/*---------------------------------------------------------------------------*
  Project:  TwlSDK - FS - libraries
  File:     fs_hook.c

  Copyright 2007-2008 Nintendo. All rights reserved.

  These coded instructions, statements, and computer programs contain
  proprietary information of Nintendo of America Inc. and/or Nintendo
  Company Ltd., and are protected by Federal copyright law. They may
  not be disclosed to third parties or copied or duplicated in any form,
  in whole or in part, without the prior written consent of Nintendo.

  $Date:: 2008-09-17#$
  $Rev: 8556 $
  $Author: okubata_ryoma $

 *---------------------------------------------------------------------------*/

#include <nitro/fs/archive.h>
#include <nitro/fs/hook.h>
#include <nitro/card/common.h>
#include <nitro/std/string.h>
#ifdef SDK_TWL
#include <twl/fatfs/common/types.h>
#endif // SDK_TWL

/*---------------------------------------------------------------------------*/
/* Variables */

// Event hook management information
typedef struct FSEventHookContext
{
    FSEventHook     *chain;
    CARDHookContext  hook[1];
}
FSEventHookContext;

static FSEventHookContext FSiEventHookStaticWork[1];


/*---------------------------------------------------------------------------*/
/* functions */

/*---------------------------------------------------------------------------*
  Name:         FSi_SystemEvents

  Description:  System event monitoring callback

  Arguments:    userdata         Any user-defined data
                event       Occurred event
                argument        Argument for each event

  Returns:      None.
 *---------------------------------------------------------------------------*/
static void FSi_SystemEvents(void *userdata, CARDEvent event, void *argument)
{
    FSEventHookContext *context = (FSEventHookContext*)userdata;
    FSArchive  *target = NULL;
    FSEvent     fsevent = FS_EVENT_NONE;
    (void)argument;
    // Convert entire media event of the system to each archive event.
    if (event == CARD_EVENT_SLOTRESET)
    {
        target = FS_FindArchive("rom", 3);
        fsevent = FS_EVENT_MEDIA_INSERTED;
    }
    else if (event == CARD_EVENT_PULLEDOUT)
    {
        target = FS_FindArchive("rom", 3);
        fsevent = FS_EVENT_MEDIA_REMOVED;
    }
#ifdef SDK_TWL
    else if (event == FATFS_EVENT_SD_INSERTED)
    {
        target = FS_FindArchive("sdmc", 4);
        fsevent = FS_EVENT_MEDIA_INSERTED;
    }
    else if (event == FATFS_EVENT_SD_REMOVED)
    {
        target = FS_FindArchive("sdmc", 4);
        fsevent = FS_EVENT_MEDIA_REMOVED;
    }
#endif // SDK_TWL
    if (fsevent != FS_EVENT_NONE)
    {
        FSEventHook   **pp = &context->chain;
        while (*pp != NULL)
        {
            FSEventHook    *hook = *pp;
            if ((hook->arc == target) && (hook->callback != NULL))
            {
                (*hook->callback)(hook->userdata, fsevent, argument);
            }
            if (*pp == hook)
            {
                pp = &(*pp)->next;
            }
        }
    }
}

/*---------------------------------------------------------------------------*
  Name:         FS_RegisterEventHook

  Description:  Registers the hook for events in the archive

  Arguments:    arcname          Archive of the register target
                hook             FSEventHook structure to register
                callback         Callback function when an event occurs
                userdata         Arbitrary user defined data (if not necessary, NULL)

  Returns:      None.
 *---------------------------------------------------------------------------*/
void FS_RegisterEventHook(const char *arcname, FSEventHook *hook, FSEventFunction callback, void *userdata)
{
    FSEventHookContext *context = FSiEventHookStaticWork;
    OSIntrMode  bak = OS_DisableInterrupts();
    FSArchive  *arc = FS_FindArchive(arcname, STD_GetStringLength(arcname));
    if (arc)
    {
        // If not explicitly used, consider so that the hook feature is not linked
        if (!context->hook->callback)
        {
            CARDi_RegisterHook(context->hook, FSi_SystemEvents, context);
        }
        hook->callback = callback;
        hook->userdata = userdata;
        hook->arc = arc;
        hook->next = context->chain;
        context->chain = hook;
    }
    (void)OS_RestoreInterrupts(bak);
}

/*---------------------------------------------------------------------------*
  Name:         FS_UnregisterEventHook

  Description:  Releases the hook for events in the registered archive.

  Arguments:    hook           Registered FSEventHook structure

  Returns:      None.
 *---------------------------------------------------------------------------*/
void FS_UnregisterEventHook(FSEventHook *hook)
{
    FSEventHookContext *context = FSiEventHookStaticWork;
    OSIntrMode      bak = OS_DisableInterrupts();
    FSEventHook   **pp;
    for (pp = &context->chain; *pp; pp = &(*pp)->next)
    {
        if (*pp == hook)
        {
            *pp = (*pp)->next;
            break;
        }
    }
    (void)OS_RestoreInterrupts(bak);
}