import { getApiConfig } from '../config/api';

export class ApiRequestError extends Error {
    constructor(
        message: string,
        readonly statusCode = 0,
        readonly reason = '',
    ) {
        super(message);
        this.name = 'ApiRequestError';
    }
}

export interface RequestOptions {
    method?: 'GET' | 'POST' | 'PUT' | 'DELETE';
    data?: Record<string, unknown>;
    header?: Record<string, string>;
    timeout?: number;
    upload?: { filePath: string; uploadId: string };
}

/** 底层只发请求，不触发登录；登录接口与鉴权包装共用，避免循环依赖。 */
export function requestApi<T>(
    path: string,
    options: RequestOptions = {},
    config = getApiConfig(),
): Promise<T> {
    if (!path.startsWith('/') || path.startsWith('//'))
        throw new Error('接口路径不正确');
    return new Promise((resolve, reject) => {
        const success = (res: { statusCode: number; data: unknown }) => {
            const body = res.data as {
                code?: number;
                data?: T;
                reason?: string;
            } | null;
            if (res.statusCode < 200 || res.statusCode >= 300) {
                reject(
                    new ApiRequestError(
                        res.statusCode === 404
                            ? '内容暂不可用'
                            : '接口请求失败，请稍后重试',
                        res.statusCode,
                        typeof body?.reason === 'string' &&
                            /^[A-Z_]{1,64}$/.test(body.reason)
                            ? body.reason
                            : '',
                    ),
                );
            } else if (
                !body ||
                body.code !== 0 ||
                !Object.prototype.hasOwnProperty.call(body, 'data')
            ) {
                reject(
                    new ApiRequestError(
                        '接口返回异常，请稍后重试',
                        res.statusCode,
                    ),
                );
            } else resolve(body.data as T);
        };
        const fail = () =>
            reject(new ApiRequestError('连接失败，请确认后端已启动及网络配置'));
        if (options.upload) {
            // wx.uploadFile 由运行时生成 multipart boundary，不能自行设置 JSON Content-Type。
            wx.uploadFile({
                url: `${config.baseUrl}${path}`,
                filePath: options.upload.filePath,
                name: 'file',
                formData: { uploadId: options.upload.uploadId },
                header: options.header,
                timeout: 60000,
                success(res) {
                    let data: unknown;
                    try {
                        data = JSON.parse(res.data);
                    } catch {
                        reject(new ApiRequestError('上传响应格式异常'));
                        return;
                    }
                    success({ statusCode: res.statusCode, data });
                },
                fail,
            });
        } else
            wx.request({
                url: `${config.baseUrl}${path}`,
                method: options.method || 'GET',
                data: options.data,
                header: {
                    'Content-Type': 'application/json',
                    ...options.header,
                },
                timeout: options.timeout ?? config.timeout,
                success,
                fail,
            });
    });
}