/* Copyright (c) 2013, Philipp Tölke
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the <organization> nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "vfs.h"
#include <source/ff.h>
#include <string.h>
#include <stdlib.h>
#include <time.h>

/* dirent that will be given to callers;
 * note: both APIs assume that only one dirent ever exists
 */
vfs_dirent_t dir_ent;

FIL guard_for_the_whole_fs;

int vfs_read (void* buffer, int dummy, int len, vfs_file_t* file) {
	unsigned int bytesread;
	FRESULT r = f_read(file, buffer, len, &bytesread);
	if (r != FR_OK) return 0;
	return bytesread;
}

vfs_dirent_t* vfs_readdir(vfs_dir_t* dir) {
	FILINFO fi;
#if _USE_LFN
	fi.lfname = NULL;
#endif
	FRESULT r = f_readdir(dir, &fi);
	if (r != FR_OK) return NULL;
	if (fi.fname[0] == 0) return NULL;
	memcpy(dir_ent.name, fi.fname, sizeof(fi.fname));
	return &dir_ent;
}

int vfs_stat(vfs_t* vfs, const char* filename, vfs_stat_t* st) {
	FILINFO f;
#if _USE_LFN
	f.lfname = NULL;
#endif
	if (FR_OK != f_stat(filename, &f)) {
		return 1;
	}
	st->st_size = f.fsize;
	st->st_mode = f.fattrib;
	struct tm tm = {
		.tm_sec = 2*(f.ftime & 0x1f),
		.tm_min = (f.ftime >> 5) & 0x3f,
		.tm_hour = (f.ftime >> 11) & 0x1f,
		.tm_mday = f.fdate & 0x1f,
		.tm_mon = (f.fdate >> 5) & 0xf,
		.tm_year = 80 + (f.fdate >> 9) & 0x7f,
	};
	st->st_mtime = mktime(&tm);
	return 0;
}

void vfs_close(vfs_t* vfs) {
	if (vfs != &guard_for_the_whole_fs) {
		/* Close a file */
		f_close(vfs);
		free(vfs);
	}
}

int vfs_write (void* buffer, int dummy, int len, vfs_file_t* file) {
	unsigned int byteswritten;
	FRESULT r = f_write(file, buffer, len, &byteswritten);
	if (r != FR_OK) return 0;
	return byteswritten;
}

vfs_t* vfs_openfs() {
	return &guard_for_the_whole_fs;
}

vfs_file_t* vfs_open(vfs_t* vfs, const char* filename, const char* mode) {
	vfs_file_t *f = malloc(sizeof(vfs_file_t));
	BYTE flags = 0;
	while (*mode != '\0') {
		if (*mode == 'r') flags |= FA_READ;
		if (*mode == 'w') flags |= FA_WRITE | FA_CREATE_ALWAYS;
		mode++;
	}
	FRESULT r = f_open(f, filename, flags);
	if (FR_OK != r) {
		free(f);
		return NULL;
	}
	return f;
}

char* vfs_getcwd(vfs_t* vfs, void* dummy1, int dummy2) {
	char* cwd = malloc(255);
	FRESULT r = f_getcwd(cwd, 255);
	if (r != FR_OK) {
		free(cwd);
		return NULL;
	}
	return cwd;
}

vfs_dir_t* vfs_opendir(vfs_t* vfs, const char* path) {
	vfs_dir_t* dir = malloc(sizeof *dir);
	FRESULT r = f_opendir(dir, path);
	if (FR_OK != r) {
		free(dir);
		return NULL;
	}
	return dir;
}

void vfs_closedir(vfs_dir_t* dir) {
	if (dir) {
		f_closedir(dir);
		free(dir);
	}
}

struct tm dummy = {
	.tm_year = 70,
	.tm_mon  = 0,
	.tm_mday = 1,
	.tm_hour = 0,
	.tm_min  = 0
};
struct tm* gmtime(const time_t* c_t) {
	return &dummy;
}