client.cpp

#include <iostream>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <cstring>
#include <thread>
#include <ctime>
#include <atomic>
#include <fstream>
#include <sstream>
#include <sys/stat.h>

using namespace std;

atomic<bool> running(true);
string username;
int globalSocket;  // For file receiving

// Print message with timestamp
void printMessage(const char* sender, const char* msg) {
    time_t now = time(0);
    char timestamp[9];
    strftime(timestamp, sizeof(timestamp), "%H:%M:%S", localtime(&now));
    cout << "\033[90m[" << timestamp << "]\033[0m ";
    cout << "\033[36m" << sender << ":\033[0m ";
    cout << msg << endl;
}

void printSystem(const char* msg) {
    cout << "\033[33m[System] " << msg << "\033[0m" << endl;
}

// Save received file
void saveFile(const string& sender, const string& filename, const string& data) {
    // Create downloads folder if it doesn't exist
    mkdir("downloads", 0777);

    string savePath = "downloads/" + filename;

    // If file exists, add number
    struct stat buffer;
    int count = 1;
    string finalPath = savePath;
    while (stat(finalPath.c_str(), &buffer) == 0) {
        size_t dotPos = savePath.find_last_of('.');
        if (dotPos != string::npos) {
            finalPath = savePath.substr(0, dotPos) + "_" + to_string(count) + savePath.substr(dotPos);
        } else {
            finalPath = savePath + "_" + to_string(count);
        }
        count++;
    }

    ofstream file(finalPath, ios::binary);
    if (file.is_open()) {
        file.write(data.c_str(), data.length());
        file.close();
        cout << "\033[32m[File] Received '" << filename << "' from " << sender
             << " → saved to " << finalPath << "\033[0m" << endl;
    } else {
        cout << "\033[31m[Error] Could not save file: " << filename << "\033[0m" << endl;
    }
}

// Receive messages from server
void receiveMessages(int socket) {
    char buf[65536];  // Larger buffer for files
    while (running) {
        memset(buf, 0, sizeof(buf));
        int bytesReceived = recv(socket, buf, sizeof(buf), 0);

        if (bytesReceived == -1) {
            if (running) printSystem("Connection error.");
            break;
        }
        if (bytesReceived == 0) {
            printSystem("Server disconnected.");
            break;
        }

        string message(buf, bytesReceived);

        // Check if it's a file transfer
        if (message.rfind("FILE:", 0) == 0) {
            // Parse: FILE:sender:filename:filesize:data
            size_t pos1 = message.find(':', 5);
            size_t pos2 = message.find(':', pos1 + 1);
            size_t pos3 = message.find(':', pos2 + 1);

            if (pos1 != string::npos && pos2 != string::npos && pos3 != string::npos) {
                string sender = message.substr(5, pos1 - 5);
                string filename = message.substr(pos1 + 1, pos2 - pos1 - 1);
                string fileData = message.substr(pos3 + 1);

                saveFile(sender, filename, fileData);
            }
        } else {
            // Regular message
            time_t now = time(0);
            char ts[9];
            strftime(ts, sizeof(ts), "%H:%M:%S", localtime(&now));
            cout << "\033[90m[" << ts << "]\033[0m " << message << endl;
        }
    }
    running = false;
}

// Read file into string
bool readFile(const string& filepath, string& content) {
    ifstream file(filepath, ios::binary);
    if (!file.is_open()) {
        return false;
    }

    stringstream buffer;
    buffer << file.rdbuf();
    content = buffer.str();
    file.close();
    return true;
}

// Get just the filename from path
string getFilename(const string& path) {
    size_t pos = path.find_last_of("/\\");
    if (pos != string::npos) {
        return path.substr(pos + 1);
    }
    return path;
}

// Send messages to server
void sendMessages(int socket) {
    char buf[4096];

    while (running) {
        cin.getline(buf, sizeof(buf));

        if (!running) break;
        if (strlen(buf) == 0) continue;

        string input = buf;

