/*
 * File      : rtthread.h
 * This file is part of RT-Thread RTOS
 * COPYRIGHT (C) 2006-2012, RT-Thread Development Team
 *
 * The license and distribution terms for this file may be
 * found in the file LICENSE in this distribution or at
 * http://www.rt-thread.org/license/LICENSE.
 *
 * Change Logs:
 * Date           Author       Notes
 * 2011-10-22     prife        the first version
 * 2012-03-28     prife        use mtd device interface
 * 2012-04-05     prife        update uffs with official repo and use uffs_UnMount/Mount
*/
#include <rtthread.h>

#include <dfs_fs.h>
#include <dfs_def.h>
#include <rtdevice.h>
#include "dfs_uffs.h"

#include "uffs/uffs_fd.h" /* posix file api is here */
#include "uffs/uffs_mtb.h"
#include "uffs/uffs_mem.h"
#include "uffs/uffs_utils.h"

/*
 * RT-Thread DFS Interface for uffs
 */
#define UFFS_DEVICE_MAX	        2	 /* the max partions on a nand deivce*/
#define UFFS_MOUNT_PATH_MAX     128	 /* the mount point max length */
#define FILE_PATH_MAX	        256	 /* the longest file path */

struct _nand_dev
{
	struct rt_mtd_nand_device * dev;
	struct uffs_StorageAttrSt storage;
	uffs_Device uffs_dev;
	uffs_MountTable mount_table;
	char mount_path[UFFS_MOUNT_PATH_MAX];
	void * data;  /* when uffs use static buf, it will save ptr here */	
};
/* make sure the following struct var had been initilased to 0! */
static struct _nand_dev nand_part[UFFS_DEVICE_MAX] = {0};

static int uffs_result_to_dfs(int result)
{
	int status = -1;

	result = result < 0 ? -result : result;
	switch (result)
	{
	case UENOERR:/** no error */
		break;
	case UEACCES:/** Tried to open read-only file for writing, or files sharing mode
				   does not allow specified operations, or given path is directory */
		status = -DFS_STATUS_EINVAL;
		break;/* no suitable */
	case UEEXIST:   /** _O_CREAT and _O_EXCL flags specified, but filename already exists */
		status = -DFS_STATUS_EEXIST;
		break;
	case UEINVAL:  /** Invalid oflag or pmode argument */
		status = -DFS_STATUS_EINVAL;
		break;
	case UEMFILE: /** No more file handles available(too many open files)  */
		status = -1;
		break;
	case UENOENT: /** file or path not found */
		status = -DFS_STATUS_ENOENT;
		break;
	case UETIME: /** can't set file time */
		status = -1;
		break;
	case UEBADF: /** invalid file handle */
		status = -DFS_STATUS_EBADF;
		break;
	case UENOMEM:/** no enough memory */
		status = -DFS_STATUS_ENOSPC;
		break;
	case UEIOERR: /** I/O error from lower level flash operation */
		status = -DFS_STATUS_EIO;
		break;
	case UENOTDIR: /** Not a directory */
		status = -DFS_STATUS_ENOTDIR;
		break;
	case UEISDIR: /** Is a directory */
		status = -DFS_STATUS_EISDIR;
		break;
	case UEUNKNOWN_ERR:
	default:
		status = -1;
		break; /* unknown error! */
	}

	return status;
}

static URET _device_init(uffs_Device *dev)
{
	dev->attr->_private = NULL;	// hook nand_chip data structure to attr->_private
	dev->ops = (struct uffs_FlashOpsSt *)&nand_ops;

	return U_SUCC;
}

static URET _device_release(uffs_Device *dev)
{
	return U_SUCC;
}

static int init_uffs_fs(
	struct _nand_dev * nand_part)
{
    uffs_MountTable * mtb;
    struct rt_mtd_nand_device * nand;
    struct uffs_StorageAttrSt * flash_storage;

    mtb = &nand_part->mount_table;
    nand = nand_part->dev;
    flash_storage = &nand_part->storage;

