/*
 * File      : dfs_fs.c
 * This file is part of Device File System in RT-Thread RTOS
 * COPYRIGHT (C) 2004-2010, 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
 * 2005-02-22     Bernard      The first version.
 * 2010-06-30     Bernard      Optimize for RT-Thread RTOS
 */
#include <dfs_fs.h>
#include <dfs_file.h>

/**
 * this function will register a file system instance to device file system.
 *
 * @param ops the file system instance to be registered.
 *
 * @return 0 on sucessful, -1 on failed.
 */
int dfs_register(const struct dfs_filesystem_operation* ops)
{
    int index, result;

	result = 0;

	/* lock filesystem */
	dfs_lock();

    /* check if this filesystem was already registered */
    for (index = 0; index < DFS_FILESYSTEM_TYPES_MAX; index++)
    {
        if (filesystem_operation_table[index] != RT_NULL &&
                strcmp(filesystem_operation_table[index]->name, ops->name) == 0)
        {
        	result = -1;
            goto err;
        }
    }

    /* find out an empty filesystem type entry */
    for (index = 0; index < DFS_FILESYSTEM_TYPES_MAX && filesystem_operation_table[index] != RT_NULL;
            index++) ;

    /* filesystem type table full */
    if (index == DFS_FILESYSTEM_TYPES_MAX)
	{
		result = -1;
		goto err;
    }

    /* save the filesystem's operations */
    filesystem_operation_table[index] = ops;

err:
	dfs_unlock();
    return result;
}

/**
 * this function will return the file system mounted on specified path.
 *
 * @param path the specified path string.
 *
 * @return the found file system or NULL if no file system mounted on 
 * specified path
 */
struct dfs_filesystem* dfs_filesystem_lookup(const char *path)
{
    struct dfs_filesystem* fs;
    rt_uint32_t index, fspath, prefixlen;

    fs = RT_NULL;
    prefixlen = 0;

    /* lock filesystem */
	dfs_lock();

    /* lookup it in the filesystem table */
    for (index = 0; index < DFS_FILESYSTEMS_MAX + 1; index++)
    {
        fspath = strlen(filesystem_table[index].path);
        if (fspath < prefixlen) continue;

        if ((filesystem_table[index].ops != RT_NULL) &&
                strncmp(filesystem_table[index].path, path, fspath) == 0)
        {
            fs = &filesystem_table[index];
            prefixlen = fspath;
        }
    }

	dfs_unlock();

    return fs;
}

/**
 * this function will fetch the partition table on specified buffer.
 *
 * @param part the returned partition structure.
 * @param buf the buffer contains partition table.
 * @param pindex the index of partition table to fetch.
 *
 * @return RT_EOK on successful or -RT_ERROR on failed.
 */
rt_err_t dfs_filesystem_get_partition(struct dfs_partition* part, rt_uint8_t* buf, rt_uint32_t pindex)
{
#define DPT_ADDRESS		0x1be		/* device partition offset in Boot Sector */
#define DPT_ITEM_SIZE	16			/* partition item size */

    rt_uint8_t* dpt;
    rt_uint8_t type;
    rt_err_t result;

    RT_ASSERT(part != RT_NULL);
    RT_ASSERT(buf != RT_NULL);

    result = RT_EOK;

    dpt = buf + DPT_ADDRESS + pindex * DPT_ITEM_SIZE;

    if ((*dpt != 0x80) && (*dpt != 0x00))
    {
        /* which is not a partition table */
        result = -RT_ERROR;
        return result;
    }

    /* get partition type */
    type = *(dpt+4);

    if (type != 0)
    {
        /* set partition type */
        part->type = type;

