
#include "main_sp.h"
#include "global.h"


// ----------------------------------------------------------------------------
// functions for loading Supaplex level
// ----------------------------------------------------------------------------

static void setTapeInfoToDefaults_SP(void)
{
  native_sp_level.demo.is_available = FALSE;
  native_sp_level.demo.length = 0;
}

void setLevelInfoToDefaults_SP(void)
{
  LevelInfoType *header = &native_sp_level.header;
  char *empty_title = "-------- EMPTY --------";
  int i, x, y;

  native_sp_level.width  = SP_STD_PLAYFIELD_WIDTH;
  native_sp_level.height = SP_STD_PLAYFIELD_HEIGHT;

  for (x = 0; x < native_sp_level.width; x++)
    for (y = 0; y < native_sp_level.height; y++)
      native_sp_level.playfield[x][y] = fiSpace;

  // copy string (without terminating '\0' character!)
  for (i = 0; i < SP_LEVEL_NAME_LEN; i++)
    header->LevelTitle[i] = empty_title[i];

  header->InitialGravity = 0;
  header->Version = 0;
  header->InitialFreezeZonks = 0;
  header->InfotronsNeeded = 0;
  header->SpecialPortCount = 0;
  header->SpeedByte = 0;
  header->CheckSumByte = 0;
  header->DemoRandomSeed = 0;

  for (i = 0; i < SP_MAX_SPECIAL_PORTS; i++)
  {
    SpecialPortType *port = &header->SpecialPort[i];

    port->PortLocation = 0;
    port->Gravity = 0;
    port->FreezeZonks = 0;
    port->FreezeEnemies = 0;
  }

  // set raw header bytes (used for subsequent buffer zone) to "hardware"
  for (i = 0; i < SP_HEADER_SIZE; i++)
    native_sp_level.header_raw_bytes[i] = 0x20;

  setTapeInfoToDefaults_SP();
}

void copyInternalEngineVars_SP(void)
{
  int count;
  int i, x, y;

  LInfo = native_sp_level.header;

  FieldWidth  = native_sp_level.width;
  FieldHeight = native_sp_level.height;
  HeaderSize = 96;

  FieldMax = (FieldWidth * FieldHeight) + HeaderSize - 1;
  LevelMax = (FieldWidth * FieldHeight) - 1;

  // initialize preceding playfield buffer
  for (i = -game_sp.preceding_buffer_size; i < 0; i++)
    PlayField16[i] = 0;

  // initialize preceding playfield buffer
  for (i = -SP_MAX_PLAYFIELD_WIDTH; i < 0; i++)
    PlayField8[i] = 0;

  count = 0;
  for (i = 0; game_sp.preceding_buffer[i] != NULL; i++)
  {
    char *s = game_sp.preceding_buffer[i];
    boolean hi_byte = FALSE;	// little endian data => start with low byte

    while (s[0] != '\0' && s[1] != '\0')
    {
      int hi_nibble = s[0] - (s[0] > '9' ? 'a' - 10 : '0');
      int lo_nibble = s[1] - (s[1] > '9' ? 'a' - 10 : '0');
      int byte = (hi_nibble << 4) | lo_nibble;

      if (hi_byte)
	byte <<= 8;

      PlayField16[-game_sp.preceding_buffer_size + count] |= byte;

      if (hi_byte)
	count++;

      hi_byte = !hi_byte;

      s += 2;

      while (*s == ' ')
	s++;
    }
  }

  count = 0;
  for (y = 0; y < native_sp_level.height; y++)
    for (x = 0; x < native_sp_level.width; x++)
      PlayField8[count++] = native_sp_level.playfield[x][y];

  // add raw header bytes to subsequent playfield buffer zone
  for (i = 0; i < SP_HEADER_SIZE; i++)
    PlayField8[count++] = native_sp_level.header_raw_bytes[i];

  for (i = 0; i < count; i++)
  {
    PlayField16[i] = PlayField8[i];
    DisPlayField[i] = PlayField8[i];
    PlayField8[i] = 0;
  }

  if (native_sp_level.demo.is_available)
    DemoAvailable = True;