	/* setup nand storage attributes */
	uffs_setup_storage(flash_storage, nand);

	/* register mount table */
	if(mtb->dev)
	{
		/* set memory allocator for uffs */
#if CONFIG_USE_SYSTEM_MEMORY_ALLOCATOR > 0
		uffs_MemSetupSystemAllocator(&mtb->dev->mem);
#endif
		/* setup device init/release entry */
		mtb->dev->Init = _device_init;
		mtb->dev->Release = _device_release;
		mtb->dev->attr = flash_storage;

		uffs_RegisterMountTable(mtb);
	}
	/* mount uffs partion on nand device */
	return uffs_Mount(nand_part->mount_path) == U_SUCC ? 0 : -1;
}

static int dfs_uffs_mount(
	struct dfs_filesystem* fs,
    unsigned long rwflag,
    const void* data)
{
	rt_base_t index;
	uffs_MountTable * mount_part;
	struct rt_mtd_nand_device * dev;
	
	RT_ASSERT(rt_strlen(fs->path) < (UFFS_MOUNT_PATH_MAX-1));
	dev = RT_MTD_NAND_DEVICE(fs->dev_id);

	/*1. find a empty entry in partition table */
	for (index = 0; index < UFFS_DEVICE_MAX ; index ++)
	{
		if (nand_part[index].dev == RT_NULL)
			break;
	}
	if (index == UFFS_DEVICE_MAX)
		return -DFS_STATUS_ENOENT;

	/*2. fill partition structure */
	nand_part[index].dev = dev;

	/* make a right mount path for uffs, end with '/' */
	rt_snprintf(nand_part[index].mount_path, UFFS_MOUNT_PATH_MAX, "%s/", fs->path);
	if (nand_part[index].mount_path[1] == '/')
		nand_part[index].mount_path[1] = 0;

	mount_part = &(nand_part[index].mount_table);
	mount_part->mount	= nand_part[index].mount_path;
	mount_part->dev = &(nand_part[index].uffs_dev);
	rt_memset(mount_part->dev, 0, sizeof(uffs_Device));//in order to make uffs happy.
	mount_part->dev->_private = dev;   /* save dev_id into uffs */
	mount_part->start_block = dev->block_start;
	mount_part->end_block = dev->block_end;
	/*3. mount uffs */
	if (init_uffs_fs(&nand_part[index]) < 0)
	{
		return uffs_result_to_dfs(uffs_get_error());
	}
	return 0;
}

static int dfs_uffs_unmount(struct dfs_filesystem* fs)
{
	rt_base_t index;
	int result;

	/* find the device index and then unmount it */
	for (index = 0; index < UFFS_DEVICE_MAX; index++)
	{
		if (nand_part[index].dev == RT_MTD_NAND_DEVICE(fs->dev_id))
		{
			nand_part[index].dev = RT_NULL;
			result = uffs_UnMount(nand_part[index].mount_path);
			if (result != U_SUCC)
				break;

			result = uffs_UnRegisterMountTable(& nand_part[index].mount_table);
			return (result == U_SUCC) ? DFS_STATUS_OK : -1;
		}
	}
	return -DFS_STATUS_ENOENT;
}

static int dfs_uffs_mkfs(const char* device_name)
{
	rt_base_t index;
	rt_uint32_t block;
	struct rt_mtd_nand_device * mtd;

	/*1. find the device index */
	for (index = 0; index < UFFS_DEVICE_MAX; index++)
	{
		if (rt_strncmp(nand_part[index].dev->parent.parent.name,
				       device_name, RT_NAME_MAX) == 0)
			break;
	}

	if (index == UFFS_DEVICE_MAX)
	{
		/* can't find device driver */
		rt_kprintf("can not find device driver: %s\n", device_name);
		return -DFS_STATUS_ENOENT;
	}

	/*2. then unmount the partition */
	uffs_Mount(nand_part[index].mount_path);
	mtd = nand_part[index].dev;

