/// <reference path="../typings/polyfill.d.ts" />
import './polyfill';
import { IncomingHttpHeaders, createServer } from "http";
import PathLib, { join } from 'path';
import Koa from 'koa';
import KoaRouter from 'koa-router';
import KoaBody from 'koa-body';
import logger from 'koa-logger';

import { AppLoader, getClusterInfo, ClusterAppLoader } from 'oak-backend-base';
import { BackendRuntimeContext } from 'oak-frontend-base/lib/context/BackendRuntimeContext';
import { OakException, Connector, EntityDict, ClusterInfo } from 'oak-domain/lib/types';
import { EntityDict as BaseEntityDict } from 'oak-domain/lib/base-app-domain';
import { AsyncRowStore, AsyncContext } from 'oak-domain/lib/store/AsyncRowStore';
import { SyncContext } from 'oak-domain/lib/store/SyncRowStore';
import { createAdapter } from "@socket.io/cluster-adapter";
import { setupWorker } from "@socket.io/sticky";
import { createAdapter as createRedisAdapter } from "@socket.io/redis-adapter";
import Redis from "ioredis";
import { Server, ServerOptions } from "socket.io";
import { ServerConfiguration } from 'oak-domain/lib/types/Configuration';
import { instrument } from "@socket.io/admin-ui";
import serve from 'koa-static';
import mount from 'koa-mount';
import chalk from 'chalk';
import { checkNodeVersion, randomString } from '../utils';
import bcrypt from 'bcryptjs';
import { LogFormatter, polyfillConsole, removePolyfill } from './polyfill';
import { ErrorHandler } from '../types';

checkNodeVersion()

const socketAdminUI = join(__dirname, '../../ui/socket-admin');

const DATA_SUBSCRIBE_NAMESPACE = '/dsn';
const SOCKET_NAMESPACE = '/sn';
const SERVER_SUBSCRIBER_NAMESPACE = process.env.OAK_SSUB_NAMESPACE || '/ssub';
const ExceptionMask = '内部不可知错误';


function concat(...paths: string[]) {
    return paths.reduce(
        (prev, current) => {
            if (current.startsWith('/')) {
                return `${prev}${current}`;
            }
            return `${prev}/${current}`;
        }
    );
}

export async function startup<ED extends EntityDict & BaseEntityDict, FrontCxt extends SyncContext<ED>, Cxt extends BackendRuntimeContext<ED>>(
    path: string,
    connector: Connector<ED, FrontCxt>,
    omitWatchers?: boolean,
    omitTimers?: boolean,
    routine?: (context: AsyncContext<ED>) => Promise<void>,
): Promise<(() => Promise<any>) | any> {

    let errorHandler: ErrorHandler<ED> | undefined = undefined;

    try {
        errorHandler = require(join(
            path,
            'lib',
            'configuration',
            'errors'
        )).default;
    } catch (err) {
        // 不存在errors配置
    }

    const serverConfiguration: ServerConfiguration = require(join(
        path,
        'lib',
        'configuration',
        'server'
    )).default;
    // 拿到package.json，用作项目的唯一标识，否则无法区分不同项目的Redis+socketIO连接
    const packageJson = require(join(path, 'package.json'));
    const corsHeaders = [
        'Content-Type',
        'Content-Length',
        'Authorization',
        'Accept',
        'X-Requested-With',
    ];
    const corsMethods = ['PUT', 'POST', 'GET', 'DELETE', 'OPTIONS'];

    const koa = new Koa();
    // 使用 koa-logger 中间件打印日志
    koa.use(logger());
    // socket
    const httpServer = createServer(koa.callback());
    const socketPath = connector.getSocketPath();
    const socketOption: Partial<ServerOptions> = {
        path: socketPath,
        cors: ['development', 'staging'].includes(process.env.NODE_ENV!)
            ? {
                origin: '*',
                allowedHeaders: corsHeaders.concat(connector.getCorsHeader()),
            }
            : serverConfiguration.cors
                ? {
                    origin: serverConfiguration.cors.origin, //socket.io配置cors origin是支持数组和字符串
                    allowedHeaders: [
                        ...corsHeaders.concat(connector.getCorsHeader()),
                        ...(serverConfiguration.cors!.headers || []),
                    ],
                }
                : undefined,
    };
    const io = new Server(httpServer, socketOption);
    const clusterInfo = getClusterInfo();
    if (clusterInfo.usingCluster) {
        // 目前只支持单物理结点的pm2模式
        // pm2环境下要接入clusterAdapter
        // https://socket.io/zh-CN/docs/v4/pm2/

