#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>

#include <physio.h>
#include <fs.h>

#include "bloc.h"
#include "freeblock.h"

uint32_t new_block(unsigned int volume)
{
  struct dskinfo_t info = dskinfo();
  struct superblock_desc_t super;
  struct freeblock_t fblock;

  load_super(volume, &super);

  /* Plus d'espace disponible */
  if ( super.first_free_block == 0 )
    return 0;

  uintptr_t *data = malloc(info.taille_sec);
  read_bloc(volume, super.first_free_block, data);
  memcpy(&fblock, data, sizeof(struct freeblock_t));

  uint32_t chosen_block=0;

  /* Si on a plus d'un bloc disponible, on donne le dernier */
  if ( fblock.block_count > 1 )
    {
      /* modification de l'indicateur de blocs libres */
      fblock.block_count--;
      memcpy(data, &fblock, sizeof(struct freeblock_t));
      write_bloc(volume, super.first_free_block, data);

      chosen_block = super.first_free_block + fblock.block_count;
    }
  /* Sinon, on donne le bloc courant et on lie le suivant */
  else
    {
      chosen_block = super.first_free_block;
      super.first_free_block = fblock.next_block;
    }

  free(data);

  /* Ecriture du super block */
  super.free_space--;
  save_super(volume, &super);
  
  return chosen_block;
}

void free_block(unsigned int volume, uint32_t block)
{
  struct dskinfo_t info = dskinfo();
  struct superblock_desc_t super;
  struct freeblock_t newfreeblock;

  load_super(volume, &super);

  uintptr_t *data = malloc(info.taille_sec);

  /* Le nouveau bloc libre */
  newfreeblock.block_count = 1;
  newfreeblock.next_block = super.first_free_block;

  memcpy(data, &newfreeblock, sizeof(struct freeblock_t));
  write_bloc(volume, block, data);

  /* Incrémenter le compteur d'espace du volume */
  super.free_space++;

  /* Relier le nouvel élément */
  super.first_free_block = block;

  free(data);

  /* Sauvegarde du superbloc */
  save_super(volume, &super);
  
}