	/*3. erase all blocks on the partition */
	block = mtd->block_start;
	for (; block <= mtd->block_end; block++)
	{
		rt_mtd_nand_erase_block(mtd, block);
		if (rt_mtd_nand_check_block(mtd, block) != RT_EOK)
		{
			rt_kprintf("found bad block %d\n", block);
			rt_mtd_nand_mark_badblock(mtd, block);
		}
	}

	/*4. remount it */
	if (init_uffs_fs(&nand_part[index]) < 0)
	{
		return uffs_result_to_dfs(uffs_get_error());
	}
	return DFS_STATUS_OK;
}

static int dfs_uffs_statfs(struct dfs_filesystem* fs,
                    struct statfs *buf)
{
	rt_base_t index;
	struct rt_mtd_nand_device * mtd = RT_MTD_NAND_DEVICE(fs->dev_id);

	RT_ASSERT(mtd != RT_NULL);

	/* find the device index */
	for (index = 0; index < UFFS_DEVICE_MAX; index++)
	{
		if (nand_part[index].dev == (void *)mtd)
			break;
	}
	if (index == UFFS_DEVICE_MAX)
		return -DFS_STATUS_ENOENT;
	
	buf->f_bsize = mtd->page_size;
	buf->f_blocks = (mtd->block_size)/(mtd->page_size)*
	                (mtd->block_end - mtd->block_start + 1);
	buf->f_bfree = uffs_GetDeviceFree(&nand_part[index].uffs_dev) / mtd->page_size;
	
	return 0;
}

static int dfs_uffs_open(struct dfs_fd* file)
{
	int fd;
	int oflag, mode;
	char * file_path;

	oflag = file->flags;
	if (oflag & DFS_O_DIRECTORY)   /* operations about dir */
	{
		uffs_DIR * dir;

		if (oflag & DFS_O_CREAT)   /* create a dir*/
		{
			if (uffs_mkdir(file->path) < 0)
				return uffs_result_to_dfs(uffs_get_error());
		}
		/* open dir */
		file_path = rt_malloc(FILE_PATH_MAX);
		if(file_path == RT_NULL)
			return -DFS_STATUS_ENOMEM;			

		if (file->path[0] == '/' && !(file->path[1] == 0))
			rt_snprintf(file_path, FILE_PATH_MAX, "%s/", file->path);
		else
		{
			file_path[0] = '/';
			file_path[1] = 0;
		}

		dir = uffs_opendir(file_path);

		if (dir == RT_NULL)
		{
			rt_free(file_path);			
			return uffs_result_to_dfs(uffs_get_error());
		}
		/* save this pointer,will used by  dfs_uffs_getdents*/
		file->data = dir;
		rt_free(file_path);
		return DFS_STATUS_OK;
	}
	/* regular file operations */
	/* int uffs_open(const char *name, int oflag, ...); what is this?
	 * uffs_open can open dir!!  **/
	mode = 0;
	if (oflag & DFS_O_RDONLY) mode |= UO_RDONLY;
	if (oflag & DFS_O_WRONLY) mode |= UO_WRONLY;
	if (oflag & DFS_O_RDWR)   mode |= UO_RDWR;
	/* Opens the file, if it is existing. If not, a new file is created. */
	if (oflag & DFS_O_CREAT) mode |= UO_CREATE;
	/* Creates a new file. If the file is existing, it is truncated and overwritten. */
	if (oflag & DFS_O_TRUNC) mode |= UO_TRUNC;
	/* Creates a new file. The function fails if the file is already existing. */
	if (oflag & DFS_O_EXCL) mode |= UO_EXCL;

	fd = uffs_open(file->path, mode);
	if (fd < 0)
	{
		return uffs_result_to_dfs(uffs_get_error());
	}

