import * as fs from "fs";
import * as http from "http";
import { HttpsProxyAgent } from "https-proxy-agent";
import * as os from "os";
import * as path from "path";
import { Socket, io } from "socket.io-client";
import { TunnelRequest, TunnelResponse } from "./lib";
import { addPrefixOnHttpSchema, generateUUID } from "./util";

import { PROFILE_DEFAULT, PROFILE_PATH, SERVER_DEFAULT_URL, TOKEN_FREE } from "./constant";
import { ClientOptions, Options } from "./interface";
import { getTokenFree } from './sdk';

// create socket instance
let socket: Socket | null = null;
let keepAliveTimer: NodeJS.Timeout | null = null;

function keepAlive() {
    keepAliveTimer = setTimeout(() => {
        if (socket && socket.connected) {
            socket.send("ping");
        }
        keepAlive();
    }, 5000);
}

// Init the Client
const initClient = async (options: any) => {
    const configDir = path.resolve(os.homedir(), PROFILE_PATH);

    if (!fs.existsSync(configDir)) {
        fs.mkdirSync(configDir);
        console.log(`config file ${configDir} was created`);
    }

    let config: any = {};
    const configFilename = `${options.profile}.json`;
    const configFilePath = path.resolve(configDir, configFilename);

    if (fs.existsSync(configFilePath)) {
        config = JSON.parse(fs.readFileSync(configFilePath, "utf8"));
    }

    // Force reset config server from client init
    if (!config.server || options.force) {
        config.server = options.server || SERVER_DEFAULT_URL;
    }

    if (!config.token && options.token) {
        config.token = options.token;
    }

    if (!config.access) {
        config.access = options.access || TOKEN_FREE;
    }

    if (!config.clientId) {
        config.clientId = options.client || generateUUID();
    }

    if (!config.apiKey && options.key) {
        config.apiKey = options.key;
    }

    let errorCode = 0;
    if (!config.token || options.force) {
        console.log(`Generating token from server: ${config.server}`);
        await getTokenFree(config.server, {
            timestamp: (new Date().getTime()),
            clientId: config.clientId,
            apiKey: config.apiKey,
        })
            .then((resp: any) => {
                if (resp.data?.token) {
                    console.log("Token generated successfully!");
                    config.token = resp.data?.token;
                } else {
                    errorCode = 1;
                    console.error("Generate free token failed, return with null or empty from server!", resp);
                    return;
                }
            })
            .catch((err: any) => {
                errorCode = 1;
                console.error("cannot get free token from server", err);
                return;
            });
    }

    if (errorCode === 0) {
        fs.writeFileSync(configFilePath, JSON.stringify(config, null, 2));
        console.log(`initialized config saved successfully to: ${configFilePath}`);
    }
};

// Start Client
const initStartClient = async (options: Options) => {
    // Please change this if your domain goes wrong here
    // Current style using sub-domain: https://{{clientId}}-tunnel.myhostingdomain.com
    // (Original server: https://tunnel.myhostingdomain.com)
    const profile = options.profile || PROFILE_DEFAULT;
    const clientId = `${options.apiKey || options.clientId || generateUUID()}`;
    const clientIdSub =
        profile === PROFILE_DEFAULT ? `${clientId}-` : `${clientId}-${profile}-`;
    const clientEndpoint = (
        options.suffix ? `${clientIdSub}${options.suffix}-` : clientIdSub
    )
        .toLowerCase()
        .trim();
    const serverUrl = addPrefixOnHttpSchema(options.server || SERVER_DEFAULT_URL, clientEndpoint);

    // extra options for socket to identify the client (authentication and options of tunnel)
    const defaultParams = {
        apiKey: options.apiKey,
        clientId: options.clientId,
        profile: options.profile,
        clientIdSub: clientIdSub,
        clientEndpoint: clientEndpoint,
        serverUrl: serverUrl,
        access: options.access,
        keep_connection: options.keep_connection || true,
    };

    // extra info for notify about the running of the tunnel (it's private info, other platfom cannot access this)
    // this using for internal only (don't worry about this)
    const osInfo = {
        hostname: os.hostname(),
        platform: os.platform(),
        arch: os.arch(),
        release: os.release(),
    };

    const initParams: any = {
        path: "/$cubetiq_http_tunnel",
        transports: ["websocket"],
        auth: {
            token: options.token,
            ...defaultParams,
        },
        headers: {
            ...defaultParams,
            os: osInfo,
        },
        // reconnection: true,
    };

    const http_proxy = process.env.https_proxy || process.env.http_proxy;
    if (http_proxy) {
        initParams.agent = new HttpsProxyAgent(http_proxy);
    }