        // 在单机的所有实例之间使用pm2的集群适配器
        io.adapter(createAdapter());
        setupWorker(io);

        if (clusterInfo.enableRedis) {
            // 在多机器之间使用redis适配器
            const redisConfig = serverConfiguration.redis
            if (!redisConfig) {
                console.error('未配置Redis连接信息！');
                process.exit(-1);
            }
            const isCluster = Array.isArray(redisConfig);
            // 创建 Redis 客户端
            const pubClient = isCluster ?
                new Redis.Cluster(redisConfig.map((config) => ({
                    ...config,
                    lazyConnect: true,
                })))
                : new Redis({
                    ...redisConfig,
                    lazyConnect: true,
                });
            const subClient = pubClient.duplicate();
            pubClient.on('connect', () => {
                console.log('PUB已成功连接到Redis服务器');
            });
            pubClient.on('error', (err) => {
                console.error('连接到Redis失败！', err);
                // 如果连接到Redis失败，直接退出
                process.exit(-1);
            });
            subClient.on('connect', () => {
                console.log('SUB已成功连接到Redis服务器');
            });
            subClient.on('error', (err) => {
                console.error('连接到Redis失败！', err);
                // 如果连接到Redis失败，直接退出
                process.exit(-1);
            });
            await Promise.all([
                pubClient.connect(),
                subClient.connect(),
            ]);
            io.adapter(
                // 为了使单台Redis可以在多个项目之间复用，需要为每个项目创建一个唯一的key
                createRedisAdapter(pubClient, subClient, {
                    key: `${packageJson.name}-socket.io-${process.env.NODE_ENV || 'development'}`
                        .replace(/[^a-zA-Z0-9-_:.]/g, '') // 移除特殊字符（只保留字母、数字、-、_、:、.）
                        .replace(/\s+/g, '-')             // 将空格替换为-
                        .toLowerCase(),                  // 转换为小写（统一格式）
                })
            );
            console.log('已启用Redis适配器');
        } else {
            // 如果没有启用Redis，不应该出现instanceCount大于实际实例数的情况
            console.warn('正处于单机集群环境，请确保实例数正确！');
        }
        console.log(
            `以集群模式启动，实例总数『${clusterInfo.instanceCount}』，当前实例号『${clusterInfo.instanceId}』`
        );
    } else {
        console.log('以单实例模式启动');
    }

    const { ui } = serverConfiguration;
    const isPasswordSet = !!(process.env.SOCKET_ADMIN_PASSWORD || ui?.password)
    // 密码使用随机字符串
    const passwordForAdminUI = process.env.SOCKET_ADMIN_PASSWORD || ui?.password || randomString(16);

    if (!ui?.disable) {
        instrument(io, {
            auth: {
                type: "basic", // 使用基本认证，生产建议关闭或换成自定义 auth
                username: ui?.username || "admin",
                password: bcrypt.hashSync(passwordForAdminUI, 10), // 必须使用 bcrypt 加密之后的密码
            },
            mode: process.env.NODE_ENV === 'production' ? "production" : "development", // 根据环境设置模式
        });
    }

    const appLoader = clusterInfo.usingCluster
        ? new ClusterAppLoader<ED, Cxt>(
            path,
            io.of(DATA_SUBSCRIBE_NAMESPACE),
            io.of(SOCKET_NAMESPACE),
            io.of(SERVER_SUBSCRIBER_NAMESPACE),
            connector.getSocketPath()
        )
        : new AppLoader<ED, Cxt>(
            path,
            io.of(DATA_SUBSCRIBE_NAMESPACE),
            io.of(SOCKET_NAMESPACE),
            io.of(SERVER_SUBSCRIBER_NAMESPACE)
        );
    await appLoader.mount();
    await appLoader.execStartRoutines();
    if (routine) {
        // 如果传入了routine，执行完成后就结束
        const result = await appLoader.execRoutine(routine);
        await appLoader.unmount();
        return result;
    }

    if (errorHandler && typeof errorHandler === 'function') {
        polyfillConsole("startup", true, (props) => {
            if (props.level === "error") {
                appLoader.execRoutine(async (ctx) => {
                    await errorHandler(props.caller, props.args, ctx);
                }).catch((err) => {
                    console.warn('执行全局错误处理失败：', err);
                });
            }
            return props.args;
        });
    }

