FACULTATE-LICENTA/User/src/helpers/network_scanner.ts

import {JsonManager} from "./json_manager";
import {UdpClient} from "../network/udp/udp_client";
import {parentPort} from "worker_threads";
import {TcpCommunicator} from "./tcp_communicator";
import {operationCodes} from "../network/operation_codes";
import {ParsedMessage} from "../network/message_handler";

export class NetworkScanner {
    private applicationInfo: JsonManager;
    private userConfig: JsonManager;
    private readonly udpPort: number;
    private readonly tcpPort: number;
    private readonly okPage: string;
    private readonly errorPage: string;
    private readonly databaseResetPage: string;
    private appStarted = false;
    private intervalIds: NodeJS.Timeout[] = [];

    // Flags to prevent overlapping executions
    private ucCheckBusy = false;
    private ipLookupBusy = false;
    private sendLoginBusy = false;

    constructor(applicationInfoPath: string, userConfigPath: string, udpPort: number, tcpPort: number, okPage: string, errorPage: string, databaseResetPage: string) {
        this.applicationInfo = new JsonManager(applicationInfoPath);
        this.userConfig = new JsonManager(userConfigPath);
        this.udpPort = udpPort;
        this.tcpPort = tcpPort;
        this.okPage = okPage;
        this.errorPage = errorPage;
        this.databaseResetPage = databaseResetPage;

        // Start tasks
        this.startUCCheck();
        this.startUserIPLookup();
        this.sendLoginRequest();
    }

    // Log helper function for consistent logging format
    private log(message: string, level: 'log' | 'error' = 'log', methodName: string = ''): void {
        const prefix = `[NetworkScanner${methodName ? `.${methodName}` : ''}]`;
        if (level === 'error') {
            console.error(`${prefix} ${message}`);
        } else {
            console.log(`${prefix} ${message}`);
        }
    }

    // UC Check Task
    private startUCCheck(interval: number = 5000): void {
        const intervalId = setInterval(async () => {
            if (this.ucCheckBusy) return;
            this.ucCheckBusy = true;

            try {
                this.log('UC Check running...', 'log', 'startUCCheck');
                const udpClient = new UdpClient(this.udpPort);
                const aliveClients = await udpClient.getAliveClients();
                const storedIp = await this.applicationInfo.readValue('serverIp');
                const foundClient = aliveClients.length > 0;

                if (foundClient) {
                    const ipAddress = aliveClients[0]; // Use the first alive client

                    if (!storedIp || storedIp !== ipAddress) {
                        await this.applicationInfo.writeValue('serverIp', ipAddress);
                        if (!this.appStarted) {
                            parentPort?.postMessage({ type: 'changeContent', page: this.okPage });
                        }
                        this.appStarted = true;
                    } else if (!this.appStarted) {
                        parentPort?.postMessage({ type: 'changeContent', page: this.okPage });
                        this.appStarted = true;
                    }
                } else {
                    parentPort?.postMessage({ type: 'changeContent', page: this.errorPage });
                }
            } catch (err) {
                this.log(`Error checking UC: ${err}`, 'error', 'startUCCheck');
                parentPort?.postMessage({ type: 'changeContent', page: this.errorPage });
            } finally {
                this.ucCheckBusy = false;
            }
        }, interval);

        this.intervalIds.push(intervalId);
    }

    // IP Lookup Task
    private startUserIPLookup(interval: number = 10000): void {
        const intervalId = setInterval(async () => {
            if (this.ipLookupBusy) return;
            this.ipLookupBusy = true;

            try {
                this.log('IP Lookup running...', 'log', 'startUserIPLookup');
                const serverIp = await this.applicationInfo.readValue('serverIp');
                const udpClient = new UdpClient(this.udpPort);
                const activeIPs = await udpClient.getAliveClients();
                const filteredIPs = activeIPs.filter(ip => ip !== serverIp);

                // Save the filtered IPs to 'users_ip'
                await this.applicationInfo.writeValue('users_ip', filteredIPs);
            } catch (err) {
                this.log(`Error during user IP lookup: ${err}`, 'error', 'startUserIPLookup');
            } finally {
                this.ipLookupBusy = false;
            }
        }, interval);

        this.intervalIds.push(intervalId);
    }

    // Login Request Task
    private sendLoginRequest(interval: number = 5000): void {
        const intervalId = setInterval(async () => {
            if (this.sendLoginBusy || this.appStarted) return;
            this.sendLoginBusy = true;

            try {
                const userInfo = await this.userConfig.readValue('user_info');
                if (!userInfo || !userInfo.email || !userInfo.password) {
                    this.log("Email or password not found in user config.", 'error', 'sendLoginRequest');
                    return;
                }

                const app_type = await this.userConfig.readValue('app_type');
                const email = userInfo.email;
                const password = userInfo.password;
                const serverIp = await this.applicationInfo.readValue('serverIp');

                if (!serverIp) {
                    this.log("Server IP not found in application info.", 'error', 'sendLoginRequest');
                    return;
                }

                const tcpCommunicator = new TcpCommunicator(serverIp, this.tcpPort);

                if (!await tcpCommunicator.connect()) {
                    this.log("Failed to connect to the server.", 'error', 'sendLoginRequest');
                    return;
                }

                const metaInfo = { email, password, app_type };
                if (!await tcpCommunicator.sendMessage(operationCodes.LOGIN, metaInfo)) {
                    this.log("Failed to send login request.", 'error', 'sendLoginRequest');
                    await tcpCommunicator.disconnect();
                    return;
                }

                const response = await this.waitForResponse(tcpCommunicator);
                if (response?.operationCode !== operationCodes.OK) {
                    await this.userConfig.resetFile();
                    await this.userConfig.writeValue('app_type', app_type);
                    parentPort?.postMessage({ type: 'changeContent', page: this.databaseResetPage });
                }
            } catch (err) {
                this.log(`Error during login request: ${err}`, 'error', 'sendLoginRequest');
            } finally {
                this.sendLoginBusy = false;
            }
        }, interval);

        this.intervalIds.push(intervalId);
    }

    // Helper function to wait for a response from the TCP communicator
    private async waitForResponse(tcpCommunicator: TcpCommunicator): Promise<ParsedMessage | null> {
        return new Promise((resolve) => {
            const checkInterval = setInterval(() => {
                if (tcpCommunicator.hasResponseArrived()) {
                    clearInterval(checkInterval);
                    resolve(tcpCommunicator.getLastResult());
                }
            }, 100);
        });
    }

    // Method to stop all intervals (for cleanup if needed)
    public stopAllIntervals(): void {
        for (const id of this.intervalIds) {
            clearInterval(id);
        }
        this.log("All intervals have been stopped.", 'log', 'stopAllIntervals');
    }
}