    // Connecting to socket server and agent here...
    console.log(`client connecting to server: ${serverUrl}`);
    socket = io(serverUrl, initParams);

    const clientLogPrefix = `client: ${clientId} on profile: ${profile}`;
    socket.on("connect", () => {
        if (socket!.connected) {
            console.log(`${clientLogPrefix} is connected to server successfully!`);
        }
    });

    socket.on("connect_error", (e) => {
        console.error(
            `${clientLogPrefix} connect error:`,
            (e && e.message) || "something wrong"
        );
        if (e && e.message && e.message.startsWith("[40")) {
            process.exit(1);
        }
    });

    socket.on("disconnect", (reason) => {
        console.warn(`${clientLogPrefix} disconnected: ${reason}!`);
    });

    socket.on("disconnect_exit", (reason) => {
        console.warn(`${clientLogPrefix} disconnected and exited ${reason}!`);
        socket?.disconnect();
        process.exit(1);
    });

    socket.on("request", (requestId, request) => {
        const isWebSocket = request.headers.upgrade === "websocket";
        console.log(`${isWebSocket ? "WS" : request.method}: `, request.path);
        request.port = options.port;
        request.hostname = options.host;

        if (options.origin) {
            request.headers.host = options.origin;
        }

        const tunnelRequest = new TunnelRequest(socket!, requestId);

        const localReq = http.request(request);
        tunnelRequest.pipe(localReq);

        const onTunnelRequestError = (e: any) => {
            console.error("tunnel request error: ", e);
            tunnelRequest.off("end", onTunnelRequestEnd);
            localReq.destroy(e);
        };

        const onTunnelRequestEnd = () => {
            tunnelRequest.off("error", onTunnelRequestError);
        };

        tunnelRequest.once("error", onTunnelRequestError);
        tunnelRequest.once("end", onTunnelRequestEnd);

        const onLocalResponse = (localRes: any) => {
            localReq.off("error", onLocalError);

            if (isWebSocket && localRes.upgrade) {
                return;
            }

            const tunnelResponse = new TunnelResponse(socket!, requestId);

            tunnelResponse.writeHead(
                localRes.statusCode,
                localRes.statusMessage,
                localRes.headers,
                localRes.httpVersion
            );

            localRes.pipe(tunnelResponse);
        };

        const onLocalError = (error: any) => {
            console.error("local error:", error);
            localReq.off("response", onLocalResponse);
            socket?.emit("request-error", requestId, error && error.message);
            tunnelRequest.destroy(error);
        };

        const onUpgrade = (localRes: any, localSocket: any, localHead: any) => {
            // localSocket.once('error', onTunnelRequestError);
            if (localHead && localHead.length) localSocket.unshift(localHead);

            const tunnelResponse = new TunnelResponse(socket!, requestId, true);
            tunnelResponse.writeHead(null, null, localRes.headers);
            localSocket.pipe(tunnelResponse).pipe(localSocket);
        };

        localReq.once("error", onLocalError);
        localReq.once("response", onLocalResponse);

        if (isWebSocket) {
            localReq.on("upgrade", onUpgrade);
        }
    });

    // reconnect manually
    // const tryReconnect = () => {
    //     setTimeout(() => {
    //         socket!.io.open((err) => {
    //             if (err) {
    //                 tryReconnect();
    //             }
    //         });
    //     }, 2000);
    // };
    // socket.io.on("close", tryReconnect);

    keepAlive();
};

const startClient = (clientOptions: ClientOptions) => {
    const { port, options = {} } = clientOptions;
    const configDir = path.resolve(os.homedir(), PROFILE_PATH);

    if (!fs.existsSync(configDir)) {
        fs.mkdirSync(configDir);
    }

    let config: any = {};
    const configFilename = `${options.profile || PROFILE_DEFAULT}.json`;
    const configFilePath = path.resolve(configDir, configFilename);

    if (fs.existsSync(configFilePath)) {
        config = JSON.parse(fs.readFileSync(configFilePath, "utf8"));
    }

    if (!config.server) {
        config.server = SERVER_DEFAULT_URL;
    }

    if (!config.token) {
        console.info(`please init or set token for ${config.server}`);
        return;
    }

    if (!config.clientId) {
        if (!config.apiKey) {
            console.info(`please init or create a client for ${config.server}`);
        } else {
            config.clientId = config.apiKey;
        }
        return;
    }

    options.port = port;
    options.token = config.token;
    options.access = config.access;
    options.server = config.server;
    options.clientId = config.clientId;
    options.apiKey = options.key || config.apiKey;

    if (options.suffix === "port" || options.suffix === "true") {
        options.suffix = `${port}`;
    } else if (options.suffix === "false") {
        options.suffix = undefined;
    } else if (options.suffix === "gen" || options.suffix === "uuid") {
        options.suffix = generateUUID();
    }

    initStartClient(options);
};

const stopClient = () => {
    if (socket) {
        socket.disconnect();
        socket.close();
        socket = null;
        keepAliveTimer && clearInterval(keepAliveTimer);

        console.log("client stopped");
    }
};

export {
    initClient,
    startClient,
    stopClient,
};