/* *****************************************************************************
 * utils/file.c -- FILE-related functions.
 * Copyright (C) 2017 Thomas "Cakeisalie5" Touhey <thomas@touhey.fr>
 *
 * This file is part of libg1m.
 * libg1m is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 3.0 of the License,
 * or (at your option) any later version.
 *
 * libg1m is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with libg1m; if not, see <http://www.gnu.org/licenses/>.
 * ************************************************************************** */
#include <libg1m/internals.h>
#include <libg1m/internals/stdio_ext.h>
#include <stdlib.h>
#ifndef G1M_DISABLED_FILE

/* ************************************************************************** */
/*  Open a FILE                                                               */
/* ************************************************************************** */
/**
 *	g1m_open:
 *	Open a file using its path, and decode it.
 *
 *	@arg	handle		the handle to create.
 *	@arg	path		the path of the file to open.
 *	@arg	expected	the expected types (0 if none).
 *	@return				the error code (0 if ok).
 */

int g1m_open(g1m_handle_t **handle, const char *path,
	g1m_type_t expected)
{
	/* open stream and decode */
	FILE *f = fopen(path, "r");
	int err = g1m_fopen(handle, path, f, expected);

	/* close opened stream and return error code (or 0 if ok) */
	if (f) fclose(f);
	return (err);
}

/**
 *	g1m_fopen:
 *	Decode a file using a FILE structure.
 *
 *	Will not seek, and will not keep the stream.
 *	Make sure to fclose the stream after use.
 *
 *	@arg	handle		the handle to create.
 *	@arg	path		the file path.
 *	@arg	stream		the stream.
 *	@arg	expected	the expected types (0 if none).
 *	@return				the error code (0 if ok)
 */

int g1m_fopen(g1m_handle_t **handle, const char *path, FILE *stream,
	g1m_type_t expected)
{
	/* check stream */
	if (!stream) return (g1m_error_nostream);
	if (!__freadable(stream)) return (g1m_error_noread);

	/* make the buffer */
	g1m_buffer_t buffer = {
		.g1m_buffer_cookie = stream,
		.g1m_buffer_read = g1m_filebuffer_read
	};

	/* decode opened file */
	return (g1m_decode(handle, path, &buffer, expected));
}

/* ************************************************************************** */
/*  Open a FILE and write into it                                             */
/* ************************************************************************** */
/**
 *	g1m_write:
 *	Open a file and encode the file into it.
 *
 *	@arg	handle		the handle to encode.
 *	@arg	path		the file path.
 *	@return				the error code (0 if ok).
 */

int g1m_write(g1m_handle_t *handle, const char *path)
{
	/* open the stream and write */
	FILE *f = fopen(path, "w");
	int err = g1m_fwrite(handle, f);

	/* close opened stream in case of error */
	if (f) fclose(f);
	if (f && err) remove(path);
	return (err);
}

/**
 *	g1m_fwrite:
 *	Write to a FILE pointer.
 *
 *	@arg	handle		the handle to encode.
 *	@arg	stream		the FILE stream.
 *	@return				the error code (0 if ok).
 */

int g1m_fwrite(g1m_handle_t *handle, FILE *stream)
{
	/* check stream */
	if (!stream) return (g1m_error_nostream);
	if (!__fwritable(stream)) return (g1m_error_nowrite);

	/* make the buffer */
	g1m_buffer_t buffer = {
		.g1m_buffer_cookie = stream,
		.g1m_buffer_write = g1m_filebuffer_write
	};

	/* encode to file */
	return (g1m_encode(handle, &buffer));
}

#endif