/* gameplaySP
 *
 * Copyright (C) 2006 Exophase <exophase@gmail.com>
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "common.h"
#include <ctype.h>

timer_type timer[4];

u32 global_cycles_per_instruction = 1;

u32 cpu_ticks = 0;

u32 execute_cycles = 960;
s32 video_count = 960;
u32 ticks;

u32 arm_frame = 0;
u32 thumb_frame = 0;
u32 last_frame = 0;

u32 cycle_memory_access = 0;
u32 cycle_pc_relative_access = 0;
u32 cycle_sp_relative_access = 0;
u32 cycle_block_memory_access = 0;
u32 cycle_block_memory_sp_access = 0;
u32 cycle_block_memory_words = 0;
u32 cycle_dma16_words = 0;
u32 cycle_dma32_words = 0;
u32 flush_ram_count = 0;
u32 gbc_update_count = 0;
u32 oam_update_count = 0;

char main_path[512];
char save_path[512];

void trigger_ext_event();

#define check_count(count_var)                                                \
  if(count_var < execute_cycles)                                              \
    execute_cycles = count_var;                                               \

#define check_timer(timer_number)                                             \
  if(timer[timer_number].status == TIMER_PRESCALE)                            \
    check_count(timer[timer_number].count);                                   \

#define update_timer(timer_number)                                            \
  if(timer[timer_number].status != TIMER_INACTIVE)                            \
  {                                                                           \
    if(timer[timer_number].status != TIMER_CASCADE)                           \
    {                                                                         \
      timer[timer_number].count -= execute_cycles;                            \
      io_registers[REG_TM##timer_number##D] =                                 \
       -(timer[timer_number].count >> timer[timer_number].prescale);          \
    }                                                                         \
                                                                              \
    if(timer[timer_number].count <= 0)                                        \
    {                                                                         \
      if(timer[timer_number].irq == TIMER_TRIGGER_IRQ)                        \
        irq_raised |= IRQ_TIMER##timer_number;                                \
                                                                              \
      if((timer_number != 3) &&                                               \
       (timer[timer_number + 1].status == TIMER_CASCADE))                     \
      {                                                                       \
        timer[timer_number + 1].count--;                                      \
        io_registers[REG_TM0D + (timer_number + 1) * 2] =                     \
         -(timer[timer_number + 1].count);                                    \
      }                                                                       \
                                                                              \
      if(timer_number < 2)                                                    \
      {                                                                       \
        if(timer[timer_number].direct_sound_channels & 0x01)                  \
          sound_timer(timer[timer_number].frequency_step, 0);                 \
                                                                              \
        if(timer[timer_number].direct_sound_channels & 0x02)                  \
          sound_timer(timer[timer_number].frequency_step, 1);                 \
      }                                                                       \
                                                                              \
      timer[timer_number].count +=                                            \
       (timer[timer_number].reload << timer[timer_number].prescale);          \
    }                                                                         \
  }                                                                           \

void init_main()
{
  u32 i;

  for(i = 0; i < 4; i++)
  {
    dma[i].start_type = DMA_INACTIVE;
    dma[i].direct_sound_channel = DMA_NO_DIRECT_SOUND;
    timer[i].status = TIMER_INACTIVE;
    timer[i].reload = 0x10000;
    timer[i].stop_cpu_ticks = 0;
  }

  timer[0].direct_sound_channels = TIMER_DS_CHANNEL_BOTH;
  timer[1].direct_sound_channels = TIMER_DS_CHANNEL_NONE;

  cpu_ticks = 0;

  execute_cycles = 960;
  video_count = 960;

  flush_translation_cache_rom();
  flush_translation_cache_ram();
  flush_translation_cache_bios();
}

u32 no_alpha = 0;

u32 update_gba()
{
  irq_type irq_raised = IRQ_NONE;

  do
  {
    cpu_ticks += execute_cycles;

    reg[CHANGED_PC_STATUS] = 0;

    if(gbc_sound_update)
    {
      gbc_update_count++;
      update_gbc_sound(cpu_ticks);
      gbc_sound_update = 0;
    }

    update_timer(0);
    update_timer(1);
    update_timer(2);
    update_timer(3);

    video_count -= execute_cycles;

    if(video_count <= 0)
    {
      u32 vcount = io_registers[REG_VCOUNT];
      u32 dispstat = io_registers[REG_DISPSTAT];

      if((dispstat & 0x02) == 0)
      {
        // Transition from hrefresh to hblank
        video_count += (272);
        dispstat |= 0x02;

        if((dispstat & 0x01) == 0)
        {
          u32 i;
          if(oam_update)
            oam_update_count++;

          if(no_alpha)
            io_registers[REG_BLDCNT] = 0;
          update_scanline();

