#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <pthread.h>
#include <arpa/inet.h>

#define PORT 8081
#define BUFFER_SIZE 1024

// structure to store client data
typedef struct {
    int client_socket;
    struct sockaddr_in client_addr;
} client_data_t;
//function to handle thread
void *handle_client(void *arg)
{
    client_data_t *data = (client_data_t *)arg;
    int client_socket = data->client_socket;
    struct sockaddr_in client_addr = data->client_addr;
    char buffer[BUFFER_SIZE]={0};
    int n;
    printf("client connected\n");
    while(1)
    {
        n = recv(client_socket, buffer, sizeof(buffer), 0);
        if (n <= 0)
        {
            printf("Client disconnected\n");
            break;
        }
         printf("Received from client: %s\n", buffer);
         send(client_socket, buffer, strlen(buffer), 0);
    }
    close(client_socket);
    free(data); // Free the memory allocated for client data
    pthread_exit(NULL);

}
void main()
{
    int server_socket, client_socket;
    struct sockaddr_in server_addr={0}, client_addr;
    socklen_t client_len = sizeof(client_addr);
    pthread_t thread_id;
    // create server socket
    if ((server_socket = socket(AF_INET, SOCK_STREAM, 0)) < 0)
    {
        perror("Socket creation failed");
        exit(EXIT_FAILURE);
    }
    // server address setup
    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = INADDR_ANY;  // Listen on all interfaces
    server_addr.sin_port = htons(PORT);
    //bind the server socket to port_no and ip
    if (bind(server_socket, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0)
    {
        perror("Bind failed");
        close(server_socket);
        exit(EXIT_FAILURE);
    }
    //listen for connection
    if (listen(server_socket, 5) < 0)
    {
        perror("Listen failed");
        close(server_socket);
        exit(EXIT_FAILURE);
    }
    printf("server listening\n");

    while(1)
    {
        // accept incomming client
        client_socket = accept(server_socket, (struct sockaddr *)&client_addr, &client_len);
        if (client_socket < 0)
        {
            perror("Client accept failed");
            continue;  // Continue to accept new clients
        }
        //allocate memory for client structure 
        client_data_t *data = malloc(sizeof(client_data_t));
        data->client_socket = client_socket;
        data->client_addr = client_addr;
        //create new thread to handle every new client 
        if (pthread_create(&thread_id, NULL, handle_client, data) != 0)
        {
            perror("Thread creation failed");
            close(client_socket);
            free(data);
        } else
        {
            //Detach the thread to allow it to clean up automatically after finishing
            pthread_detach(thread_id);
        }
    }
     close(server_socket);
}