    // 否则启动服务器模式
    koa.use(async (ctx, next) => {
        try {
            await next();
        } catch (err) {
            console.error(err);
            const { request } = ctx;
            const exception =
                err instanceof OakException
                    ? err
                    : new OakException<ED>(
                        serverConfiguration?.internalExceptionMask ||
                        ExceptionMask
                    );
            const { body } = connector.serializeException(
                exception,
                request.headers,
                request.body
            );
            ctx.response.body = body;
            return;
        }
    });
    koa.use(
        KoaBody(Object.assign({
            multipart: true,
        }, serverConfiguration.koaBody))
    );
    const router = new KoaRouter();

    // 如果是开发环境，允许options
    if (['development', 'staging'].includes(process.env.NODE_ENV!)) {
        koa.use(async (ctx, next) => {
            ctx.set('Access-Control-Allow-Origin', '*');
            ctx.set('Access-Control-Allow-Headers', corsHeaders.concat(connector.getCorsHeader()));
            ctx.set('Access-Control-Allow-Methods', corsMethods);
            if (ctx.method == 'OPTIONS') {
                ctx.body = 200;
            } else {
                await next();
            }
        });
    } else if (serverConfiguration.cors) {
        koa.use(async (ctx, next) => {
            if (serverConfiguration.cors!.origin instanceof Array) {
                // 获取到req.headers.origin格式：https://xxx.xx.com 加上端口号
                const origin = ctx.req.headers.origin;
                if (serverConfiguration.cors!.origin.includes(origin!)) {
                    ctx.set('Access-Control-Allow-Origin', origin!);
                }
            }
            else {
                ctx.set(
                    'Access-Control-Allow-Origin',
                    serverConfiguration.cors!.origin!
                );
            }

            ctx.set('Access-Control-Allow-Headers', [
                ...corsHeaders.concat(connector.getCorsHeader()),
                ...(serverConfiguration.cors!.headers || []),
            ]);
            ctx.set(
                'Access-Control-Allow-Methods',
                serverConfiguration.cors!.methods || corsMethods
            );
            if (ctx.method == 'OPTIONS') {
                ctx.body = 200;
            } else {
                await next();
            }
        });
    }

    router.post(connector.getRouter(), async (ctx) => {
        const { request } = ctx;
        const { contextString, aspectName, data } = connector.parseRequest(
            request.headers,
            request.body,
            request.files
        );

        const { result, opRecords, message } = await appLoader.execAspect(
            aspectName,
            request.headers,
            contextString,
            data
        );
        const { body, headers } = await connector.serializeResult(
            result,
            opRecords,
            request.headers,
            request.body,
            message
        );
        ctx.response.body = body;
        return;
    });

    // 桥接访问外部资源的入口
    router.get(connector.getBridgeRouter(), async (ctx) => {
        const {
            request: { querystring },
            response,
        } = ctx;
        const { url, headers } = connector.parseBridgeRequestQuery(querystring);

        // headers待处理
        const res = await fetch(url as string);
        response.body = res.body;
        return;
    });

    // 外部socket接口
    /**
     *  不用pm2		不用nginx：     socket与http同端口
        用pm2		不用nginx:      socket监听8080
        不用pm2		用nginx:		nginx映射路径到server端口（手动配置），socket与http同端口（加路径）
        用pm2		用nginx:		nginx映射路径到8080（手动配置），socket与http同端口（加路径）
     */
    const { nginx, hostname, port, socket: getSocketConfig } = serverConfiguration;
    const protocol = nginx?.ssl ? 'https://' : 'http://';
    let url = `${protocol}${hostname}`;
    if (nginx) {
        if (nginx.port) {
            url += `:${nginx.port}`;
        }
    } else if (clusterInfo.usingCluster) {
        url += `:${process.env.PM2_PORT || 8080}`;
    } else {
        url += `:${port}`;
    }

