/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   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>
#include <stdint.h>
#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"

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

static int32_t	e_unroll_pipes(int32_t fd[256][2],
							char *fullpath[],
							size_t pipes,
							t_msh *msh)
{
	struct s_lpipes	*head;
	int32_t			pid;
	uint16_t		i;

	head = msh->pipes;
	i = 0;
	while (i <= pipes && i < 255)
	{
		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, i, head->com, msh);
		}
		head = head->next;
		i++;
	}
	return (pid);
}

/*
** TODO: error mgmnt
*/

static void		e_pipe_exec_path(char *fullpath[],
								size_t pipes,
								t_msh *msh)
{
	int32_t		fd[256][2];
	int32_t		pid;
	int32_t		status;
	uint16_t	i;

	i = 0;
	while (i < pipes && i < 255)
	{
		pipe(fd[i]);
		i++;
	}
	pid = e_unroll_pipes(fd, fullpath, 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);
}

static char		*e_get_current_path(struct s_lpipes *rptr, t_msh *msh)
{
	char	tmp[PATH_MAX];
	char	*path;

	path = NULL;
	if (rptr->com->bin != NULL && ft_ischarset("/.", rptr->com->bin[0]) == TRUE)
	{
		if ((path = ft_strdup(rptr->com->bin)) == NULL)
			f_alloc_and_destroy_msh(msh);
	}
	else
	{
		if (u_get_builtin_id(rptr->com->bin) < B_BUILTINS_COUNT)
		{
			if ((path = ft_strdup("builtin")) == NULL)
				f_alloc_and_destroy_msh(msh);
		}
		else
		{
			u_search_in_path(tmp, rptr->com->bin, PATH_MAX, msh);
			if ((path = ft_strdup(tmp)) == NULL)
				f_alloc_and_destroy_msh(msh);
		}
	}
	return (path);
}

static char		**e_get_fullpath(size_t pipes, t_msh *msh)
{
	struct s_lpipes	*rptr;
	char			**fullpath;
	size_t			i;

	rptr = msh->pipes;
	if ((fullpath = (char **)malloc((pipes + 2) * sizeof(char *))) == NULL)
		f_alloc_and_destroy_msh(msh);
	fullpath[pipes + 1] = NULL;
	i = 0;
	while (rptr != NULL)
	{
		fullpath[i] = e_get_current_path(rptr, msh);
		i++;
		rptr = rptr->next;
	}
	return (fullpath);
}

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

	fullpath = e_get_fullpath(pipes, msh);
	e_pipe_exec_path(fullpath, pipes, msh);
	ft_delwords(fullpath);
	s_lpipes_clear(&msh->pipes);
}