  GravityFlag = LInfo.InitialGravity;
  FreezeZonks = LInfo.InitialFreezeZonks;

  LevelLoaded = True;

  // random seed set by main game tape code to native random generator seed
}

static void LoadNativeLevelFromFileStream_SP(File *file, int width, int height,
					     boolean demo_available)
{
  LevelInfoType *header = &native_sp_level.header;
  int i, x, y;

  // for details of the Supaplex level format, see Herman Perk's Supaplex
  // documentation file "SPFIX63.DOC" from his Supaplex "SpeedFix" package

  native_sp_level.width  = MIN(width,  SP_MAX_PLAYFIELD_WIDTH);
  native_sp_level.height = MIN(height, SP_MAX_PLAYFIELD_HEIGHT);

  // read level playfield (width * height == 60 * 24 tiles == 1440 bytes)
  // (MPX levels may have non-standard playfield size -- check max. size)
  for (y = 0; y < height; y++)
  {
    for (x = 0; x < width; x++)
    {
      byte element = getFile8Bit(file);

      if (x < SP_MAX_PLAYFIELD_WIDTH &&
	  y < SP_MAX_PLAYFIELD_HEIGHT)
	native_sp_level.playfield[x][y] = element;
    }
  }

  // read level header (96 bytes)

  ReadUnusedBytesFromFile(file, 4);	// (not used by Supaplex engine)

  // initial gravity: 1 == "on", anything else (0) == "off"
  header->InitialGravity = getFile8Bit(file);

  // SpeedFixVersion XOR 0x20
  header->Version = getFile8Bit(file);

  // level title in uppercase letters, padded with dashes ("-") (23 bytes)
  for (i = 0; i < SP_LEVEL_NAME_LEN; i++)
    header->LevelTitle[i] = getFile8Bit(file);

  // initial "freeze zonks": 2 == "on", anything else (0, 1) == "off"
  header->InitialFreezeZonks = getFile8Bit(file);

  // number of infotrons needed; 0 means that Supaplex will count the total
  // amount of infotrons in the level and use the low byte of that number
  // (a multiple of 256 infotrons will result in "0 infotrons needed"!)
  header->InfotronsNeeded = getFile8Bit(file);

  // number of special ("gravity") port entries below (maximum 10 allowed)
  header->SpecialPortCount = getFile8Bit(file);

  // database of properties of up to 10 special ports (6 bytes per port)
  for (i = 0; i < SP_MAX_SPECIAL_PORTS; i++)
  {
    SpecialPortType *port = &header->SpecialPort[i];

    /* high and low byte of the location of a special port; if (x, y) are the
       coordinates of a port in the field and (0, 0) is the top-left corner,
       the 16 bit value here calculates as 2 * (x + (y * 60)) (this is twice
       of what may be expected: Supaplex works with a game field in memory
       which is 2 bytes per tile) */
    port->PortLocation = getFile16BitBE(file);		// yes, big endian

    // change gravity: 1 == "turn on", anything else (0) == "turn off"
    port->Gravity = getFile8Bit(file);

    // "freeze zonks": 2 == "turn on", anything else (0, 1) == "turn off"
    port->FreezeZonks = getFile8Bit(file);

    // "freeze enemies": 1 == "turn on", anything else (0) == "turn off"
    port->FreezeEnemies = getFile8Bit(file);

    ReadUnusedBytesFromFile(file, 1);	// (not used by Supaplex engine)
  }

  // SpeedByte XOR Highbyte(RandomSeed)
  header->SpeedByte = getFile8Bit(file);

  // CheckSum XOR SpeedByte
  header->CheckSumByte = getFile8Bit(file);

  // random seed used for recorded demos
  header->DemoRandomSeed = getFile16BitLE(file);	// yes, little endian

