#include "libultra_internal.h"
#include "controller.h"

static s32 __osPfsGetNextPage(OSPfs *pfs, u8 *bank, __OSInode *inode, __OSInodeUnit *page)
{
    s32 ret;
    if (*bank != page->inode_t.bank)
    {
        *bank = page->inode_t.bank;
        ERRCK(__osPfsRWInode(pfs, inode, 0, *bank));
    }
    *page = inode->inode_page[page->inode_t.page];
    if (page->ipage < pfs->inode_start_page ||
        page->inode_t.bank >= pfs->banks ||
        page->inode_t.page <= 0 ||
        page->inode_t.page >= ARRLEN(inode->inode_page))
    {
        if (page->ipage == 1)
            return PFS_ERR_INVALID;
        return PFS_ERR_INCONSISTENT;
    }
    return 0;
}
s32 osPfsReadWriteFile(OSPfs *pfs, s32 file_no, u8 flag, int offset, int size_in_bytes, u8 *data_buffer)
{
    s32 ret;
    __OSDir dir;
    __OSInode inode;
    __OSInodeUnit cur_page;
    int cur_block;
    int siz_block;
    u8 *buffer;
    u8 bank;
    u16 blockno;
    if (file_no >= pfs->dir_size || file_no < 0)
        return PFS_ERR_INVALID;
    if (size_in_bytes <= 0 || ((size_in_bytes & (BLOCKSIZE - 1)) != 0))
        return PFS_ERR_INVALID;
    if (offset < 0 || ((offset & (BLOCKSIZE - 1)) != 0))
        return PFS_ERR_INVALID;

    PFS_CHECK_STATUS;
    PFS_CHECK_ID;
    SET_ACTIVEBANK_TO_ZERO;
    ERRCK(__osContRamRead(pfs->queue, pfs->channel, pfs->dir_table + file_no, (u8*)&dir));

    if (dir.start_page.ipage < pfs->inode_start_page ||
        dir.start_page.inode_t.bank >= pfs->banks ||
        dir.start_page.inode_t.page <= 0 ||
        dir.start_page.inode_t.page >= ARRLEN(inode.inode_page))
    {

        if ((dir.start_page.ipage == 1))
            return PFS_ERR_INVALID;
        return PFS_ERR_INCONSISTENT;
    }
    if (flag == PFS_READ && (dir.status & DIR_STATUS_OCCUPIED) == 0)
        return PFS_ERR_BAD_DATA;
    bank = -1;
    cur_block = offset / BLOCKSIZE;
    cur_page = dir.start_page;
    while (cur_block >= PFS_ONE_PAGE)
    {
        ERRCK(__osPfsGetNextPage(pfs, &bank, &inode, &cur_page));
        cur_block -= PFS_ONE_PAGE;
    }
    siz_block = size_in_bytes / BLOCKSIZE;
    buffer = data_buffer;
    while (siz_block > 0)
    {
        if (cur_block == PFS_ONE_PAGE)
        {
            ERRCK(__osPfsGetNextPage(pfs, &bank, &inode, &cur_page));
            cur_block = 0;
        }
        if (pfs->activebank != cur_page.inode_t.bank)
        {
            pfs->activebank = cur_page.inode_t.bank;
            ERRCK(__osPfsSelectBank(pfs));
        }
        blockno = cur_page.inode_t.page * PFS_ONE_PAGE + cur_block;
        if (flag == OS_READ)
            ret = __osContRamRead(pfs->queue, pfs->channel, blockno, buffer);
        else
            ret = __osContRamWrite(pfs->queue, pfs->channel, blockno, buffer, FALSE);
        if (ret != 0)
            return ret;
        buffer += BLOCKSIZE;
        cur_block++;
        siz_block--;
    }
    if (flag == PFS_WRITE && (dir.status & DIR_STATUS_OCCUPIED) == 0)
    {
        dir.status |= DIR_STATUS_OCCUPIED;
        pfs->activebank = 0;
        ERRCK(__osPfsSelectBank(pfs));
        ERRCK(__osContRamWrite(pfs->queue, pfs->channel, pfs->dir_table + file_no, (u8*)&dir, FALSE));
    }
    return 0;

}