	/* save this pointer, it will be used when calling read()£¬write(),
	 * flush(), seek(), and will be free when calling close()*/

	file->data = (void *)fd;
	file->pos  = uffs_seek(fd, 0, USEEK_CUR);
	file->size = uffs_seek(fd, 0, USEEK_END);
	uffs_seek(fd, file->pos, USEEK_SET);

	if (oflag & DFS_O_APPEND)
	{
		file->pos = uffs_seek(fd, 0, USEEK_END);
	}
	return 0;
}

static int dfs_uffs_close(struct dfs_fd* file)
{
	int oflag;
	int fd;

	oflag = file->flags;
	if (oflag & DFS_O_DIRECTORY)
	{
		/* operations about dir */
		if (uffs_closedir((uffs_DIR *)(file->data)) < 0)
			return uffs_result_to_dfs(uffs_get_error());

		return 0;
	}
	/* regular file operations */
	fd = (int)(file->data);

	if (uffs_close(fd) == 0)
		return 0;

	return uffs_result_to_dfs(uffs_get_error());
}

static int dfs_uffs_ioctl(struct dfs_fd * file, int cmd, void* args)
{
	return -DFS_STATUS_ENOSYS;
}

static int dfs_uffs_read(struct dfs_fd * file, void* buf, rt_size_t len)
{
	int fd;
	int char_read;

	fd = (int)(file->data);
	char_read = uffs_read(fd, buf, len);
	if (char_read < 0)
		return uffs_result_to_dfs(uffs_get_error());

	/* update position */
	file->pos = uffs_seek(fd, 0, USEEK_CUR);
	return char_read;
}

static int dfs_uffs_write(struct dfs_fd* file,
                   const void* buf,
                   rt_size_t len)
{
	int fd;
	int char_write;

	fd = (int)(file->data);

	char_write = uffs_write(fd, buf, len);
	if (char_write < 0)
		return uffs_result_to_dfs(uffs_get_error());

	/* update position */
	file->pos = uffs_seek(fd, 0, USEEK_CUR);
	return char_write;
}

static int dfs_uffs_flush(struct dfs_fd* file)
{
	int fd;
	int result;

	fd = (int)(file->data);

	result = uffs_flush(fd);
	if (result < 0 )
		return uffs_result_to_dfs(uffs_get_error());
	return 0;
}

static int dfs_uffs_seek(struct dfs_fd* file,
                  rt_off_t offset)
{
	int fd;
	int result;

	fd = (int)(file->data);

	/* set offset as current offset */
	result = uffs_seek(fd, offset, USEEK_SET);
	if (result < 0)
		return uffs_result_to_dfs(uffs_get_error());
	return result;
}

/* return the size of struct dirent*/
static int dfs_uffs_getdents(
    struct dfs_fd* file,
    struct dirent* dirp,
    rt_uint32_t count)
{
	rt_uint32_t index;
	char * file_path;
	struct dirent* d;
	uffs_DIR* dir;
	struct uffs_dirent * uffs_d;
	
	dir = (uffs_DIR*)(file->data);
	RT_ASSERT(dir != RT_NULL);
	
	/* round count, count is always 1 */
	count = (count / sizeof(struct dirent)) * sizeof(struct dirent);
	if (count == 0) return -DFS_STATUS_EINVAL;

	/* allocate file name */
	file_path = rt_malloc(FILE_PATH_MAX);
	if (file_path == RT_NULL)
		return -DFS_STATUS_ENOMEM;
		
	index = 0;
	/* usually, the while loop should only be looped only once! */
	while (1)
	{
		struct uffs_stat s;
		
		d = dirp + index;

		uffs_d = uffs_readdir(dir);
		if (uffs_d == RT_NULL)
		{
			rt_free(file_path);
			return (uffs_result_to_dfs(uffs_get_error()));
		}

		if (file->path[0] == '/' && !(file->path[1] == 0))
			rt_snprintf(file_path, FILE_PATH_MAX, "%s/%s", file->path, uffs_d->d_name);
		else
			rt_strncpy(file_path, uffs_d->d_name, FILE_PATH_MAX);

		uffs_stat(file_path, &s); 
		switch(s.st_mode & US_IFMT)   /* file type mark */
		{
		case US_IFREG: /* directory */
			d->d_type = DFS_DT_REG;
			break;
		case US_IFDIR: /* regular file */
			d->d_type = DFS_DT_DIR;
			break;
		case US_IFLNK: /* symbolic link */
		case US_IREAD: /* read permission */
		case US_IWRITE:/* write permission */
		default:
			d->d_type = DFS_DT_UNKNOWN;
			break;
		}

