/***************************************************************************************
 *  Genesis Plus
 *  Savestate support
 *
 *  Copyright (C) 2007, 2008, 2009  Eke-Eke (GCN/Wii port)
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 ****************************************************************************************/

#include "shared.h"

#define STATE_VERSION "GENPLUS-GX 1.4.x"

#define load_param(param, size) \
  memcpy(param, &state[bufferptr], size); \
  bufferptr+= size;

#define save_param(param, size) \
  memcpy(&state[bufferptr], param, size); \
  bufferptr+= size;

int state_load(unsigned char *buffer)
{
  /* buffer size */
  int bufferptr = 0;

  /* first allocate state buffer */
  unsigned char *state = (unsigned char *)malloc(STATE_SIZE);
  if (!state) return 0;

  /* uncompress savestate */
  unsigned long inbytes, outbytes;
  memcpy(&inbytes, buffer, 4);
  outbytes = STATE_SIZE;
  uncompress ((Bytef *)state, &outbytes, (Bytef *)(buffer + 4), inbytes);

  /* version check */
  char version[16];
  load_param(version,16);
  if (strncmp(version,STATE_VERSION,16))
  {
    free(state);
    return -1;
  }

  /* reset system */
  system_reset();
  m68k_memory_map[0].base = cart.base;

  // GENESIS
  load_param(work_ram, sizeof(work_ram));
  load_param(zram, sizeof(zram));
  load_param(&zstate, sizeof(zstate));
  load_param(&zbank, sizeof(zbank));

  // IO
  load_param(io_reg, sizeof(io_reg));

  // VDP
  uint8 temp_reg[0x20];
  load_param(sat, sizeof(sat));
  load_param(vram, sizeof(vram));
  load_param(cram, sizeof(cram));
  load_param(vsram, sizeof(vsram));
  load_param(temp_reg, sizeof(temp_reg));
  load_param(&addr, sizeof(addr));
  load_param(&addr_latch, sizeof(addr_latch));
  load_param(&code, sizeof(code));
  load_param(&pending, sizeof(pending));
  load_param(&status, sizeof(status));
  load_param(&dmafill, sizeof(dmafill));
  load_param(&hint_pending, sizeof(hint_pending));
  load_param(&vint_pending, sizeof(vint_pending));
  load_param(&irq_status, sizeof(irq_status));
  vdp_restore(temp_reg);

  // FM 
  YM2612Restore(&state[bufferptr]);
  bufferptr+= YM2612GetContextSize();

  // PSG
  load_param(SN76489_GetContextPtr(),SN76489_GetContextSize());

  // 68000 
  uint16 tmp16;
  uint32 tmp32;
  load_param(&tmp32, 4); m68k_set_reg(M68K_REG_D0, tmp32);
  load_param(&tmp32, 4); m68k_set_reg(M68K_REG_D1, tmp32);
  load_param(&tmp32, 4); m68k_set_reg(M68K_REG_D2, tmp32);
  load_param(&tmp32, 4); m68k_set_reg(M68K_REG_D3, tmp32);
  load_param(&tmp32, 4); m68k_set_reg(M68K_REG_D4, tmp32);
  load_param(&tmp32, 4); m68k_set_reg(M68K_REG_D5, tmp32);
  load_param(&tmp32, 4); m68k_set_reg(M68K_REG_D6, tmp32);
  load_param(&tmp32, 4); m68k_set_reg(M68K_REG_D7, tmp32);
  load_param(&tmp32, 4); m68k_set_reg(M68K_REG_A0, tmp32);
  load_param(&tmp32, 4); m68k_set_reg(M68K_REG_A1, tmp32);
  load_param(&tmp32, 4); m68k_set_reg(M68K_REG_A2, tmp32);
  load_param(&tmp32, 4); m68k_set_reg(M68K_REG_A3, tmp32);
  load_param(&tmp32, 4); m68k_set_reg(M68K_REG_A4, tmp32);
  load_param(&tmp32, 4); m68k_set_reg(M68K_REG_A5, tmp32);
  load_param(&tmp32, 4); m68k_set_reg(M68K_REG_A6, tmp32);
  load_param(&tmp32, 4); m68k_set_reg(M68K_REG_A7, tmp32);
  load_param(&tmp32, 4); m68k_set_reg(M68K_REG_PC, tmp32);  
  load_param(&tmp16, 2); m68k_set_reg(M68K_REG_SR, tmp16);
  load_param(&tmp32, 4); m68k_set_reg(M68K_REG_USP,tmp32);

