FACULTATE-LICENTA/CEO/src/helpers/file_sharer.ts

import fs from "fs";
import path from "path";
import { QueueManager } from './queue_manager';
import { TcpCommunicator } from "./tcp_communicator";
import { operationCodes } from '../network/operation_codes';
import { compareFnFileItemTask, FileItemTask } from "../interfaces/file_item_task";
import { ParsedMessage } from "../network/message_handler";

interface FileSendTask {
    ip: string;
    path: string;
    userName: string;
}

export class FileSharer {
    private queueManager: QueueManager<FileSendTask>;
    private readonly clientPort: number;
    private isBusy: boolean;
    private tcpCommunicator: TcpCommunicator | null = null;
    private stopRequested: boolean = false;
    private intervalId: NodeJS.Timeout | null = null;

    constructor(queueFilePath: string, clientPort: number) {
        this.queueManager = new QueueManager<FileItemTask>(queueFilePath, compareFnFileItemTask);
        this.clientPort = clientPort;
        this.isBusy = false; // Initialize the busy flag
    }

    // Start processing the file queue
    async start(): Promise<void> {
        this.intervalId = setInterval(async () => {
            if (!this.isBusy || !this.stopRequested) {  // Check if the queue is already being processed
                this.isBusy = true;  // Set busy flag to true before starting
                this.log("Start successfully. Processing the queue.");
                await this.processQueue();
            }

            if (global.gc) {
                global.gc();
            }
        }, 10000); // 10 seconds interval
    }

    // Method to process the queue
    private async processQueue(): Promise<void> {
        while (!this.queueManager.isEmpty()) {
            const task = this.queueManager.peek();
            this.log('trimiti fisier');

            if (task) {
                this.log(`Processing task for file: ${task.path} to IP: ${task.ip}`);
                const success = await this.sendFile(task);

                if (!success) {
                    this.log(`Failed to send file: ${task.path} to IP: ${task.ip}. Re-adding to queue.`, 'error');
                    this.queueManager.dequeue();
                    this.queueManager.enqueue(task);  // Re-add to queue if failed
                } else {
                    this.log(`File sent successfully: ${task.path} to IP: ${task.ip}`);
                    this.queueManager.dequeue();
                }
            }
        }
        this.isBusy = false;  // Reset busy flag after the queue is processed
    }

    // Method to send the file to a specific IP using TcpCommunicator
    private async sendFile(task: FileSendTask): Promise<boolean> {
        const { ip, path: filePath, userName } = task;

        // Ensure the file exists before attempting to send
        if (!fs.existsSync(filePath)) {
            this.log(`File not found: ${filePath}`, 'error');
            return false;
        }

        // Read the file contents
        const fileContent = fs.readFileSync(filePath);

        // Extract the file name from the file path using path.basename
        const fileName = path.basename(filePath);

        const metaInfo = {
            userName,  // Sender's username
            relativeFilePath: fileName,  // Use the file name instead of the full path
        };

        this.tcpCommunicator = new TcpCommunicator(ip, this.clientPort);

        if (!await this.tcpCommunicator.connect()) {
            this.log(`Failed to connect to IP: ${ip}`, 'error');
            return false;
        }

        this.log(`Sending file: ${filePath} to IP: ${ip}`);

        if (!await this.tcpCommunicator.sendMessage(operationCodes.SHARE_FILE, metaInfo, fileContent)) return false;

        const response = await this.waitForResponse();
        if (!response || response.operationCode !== operationCodes.OK) {
            this.log(`Failed to send file: ${filePath} to IP: ${ip}`, 'error');
            return false;
        }

        await this.tcpCommunicator.disconnect();
        return true;
    }

    async stop(): Promise<void> {
        this.stopRequested = true; // Signal that stop is requested

        if (this.intervalId) {
            clearInterval(this.intervalId);
            this.intervalId = null;
        }

        // Wait for any ongoing process to complete if busy
        while (this.isBusy) {
            await new Promise((resolve) => setTimeout(resolve, 100));
        }

        console.log("[BackupManager] Stopped successfully.");
    }

    private async waitForResponse(): Promise<ParsedMessage | null> {
        return new Promise((resolve) => {
            const idResponseCheck = setInterval(async () => {
                if (!this.tcpCommunicator) return null;
                if (this.tcpCommunicator.hasResponseArrived()) {
                    clearInterval(idResponseCheck);
                    resolve(this.tcpCommunicator.getLastResult());  // Resolve the response or null if not available
                }
            }, 100);  // Check every 100 milliseconds if the response has arrived
        });
    }

    // Unified logging function
    private log(message: string, level: 'log' | 'error' = 'log'): void {
        const prefix = '[FileSharer]';
        if (level === 'error') {
            console.error(`${prefix} ${message}`);
        } else {
            console.log(`${prefix} ${message}`);
        }
    }
}