import fs from 'fs';
import path from 'path';
import { TcpCommunicator } from './tcp_communicator';
import { operationCodes } from '../network/operation_codes';
import { JsonManager } from './json_manager';
import { MemoryManager } from './memory_manager';
import { ParsedMessage } from "../network/message_handler";

export class DepartmentSharer {
    private userConfig: JsonManager;
    private applicationInfo: JsonManager;
    private memoryManager: MemoryManager;
    private departmentDirectory: string | null;
    private readonly clientPort: number;
    private isBusy: boolean = false;
    private tcpCommunicator: TcpCommunicator | null = null;
    private stopRequested: boolean = false;
    private intervalId: NodeJS.Timeout | null = null;

    constructor(
        userConfigPath: string,
        applicationInfoPath: string,
        memoryManagerPath: string,
        clientPort: number
    ) {
        this.userConfig = new JsonManager(userConfigPath);
        this.applicationInfo = new JsonManager(applicationInfoPath);
        this.memoryManager = new MemoryManager(memoryManagerPath);
        this.clientPort = clientPort;
        this.departmentDirectory = null;
    }

    // Start sharing files with the department every minute
    async start(): Promise<void> {
        this.intervalId = setInterval(async () => {
            if (!this.isBusy || !this.stopRequested) {
                this.isBusy = true;
                this.log('Start successfully. Sharing files with the department.');
                await this.shareFilesWithDepartment();
            }

            if (global.gc) {
                global.gc();
            }
        }, 10000);  // 10-second interval for testing
    }

    // Share files with users in the same department
    private async shareFilesWithDepartment(): Promise<void> {
        try {
            // Get the current user's department information
            const userInfo = await this.userConfig.readValue('user_info');
            if (!userInfo || !userInfo.departmentId || !userInfo.name) {
                throw new Error('User information or department ID is missing in the configuration.');
            }

            const departmentId = userInfo.departmentId;
            const userName = userInfo.name;

            // Get the list of active users from applicationInfo
            const activeUsersId = await this.applicationInfo.readValue('active_users_info');
            if (!activeUsersId) {
                throw new Error('No active users found.');
            }

            const activeUsers = await this.memoryManager.retrieveMetaInformation(activeUsersId);
            if (!activeUsers || activeUsers.length === 0) {
                throw new Error('No active users found.');
            }

            // Filter users who belong to the same department
            const departmentUsers = activeUsers.filter((user: any) => user.user_info.departmentId === departmentId);
            if (departmentUsers.length === 0) {
                throw new Error('No users found in the same department.');
            }

            // Get department directory info
            const departmentData = await this.applicationInfo.readValue('departmentDirectory');
            if (!departmentData || !departmentData.path || !departmentData.id) {
                throw new Error('No department directory found.');
            }

            this.departmentDirectory = departmentData.path;

            // Read files from the MemoryManager related to this department
            const departmentFiles = await this.memoryManager.retrieveMetaInformation(departmentData.id);
            if (!departmentFiles || !departmentFiles.structure) {
                throw new Error('No files found for this department in the memory manager.');
            }

            // Iterate over all department users and perform the operations
            for (const user of departmentUsers) {
                const userIp = user.ip;
                this.tcpCommunicator = new TcpCommunicator(userIp, this.clientPort);

                if (!await this.tcpCommunicator.connect()) continue;

                // First clear the department directory;
                if (await this.clearDepartmentDirectory(userName)) {
                    await this.sendFilesToUser(departmentFiles.structure, userName);
                }

                await this.tcpCommunicator.disconnect();
            }
        }
        catch(error: any) {
            this.log(error.message, 'error');
        }
        finally{
            this.log('Department sharing completed.');
            this.isBusy = false;
        }
    }

    // Clear the department directory for a user
    private async clearDepartmentDirectory(userName: string): Promise<boolean> {
        if(!this.tcpCommunicator) return false;

        if (!await this.tcpCommunicator.sendMessage(operationCodes.CLEAR_DEPARTMENT, {userName: userName})) return false;
        const response = await this.waitForResponse();

        if (!response || response.operationCode !== operationCodes.OK){
            this.log('Failed to clear the department directory.', 'error');
            return false;
        }

        return true;
    }

    // Send the files to a user in the department
    private async sendFilesToUser(files: { [key: string]: string }, userName: string): Promise<void> {
        if(!this.tcpCommunicator) return;
        const unsentFiles = Object.keys(files);

        console.log(`\n\n${unsentFiles}\n\n`);

        for (const fileName of unsentFiles) {
            const filePath = files[fileName];

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

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

            // Get the relative path of the file (used in the meta info)
            if (!this.departmentDirectory) return;
            const relativeFilePath = path.relative(this.departmentDirectory, filePath);

            // Prepare the metaInfo (same structure as FileSharer)
            const metaInfo = {
                userName,
                relativeFilePath
            };

            // Send the file
            if (!await this.tcpCommunicator.sendMessage(operationCodes.DEPARTMENT_FILE, metaInfo, Buffer.from(fileContent))) return;

            console.log(`\n\nSending file: ${fileName} to ${userName}\n\n`);

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

            this.log(`File sent successfully: ${fileName} to ${userName}`);

            unsentFiles.splice(unsentFiles.indexOf(fileName), 1);
            await this.tcpCommunicator.disconnect();
        }
    }

    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());
                }
            }, 100);
        });
    }

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