'use strict';

const uniID = require('uni-id-common');
const checkVersion = require('./checkVersion');

const success = { success: true };
const fail = { success: false };
const appListDBName = 'opendb-app-list';
const appVersionDBName = 'opendb-app-versions';

function errorResult(code, message, extra = {}) {
	return { ...fail, code, msg: message, ...extra };
}

function isObject(value) {
	return value !== null && typeof value === 'object' && !Array.isArray(value);
}

function isNonEmptyString(value) {
	return typeof value === 'string' && value.trim().length > 0;
}

function parseRequest(event) {
	if (!isObject(event)) return { error: errorResult(400, '请求参数必须是对象') };
	if (!event.headers) return { data: event };

	const method = String(event.httpMethod || 'GET').toLowerCase();
	let payload;
	try {
		if (method === 'get') {
			payload = event.queryStringParameters || {};
			if (typeof payload === 'string') payload = JSON.parse(payload || '{}');
		} else if (event.body && typeof event.body === 'object') {
			payload = event.body;
		} else {
			payload = JSON.parse(event.body || '{}');
		}
	} catch (e) {
		return { error: errorResult(400, '请求参数格式错误') };
	}
	if (!isObject(payload)) return { error: errorResult(400, '请求参数必须是对象') };
	return { data: { ...event, ...payload } };
}

function getParams(event) {
	if (isObject(event.data)) return event.data;
	if (isObject(event.params)) return event.params;
	return {};
}

async function checkPermission(uniIDIns, uniIdToken, permission) {
	if (!isNonEmptyString(uniIdToken)) return errorResult(401, '缺少有效的uniIdToken');
	try {
		const checkTokenRes = await uniIDIns.checkToken(uniIdToken);
		if (!checkTokenRes || checkTokenRes.errCode !== 0) {
			return errorResult(401, checkTokenRes && (checkTokenRes.message || checkTokenRes.errMsg) || '登录状态无效');
		}
		const permissions = Array.isArray(checkTokenRes.permission) ? checkTokenRes.permission : [];
		const roles = Array.isArray(checkTokenRes.role) ? checkTokenRes.role : [];
		if (permissions.includes(permission) || roles.includes('admin')) return true;
		return errorResult(403, '权限不足');
	} catch (e) {
		console.error('[checkPermission]', e);
		return errorResult(401, '登录状态校验失败');
	}
}

function validateId(value, fieldName) {
	if (!isNonEmptyString(value) && !(typeof value === 'number' && Number.isFinite(value))) {
		return errorResult(400, `${fieldName}不能为空`);
	}
	return null;
}

exports.main = async (event, context) => {
	const parsed = parseRequest(event);
	if (parsed.error) return parsed.error;

	const request = parsed.data;
	const params = getParams(request);
	const action = request.action || params.action;
	if (!isNonEmptyString(action)) return errorResult(400, '缺少有效的action');

	try {
		const db = uniCloud.database();
		const uniIDIns = uniID.createInstance({ context: context || {} });

		switch (action) {
			case 'checkVersion':
				return await checkVersion({ ...request, ...params }, context || {});

			case 'deleteFile': {
				const permission = await checkPermission(uniIDIns, request.uniIdToken, 'DELETE_OPENDB_APP_VERSIONS');
				if (permission !== true) return permission;
				if (!Array.isArray(params.fileList) || params.fileList.length === 0 ||
					params.fileList.some(file => !isNonEmptyString(file))) {
					return errorResult(400, 'fileList必须是非空文件路径数组');
				}
				const result = await uniCloud.deleteFile({ fileList: params.fileList });
				return { ...success, ...(result || {}) };
			}

			case 'setNewAppData': {
				const permission = await checkPermission(uniIDIns, request.uniIdToken, 'UPDATE_OPENDB_APP_LIST');
				if (permission !== true) return permission;
				const idError = validateId(params.id, 'id');
				if (idError) return idError;
				if (!isObject(params.value)) return errorResult(400, 'value必须是对象');
				const value = { ...params.value, create_date: Date.now() };
				const result = await db.collection(appListDBName).doc(String(params.id)).set(value);
				return { ...success, ...(result || {}) };
			}

			case 'getAppInfo': {
				if (!isNonEmptyString(params.appid)) return errorResult(400, 'appid不能为空');
				const result = await db.collection(appListDBName).where({
					appid: params.appid.trim()
				}).get();
				if (result && Array.isArray(result.data) && result.data.length > 0) {
					return { ...success, ...result.data[0] };
				}
				return errorResult(404, '应用信息不存在');
			}

			case 'getAppVersionInfo': {
				if (!isNonEmptyString(params.appid) || !isNonEmptyString(params.platform)) {
					return errorResult(400, 'appid和platform不能为空');
				}
				const result = await db.collection(appVersionDBName).where({
					appid: params.appid.trim(),
					platform: params.platform,
					type: 'native_app',
					stable_publish: true
				}).orderBy('create_date', 'desc').get();
				if (result && Array.isArray(result.data) && result.data.length > 0) {
					return { ...result.data[0], ...success };
				}
				return errorResult(404, '应用版本信息不存在');
			}

			default:
				return errorResult(400, `不支持的action：${action}`);
		}
	} catch (e) {
		console.error('[uni-upgrade-center]', e);
		return errorResult(500, '请求处理失败');
	}
};