// Main pipex function handling pipe communication
int main(int argc, char **argv, char **envp)
{
    int     pipe_fd[2];
    pid_t   pid1, pid2;
    
    if (argc != 5)
    {
        ft_putstr_fd("Usage: ./pipex file1 cmd1 cmd2 file2\n", 2);
        return (1);
    }
    
    if (pipe(pipe_fd) == -1)
        error_exit("Pipe creation failed");
    
    pid1 = fork();
    if (pid1 == 0)
        first_child(argv, envp, pipe_fd);
    
    pid2 = fork();
    if (pid2 == 0)
        second_child(argv, envp, pipe_fd);
    
    close(pipe_fd[0]);
    close(pipe_fd[1]);
    
    waitpid(pid1, NULL, 0);
    waitpid(pid2, NULL, 0);
    
    return (0);
}

// First child process handling
void first_child(char **argv, char **envp, int *pipe_fd)
{
    int infile;
    
    infile = open(argv[1], O_RDONLY);
    if (infile == -1)
        error_exit("Input file error");
    
    dup2(infile, STDIN_FILENO);
    dup2(pipe_fd[1], STDOUT_FILENO);
    
    close(pipe_fd[0]);
    close(pipe_fd[1]);
    close(infile);
    
    execute_command(argv[2], envp);
}

// Second child process handling
void second_child(char **argv, char **envp, int *pipe_fd)
{
    int outfile;
    
    outfile = open(argv[4], O_WRONLY | O_CREAT | O_TRUNC, 0644);
    if (outfile == -1)
        error_exit("Output file error");
    
    dup2(pipe_fd[0], STDIN_FILENO);
    dup2(outfile, STDOUT_FILENO);
    
    close(pipe_fd[0]);
    close(pipe_fd[1]);
    close(outfile);
    
    execute_command(argv[3], envp);
}