//
//	Made by lejulien
//

#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>

int
	ft_strlen(char *str)
{
	int i = 0;
	while (str[i])
		i++;
	return (i);
}

int
	ft_put_error(char *str)
{
	write(2, str, ft_strlen(str));
	return (1);
}

char
	*get_next_sep(char **av)
{
	int i = 0;
	while (av[i] && strcmp(av[i], "|") != 0 && strcmp(av[i], ";") != 0)
		i++;
	return (av[i]);
}

int
	get_next_sep_pos(char **av)
{
	int i = 0;
	while (av[i] && strcmp(av[i], "|") != 0 && strcmp(av[i], ";") != 0)
		i++;
	return (i);
}

int
	get_next_cmd(char **av)
{
	int i = 0;
	while (av[i] && strcmp(av[i], "|") != 0 && strcmp(av[i], ";") != 0)
		i++;
	while (av[i] && (strcmp(av[i], "|") == 0 || strcmp(av[i], ";") == 0))
		i++;
	return (i);
}

void
	do_cd(char **av)
{
	if (av[1] && strcmp(av[1], "|") != 0 && strcmp(av[1], ";") != 0)
	{
		if (av[2] == NULL || (av[2] && strcmp(av[2], ";") == 0))
		{
			if (chdir(av[1]) < 0)
			{
				ft_put_error("error: cd: canot chang directory to ");
				ft_put_error(av[1]);
				ft_put_error("\n");
			}
		}
		else
			ft_put_error("error: cd: bad arguments");
	}
	else
		ft_put_error("error: cd: bad arguments");
}

int		pip[2];
int		prev_pip[2];
void
	exec(char **av, char **envp)
{
	pid_t	pid;
	int		status;
	int		is_pipe = 0;
	int		ret;
	char	*tmp;

	if (get_next_sep(av) != NULL &&  strcmp(get_next_sep(av), "|") == 0)
	{
		if (pipe(pip))
			exit(ft_put_error("error: fatal\n"));
		is_pipe = 1;
	}
	if ((pid = fork()) < 0)
		exit(ft_put_error("error: fatal\n"));
	if (pid == 0)
	{
		if (is_pipe)
		{
			if (dup2(pip[1], 1) < 0)
				exit(ft_put_error("error: fatali\n"));
		}
		if (strcmp(av[-1], "|") == 0)
		{
			if (dup2(prev_pip[0], 0) < 0)
				exit(ft_put_error("error: fatal\n"));
		}
		tmp = get_next_sep(av);
		av[get_next_sep_pos(av)] = NULL;
		if ((ret = execve(*av, av, envp)) == -1)
		{
			ft_put_error("error: cannot execute ");
			ft_put_error(*av);
			exit(ft_put_error("\n"));
		}
		av[get_next_sep_pos(av)] = tmp;
	}
	else
	{
		if (is_pipe)
			close(pip[1]);
		if (strcmp(av[-1], "|") == 0)
			close(prev_pip[0]);
		waitpid(pid, &status, 0);
	}
	prev_pip[0] = pip[0];
	prev_pip[1] = pip[1];
	is_pipe = 0;
}

int
	main(int ac, char **av, char **envp)
{
	av = &av[1];

	while (*av)
	{
		if (strcmp(*av, "cd") == 0)
			do_cd(av);
		else
			exec(av, envp);
		av = &av[get_next_cmd(av)];
	}
	return (0);
}

//	Made by lejulien@42