/**
 * Copyright (c) 2011-2018 Bill Greiman
 * This file is part of the SdFat library for SD memory cards.
 *
 * MIT License
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */
#include "FatVolume.h"
#include <string.h>
//------------------------------------------------------------------------------
cache_t *FatCache::read(uint32_t lbn, uint8_t option)
{
    if (m_lbn != lbn)
    {
        if (!sync())
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
        if (!(option & CACHE_OPTION_NO_READ))
        {
            if (!m_vol->readBlock(lbn, m_block.data))
            {
                DBG_FAIL_MACRO;
                goto fail;
            }
        }
        m_status = 0;
        m_lbn = lbn;
    }
    m_status |= option & CACHE_STATUS_MASK;
    return &m_block;

fail:

    return 0;
}
//------------------------------------------------------------------------------
bool FatCache::sync()
{
    if (m_status & CACHE_STATUS_DIRTY)
    {
        if (!m_vol->writeBlock(m_lbn, m_block.data))
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
        // mirror second FAT
        if (m_status & CACHE_STATUS_MIRROR_FAT)
        {
            uint32_t lbn = m_lbn + m_vol->blocksPerFat();
            if (!m_vol->writeBlock(lbn, m_block.data))
            {
                DBG_FAIL_MACRO;
                goto fail;
            }
        }
        m_status &= ~CACHE_STATUS_DIRTY;
    }
    return true;

fail:
    return false;
}
//------------------------------------------------------------------------------
bool FatVolume::allocateCluster(uint32_t current, uint32_t *next)
{
    uint32_t find;
    bool setStart;
    if (m_allocSearchStart < current)
    {
        // Try to keep file contiguous. Start just after current cluster.
        find = current;
        setStart = false;
    }
    else
    {
        find = m_allocSearchStart;
        setStart = true;
    }
    while (1)
    {
        find++;
        if (find > m_lastCluster)
        {
            if (setStart)
            {
                // Can't find space, checked all clusters.
                DBG_FAIL_MACRO;
                goto fail;
            }
            find = m_allocSearchStart;
            setStart = true;
            continue;
        }
        if (find == current)
        {
            // Can't find space, already searched clusters after current.
            DBG_FAIL_MACRO;
            goto fail;
        }
        uint32_t f;
        int8_t fg = fatGet(find, &f);
        if (fg < 0)
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
        if (fg && f == 0)
        {
            break;
        }
    }
    if (setStart)
    {
        m_allocSearchStart = find;
    }
    // Mark end of chain.
    if (!fatPutEOC(find))
    {
        DBG_FAIL_MACRO;
        goto fail;
    }
    if (current)
    {
        // Link clusters.
        if (!fatPut(current, find))
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
    }
    updateFreeClusterCount(-1);
    *next = find;
    return true;

fail:
    return false;
}
//------------------------------------------------------------------------------
// find a contiguous group of clusters
bool FatVolume::allocContiguous(uint32_t count, uint32_t *firstCluster, uint32_t startCluster)
{
    // flag to save place to start next search
    bool setStart;
    // start of group
    uint32_t bgnCluster;
    // end of group
    uint32_t endCluster;
    if (startCluster != 0)
    {
        bgnCluster = startCluster;
        setStart = false;
    }
    else
    {
        // Start at cluster after last allocated cluster.
        bgnCluster = m_allocSearchStart + 1;
        setStart = true;
    }
    endCluster = bgnCluster;
    // search the FAT for free clusters
    while (1)
    {
        if (endCluster > m_lastCluster)
        {
            // Can't find space.
            DBG_FAIL_MACRO;
            goto fail;
        }
        uint32_t f;
        int8_t fg = fatGet(endCluster, &f);
        if (fg < 0)
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
        if (f || fg == 0)
        {
            if (startCluster)
            {
                DBG_FAIL_MACRO;
                goto fail;
            }
            // don't update search start if unallocated clusters before endCluster.
            if (bgnCluster != endCluster)
            {
                setStart = false;
            }
            // cluster in use try next cluster as bgnCluster
            bgnCluster = endCluster + 1;
        }
        else if ((endCluster - bgnCluster + 1) == count)
        {
            // done - found space
            break;
        }
        endCluster++;
    }
    // Remember possible next free cluster.
    if (setStart)
    {
        m_allocSearchStart = endCluster;
    }
    // mark end of chain
    if (!fatPutEOC(endCluster))
    {
        DBG_FAIL_MACRO;
        goto fail;
    }
    // link clusters
    while (endCluster > bgnCluster)
    {
        if (!fatPut(endCluster - 1, endCluster))
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
        endCluster--;
    }
    // Maintain count of free clusters.
    updateFreeClusterCount(-count);