  // Z80 
  load_param(&Z80, sizeof(Z80_Regs));

  free(state);
  return 1;
}

int state_save(unsigned char *buffer)
{
  /* buffer size */
  int bufferptr = 0;

  /* first allocate state buffer */
  unsigned char *state = (unsigned char *)malloc(STATE_SIZE);
  if (!state) return 0;

  /* version string */
  char version[16];
  strncpy(version,STATE_VERSION,16);
  save_param(version, 16);

  // GENESIS
  save_param(work_ram, sizeof(work_ram));
  save_param(zram, sizeof(zram));
  save_param(&zstate, sizeof(zstate));
  save_param(&zbank, sizeof(zbank));

  // IO
  save_param(io_reg, sizeof(io_reg));

  // VDP
  save_param(sat, sizeof(sat));
  save_param(vram, sizeof(vram));
  save_param(cram, sizeof(cram));
  save_param(vsram, sizeof(vsram));
  save_param(reg, sizeof(reg));
  save_param(&addr, sizeof(addr));
  save_param(&addr_latch, sizeof(addr_latch));
  save_param(&code, sizeof(code));
  save_param(&pending, sizeof(pending));
  save_param(&status, sizeof(status));
  save_param(&dmafill, sizeof(dmafill));
  save_param(&hint_pending, sizeof(hint_pending));
  save_param(&vint_pending, sizeof(vint_pending));
  save_param(&irq_status, sizeof(irq_status));

  // FM 
  save_param(YM2612GetContextPtr(),YM2612GetContextSize());

  // PSG 
  save_param(SN76489_GetContextPtr(),SN76489_GetContextSize());

  // 68000 
  uint16 tmp16;
  uint32 tmp32;
  tmp32 = m68k_get_reg(NULL, M68K_REG_D0);  save_param(&tmp32, 4);
  tmp32 = m68k_get_reg(NULL, M68K_REG_D1);  save_param(&tmp32, 4);
  tmp32 = m68k_get_reg(NULL, M68K_REG_D2);  save_param(&tmp32, 4);
  tmp32 = m68k_get_reg(NULL, M68K_REG_D3);  save_param(&tmp32, 4);
  tmp32 = m68k_get_reg(NULL, M68K_REG_D4);  save_param(&tmp32, 4);
  tmp32 = m68k_get_reg(NULL, M68K_REG_D5);  save_param(&tmp32, 4);
  tmp32 = m68k_get_reg(NULL, M68K_REG_D6);  save_param(&tmp32, 4);
  tmp32 = m68k_get_reg(NULL, M68K_REG_D7);  save_param(&tmp32, 4);
  tmp32 = m68k_get_reg(NULL, M68K_REG_A0);  save_param(&tmp32, 4);
  tmp32 = m68k_get_reg(NULL, M68K_REG_A1);  save_param(&tmp32, 4);
  tmp32 = m68k_get_reg(NULL, M68K_REG_A2);  save_param(&tmp32, 4);
  tmp32 = m68k_get_reg(NULL, M68K_REG_A3);  save_param(&tmp32, 4);
  tmp32 = m68k_get_reg(NULL, M68K_REG_A4);  save_param(&tmp32, 4);
  tmp32 = m68k_get_reg(NULL, M68K_REG_A5);  save_param(&tmp32, 4);
  tmp32 = m68k_get_reg(NULL, M68K_REG_A6);  save_param(&tmp32, 4);
  tmp32 = m68k_get_reg(NULL, M68K_REG_A7);  save_param(&tmp32, 4);
  tmp32 = m68k_get_reg(NULL, M68K_REG_PC);  save_param(&tmp32, 4);
  tmp16 = m68k_get_reg(NULL, M68K_REG_SR);  save_param(&tmp16, 2); 
  tmp32 = m68k_get_reg(NULL, M68K_REG_USP); save_param(&tmp32, 4);

  // Z80 
  save_param(&Z80, sizeof(Z80_Regs));

  /* compress state file */
  unsigned long inbytes   = bufferptr;
  unsigned long outbytes  = STATE_SIZE;
  compress2 ((Bytef *)(buffer + 4), &outbytes, (Bytef *)state, inbytes, 9);
  memcpy(buffer, &outbytes, 4);
  free(state);

  /* return total size */
  return (outbytes + 4);
}