        /* get partition offset and size */
        part->offset = *(dpt+ 8) | *(dpt+ 9) << 8 |
                       *(dpt+10) << 16 | *(dpt+11) << 24;
        part->size = *(dpt+12) | *(dpt+13) << 8 |
                     *(dpt+14) << 16 | *(dpt+15) << 24;

        rt_kprintf("found part[%d], begin: %d, size: ",
                   pindex, part->offset * 512);
        if ( (part->size>>11) > 0 ) /* MB */
        {
            unsigned int part_size;
            part_size = part->size>>11;/* MB */
            if ( (part_size>>10) > 0) /* GB */
            {
                rt_kprintf("%d.%d%s",part_size>>10,part_size&0x3FF,"GB\r\n");/* GB */
            }
            else
            {
                rt_kprintf("%d.%d%s",part_size,(part->size>>1)&0x3FF,"MB\r\n");/* MB */
            }
        }
        else
        {
            rt_kprintf("%d%s",part->size>>1,"KB\r\n");/* KB */
        }
    }
    else
    {
        result = -RT_ERROR;
    }

    return result;
}

/**
 * this function will mount a file system on a specified path.
 *
 * @param device_name the name of device which includes a file system.
 * @param filesystemtype the file system type
 * @param rwflag the read/write etc. flag.
 * @param data the privated data(parameter) for this file system.
 *
 * @return 0 on successful or -1 on failed.
 */
int dfs_mount(const char* device_name, const char* path,
              const char* filesystemtype, unsigned long rwflag, const
              void* data)
{
    const struct dfs_filesystem_operation* ops;
    struct dfs_filesystem* fs;
    char *fullpath=RT_NULL;
    rt_device_t dev_id;
    int index;

    /* open specific device */
	if (device_name != RT_NULL)
	{
		dev_id = rt_device_find(device_name);
		if (dev_id == RT_NULL)
		{
			/* no this device */
			rt_set_errno(-DFS_STATUS_ENODEV);
			return -1;
		}
	}
	else
	{
		/* which is a non-device filesystem mount */
		dev_id = RT_NULL;
	}

    /* find out specific filesystem */
	dfs_lock();
    for ( index = 0; index < DFS_FILESYSTEM_TYPES_MAX; index++ )
    {
        if (strcmp(filesystem_operation_table[index]->name, filesystemtype) == 0)break;
    }

    /* can't find filesystem */
    if ( index == DFS_FILESYSTEM_TYPES_MAX )
    {
        rt_set_errno(-DFS_STATUS_ENODEV);
        dfs_unlock();
        return -1;
    }
    ops = filesystem_operation_table[index];
    dfs_unlock();

    /* make full path for special file */
	fullpath = dfs_normalize_path(RT_NULL, path);
    if ( fullpath == RT_NULL) /* not an abstract path */
    {
        rt_set_errno(-DFS_STATUS_ENOTDIR);
        return -1;
    }

    /* Check if the path exists or not, raw APIs call, fixme */
    if ( (strcmp(fullpath, "/") != 0) && (strcmp(fullpath, "/dev") != 0) )
    {
        struct dfs_fd fd;

        if ( dfs_file_open(&fd, fullpath, DFS_O_RDONLY | DFS_O_DIRECTORY) < 0 )
        {
        	rt_free(fullpath);
            rt_set_errno(-DFS_STATUS_ENOTDIR);
            return -1;
        }
        dfs_file_close(&fd);
    }

    /* check whether the file system mounted or not */
	dfs_lock();
    for (index =0; index < DFS_FILESYSTEMS_MAX; index++)
    {
        if ( filesystem_table[index].ops != RT_NULL &&
                strcmp(filesystem_table[index].path, path) == 0 )
        {
            rt_set_errno(-DFS_STATUS_EINVAL);
            goto err1;
        }
    }

    /* find out en empty filesystem table entry */
    for (index = 0; index < DFS_FILESYSTEMS_MAX && filesystem_table[index].ops != RT_NULL;
            index++) ;
    if ( index == DFS_FILESYSTEMS_MAX )	/* can't find en empty filesystem table entry */
    {
        rt_set_errno(-DFS_STATUS_EMMOUNT);
        goto err1;
    }

    /* register file system */
    fs = &(filesystem_table[index]);
	fs->path = fullpath;
    fs->ops = ops;
    fs->dev_id = dev_id;
    /* release filesystem_table lock */
	dfs_unlock();

