// ----------------------------------------------------------------------------
//   ___  ___  ___  ___       ___  ____  ___  _  _
//  /__/ /__/ /  / /__  /__/ /__    /   /_   / |/ /
// /    / \  /__/ ___/ ___/ ___/   /   /__  /    /  emulator
//
// ----------------------------------------------------------------------------
// Copyright 2003, 2004 Greg Stanton
// 
// 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., 675 Mass Ave, Cambridge, MA 02139, USA.
// ----------------------------------------------------------------------------
// ProSystem.cpp
// ----------------------------------------------------------------------------
#include "ProSystem.h"
#define PRO_SYSTEM_STATE_HEADER "PRO-SYSTEM STATE"
#define PRO_SYSTEM_SOURCE "ProSystem.cpp"

bool prosystem_active = false;
bool prosystem_paused = false;
word prosystem_frequency = 60;
byte prosystem_frame = 0;
word prosystem_scanlines = 262;
uint prosystem_cycles = 0;

// ----------------------------------------------------------------------------
// Reset
// ----------------------------------------------------------------------------
void prosystem_Reset( ) {
  if(cartridge_IsLoaded( )) {
    prosystem_paused = false;
    prosystem_frame = 0;
    region_Reset( );
    tia_Clear( );
    tia_Reset( );
    pokey_Clear( );
    pokey_Reset( );
    memory_Reset( );
    maria_Clear( );
    maria_Reset( );
	riot_Reset ( );
    if(bios_enabled) {
      bios_Store( );
    }
    else {
      cartridge_Store( );
    }
    prosystem_cycles = sally_ExecuteRES( );
    prosystem_active = true;
  }
}

// ----------------------------------------------------------------------------
// ExecuteFrame
// ----------------------------------------------------------------------------
void prosystem_ExecuteFrame(const byte* input) {
  riot_SetInput(input);
  
  for(maria_scanline = 1; maria_scanline <= prosystem_scanlines; maria_scanline++) {
    if(maria_scanline == maria_displayArea.top) {
      memory_ram[MSTAT] = 0;
    }
    if(maria_scanline == maria_displayArea.bottom) {
      memory_ram[MSTAT] = 128;
    }
    
    uint cycles;
    prosystem_cycles %= 456;
    while(prosystem_cycles < 28) {
      cycles = sally_ExecuteInstruction( );
      prosystem_cycles += (cycles << 2);
      if(riot_timing) {
        riot_UpdateTimer(cycles);
      }
      if(memory_ram[WSYNC] && !(cartridge_flags & CARTRIDGE_WSYNC_MASK)) {
        prosystem_cycles = 456;
        memory_ram[WSYNC] = false;
        break;
      }
    }
    
    cycles = maria_RenderScanline( );
    if(cartridge_flags & CARTRIDGE_CYCLE_STEALING_MASK) {
      prosystem_cycles += cycles;
    }
    
    while(prosystem_cycles < 456) {
      cycles = sally_ExecuteInstruction( );
      prosystem_cycles += (cycles << 2);
      if(riot_timing) {
        riot_UpdateTimer(cycles);
      }
      if(memory_ram[WSYNC] && !(cartridge_flags & CARTRIDGE_WSYNC_MASK)) {
        prosystem_cycles = 456;
        memory_ram[WSYNC] = false;
        break;
      }
    }
    tia_Process(2);
    //if(cartridge_pokey) {
      pokey_Process(2);
    //}
  }
  prosystem_frame++;
  if(prosystem_frame >= prosystem_frequency) {
    prosystem_frame = 0;
  }
}

// ----------------------------------------------------------------------------
// Save
// ----------------------------------------------------------------------------
bool prosystem_Save(std::string filename, bool compress) {
  if(filename.empty( ) || filename.length( ) == 0) {
    logger_LogError("Filename is invalid.", PRO_SYSTEM_SOURCE);
    return false;
  }

  logger_LogInfo("Saving game state to file " + filename + ".", PRO_SYSTEM_SOURCE);
  
  byte buffer[32829] = {0};
  uint size = 0;
  
  uint index;
  for(index = 0; index < 16; index++) {
    buffer[size + index] = PRO_SYSTEM_STATE_HEADER[index];
  }
  size += 16;
  
  buffer[size++] = 1;
  for(index = 0; index < 4; index++) {
    buffer[size + index] = 0;
  }
  size += 4;

  for(index = 0; index < 32; index++) {
    buffer[size + index] = cartridge_digest[index];
  }
  size += 32;

  buffer[size++] = sally_a;
  buffer[size++] = sally_x;
  buffer[size++] = sally_y;
  buffer[size++] = sally_p;
  buffer[size++] = sally_s;
  buffer[size++] = sally_pc.b.l;
  buffer[size++] = sally_pc.b.h;
  buffer[size++] = cartridge_bank;

  for(index = 0; index < 16384; index++) {
    buffer[size + index] = memory_ram[index];
  }
  size += 16384;
  