  // auto-determine number of infotrons if it was stored as "0" -- see above
  if (header->InfotronsNeeded == 0)
  {
    for (x = 0; x < native_sp_level.width; x++)
      for (y = 0; y < native_sp_level.height; y++)
	if (native_sp_level.playfield[x][y] == fiInfotron)
	  header->InfotronsNeeded++;

    header->InfotronsNeeded &= 0xff;	// only use low byte -- see above
  }

  // read raw level header bytes (96 bytes)

  seekFile(file, -(SP_HEADER_SIZE), SEEK_CUR);	// rewind file
  for (i = 0; i < SP_HEADER_SIZE; i++)
    native_sp_level.header_raw_bytes[i] = getByteFromFile(file);

  // also load demo tape, if available (only in single level files)

  if (demo_available)
  {
    int level_nr = getFile8Bit(file);

    level_nr &= 0x7f;			// clear highest bit
    level_nr = (level_nr < 1   ? 1   :
		level_nr > 111 ? 111 : level_nr);

    native_sp_level.demo.level_nr = level_nr;

    for (i = 0; i < SP_MAX_TAPE_LEN && !checkEndOfFile(file); i++)
    {
      native_sp_level.demo.data[i] = getFile8Bit(file);

      if (native_sp_level.demo.data[i] == 0xff)	// "end of demo" byte
	break;
    }

    if (i >= SP_MAX_TAPE_LEN)
      Warn("SP demo truncated: size exceeds maximum SP demo size %d",
	    SP_MAX_TAPE_LEN);

    native_sp_level.demo.length = i;
    native_sp_level.demo.is_available = (native_sp_level.demo.length > 0);
  }
}

boolean LoadNativeLevel_SP(char *filename, int level_pos,
			   boolean level_info_only)
{
  File *file;
  int i, l, x, y;
  char name_first, name_last;
  struct LevelInfo_SP multipart_level;
  int multipart_xpos, multipart_ypos;
  boolean is_multipart_level;
  boolean is_first_part;
  boolean reading_multipart_level = FALSE;
  boolean use_empty_level = FALSE;
  LevelInfoType *header = &native_sp_level.header;
  boolean is_single_level_file = (strSuffixLower(filename, ".sp") ||
				  strSuffixLower(filename, ".mpx"));
  boolean demo_available = is_single_level_file;
  boolean is_mpx_file = strSuffixLower(filename, ".mpx");
  int file_seek_pos = level_pos * SP_STD_LEVEL_SIZE;
  int level_width  = SP_STD_PLAYFIELD_WIDTH;
  int level_height = SP_STD_PLAYFIELD_HEIGHT;

  // always start with reliable default values
  setLevelInfoToDefaults_SP();
  copyInternalEngineVars_SP();

  if (!(file = openFile(filename, MODE_READ)))
  {
    if (!level_info_only)
      Warn("cannot open file '%s' -- using empty level", filename);

    return FALSE;
  }

  if (is_mpx_file)
  {
    char mpx_chunk_name[4 + 1];
    int mpx_version;
    int mpx_level_count;
    LevelDescriptor *mpx_level_desc;

    getFileChunkBE(file, mpx_chunk_name, NULL);

    if (!strEqual(mpx_chunk_name, "MPX "))
    {
      Warn("cannot find MPX ID in file '%s' -- using empty level", filename);

      return FALSE;
    }

    mpx_version = getFile16BitLE(file);

    if (mpx_version != 1)
    {
      Warn("unknown MPX version in file '%s' -- using empty level", filename);

      return FALSE;
    }

    mpx_level_count = getFile16BitLE(file);

    if (mpx_level_count < 1)
    {
      Warn("no MPX levels found in file '%s' -- using empty level", filename);

      return FALSE;
    }

    if (level_pos >= mpx_level_count)
    {
      Warn("MPX level not found in file '%s' -- using empty level", filename);

