/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   e_pipes.c                                          :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: rbousset <marvin@42.fr>                    +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2020/02/14 17:19:27 by rbousset          #+#    #+#             */
/*   Updated: 2020/02/14 17:19:29 by rbousset         ###   ########lyon.fr   */
/*                                                                            */
/* ************************************************************************** */

#include <sys/wait.h>
#include <libft.h>
#include <stdlib.h>
#ifdef __linux__
# include <linux/limits.h>
#else
# include <limits.h>
#endif
#include <unistd.h>

#include "e_builtins.h"
#include "e_pipes_next.h"
#include "f_fail.h"
#include "s_lpipes.h"
#include "s_struct.h"
#include "u_utils.h"
#include "u_path.h"

static unsigned char	e_get_current_path(char fullpath[],
									struct s_lpipes *ptr,
									t_msh *msh)
{
	unsigned char	fp_ret;

	fp_ret = 0;
	if (ptr->com->bin != NULL && ft_ischarset("/.", ptr->com->bin[0]) == TRUE)
	{
		ft_strlcpy(fullpath, ptr->com->bin, PATH_MAX);
	}
	else if (ptr->com->bin != NULL)
	{
		if (u_get_builtin_id(ptr->com->bin) < B_BUILTINS_COUNT)
		{
			ft_strlcpy(fullpath, "builtin", 8);
		}
		else
		{
			fp_ret = u_search_in_path(fullpath, ptr->com->bin, PATH_MAX, msh);
		}
	}
	return (fp_ret);
}

/*
** TODO: handle fork() failed, etc
*/

static int	e_unroll_pipes(int fd[256][2],
							size_t pipes,
							t_msh *msh)
{
	struct s_lpipes	*head;
	char			fullpath[PATH_MAX];
	int			pid;
	unsigned short		i;
	unsigned char			fp_ret;

	head = msh->pipes;
	i = 0;
	while (i <= pipes && i < 255)
	{
		fp_ret = e_get_current_path(fullpath, head, msh);
		if ((pid = fork()) == 0)
		{
			if (i != 0)
				dup2(fd[i - 1][E_WRITE_END], STDIN_FILENO);
			if (i != pipes)
				dup2(fd[i][E_READ_END], STDOUT_FILENO);
			e_close_unused_fds(fd, pipes);
			e_pipe_child(fullpath, fp_ret, head->com, msh);
		}
		head = head->next;
		i++;
	}
	return (pid);
}

/*
** TODO: error mgmnt
*/

static void		e_pipe_exec(size_t pipes, t_msh *msh)
{
	int		fd[256][2];
	int		pid;
	int		status;
	unsigned short	i;

	i = 0;
	while (i < pipes && i < 255)
	{
		pipe(fd[i]);
		i++;
	}
	pid = e_unroll_pipes(fd, pipes, msh);
	i = 0;
	while (i < pipes && i < 255)
	{
		close(fd[i][E_WRITE_END]);
		close(fd[i][E_READ_END]);
		i++;
	}
	waitpid(pid, &status, 0);
	msh->ret = WEXITSTATUS(status);
}

void			e_pipes(t_msh *msh)
{
	const size_t	pipes = e_get_pipes_count(msh->pipes);

	e_pipe_exec(pipes, msh);
	s_lpipes_clear(&msh->pipes);
}