    // Example:
    // import { io } from "socket.io-client";
    // const socket = io('https://example.com/order', {
    //    path: '/my-custom-path/',
    // });
    // the Socket instance is attached to the "order" Namespace
    // the HTTP requests will look like: GET https://example.com/my-custom-path/?EIO=4&transport=polling&t=ML4jUwU
    // 文档 https://socket.io/docs/v4/client-options/
    router.get(connector.getSocketPointRouter(), async (ctx) => {
        const { response } = ctx;
        let subscribeUrl = concat(url, DATA_SUBSCRIBE_NAMESPACE);
        let socketUrl = concat(url, SOCKET_NAMESPACE);
        if (typeof getSocketConfig === 'function') {
            const socketConfig = getSocketConfig(ctx);
            const url2 = socketConfig?.url;
            if (url2) {
                subscribeUrl = concat(url2, DATA_SUBSCRIBE_NAMESPACE);
                socketUrl = concat(url2, SOCKET_NAMESPACE);
            }
        }

        response.body = {
            path: (nginx?.socketPath ? `/${nginx.socketPath}` : '') + connector.getSocketPath(),
            socketUrl,
            subscribeUrl,
        };
        return;
    });

    // 注入所有的endpoints
    const endpoints = appLoader.getEndpoints(connector.getEndpointRouter());
    endpoints.forEach(([name, method, url, fn]) => {
        router[method](url, async (ctx) => {
            const { req, request, params, response, res } = ctx;
            const { body, headers, files } = request;
            try {
                const result = await fn(params, headers, req, files ? Object.assign({}, body, files) : body);
                const { headers: headers2, data, statusCode } = result;
                response.body = data;
                if (headers2) {
                    Object.keys(headers2).forEach(
                        (k) => res.setHeader(k, headers2[k])
                    )
                }
                if (statusCode) {
                    res.statusCode = statusCode
                }
                return;
            } catch (err) {
                ctx.response.status = 500;
                return;
            }
        });
    });

    router.get(connector.getEndpointRouter(), async (ctx) => {
        ctx.response.body = endpoints;
    });

    const socketAdminMountRaw = ui?.path || '/socket-admin'
    const socketAdminMount = socketAdminMountRaw.startsWith('/')
        ? socketAdminMountRaw : `/${socketAdminMountRaw}`;
    // 注册静态资源
    if (!ui?.disable) {
        koa.use(mount(socketAdminMount, serve(socketAdminUI)));
    }

    koa.use(router.routes());

    koa.on('error', (err) => {
        console.error(err);
        throw err;
    });

    httpServer.listen(serverConfiguration.port, () => {
        const protocol = nginx?.ssl ? 'https' : 'http';
        const host = hostname || 'localhost';
        const port = nginx?.port || (clusterInfo.usingCluster ? (process.env.PM2_PORT || 8080) : serverConfiguration.port);
        const baseUrl = `${protocol}://${host}:${port}`;
        const adminUIUrl = `${baseUrl}${socketAdminMount}`;

        console.log(chalk.greenBright.bold('\n🚀 Server started successfully!\n'));
        console.log(`🔗 ${chalk.cyan('Server URL')}:     ${chalk.underline(baseUrl)}`);
        // socketio地址
        console.log(`🔗 ${chalk.cyan('Socket URL')}:     ${chalk.underline(concat(url, socketPath))}\n`);
        if (!ui?.disable) {
            console.log(`🛠️  ${chalk.magenta('Socket Admin UI')}: ${chalk.underline(adminUIUrl)}`);
            // 账号密码
            // 是否设置密码
            if (isPasswordSet) {
                console.log(`🔑 ${chalk.yellow('Socket Admin UI Password has been set, check the config file\n')}`)
            } else {
                console.log(chalk.yellow('Socket Admin UI Password Generated: ') + chalk.red(passwordForAdminUI));
                console.log(chalk.yellow('Please set the password when running prod env.\n'));
            }
        }
    });

    if (!omitWatchers) {
        appLoader.startWatchers();
    }
    if (!omitTimers) {
        appLoader.startTimers();
    }

    process.on('SIGINT', async () => {
        await appLoader.unmount();
        process.exit(0);
    });

    const shutdown = async () => {
        await httpServer.close();
        await koa.removeAllListeners();
        await appLoader.unmount();

        removePolyfill("startup");
    }

    return shutdown
}