      return FALSE;
    }

    mpx_level_desc = checked_calloc(mpx_level_count * sizeof(LevelDescriptor));

    for (i = 0; i < mpx_level_count; i++)
    {
      LevelDescriptor *ldesc = &mpx_level_desc[i];

      ldesc->Width  = getFile16BitLE(file);
      ldesc->Height = getFile16BitLE(file);
      ldesc->OffSet = getFile32BitLE(file);	// starts with 1, not with 0
      ldesc->Size   = getFile32BitLE(file);
    }

    level_width  = mpx_level_desc[level_pos].Width;
    level_height = mpx_level_desc[level_pos].Height;

    file_seek_pos = mpx_level_desc[level_pos].OffSet - 1;
  }

  // position file stream to the requested level (in case of level package)
  if (seekFile(file, file_seek_pos, SEEK_SET) != 0)
  {
    Warn("cannot fseek in file '%s' -- using empty level", filename);

    return FALSE;
  }

  /* there exist Supaplex level package files with multi-part levels which
     can be detected as follows: instead of leading and trailing dashes ('-')
     to pad the level name, they have leading and trailing numbers which are
     the x and y coordinations of the current part of the multi-part level;
     if there are '?' characters instead of numbers on the left or right side
     of the level name, the multi-part level consists of only horizontal or
     vertical parts */

  for (l = level_pos; l < SP_NUM_LEVELS_PER_PACKAGE; l++)
  {
    LoadNativeLevelFromFileStream_SP(file, level_width, level_height,
				     demo_available);

    // check if this level is a part of a bigger multi-part level

    if (is_single_level_file)
      break;

    name_first = header->LevelTitle[0];
    name_last  = header->LevelTitle[SP_LEVEL_NAME_LEN - 1];

    is_multipart_level =
      ((name_first == '?' || (name_first >= '0' && name_first <= '9')) &&
       (name_last  == '?' || (name_last  >= '0' && name_last  <= '9')));

    is_first_part =
      ((name_first == '?' || name_first == '1') &&
       (name_last  == '?' || name_last  == '1'));

    if (is_multipart_level)
    {
      // correct leading multipart level meta information in level name
      for (i = 0;
	   i < SP_LEVEL_NAME_LEN && header->LevelTitle[i] == name_first;
	   i++)
	header->LevelTitle[i] = '-';

      // correct trailing multipart level meta information in level name
      for (i = SP_LEVEL_NAME_LEN - 1;
	   i >= 0 && header->LevelTitle[i] == name_last;
	   i--)
	header->LevelTitle[i] = '-';
    }

    // ---------- check for normal single level ----------

    if (!reading_multipart_level && !is_multipart_level)
    {
      // the current level is simply a normal single-part level, and we are
      // not reading a multi-part level yet, so return the level as it is

      break;
    }

    // ---------- check for empty level (unused multi-part) ----------

    if (!reading_multipart_level && is_multipart_level && !is_first_part)
    {
      // this is a part of a multi-part level, but not the first part
      // (and we are not already reading parts of a multi-part level);
      // in this case, use an empty level instead of the single part

      use_empty_level = TRUE;

      break;
    }

    // ---------- check for finished multi-part level ----------

    if (reading_multipart_level &&
	(!is_multipart_level ||
	 !strEqualN(header->LevelTitle, multipart_level.header.LevelTitle,
		    SP_LEVEL_NAME_LEN)))
    {
      // we are already reading parts of a multi-part level, but this level is
      // either not a multi-part level, or a part of a different multi-part
      // level; in both cases, the multi-part level seems to be complete

      break;
    }

    // ---------- here we have one part of a multi-part level ----------

    reading_multipart_level = TRUE;

    if (is_first_part)	// start with first part of new multi-part level
    {
      // copy level info structure from first part
      multipart_level = native_sp_level;