        // Commands
        if (input[0] == '/') {
            if (input == "/quit" || input == "/q") {
                printSystem("Goodbye!");
                running = false;
                close(socket);
                break;
            }
            else if (input == "/help" || input == "/h") {
                cout << "\n\033[33m============== COMMANDS ==============\033[0m\n";
                cout << "  /help, /h              Show this help\n";
                cout << "  /quit, /q              Disconnect and exit\n";
                cout << "  /clear, /c             Clear the screen\n";
                cout << "  /users                 List online users\n";
                cout << "  /msg <user> <message>  Private message\n";
                cout << "  /sendfile <user> <file>  Send file to user\n";
                cout << "  /sendfile all <file>   Send file to everyone\n";
                cout << "  /me <action>           Action message\n";
                cout << "\033[33m======================================\033[0m\n\n";
            }
            else if (input == "/clear" || input == "/c") {
                cout << "\033[2J\033[H";
                printSystem("Screen cleared.");
            }
            else if (input == "/users") {
                send(socket, "USERS", 5, 0);
            }
            else if (input.rfind("/msg ", 0) == 0) {
                //Private message: /msg darren hello there
                size_t space1 = input.find(' ', 5);
                if (space1 != string::npos) {
                    string recipient = input.substr(5, space1 - 5);
                    string message = input.substr(space1 + 1);
                    string formatted = "MSG:" + recipient + ":" + message;
                    send(socket, formatted.c_str(), formatted.length(), 0);
                    cout << "\033[90m[PM to " << recipient << "]\033[0m " << message << endl;
                } else {
                    printSystem("Usage: /msg <username> <message>");
                }
            }
            else if (input.rfind("/sendfile ", 0) == 0) {
                // File transfer
                size_t space1 = input.find(' ', 10);
                if (space1 != string::npos) {
                    string recipient = input.substr(10, space1 - 10);
                    string filepath = input.substr(space1 + 1);

                    string fileContent;
                    if (readFile(filepath, fileContent)) {
                        string filename = getFilename(filepath);

                        //Build message: FILE:recipient:filename:size:data
                        string header = "FILE:" + recipient + ":" + filename + ":" +
                                       to_string(fileContent.length()) + ":";
                        string fullMessage = header + fileContent;

                        send(socket, fullMessage.c_str(), fullMessage.length(), 0);

                        cout << "\033[32m[File] Sending '" << filename << "' ("
                             << fileContent.length() << " bytes) to " << recipient << "\033[0m" << endl;
                    } else {
                        cout << "\033[31m[Error] Could not read file: " << filepath << "\033[0m" << endl;
                    }
                } else {
                    printSystem("Usage: /sendfile <username|all> <filepath>");
                }
            }
            else if (input.rfind("/me ", 0) == 0) {
                string action = "* " + username + " " + input.substr(4);
                send(socket, action.c_str(), action.length(), 0);
                printMessage("You", action.c_str());
            }
            else {
                printSystem("Unknown command. Type /help for commands.");
            }
        }
        else {
            send(socket, buf, strlen(buf), 0);
            printMessage("You", buf);
        }
    }
}

int main() {
    cout << "\033[2J\033[H";
    cout << "\033[36m";
    cout << "================================\n";
    cout << "      CHAT CLIENT v4.0         \n";
    cout << "     (with file transfer)      \n";
    cout << "================================\n";
    cout << "\033[0m\n";

    cout << "Enter your username: ";
    getline(cin, username);
    if (username.empty()) username = "Anonymous";

    int sock = socket(AF_INET, SOCK_STREAM, 0);
    if (sock == -1) {
        cerr << "Can't create a socket! Quitting" << endl;
        return 1;
    }

    sockaddr_in hint;
    hint.sin_family = AF_INET;
    hint.sin_port = htons(54000);
    inet_pton(AF_INET, "127.0.0.1", &hint.sin_addr);

    printSystem("Connecting to server...");

    int connectRes = connect(sock, (struct sockaddr*)&hint, sizeof(hint));
    if (connectRes == -1) {
        cerr << "Could not connect to server! Is it running?" << endl;
        return 1;
    }

    globalSocket = sock;

    send(sock, username.c_str(), username.length(), 0);

    printSystem("Connected! Type /help for commands.\n");

    thread recvThread(receiveMessages, sock);

    sendMessages(sock);

    running = false;
    if (recvThread.joinable()) {
        recvThread.join();
    }
    close(sock);

    return 0;
}