    // return first cluster number to caller
    *firstCluster = bgnCluster;
    return true;

fail:
    return false;
}
//------------------------------------------------------------------------------
uint32_t FatVolume::clusterFirstBlock(uint32_t cluster) const
{
    return m_dataStartBlock + ((cluster - 2) << m_clusterSizeShift);
}
//------------------------------------------------------------------------------
// Fetch a FAT entry - return -1 error, 0 EOC, else 1.
int8_t FatVolume::fatGet(uint32_t cluster, uint32_t *value)
{
    uint32_t lba;
    uint32_t next;
    cache_t *pc;

    // error if reserved cluster of beyond FAT
    if (cluster < 2 || cluster > m_lastCluster)
    {
        DBG_FAIL_MACRO;
        goto fail;
    }

    if (fatType() == 32)
    {
        lba = m_fatStartBlock + (cluster >> 7);
        pc = cacheFetchFat(lba, FatCache::CACHE_FOR_READ);
        if (!pc)
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
        next = pc->fat32[cluster & 0X7F] & FAT32MASK;
        goto done;
    }
    if (fatType() == 16)
    {
        lba = m_fatStartBlock + ((cluster >> 8) & 0XFF);
        pc = cacheFetchFat(lba, FatCache::CACHE_FOR_READ);
        if (!pc)
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
        next = pc->fat16[cluster & 0XFF];
        goto done;
    }
    if (FAT12_SUPPORT && fatType() == 12)
    {
        uint16_t index = cluster;
        index += index >> 1;
        lba = m_fatStartBlock + (index >> 9);
        pc = cacheFetchFat(lba, FatCache::CACHE_FOR_READ);
        if (!pc)
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
        index &= 0X1FF;
        uint16_t tmp = pc->data[index];
        index++;
        if (index == 512)
        {
            pc = cacheFetchFat(lba + 1, FatCache::CACHE_FOR_READ);
            if (!pc)
            {
                DBG_FAIL_MACRO;
                goto fail;
            }
            index = 0;
        }
        tmp |= pc->data[index] << 8;
        next = cluster & 1 ? tmp >> 4 : tmp & 0XFFF;
        goto done;
    }
    else
    {
        DBG_FAIL_MACRO;
        goto fail;
    }
done:
    if (isEOC(next))
    {
        return 0;
    }
    *value = next;
    return 1;

fail:
    return -1;
}
//------------------------------------------------------------------------------
// Store a FAT entry
bool FatVolume::fatPut(uint32_t cluster, uint32_t value)
{
    uint32_t lba;
    cache_t *pc;

    // error if reserved cluster of beyond FAT
    if (cluster < 2 || cluster > m_lastCluster)
    {
        DBG_FAIL_MACRO;
        goto fail;
    }

    if (fatType() == 32)
    {
        lba = m_fatStartBlock + (cluster >> 7);
        pc = cacheFetchFat(lba, FatCache::CACHE_FOR_WRITE);
        if (!pc)
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
        pc->fat32[cluster & 0X7F] = value;
        return true;
    }

    if (fatType() == 16)
    {
        lba = m_fatStartBlock + ((cluster >> 8) & 0XFF);
        pc = cacheFetchFat(lba, FatCache::CACHE_FOR_WRITE);
        if (!pc)
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
        pc->fat16[cluster & 0XFF] = value;
        return true;
    }

    if (FAT12_SUPPORT && fatType() == 12)
    {
        uint16_t index = cluster;
        index += index >> 1;
        lba = m_fatStartBlock + (index >> 9);
        pc = cacheFetchFat(lba, FatCache::CACHE_FOR_WRITE);
        if (!pc)
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
        index &= 0X1FF;
        uint8_t tmp = value;
        if (cluster & 1)
        {
            tmp = (pc->data[index] & 0XF) | tmp << 4;
        }
        pc->data[index] = tmp;

