/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   get_next_line.c                                    :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: kcolin <marvin@42.fr>                      +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2024/10/23 20:32:46 by kcolin            #+#    #+#             */
/*   Updated: 2024/11/01 12:41:32 by kcolin           ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "get_next_line.h"
#include <stdlib.h>

char	*ft_strchr(const char *s, int c);
size_t	ft_strlen(const char *s);
size_t	ft_strlcpy(char *dst, const char *src, size_t size);
char	*ft_strjoin_free_s1(char const *s1, char const *s2);

/*
static int num_allocs = 0;

static void *xmalloc(size_t size)
{
    if (FAIL_AFTER > 0 && num_allocs++ >= FAIL_AFTER)
    {
        return 0;
    }
    return malloc(size);
}

#define malloc(x) xmalloc(x)
*/

char	*shorten_buffer(char *buffer)
{
	char	*outbuf;
	char	*addr_of_newline;
	size_t	index_after_newline;
	size_t	outlen;

	addr_of_newline = ft_strchr(buffer, '\n');
	if (addr_of_newline == NULL)
	{
		buffer[0] = '\0';
		return (buffer);
	}
	else
	{
		index_after_newline = addr_of_newline + 1 - buffer;
		outlen = ft_strlen(buffer + index_after_newline) + 1;
		outbuf = malloc(outlen * sizeof(char));
		if (outbuf != NULL)
			ft_strlcpy(outbuf, buffer + index_after_newline, outlen);
	}
	free(buffer);
	return (outbuf);
}

/*
** returns 1 on error, 0 on success
*/
int	setup_buffers(char **buffer, char **read_buffer)
{
	if (*buffer == NULL)
	{
		*buffer = malloc(1 * sizeof(char));
		if (*buffer == NULL)
			return (1);
		*buffer[0] = '\0';
	}
	*read_buffer = malloc((BUFFER_SIZE + 1) * sizeof(char));
	if (*read_buffer == NULL)
	{
		free(*buffer);
		return (1);
	}
	return (0);
}

char	*get_next_line(int fd)
{
	static char	*buffer = NULL;
	char		*read_buffer;
	int			num_bytes_read;
	char		*outbuf;

	if (setup_buffers(&buffer, &read_buffer) != 0)
		return (NULL);
	num_bytes_read = 1;
	while (num_bytes_read != 0)
	{
		if (ft_strchr(buffer, '\n'))
		{
			outbuf = malloc((ft_strchr(buffer, '\n') - buffer + 2));
			if (outbuf == NULL)
			{
				free(read_buffer);
				free(buffer);
				buffer = NULL;
				return (NULL);
			}
			ft_strlcpy(outbuf, buffer, ft_strchr(buffer, '\n') - buffer + 2);
			buffer = shorten_buffer(buffer);
			free(read_buffer);
			return (outbuf);
		}
		num_bytes_read = read(fd, read_buffer, BUFFER_SIZE);
		if (num_bytes_read < 0)
		{
			free(read_buffer);
			free(buffer);
			buffer = NULL;
			return (NULL);
		}
		read_buffer[num_bytes_read] = '\0';
		buffer = ft_strjoin_free_s1(buffer, read_buffer);
		if (buffer == NULL)
			return (NULL);
	}
	free(read_buffer);
	outbuf = buffer;
	if (ft_strlen(buffer) == 0)
	{
		free(buffer);
		outbuf = NULL;
	}
	buffer = NULL;
	return (outbuf);
}