/*
  Adplug - Replayer for many OPL2/OPL3 audio file formats.
  Copyright (C) 1999 - 2006 Simon Peter, <dn.tlp@gmx.net>, et al.

  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.

  This library 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
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

  dtm.cpp - DTM loader by Riven the Mage <riven@ok.ru>
*/
/*
  NOTE: Panning (Ex) effect is ignored.
*/

#include "dtm.h"

/* -------- Public Methods -------------------------------- */

CPlayer *CdtmLoader::factory(Copl *newopl)
{
  return new CdtmLoader(newopl);
}

bool CdtmLoader::load(const std::string &filename, const CFileProvider &fp)
{
        binistream *f = fp.open(filename); if(!f) return false;
	const unsigned char conv_inst[11] = { 2,1,10,9,4,3,6,5,0,8,7 };
	const unsigned short conv_note[12] = { 0x16B, 0x181, 0x198, 0x1B0, 0x1CA, 0x1E5, 0x202, 0x220, 0x241, 0x263, 0x287, 0x2AE };

	int i,j,k,t=0;

	// read header
	f->readString(header.id, 12);
	header.version = f->readInt(1);
	f->readString(header.title, 20); f->readString(header.author, 20);
	header.numpat = f->readInt(1); header.numinst = f->readInt(1);

	// signature exists ? good version ?
	if(memcmp(header.id,"DeFy DTM ",9) || header.version != 0x10)
	  { fp.close (f); return false; }

	header.numinst++;

	// load description
	memset(desc,0,80*16);

	char bufstr[80];

	for (i=0;i<16;i++)
	{
		// get line length
		unsigned char bufstr_length = f->readInt(1);

      if(bufstr_length > 80) {
	fp.close(f);
	return false;
      }

		// read line
		if (bufstr_length)
		{
			f->readString(bufstr,bufstr_length);

			for (j=0;j<bufstr_length;j++)
				if (!bufstr[j])
					bufstr[j] = 0x20;

			bufstr[bufstr_length] = 0;

			strcat(desc,bufstr);
		}

		strcat(desc,"\n");
	}

	// init CmodPlayer
	realloc_instruments(header.numinst);
	realloc_order(100);
	realloc_patterns(header.numpat,64,9);
	init_notetable(conv_note);
	init_trackord();

	// load instruments
	for (i=0;i<header.numinst;i++)
	{
		unsigned char name_length = f->readInt(1);

		if (name_length)
			f->readString(instruments[i].name, name_length);

		instruments[i].name[name_length] = 0;

		for(j = 0; j < 12; j++)
		  instruments[i].data[j] = f->readInt(1);

		for (j=0;j<11;j++)
			inst[i].data[conv_inst[j]] = instruments[i].data[j];
	}

	// load order
	for(i = 0; i < 100; i++) order[i] = f->readInt(1);

	nop = header.numpat;

	unsigned char *pattern = new unsigned char [0x480];

	// load tracks
	for (i=0;i<nop;i++)
	{
		unsigned short packed_length;

		packed_length = f->readInt(2);

		unsigned char *packed_pattern = new unsigned char [packed_length];

		for(j = 0; j < packed_length; j++)
		  packed_pattern[j] = f->readInt(1);

		long unpacked_length = unpack_pattern(packed_pattern,packed_length,pattern,0x480);

		delete [] packed_pattern;

		if (!unpacked_length)
		{
			delete pattern;
			fp.close(f);
			return false;
		}

		// convert pattern
		for (j=0;j<9;j++)
		{
			for (k=0;k<64;k++)
			{
				dtm_event *event = (dtm_event *)&pattern[(k*9+j)*2];

				// instrument
				if (event->byte0 == 0x80)
				{
					if (event->byte1 <= 0x80)
						tracks[t][k].inst = event->byte1 + 1;
				}

				// note + effect
				else
				{
					tracks[t][k].note = event->byte0;

					if ((event->byte0 != 0) && (event->byte0 != 127))
							tracks[t][k].note++;

					// convert effects
					switch (event->byte1 >> 4)
					{
						case 0x0: // pattern break
							if ((event->byte1 & 15) == 1)
								tracks[t][k].command = 13;
							break;

						case 0x1: // freq. slide up
							tracks[t][k].command = 28;
							tracks[t][k].param1 = event->byte1 & 15;
							break;

						case 0x2: // freq. slide down
							tracks[t][k].command = 28;
							tracks[t][k].param2 = event->byte1 & 15;
							break;

						case 0xA: // set carrier volume
						case 0xC: // set instrument volume
							tracks[t][k].command = 22;
							tracks[t][k].param1 = (0x3F - (event->byte1 & 15)) >> 4;
							tracks[t][k].param2 = (0x3F - (event->byte1 & 15)) & 15;
							break;

						case 0xB: // set modulator volume
							tracks[t][k].command = 21;
							tracks[t][k].param1 = (0x3F - (event->byte1 & 15)) >> 4;
							tracks[t][k].param2 = (0x3F - (event->byte1 & 15)) & 15;
							break;

						case 0xE: // set panning
							break;

						case 0xF: // set speed
							tracks[t][k].command = 13;
							tracks[t][k].param2 = event->byte1 & 15;
							break;
					}
				}
			}

			t++;
		}
	}

	delete [] pattern;
	fp.close(f);

	// order length
	for (i=0;i<100;i++)
	{
		if (order[i] >= 0x80)
		{
			length = i;

			if (order[i] == 0xFF)
				restartpos = 0;
			else
				restartpos = order[i] - 0x80;

			break;
		}
	}

	// initial speed
	initspeed = 2;

	rewind(0);

	return true;
}

void CdtmLoader::rewind(int subsong)
{
	CmodPlayer::rewind(subsong);

	// default instruments
	for (int i=0;i<9;i++)
	{
		channel[i].inst = i;

		channel[i].vol1 = 63 - (inst[i].data[10] & 63);
		channel[i].vol2 = 63 - (inst[i].data[9] & 63);
	}
}

float CdtmLoader::getrefresh()
{
	return 18.2f;
}

std::string CdtmLoader::gettype()
{
	return std::string("DeFy Adlib Tracker");
}

std::string CdtmLoader::gettitle()
{
	return std::string(header.title);
}

std::string CdtmLoader::getauthor()
{
	return std::string(header.author);
}

std::string CdtmLoader::getdesc()
{
	return std::string(desc);
}

std::string CdtmLoader::getinstrument(unsigned int n)
{
	return std::string(instruments[n].name);
}

unsigned int CdtmLoader::getinstruments()
{
	return header.numinst;
}

/* -------- Private Methods ------------------------------- */

long CdtmLoader::unpack_pattern(unsigned char *ibuf, long ilen, unsigned char *obuf, long olen)
{
	unsigned char *input = ibuf;
	unsigned char *output = obuf;

	long input_length = 0;
	long output_length = 0;

	unsigned char repeat_byte, repeat_counter;

	// RLE
	while (input_length < ilen)
	{
		repeat_byte = input[input_length++];

		if ((repeat_byte & 0xF0) == 0xD0)
		{
			repeat_counter = repeat_byte & 15;
			repeat_byte = input[input_length++];
		}
		else
			repeat_counter = 1;

		for (int i=0;i<repeat_counter;i++)
		{
			if (output_length < olen)
				output[output_length++] = repeat_byte;
		}
	}

	return output_length;
}
