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

#define PORT 8081
#define SERVER_IP "100.115.45.1" // Default IP, change if needed
#define BUFFER_SIZE 4096
#define TOTAL_MB 100
#define NUM_CONNS 5
#define MB_PER_CONN (TOTAL_MB / NUM_CONNS)

void *send_data(void *arg) {
    int sock = 0;
    struct sockaddr_in serv_addr;
    char buffer[BUFFER_SIZE];
    memset(buffer, 'B', BUFFER_SIZE);

    if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
        printf("\n Socket creation error \n");
        return NULL;
    }

    serv_addr.sin_family = AF_INET;
    serv_addr.sin_port = htons(PORT);

    if (inet_pton(AF_INET, SERVER_IP, &serv_addr.sin_addr) <= 0) {
        printf("\nInvalid address/ Address not supported \n");
        return NULL;
    }

    if (connect(sock, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) < 0) {
        printf("\nConnection Failed \n");
        return NULL;
    }

    long long bytes_to_send = (long long)MB_PER_CONN * 1024 * 1024;
    long long bytes_sent = 0;

    while (bytes_sent < bytes_to_send) {
        int to_send = (bytes_to_send - bytes_sent > BUFFER_SIZE) ? BUFFER_SIZE : (bytes_to_send - bytes_sent);
        send(sock, buffer, to_send, 0);
        bytes_sent += to_send;
    }

    close(sock);
    return NULL;
}

int main(int argc, char const *argv[]) {
    pthread_t threads[NUM_CONNS];
    printf("Starting %d TCP connections, sending %d MB each (Total %d MB).\n", NUM_CONNS, MB_PER_CONN, TOTAL_MB);

    for (int i = 0; i < NUM_CONNS; i++) {
        if (pthread_create(&threads[i], NULL, send_data, NULL) != 0) {
            perror("Thread create failed");
            return 1;
        }
    }

    for (int i = 0; i < NUM_CONNS; i++) {
        pthread_join(threads[i], NULL);
    }

    printf("All connections finished sending.\n");
    return 0;
}