		/* write the rest args of struct dirent* dirp  */
		d->d_namlen = rt_strlen(uffs_d->d_name);
		d->d_reclen = (rt_uint16_t)sizeof(struct dirent);
		rt_strncpy(d->d_name, uffs_d->d_name, rt_strlen(uffs_d->d_name) + 1);

		index ++;
		if (index * sizeof(struct dirent) >= count)
			break;
	}
	
	/* free file name buf */
	rt_free(file_path);
	
	if (index == 0)
		return uffs_result_to_dfs(uffs_get_error());

	return index * sizeof(struct dirent);
}

static int dfs_uffs_unlink(struct dfs_filesystem* fs, const char* path)
{
	int result;
	struct uffs_stat s;

	/* judge file type, dir is to be delete by uffs_rmdir, others by uffs_remove */
	if (uffs_lstat(path, &s) < 0)
	{
		return uffs_result_to_dfs(uffs_get_error());
	}

	switch(s.st_mode & US_IFMT)
	{
	case US_IFREG:
		result = uffs_remove(path);
		break;
	case US_IFDIR:
		result = uffs_rmdir(path);
		break;
	default:
		/* unknown file type */
		return -1;
	}
	if (result < 0)
		return uffs_result_to_dfs(uffs_get_error());

	return 0;
}

static int dfs_uffs_rename(
    struct dfs_filesystem* fs,
    const char* oldpath,
    const char* newpath)
{
	int result;
	
	result = uffs_rename(oldpath, newpath);
	if (result < 0)
		return uffs_result_to_dfs(uffs_get_error());

	return 0;
}

static int dfs_uffs_stat(struct dfs_filesystem* fs, const char *path, struct stat *st)
{
	int result;
	struct uffs_stat s;
	struct rt_mtd_nand_device * mtd;

	result = uffs_stat(path, &s);
	if (result < 0)
		return uffs_result_to_dfs(uffs_get_error());

	/* convert uffs stat to dfs stat structure */
	/* FIXME, these field may not be the same */
	st->st_dev  = 0;
	st->st_mode = s.st_mode;
	st->st_size = s.st_size;
	st->st_mtime = s.st_mtime;

	mtd = RT_MTD_NAND_DEVICE(fs->dev_id);
	st->st_blksize = mtd->page_size;

	return 0;
}

static const struct dfs_filesystem_operation dfs_uffs_ops =
{
	"uffs", /* file system type: uffs */
#if RTTHREAD_VERSION >= 10100
	DFS_FS_FLAG_FULLPATH,
#else
#error "uffs can only work with rtthread whose version should >= 1.01\n"
#endif
	dfs_uffs_mount,
	dfs_uffs_unmount,
	dfs_uffs_mkfs,
	dfs_uffs_statfs,

	dfs_uffs_open,
	dfs_uffs_close,
	dfs_uffs_ioctl,
	dfs_uffs_read,
	dfs_uffs_write,
	dfs_uffs_flush,
	dfs_uffs_seek,
	dfs_uffs_getdents,
	dfs_uffs_unlink,
	dfs_uffs_stat,
	dfs_uffs_rename,
};

int dfs_uffs_init(void)
{
	/* register uffs file system */
	dfs_register(&dfs_uffs_ops);

	if (uffs_InitObjectBuf() == U_SUCC)
	{
		if (uffs_DirEntryBufInit() == U_SUCC)
		{
			uffs_InitGlobalFsLock();
			return RT_EOK;
		}
	}
	return -RT_ERROR;
}