	/* open device, but do not check the status of device */
	if (dev_id != RT_NULL) rt_device_open(fs->dev_id, RT_DEVICE_OFLAG_RDWR);

    if (ops->mount == RT_NULL) /* there is no mount implementation */
    {
		if (dev_id != RT_NULL) rt_device_close(dev_id);
    	dfs_lock();
        /* clear filesystem table entry */
        rt_memset(fs, 0, sizeof(struct dfs_filesystem));
		dfs_unlock();

		rt_free(fullpath);
        rt_set_errno(-DFS_STATUS_ENOSYS);
        return -1;
    }
    /* call mount of this filesystem */
    else if (ops->mount(fs, rwflag, data) < 0)
    {
        /* close device */
        if (dev_id != RT_NULL) rt_device_close(fs->dev_id);

        /* mount failed */
		dfs_lock();
        /* clear filesystem table entry */
        rt_memset(fs, 0, sizeof(struct dfs_filesystem));
		dfs_unlock();

		rt_free(fullpath);
		return -1;
    }

    return 0;

err1:
    dfs_unlock();
	if (fullpath != RT_NULL) rt_free(fullpath);

    return -1;
}

/**
 * this function will umount a file system on specified path.
 *
 * @param specialfile the specified path which mounted a file system.
 *
 * @return 0 on successful or -1 on failed.
 */
int dfs_unmount(const char *specialfile)
{
    char *fullpath;
    struct dfs_filesystem* fs = RT_NULL;

    fullpath = dfs_normalize_path(RT_NULL, specialfile);
    if (fullpath == RT_NULL)
    {
        rt_set_errno(-DFS_STATUS_ENOTDIR);
        return -1;
    }

    /* lock filesystem */
    dfs_lock();

    fs = dfs_filesystem_lookup(fullpath);
    if (fs != RT_NULL && fs->ops->unmount != RT_NULL && fs->ops->unmount(fs) < 0)
    {
        goto err1;
    }

    /* close device, but do not check the status of device */
	if (fs->dev_id != RT_NULL)
	    rt_device_close(fs->dev_id);

    /* clear this filesystem table entry */
    rt_memset(fs, 0, sizeof(struct dfs_filesystem));

	dfs_unlock();
	rt_free(fullpath);

    return 0;

err1:
	dfs_unlock();
	rt_free(fullpath);

    return -1;
}

/**
 * make a file system on the special device
 *
 * @param fs_name, the file system name
 * @param device_name, the special device name
 *
 * @return 0 on successful, otherwise failed.
 */
int dfs_mkfs(const char* fs_name, const char* device_name)
{
    int index;

	/* lock filesystem */
	dfs_lock();
    /* find the file system operations */
    for (index = 0; index < DFS_FILESYSTEM_TYPES_MAX; index++)
    {
        if (filesystem_operation_table[index] != RT_NULL &&
                strcmp(filesystem_operation_table[index]->name, fs_name) == 0)
        {
			/* find file system operation */
			const struct dfs_filesystem_operation* ops = filesystem_operation_table[index];
			dfs_unlock();

			if (ops->mkfs != RT_NULL)
				return ops->mkfs(device_name);

			break;
        }
    }
	dfs_unlock();

	return -1;
}

/**
 * this function will return the information about a mounted file system.
 *
 * @param path the path which mounted file system.
 * @param buffer the buffer to save the returned information.
 *
 * @return 0 on successful, others on failed.
 */
int dfs_statfs(const char* path, struct _statfs* buffer)
{
	struct dfs_filesystem* fs;

	fs = dfs_filesystem_lookup(path);
	if (fs != NULL)
	{
		if (fs->ops->statfs!= RT_NULL)
			return fs->ops->statfs(fs, buffer);
	}

	return -1;
}

#ifdef RT_USING_FINSH
#include <finsh.h>
void mkfs(const char* fs_name, const char* device_name)
{
	dfs_mkfs(fs_name, device_name);
}
FINSH_FUNCTION_EXPORT(mkfs, make a file system);

void df(const char* path)
{
	struct _statfs buffer;

	if (dfs_statfs(path, &buffer) == 0)
	{
		rt_kprintf("disk free: %d block[%d bytes per block]\n", buffer.f_bfree, buffer.f_bsize);
	}
}
FINSH_FUNCTION_EXPORT(df, get disk free);
#endif