      // clear playfield of new multi-part level
      for (x = 0; x < SP_MAX_PLAYFIELD_WIDTH; x++)
	for (y = 0; y < SP_MAX_PLAYFIELD_HEIGHT; y++)
	  multipart_level.playfield[x][y] = fiSpace;
    }

    if (name_first == '?')
      name_first = '1';
    if (name_last == '?')
      name_last = '1';

    multipart_xpos = (int)(name_first - '0');
    multipart_ypos = (int)(name_last  - '0');

    if (multipart_xpos * SP_STD_PLAYFIELD_WIDTH  > SP_MAX_PLAYFIELD_WIDTH ||
	multipart_ypos * SP_STD_PLAYFIELD_HEIGHT > SP_MAX_PLAYFIELD_HEIGHT)
    {
      Warn("multi-part level is too big -- ignoring part of it");

      break;
    }

    multipart_level.width  = MAX(multipart_level.width,
				 multipart_xpos * SP_STD_PLAYFIELD_WIDTH);
    multipart_level.height = MAX(multipart_level.height,
				 multipart_ypos * SP_STD_PLAYFIELD_HEIGHT);

    // copy level part at the right position of multi-part level
    for (x = 0; x < SP_STD_PLAYFIELD_WIDTH; x++)
    {
      for (y = 0; y < SP_STD_PLAYFIELD_HEIGHT; y++)
      {
	int start_x = (multipart_xpos - 1) * SP_STD_PLAYFIELD_WIDTH;
	int start_y = (multipart_ypos - 1) * SP_STD_PLAYFIELD_HEIGHT;

	multipart_level.playfield[start_x + x][start_y + y] =
	  native_sp_level.playfield[x][y];
      }
    }
  }

  closeFile(file);

  if (use_empty_level)
  {
    setLevelInfoToDefaults_SP();

    Warn("single part of multi-part level -- using empty level");
  }

  if (reading_multipart_level)
    native_sp_level = multipart_level;

  copyInternalEngineVars_SP();

  return TRUE;
}

boolean SaveNativeLevel_SP(char *filename)
{
  LevelInfoType *header = &native_sp_level.header;
  FILE *file;
  int i, x, y;

  if (!(file = fopen(filename, MODE_WRITE)))
  {
    Warn("cannot save native level file '%s'", filename);

    return FALSE;
  }

  // write level playfield (width * height == 60 * 24 tiles == 1440 bytes)
  for (y = 0; y < native_sp_level.height; y++)
    for (x = 0; x < native_sp_level.width; x++)
      putFile8Bit(file, native_sp_level.playfield[x][y]);

  // write level header (96 bytes)

  WriteUnusedBytesToFile(file, 4);

  putFile8Bit(file, header->InitialGravity);
  putFile8Bit(file, header->Version);

  for (i = 0; i < SP_LEVEL_NAME_LEN; i++)
    putFile8Bit(file, header->LevelTitle[i]);

  putFile8Bit(file, header->InitialFreezeZonks);
  putFile8Bit(file, header->InfotronsNeeded);
  putFile8Bit(file, header->SpecialPortCount);

  for (i = 0; i < SP_MAX_SPECIAL_PORTS; i++)
  {
    SpecialPortType *port = &header->SpecialPort[i];

    putFile16BitBE(file, port->PortLocation);
    putFile8Bit(file, port->Gravity);
    putFile8Bit(file, port->FreezeZonks);
    putFile8Bit(file, port->FreezeEnemies);

    WriteUnusedBytesToFile(file, 1);
  }

  putFile8Bit(file, header->SpeedByte);
  putFile8Bit(file, header->CheckSumByte);
  putFile16BitLE(file, header->DemoRandomSeed);

  // also save demo tape, if available

  if (native_sp_level.demo.is_available)
  {
    putFile8Bit(file, native_sp_level.demo.level_nr);

    for (i = 0; i < native_sp_level.demo.length; i++)
      putFile8Bit(file, native_sp_level.demo.data[i]);

    putFile8Bit(file, 0xff);	// "end of demo" byte
  }

  fclose(file);

  return TRUE;
}
