/*****************************************************************************************
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 $Id: devfs.c 169 2016-01-20 01:10:22Z reddawg $

 *****************************************************************************************/

#include <devfs/devfs.h>
#include <vfs/vfs.h>
#include <sys/device.h>
#include <ubixos/spinlock.h>
#include <ubixos/kpanic.h>
#include <lib/kmalloc.h>
#include <lib/string.h>
#include <lib/kprintf.h>

/* Spinlock for devfs we should start converting to sem/mutex */
static spinLock_t devfsSpinLock = SPIN_LOCK_INITIALIZER;

/* Length of dev list */
static int devfs_len = 0x0;

/**
 This is the initialized called by the vfs system when enabling devfs
 basically it allocates memory for the devfs module
 */
static void devfs_initialize( struct vfs_mountPoint *mp ) {
  struct devfs_info *fsInfo = 0x0;

  /* Allocate memory for the fsInfo */
  if ( (mp->fsInfo = (struct devfs_info *) kmalloc( sizeof(struct devfs_info) )) == 0x0 )
    K_PANIC( "devfs: failed to allocate memor\n" );

  fsInfo = mp->fsInfo;
  fsInfo->deviceList = 0x0;

  /* Return */
  return;
}

/**
 This is the open routine called by the vfs when a fopen or open is called within the user or kernel space
 file - this is the file node
 fd   - this is the file descriptor

 This format will be changing down the road
 */
static int devfs_open( char *file, fileDescriptor *fd ) {
  struct devfs_info *fsInfo = fd->mp->fsInfo;
  struct devfs_devices *tmpDev = 0x0;
  struct device_node *device = 0x0;

  spinLock( &devfsSpinLock );

  if ( strcmp( file, "/" ) == 0x0 ) {
    fd->start = -1;
    fd->size = devfs_len;
    spinUnlock( &devfsSpinLock );
    return (0x1);
  }
  if ( file[0] == '/' )
    file++;
  for ( tmpDev = fsInfo->deviceList; tmpDev != 0x0; tmpDev = tmpDev->next ) {
    if ( strcmp( tmpDev->devName, file ) == 0x0 ) {
      switch ( (fd->mode & 0x3) ) {
        case 0:
          case 1:
          device = device_find( tmpDev->devMajor, tmpDev->devMinor );
          fd->start = (u_int32_t *) tmpDev; /* MrOlsen (2016-01-19) FIX: I Don't Understand This */
          fd->size = device->devInfo->size;
          break;
        default:
          kprintf( "Invalid File Mode\n" );
          spinUnlock( &devfsSpinLock );
          return (-1);
          break;
      }
      spinUnlock( &devfsSpinLock );
      return (0x1);
    }
  }
  spinUnlock( &devfsSpinLock );
  return (0x0);
}

/**
 Function: int readDevFS(fileDescriptor *fd,char *data,long offset,long size)
 Description: Read File Into Data
 Notes:
 */
static int devfs_read( fileDescriptor *fd, char *data, long offset, long size ) {
  int i = 0x0, x = 0x0;
  uInt32 sectors = 0x0;
  uInt16 diff = 0x0;
  struct device_node *device = 0x0;
  struct devfs_devices *tmpDev = (void *) fd->start;

  if ( tmpDev == -1 ) {
    kprintf( "Hi Ubie [%i]!!!\n", size );
    for ( i = 0; i < size; i++ ) {
      data[i] = 'a';
      fd->buffer[i] = 'a';
    }
    data[size - 1] = '\n';
    return (size);
  }

  device = device_find( tmpDev->devMajor, tmpDev->devMinor );

  sectors = ((size + 511) / 512);
  diff = (offset - ((offset / 512) * 512));

  for ( i = 0x0; i < sectors; i++ ) {
    device->devInfo->read( device->devInfo->info, fd->buffer, i + (offset / 512), 1 );
    for ( x = 0x0; x < (size - (i * 512)); x++ ) {
      if ( diff > 0 ) {
        data[x] = fd->buffer[x + diff];
      }
      else {
        data[x] = fd->buffer[x];
      }
    }
    diff = 0x0;
    data += 512;
  }

  return (size);
}

/************************************************************************

 Function: int writeDevFS(fileDescriptor *fd,char *data,long offset,long size)
 Description: Write Data Into File
 Notes:

 ************************************************************************/
static int devfs_write( fileDescriptor *fd, char *data, long offset, long size ) {
  int i = 0x0, x = 0x0;
  struct device_node *device = 0x0;
  struct devfs_devices *tmpDev = (void *) fd->start;

  device = device_find( tmpDev->devMajor, tmpDev->devMinor );
  for ( i = 0x0; i < ((size + 511) / 512); i++ ) {
    device->devInfo->read( device->devInfo->info, fd->buffer, i + (offset / 512), 1 );
    for ( x = 0x0; ((x < 512) && ((x + (i * 512)) < size)); x++ ) {
      fd->buffer[x] = data[x];
    }
    device->devInfo->write( device->devInfo->info, fd->buffer, i + (offset / 512), 1 );
    data += 512;
  }
  return (size);
}

int devfs_makeNode( char *name, uInt8 type, uInt16 major, uInt16 minor ) {
  struct vfs_mountPoint *mp = 0x0;
  struct devfs_info *fsInfo = 0x0;
  struct devfs_devices *tmpDev = 0x0;

  spinLock( &devfsSpinLock );

  mp = vfs_findMount( "devfs" );

  if ( mp == 0x0 ) {
    kprintf( "Error: Can't Find Mount Point\n" );
    spinUnlock( &devfsSpinLock );
    return (-1);
  }

  fsInfo = mp->fsInfo;

  tmpDev = (struct devfs_devices *) kmalloc( sizeof(struct devfs_devices) );

  tmpDev->devType = type;
  tmpDev->devMajor = major;
  tmpDev->devMinor = minor;
  sprintf( tmpDev->devName, name );
  devfs_len += strlen( name ) + 1;

  tmpDev->next = fsInfo->deviceList;
  tmpDev->prev = 0x0;
  if ( fsInfo->deviceList != 0x0 ) {
    fsInfo->deviceList->prev = tmpDev;
  }

  fsInfo->deviceList = tmpDev;

  spinUnlock( &devfsSpinLock );
  return (0x0);
}

int devfs_init() {
  /* Build our devfs struct */
  struct fileSystem devFS =
      { NULL, /* prev        */
      NULL, /* next        */
      (void *) devfs_initialize, /* vfsInitFS   */
      (void *) devfs_read, /* vfsRead     */
      (void *) devfs_write, /* vfsWrite    */
      (void *) devfs_open, /* vfsOpenFile */
      NULL, /* vfsUnlink   */
      NULL, /* vfsMakeDir  */
      NULL, /* vfsRemDir   */
      NULL, /* vfsSync     */
      1 /* vfsType     */
      }; /* devFS */

  if ( vfsRegisterFS( devFS ) != 0x0 ) {
    //sysErr(systemErr,"Unable To Enable DevFS");
    return (0x1);
  }
  /* Mount our devfs this will build the devfs container node */
  vfs_mount( 0x0, 0x0, 0x0, 0x1, "devfs", "rw" ); // Mount Device File System

  /* Return */
  return (0x0);
}

/***
 END
 ***/