        index++;
        if (index == 512)
        {
            lba++;
            index = 0;
            pc = cacheFetchFat(lba, FatCache::CACHE_FOR_WRITE);
            if (!pc)
            {
                DBG_FAIL_MACRO;
                goto fail;
            }
        }
        tmp = value >> 4;
        if (!(cluster & 1))
        {
            tmp = ((pc->data[index] & 0XF0)) | tmp >> 4;
        }
        pc->data[index] = tmp;
        return true;
    }
    else
    {
        DBG_FAIL_MACRO;
        goto fail;
    }

fail:
    return false;
}
//------------------------------------------------------------------------------
// free a cluster chain
bool FatVolume::freeChain(uint32_t cluster)
{
    uint32_t next = 0;
    int8_t fg;
    do
    {
        fg = fatGet(cluster, &next);
        if (fg < 0)
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
        // free cluster
        if (!fatPut(cluster, 0))
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
        // Add one to count of free clusters.
        updateFreeClusterCount(1);

        if (cluster <= m_allocSearchStart)
        {
            m_allocSearchStart = cluster - 1;
        }
        cluster = next;
    } while (fg);

    return true;

fail:
    return false;
}
//------------------------------------------------------------------------------
int32_t FatVolume::freeClusterCount()
{
#if MAINTAIN_FREE_CLUSTER_COUNT
    if (m_freeClusterCount >= 0)
    {
        return m_freeClusterCount;
    }
#endif // MAINTAIN_FREE_CLUSTER_COUNT
    uint32_t free = 0;
    uint32_t lba;
    uint32_t todo = m_lastCluster + 1;
    uint16_t n;

    if (FAT12_SUPPORT && fatType() == 12)
    {
        for (unsigned i = 2; i < todo; i++)
        {
            uint32_t c;
            int8_t fg = fatGet(i, &c);
            if (fg < 0)
            {
                DBG_FAIL_MACRO;
                goto fail;
            }
            if (fg && c == 0)
            {
                free++;
            }
        }
    }
    else if (fatType() == 16 || fatType() == 32)
    {
        lba = m_fatStartBlock;
        while (todo)
        {
            cache_t *pc = cacheFetchFat(lba++, FatCache::CACHE_FOR_READ);
            if (!pc)
            {
                DBG_FAIL_MACRO;
                goto fail;
            }
            n = fatType() == 16 ? 256 : 128;
            if (todo < n)
            {
                n = todo;
            }
            if (fatType() == 16)
            {
                for (uint16_t i = 0; i < n; i++)
                {
                    if (pc->fat16[i] == 0)
                    {
                        free++;
                    }
                }
            }
            else
            {
                for (uint16_t i = 0; i < n; i++)
                {
                    if (pc->fat32[i] == 0)
                    {
                        free++;
                    }
                }
            }
            todo -= n;
        }
    }
    else
    {
        // invalid FAT type
        DBG_FAIL_MACRO;
        goto fail;
    }
    setFreeClusterCount(free);
    return free;

fail:
    return -1;
}
//------------------------------------------------------------------------------
bool FatVolume::init(uint8_t part)
{
    uint32_t clusterCount;
    uint32_t totalBlocks;
    uint32_t volumeStartBlock = 0;
    fat32_boot_t *fbs;
    cache_t *pc;
    uint8_t tmp;
    m_fatType = 0;
    m_allocSearchStart = 1;
    m_cache.init(this);
#if USE_SEPARATE_FAT_CACHE
    m_fatCache.init(this);
#endif // USE_SEPARATE_FAT_CACHE
    // if part == 0 assume super floppy with FAT boot sector in block zero
    // if part > 0 assume mbr volume with partition table
    if (part)
    {
        if (part > 4)
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
        pc = cacheFetchData(0, FatCache::CACHE_FOR_READ);
        if (!pc)
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
        part_t *p = &pc->mbr.part[part - 1];
        if ((p->boot & 0X7F) != 0 || p->firstSector == 0)
        {
            // not a valid partition
            DBG_FAIL_MACRO;
            goto fail;
        }
        volumeStartBlock = p->firstSector;
    }
    pc = cacheFetchData(volumeStartBlock, FatCache::CACHE_FOR_READ);
    if (!pc)
    {
        DBG_FAIL_MACRO;
        goto fail;
    }
    fbs = &(pc->fbs32);
    if (fbs->bytesPerSector != 512 || fbs->fatCount != 2 || fbs->reservedSectorCount == 0)
    {
        // not valid FAT volume
        DBG_FAIL_MACRO;
        goto fail;
    }
    m_blocksPerCluster = fbs->sectorsPerCluster;
    m_clusterBlockMask = m_blocksPerCluster - 1;
    // determine shift that is same as multiply by m_blocksPerCluster
    m_clusterSizeShift = 0;
    for (tmp = 1; m_blocksPerCluster != tmp; tmp <<= 1, m_clusterSizeShift++)
    {
        if (tmp == 0)
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
    }
    m_blocksPerFat = fbs->sectorsPerFat16 ? fbs->sectorsPerFat16 : fbs->sectorsPerFat32;

