#include "../include/BufferCache.h"
#include "../include/Kernel.h"
#include "../include/VirtualProcess.h"
#include "../include/Logcat.h"

void BufferCache::setDiskDriver(DiskDriver *diskDriver)
{
    this->diskDriver = diskDriver;
}
int BufferCache::mount()
{
    initialize();
    return diskDriver->mount();
}
void BufferCache::unmount()
{
    Bflush();
    diskDriver->unmount();
} //unmount

/**
 * 
 */
void BufferCache::initialize()
{
    int i;
    Buf *bp;

    this->bFreeList.b_forw = this->bFreeList.b_back = &(this->bFreeList);
    this->bFreeList.av_forw = this->bFreeList.av_back = &(this->bFreeList);

    for (i = 0; i < BUFFER_CACHE_NUM; i++)
    {
        bp = &(this->m_Buf[i]);
        bp->b_blkno = -1;
        bp->b_dev = -1;
        bp->b_addr = &Buffer[i];
        /* NODEV */
        //bp->b_back = &(this->bFreeList);
        //bp->b_forw = this->bFreeList.b_forw;
        //this->bFreeList.b_forw->b_back = bp;
        //this->bFreeList.b_forw = bp;
        /*  */
        bp->b_flags = Buf::B_BUSY;
        Brelse(bp); //
    }
}

/**
 * diskBlockPool
 */
Buf *BufferCache::Bread(int blkno)
{
    Buf *bp;
    /*  */
    bp = this->GetBlk(blkno);

    /* B_DONEI/O */
    if (bp->b_flags & Buf::B_DONE) //DONE
    {
        return bp; //
    }

    /* I/O */
    bp->b_flags |= Buf::B_READ;
    bp->b_wcount = DISK_BLOCK_SIZE;
    diskDriver->readBlk(blkno, bp->b_addr);
    bp->b_flags |= Buf::B_DONE;

    return bp;
}

/**
 * 
 */
void BufferCache::Bwrite(Buf *bp)
{
    unsigned int flags;

    flags = bp->b_flags;
    bp->b_flags &= ~(Buf::B_READ | Buf::B_DONE | Buf::B_ERROR | Buf::B_DELWRI);
    bp->b_wcount = DISK_BLOCK_SIZE;

    //this->m_DeviceManager->GetBlockDevice(Utility::GetMajor(bp->b_dev)).Strategy(bp);

    if ((flags & Buf::B_DELWRI) == 0)
    {
        /*
     * 
     * 
     * GetError()
     * 
     */
        Logcat::log("BufferCache", "bwrite");
    }
    else
    {
        diskDriver->writeBlk(bp->b_blkno, *bp->b_addr);
        bp->b_flags |= Buf::B_DONE;
        std::cout b_blkno b_flags |= (Buf::B_DELWRI | Buf::B_DONE);
    this->Brelse(bp);
    return;
}

/**
 * dev.
 */
void BufferCache::Bflush()
{
    Buf *bp;

    for (bp = this->bFreeList.b_forw; bp != &(this->bFreeList); bp = bp->b_forw)
    {
        /*  */
        if ((bp->b_flags & Buf::B_DELWRI))
        {
            //bwriteB_DELWRI
            //this->NotAvail(bp);
            this->Bwrite(bp);
            //this->Brelse(bp);
            //std::cout b_blkno getUser();

    /* 
	 * 
	 * 
	 */

    /* NODEV */

    /*  */
    for (bp = bFreeList.b_forw; bp != &bFreeList; bp = bp->b_forw)
    {
        /*  */
        if (bp->b_blkno != blkno)
            continue;

        /*  */
        this->NotAvail(bp);
        return bp; //
    }

    /*  */
    bp = this->bFreeList.av_forw;
    this->NotAvail(bp);

    /*  */
    if (bp->b_flags & Buf::B_DELWRI)
    {
        this->Bwrite(bp);
    }
    /* : B_BUSY */
    bp->b_flags = Buf::B_BUSY; //bit
    bp->b_blkno = blkno;
    memset(bp->b_addr, 0, DISK_BLOCK_SIZE);
    if (bp->b_dev != devno)
    {
        //
        bp->b_back = &(this->bFreeList);
        bp->b_forw = this->bFreeList.b_forw;
        this->bFreeList.b_forw->b_back = bp;
        this->bFreeList.b_forw = bp;
        bp->b_dev = devno;
    }

    return bp;
}

/**
 * Buf
 */
Buf &BufferCache::GetBFreeList()
{
    return this->bFreeList;
}

//TODO bug
void BufferCache::NotAvail(Buf *bp)
{

    /*  */
    bp->av_back->av_forw = bp->av_forw;
    bp->av_forw->av_back = bp->av_back;
    /* B_BUSY */
    bp->b_flags |= Buf::B_BUSY;
    return;
}

/**
 * 
 * B_DELWRIB_WRITEB_READB_DONE
 * B_DELWRI
 * B_DONE 
 */
void BufferCache::Brelse(Buf *bp)
{

    bp->b_flags &= ~(Buf::B_WANTED | Buf::B_BUSY | Buf::B_ASYNC); //
    (this->bFreeList.av_back)->av_forw = bp;
    bp->av_back = this->bFreeList.av_back;
    bp->av_forw = &(this->bFreeList);
    this->bFreeList.av_back = bp;
    return;
}