#include "../../libs/communication/communication.h"
#include "../../libs/protocol/protocol.h"
#include <errno.h>
#include <sys/wait.h>
#include <fcntl.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <unistd.h>

int main() {

	// Open the FIFO for writing
    chroot("/opt/djumbai/");
	const char *send_fifo_path = "fifos/send_fifo";
	if (access(send_fifo_path, F_OK) != -1) {
		// FIFO exists, delete it
		if (unlink(send_fifo_path) == -1) {
			perror("unlink");
			exit(EXIT_FAILURE);
		}
		printf("Existing FIFO deleted.\n");
	}

	// Open the FIFO for reading
	if (mkfifo(send_fifo_path, 0420) == -1) {
		perror("mkfifo");
		exit(EXIT_FAILURE);
	}

	int send_fifo_fd;
	send_fifo_fd = open(send_fifo_path, O_RDONLY);
	if (send_fifo_fd == -1) {
		if (errno == ENOENT) {
			// FIFO does not exist
			printf("FIFO '%s' does not exist. Exiting...\n", send_fifo_path);
			return 1;
		} else {
			perror("open");
			return 1;
		}
	}

	while (1) {
		// Read message from the send_fifo
		unsigned char buffer[MESSAGE_SIZE];
		read(send_fifo_fd, buffer, MESSAGE_SIZE);
		// Deserialize the message
		message msg;
		deserialize_message(buffer, MESSAGE_SIZE, &msg);

		int pipe_to_child[2];

		if (pipe(pipe_to_child) == -1) {
			perror("pipe");
			exit(EXIT_FAILURE);
		}

		pid_t pid = fork();
		if (pid == -1) {
			perror("fork");
			exit(EXIT_FAILURE);
		}

		if (pid == 0) {				 // Child process
			close(pipe_to_child[1]); // Close write end of pipe

			if (msg.header.isgroup) {
				// Message receiver is a group
				// Get the UID of the nobody user.
				const char *nobody_username = "nobody";

				struct passwd *pw = getpwnam(nobody_username);
				if (pw == NULL) {
					fprintf(stderr, "User %s not found\n", nobody_username);
					exit(EXIT_FAILURE);
				}
				// Set UID to nobody
				if (setuid(pw->pw_uid) == -1) {
					perror("setuid");
					exit(EXIT_FAILURE);
				}

				// Set gid to receiver
				if (setgid(msg.header.receiver) == -1) {
					perror("setgid");
					exit(EXIT_FAILURE);
				}
			} else {
				// Message receiver is a user
				// Change UID receiver
				if (setuid(msg.header.receiver) == -1) {
					perror("setuid");
					exit(EXIT_FAILURE);
				}

				struct passwd *pw = getpwuid(msg.header.receiver);
				if (pw == NULL) {
					fprintf(stderr, "User with uid %d not found\n", msg.header.receiver);
					exit(EXIT_FAILURE);
				}

				if (setgid(pw->pw_gid) == -1) {
					perror("setgid");
					exit(EXIT_FAILURE);
				}
			}

			// Redirect stdin to read from pipe_to_child
			dup2(pipe_to_child[0], STDIN_FILENO);

			execlp("./bin/djumbai_client_receive", "djumbai_client_receive", NULL);

			// If execlp fails
			perror("execlp");
			close(pipe_to_child[0]);
			exit(EXIT_FAILURE);
		} else {					 // Parent process
			close(pipe_to_child[0]); // Close read end of pipe

			write(pipe_to_child[1], buffer, sizeof(buffer));

			// Close the write end of the pipe
			close(pipe_to_child[1]);
			// Wait for the child process to finish
			wait(NULL);
		}
	}
	close(send_fifo_fd);
	unlink(send_fifo_path);
}