#include <ogcsys.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/stat.h>

#include "fatmounter.h"
#include "libntfs/ntfs.h"
#include "libwbfs/libwbfs.h"
#include "wbfs.h"
#include "usbstorage2.h"
#include "frag.h"
#include "utils.h"

FragList *frag_list = NULL;

void frag_init( FragList *ff, int maxnum )
{
    memset( ff, 0, sizeof( Fragment ) * ( maxnum + 1 ) );
    ff->maxnum = maxnum;
}

int frag_append( FragList *ff, u32 offset, u32 sector, u32 count )
{
    int n;
    if ( count )
    {
        n = ff->num - 1;
        if ( ff->num > 0
                && ff->frag[n].offset + ff->frag[n].count == offset
                && ff->frag[n].sector + ff->frag[n].count == sector )
        {
            // merge
            ff->frag[n].count += count;
        }
        else
        {
            // add
            if ( ff->num >= ff->maxnum )
            {
                // too many fragments
                return -500;
            }
            n = ff->num;
            ff->frag[n].offset = offset;
            ff->frag[n].sector = sector;
            ff->frag[n].count  = count;
            ff->num++;
        }
    }
    ff->size = offset + count;
    return 0;
}

int _frag_append( void *ff, u32 offset, u32 sector, u32 count )
{
    return frag_append( ff, offset, sector, count );
}

int frag_concat( FragList *ff, FragList *src )
{
    int i, ret;
    u32 size = ff->size;
    //printf("concat: %d %d <- %d %d\n", ff->num, ff->size, src->num, src->size);
    for ( i = 0; i < src->num; i++ )
    {
        ret = frag_append( ff, size + src->frag[i].offset,
                           src->frag[i].sector, src->frag[i].count );
        if ( ret ) return ret;
    }
    ff->size = size + src->size;
    //printf("concat: -> %d %d\n", ff->num, ff->size);
    return 0;
}

// in case a sparse block is requested,
// the returned poffset might not be equal to requested offset
// the difference should be filled with 0
int frag_get( FragList *ff, u32 offset, u32 count,
              u32 *poffset, u32 *psector, u32 *pcount )
{
    int i;
    u32 delta;
    //printf("frag_get(%u %u)\n", offset, count);
    for ( i = 0; i < ff->num; i++ )
    {
        if ( ff->frag[i].offset <= offset
                && ff->frag[i].offset + ff->frag[i].count > offset )
        {
            delta = offset - ff->frag[i].offset;
            *poffset = offset;
            *psector = ff->frag[i].sector + delta;
            *pcount = ff->frag[i].count - delta;
            if ( *pcount > count ) *pcount = count;
            goto out;
        }
        if ( ff->frag[i].offset > offset
                && ff->frag[i].offset < offset + count )
        {
            delta = ff->frag[i].offset - offset;
            *poffset = ff->frag[i].offset;
            *psector = ff->frag[i].sector;
            *pcount = ff->frag[i].count;
            count -= delta;
            if ( *pcount > count ) *pcount = count;
            goto out;
        }
    }
    // not found
    if ( offset + count > ff->size )
    {
        // error: out of range!
        return -1;
    }
    // if inside range, then it must be just sparse, zero filled
    // return empty block at the end of requested
    *poffset = offset + count;
    *psector = 0;
    *pcount = 0;
out:
    //printf("=>(%u %u %u)\n", *poffset, *psector, *pcount);
    return 0;
}

int frag_remap( FragList *ff, FragList *log, FragList *phy )
{
    int i;
    int ret;
    u32 offset;
    u32 sector;
    u32 count;
    u32 delta;
    for ( i = 0; i < log->num; i++ )
    {
        delta = 0;
        count = 0;
        do
        {
            ret = frag_get( phy,
                            log->frag[i].sector + delta + count,
                            log->frag[i].count - delta - count,
                            &offset, &sector, &count );
            if ( ret ) return ret; // error
            delta = offset - log->frag[i].sector;
            ret = frag_append( ff, log->frag[i].offset + delta, sector, count );
            if ( ret ) return ret; // error
        }
        while ( count + delta < log->frag[i].count );
    }
    return 0;
}


int get_frag_list( u8 *id )
{
    return WBFS_GetFragList( id );
}

int set_frag_list( u8 *id )
{
    if ( wbfs_part_fs == PART_FS_WBFS ) return 0;
    if ( frag_list == NULL )
    {
        if ( wbfs_part_fs == PART_FS_FAT )
        {
            // fall back to old fat method
//          printf("FAT: fallback to old method\n");
            return 0;
        }
        // ntfs has no fallback, return error
        return -1;
    }

    // (+1 for header which is same size as fragment)
    int size = sizeof( Fragment ) * ( frag_list->num + 1 );
    int ret = USBStorage_WBFS_SetFragList( frag_list, size );
    if ( ret )
    {
//      printf("set_frag: %d\n", ret);
        return ret;
    }

    // verify id matches
    char discid[8];
    memset( discid, 0, sizeof( discid ) );
    ret = USBStorage_WBFS_Read( 0, 6, discid );
    return 0;
}