/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   exec_command.c                                     :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: jschaft <cecile.schaft@orange.fr>          +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2024/04/24 13:48:00 by jschaft           #+#    #+#             */
/*   Updated: 2024/05/13 10:17:48 by jschaft          ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "include.h"

// Free every element of tab, then tab itself.
static void	free_tab(char **tab)
{
	int	i;

	i = 0;
	while (tab[i] != NULL)
	{
		free(tab[i]);
		i++;
	}
	free(tab);
}

// TODO is t_call.argv ended by NULL?
static void	fork_exec(const char *path, t_call call, t_pipes in, t_pipes out,
				 char *const envp[])
{
	if (in.i != 0)
		dup2(in.pipe[1], 0);
	else
		dup2(in.inout, 0);
	if (out.inout == 0)
		dup2(out.pipe[0], 1);
	else
		dup2(out.inout, 1);
	execve(path, call.argv, envp);
}

static int	execute_call(t_memclass mc, t_command cmd, t_pipes in, t_pipes out,
					char *const envp[])
{
	char **const	path = get_path(envp);
	pid_t			pid;
	const char		*program_path;
	int				status;
	int				i;

	i = in.i;
	program_path = search_path(mc, (const char **)path, cmd.calls[i].program);
	if (i == 0)
		in.inout = cmd.input_fd;
	if (out.inout == -1)
		out.inout = cmd.output_fd;
	if (!program_path)
		return (127);
	pid = fork();
	if (pid < 0)
		return (1);
	if (pid == 0)
		fork_exec(program_path, cmd.calls[i], in, out, envp);
	waitpid(pid, &status, 0);
	free_tab(path);
	return (0);
}

// TODO works with only one call (no pipe).
int	execute_command(t_memclass mc, t_command command, char *const envp[])
{
	t_pipes		*pipes;
	int			i;

	i = 0;
	while (command.calls[i].program != NULL)
		i++;
	pipes = malloc(sizeof(t_pipes) * i + 1);
	i = 0;
	while (command.calls[i].program != NULL)
	{
		if (pipe(pipes[i].pipe) < 0)
			return (exec_error());
		pipes[i].inout = 0;
		i++;
	}
	pipes[i].inout = -1;
	i = 0;
	while (command.calls[i].program != NULL)
	{
		pipes[i].i = i;
		pipes[i + 1].i = i + 1;
		execute_call(mc, command, pipes[i], pipes[i + 1], envp);
		i++;
	}
	free(pipes);
	return (0);
}