  if(cartridge_type == CARTRIDGE_TYPE_SUPERCART_RAM) {
    for(index = 0; index < 16384; index++) {
      buffer[size + index] = memory_ram[16384 + index];
    } 
    size += 16384;
  }
  
  if(!compress) {
    FILE* file = fopen(filename.c_str( ), "wb");
    if(file == NULL) {
      logger_LogError("Failed to open the file " + filename + " for writing.", PRO_SYSTEM_SOURCE);
      return false;
    }
  
    if(fwrite(buffer, 1, size, file) != size) {
      fclose(file);
      logger_LogError("Failed to write the save state data to the file " + filename + ".", PRO_SYSTEM_SOURCE);
      return false;
    }
  
    fclose(file);
  }
  else {
    if(!archive_Compress(filename.c_str( ), "Save.sav", buffer, size)) {
      logger_LogError("Failed to compress the save state data to the file " + filename + ".", PRO_SYSTEM_SOURCE);
      return false;
    }
  }
  return true;
}

// ----------------------------------------------------------------------------
// Load
// ----------------------------------------------------------------------------
bool prosystem_Load(const std::string filename) {
  if(filename.empty( ) || filename.length( ) == 0) {
    logger_LogError("Filename is invalid.", PRO_SYSTEM_SOURCE);    
    return false;
  }

 
  logger_LogInfo("Loading game state from file " + filename + ".", PRO_SYSTEM_SOURCE);
  
  byte buffer[32829] = {0};
  uint size = archive_GetUncompressedFileSize(filename);
  if(size == 0) {
    FILE* file = fopen(filename.c_str( ), "rb");
    if(file == NULL) {
      logger_LogError("Failed to open the file " + filename + " for reading.", PRO_SYSTEM_SOURCE);
      return false;
    }

    if(fseek(file, 0, SEEK_END)) {
      fclose(file);
      logger_LogError("Failed to find the end of the file.", PRO_SYSTEM_SOURCE);
      return false;
    }
  
    size = ftell(file);
    if(fseek(file, 0, SEEK_SET)) {
      fclose(file);
      logger_LogError("Failed to find the size of the file.", PRO_SYSTEM_SOURCE);
      return false;
    }

    if(size != 16445 && size != 32829) {
      fclose(file);
      logger_LogError("Save state file has an invalid size.", PRO_SYSTEM_SOURCE);
      return false;
    }
  
    if(fread(buffer, 1, size, file) != size && ferror(file)) {
      fclose(file);
      logger_LogError("Failed to read the file data.", PRO_SYSTEM_SOURCE);
      return false;
    }
    fclose(file);
  }  
  else if(size == 16445 || size == 32829) {
    archive_Uncompress(filename, buffer, size);
  }
  else {
    logger_LogError("Save state file has an invalid size.", PRO_SYSTEM_SOURCE);
    return false;
  }

  uint offset = 0;
  uint index;
  for(index = 0; index < 16; index++) {
    if(buffer[offset + index] != PRO_SYSTEM_STATE_HEADER[index]) {
      logger_LogError("File is not a valid ProSystem save state.", PRO_SYSTEM_SOURCE);
      return false;
    }
  }
  offset += 16;
  byte version = buffer[offset++];
  
  uint date = 0;
  for(index = 0; index < 4; index++) {
  }
  offset += 4;
  
  prosystem_Reset( );
  
  char digest[33] = {0};
  for(index = 0; index < 32; index++) {
    digest[index] = buffer[offset + index];
  }
  offset += 32;
  if(cartridge_digest != std::string(digest)) {
    logger_LogError("Load state digest [" + std::string(digest) + "] does not match loaded cartridge digest [" + cartridge_digest + "].", PRO_SYSTEM_SOURCE);
    return false;
  }
  
  sally_a = buffer[offset++];
  sally_x = buffer[offset++];
  sally_y = buffer[offset++];
  sally_p = buffer[offset++];
  sally_s = buffer[offset++];
  sally_pc.b.l = buffer[offset++];
  sally_pc.b.h = buffer[offset++];
  
  cartridge_StoreBank(buffer[offset++]);

  for(index = 0; index < 16384; index++) {
    memory_ram[index] = buffer[offset + index];
  }
  offset += 16384;

  if(cartridge_type == CARTRIDGE_TYPE_SUPERCART_RAM) {
    if(size != 32829) {
      logger_LogError("Save state file has an invalid size.", PRO_SYSTEM_SOURCE);
      return false;
    }
    for(index = 0; index < 16384; index++) {
      memory_ram[16384 + index] = buffer[offset + index];
    }
    offset += 16384; 
  }  

  return true;
}

// ----------------------------------------------------------------------------
// Pause
// ----------------------------------------------------------------------------
void prosystem_Pause(bool pause) {
  if(prosystem_active) {
    prosystem_paused = pause;
  }
}

// ----------------------------------------------------------------------------
// Close
// ----------------------------------------------------------------------------
void prosystem_Close( ) {
  prosystem_active = false;
  prosystem_paused = false;
  cartridge_Release( );
  maria_Reset( );
  maria_Clear( );
  memory_Reset( );
  tia_Reset( );
  tia_Clear( );
}