          // If in visible area also fire HDMA
          for(i = 0; i < 4; i++)
          {
            if(dma[i].start_type == DMA_START_HBLANK)
              dma_transfer(dma + i);
          }
        }

        if(dispstat & 0x10)
          irq_raised |= IRQ_HBLANK;
      }
      else
      {
        // Transition from hblank to next line
        video_count += 960;
        dispstat &= ~0x02;

        vcount++;

        if(vcount == 160)
        {
          // Transition from vrefresh to vblank
          u32 i;

          dispstat |= 0x01;
          if(dispstat & 0x8)
          {
            irq_raised |= IRQ_VBLANK;
          }

          affine_reference_x[0] =
           (s32)(address32(io_registers, 0x28) << 4) >> 4;
          affine_reference_y[0] =
           (s32)(address32(io_registers, 0x2C) << 4) >> 4;
          affine_reference_x[1] =
           (s32)(address32(io_registers, 0x38) << 4) >> 4;
          affine_reference_y[1] =
           (s32)(address32(io_registers, 0x3C) << 4) >> 4;

          for(i = 0; i < 4; i++)
          {
            if(dma[i].start_type == DMA_START_VBLANK)
              dma_transfer(dma + i);
          }
        }
        else

        if(vcount == 228)
        {
          // Transition from vblank to next screen
          dispstat &= ~0x01;

/*        printf("frame update (%x), %d instructions total, %d RAM flushes\n",
           reg[REG_PC], instruction_count - last_frame, flush_ram_count);
          last_frame = instruction_count;
*/
/*          printf("%d gbc audio updates\n", gbc_update_count);
          printf("%d oam updates\n", oam_update_count); */
          gbc_update_count = 0;
          oam_update_count = 0;
          flush_ram_count = 0;

          switch_to_main_thread();

          update_gbc_sound(cpu_ticks);
          gbc_sound_update = 0;

          process_cheats();

          vcount = 0;
        }

        if(vcount == (dispstat >> 8))
        {
          // vcount trigger
          dispstat |= 0x04;
          if(dispstat & 0x20)
          {
            irq_raised |= IRQ_VCOUNT;
          }
        }
        else
        {
          dispstat &= ~0x04;
        }

        io_registers[REG_VCOUNT] = vcount;
      }
      io_registers[REG_DISPSTAT] = dispstat;
    }

    if(irq_raised)
      raise_interrupt(irq_raised);

    execute_cycles = video_count;

    check_timer(0);
    check_timer(1);
    check_timer(2);
    check_timer(3);
  } while(reg[CPU_HALT_STATE] != CPU_ACTIVE);

  return execute_cycles;
}

void reset_gba()
{
  init_main();
  init_memory();
  init_cpu();
  reset_sound();
}

u32 file_length(const char *dummy, FILE *fp)
{
#ifdef PSP_BUILD
  SceIoStat stats;
  sceIoGetstat(filename, &stats);
  return stats.st_size;
#else
  u32 length;

  fseek(fp, 0, SEEK_END);
  length = ftell(fp);
  fseek(fp, 0, SEEK_SET);

  return length;
#endif
}

void change_ext(const char *src, char *buffer, const char *extension)
{
  char *dot_position;
  strcpy(buffer, src);
  dot_position = strrchr(buffer, '.');

  if(dot_position)
    strcpy(dot_position, extension);
}

#define main_savestate_builder(type)            \
void main_##type##_savestate(void)              \
{                                               \
  state_mem_##type##_variable(cpu_ticks);       \
  state_mem_##type##_variable(execute_cycles);  \
  state_mem_##type##_variable(video_count);     \
  state_mem_##type##_array(timer);              \
}

main_savestate_builder(read)
main_savestate_builder(write)


void printout(void *str, u32 val)
{
  printf(str, val);
}