    m_fatStartBlock = volumeStartBlock + fbs->reservedSectorCount;

    // count for FAT16 zero for FAT32
    m_rootDirEntryCount = fbs->rootDirEntryCount;

    // directory start for FAT16 dataStart for FAT32
    m_rootDirStart = m_fatStartBlock + 2 * m_blocksPerFat;
    // data start for FAT16 and FAT32
    m_dataStartBlock = m_rootDirStart + ((32 * fbs->rootDirEntryCount + 511) / 512);

    // total blocks for FAT16 or FAT32
    totalBlocks = fbs->totalSectors16 ? fbs->totalSectors16 : fbs->totalSectors32;
    // total data blocks
    clusterCount = totalBlocks - (m_dataStartBlock - volumeStartBlock);

    // divide by cluster size to get cluster count
    clusterCount >>= m_clusterSizeShift;
    m_lastCluster = clusterCount + 1;

    // Indicate unknown number of free clusters.
    setFreeClusterCount(-1);
    // FAT type is determined by cluster count
    if (clusterCount < 4085)
    {
        m_fatType = 12;
        if (!FAT12_SUPPORT)
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
    }
    else if (clusterCount < 65525)
    {
        m_fatType = 16;
    }
    else
    {
        m_rootDirStart = fbs->fat32RootCluster;
        m_fatType = 32;
    }
    return true;

fail:
    return false;
}
//------------------------------------------------------------------------------
bool FatVolume::wipe(print_t *pr)
{
    cache_t *cache;
    uint16_t count;
    uint32_t lbn;
    if (!fatType())
    {
        DBG_FAIL_MACRO;
        goto fail;
    }
    cache = cacheClear();
    if (!cache)
    {
        DBG_FAIL_MACRO;
        goto fail;
    }
    memset(cache->data, 0, 512);
    // Zero root.
    if (fatType() == 32)
    {
        lbn = clusterFirstBlock(m_rootDirStart);
        count = m_blocksPerCluster;
    }
    else
    {
        lbn = m_rootDirStart;
        count = m_rootDirEntryCount / 16;
    }
    for (uint32_t n = 0; n < count; n++)
    {
        if (!writeBlock(lbn + n, cache->data))
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
    }
    // Clear FATs.
    count = 2 * m_blocksPerFat;
    lbn = m_fatStartBlock;
    for (uint32_t nb = 0; nb < count; nb++)
    {
        if (pr && (nb & 0XFF) == 0)
        {
            pr->write('.');
        }
        if (!writeBlock(lbn + nb, cache->data))
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
    }
    // Reserve first two clusters.
    if (fatType() == 32)
    {
        cache->fat32[0] = 0x0FFFFFF8;
        cache->fat32[1] = 0x0FFFFFFF;
    }
    else if (fatType() == 16)
    {
        cache->fat16[0] = 0XFFF8;
        cache->fat16[1] = 0XFFFF;
    }
    else if (FAT12_SUPPORT && fatType() == 12)
    {
        cache->fat32[0] = 0XFFFFF8;
    }
    else
    {
        DBG_FAIL_MACRO;
        goto fail;
    }
    if (!writeBlock(m_fatStartBlock, cache->data) || !writeBlock(m_fatStartBlock + m_blocksPerFat, cache->data))
    {
        DBG_FAIL_MACRO;
        goto fail;
    }
    if (fatType() == 32)
    {
        // Reserve root cluster.
        if (!fatPutEOC(m_rootDirStart) || !cacheSync())
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
    }
    if (pr)
    {
        pr->write('\r');
        pr->write('\n');
    }
    m_fatType = 0;
    return true;

fail:
    m_fatType = 0;
    return false;
}
