取完整分页后才能在客户端计算收藏榜和混合排序；分页变化或缺页时整次重试。 */
export async function listAllWorksheets(): Promise<ApiWorksheet[]> {
    const pageSize = 100;
    const rows: ApiWorksheet[] = [];
    const ids = new Set<string>();
    let expectedTotal: number | undefined;
    for (let page = 1; ; page++) {
        const result = await apiRequest<WorksheetPage>('/worksheets', {
            auth: 'none',
            data: { page, pageSize },
        });
        if (
            !result ||
            !Array.isArray(result.items) ||
            !Number.isSafeInteger(result.total) ||
            result.total < 0 ||
            result.page !== page ||
            result.pageSize !== pageSize ||
            result.hasNext !== page * pageSize < result.total ||
            result.items.length !==
                Math.max(
                    0,
                    Math.min(pageSize, result.total - (page - 1) * pageSize),
                ) ||
            (expectedTotal !== undefined && result.total !== expectedTotal)
        ) {
            throw new Error('题型列表已变化，请重试');
        }
        expectedTotal = result.total;
        for (const row of result.items) {
            validateWorksheet(row);
            if (ids.has(row.id)) throw new Error('题型列表已变化，请重试');
            ids.add(row.id);
            rows.push(row);
        }
        if (!result.hasNext) return rows;
    }
}

/** 打开题型前重新检查公开详情，避免已下架内容从旧列表继续进入。 */
export async function getWorksheet(id: string): Promise<ApiWorksheet> {
    const row = await apiRequest<ApiWorksheet>(
        `/worksheets/${encodeURIComponent(id)}`,
        { auth: 'none' },
    );
    validateWorksheet(row);
    if (row.id !== id) throw new Error('题型数据异常，请稍后重试');
    return row;
}