/* Mednafen - Multi-system Emulator
*
* 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 "system.h"
#include <cstring>


namespace MDFN_IEN_WSWAN
{
#define MK_SAMPLE_CACHE	\
	{    \
	int sample; \
	sample = (((ram[((SampleRAMPos << 6) + (sample_pos[ch] >> 1) + (ch << 4)) ] >> ((sample_pos[ch] & 1) ? 4 : 0)) & 0x0F)) - 0x8;    \
	sample_cache[ch][0] = sample * ((volume[ch] >> 4) & 0x0F);        \
	sample_cache[ch][1] = sample * ((volume[ch] >> 0) & 0x0F);        \
	}

#define MK_SAMPLE_CACHE_NOISE	\
	{    \
	int sample; \
	sample = ((nreg & 1) ? 0xF : 0x0) - 0x8;	\
	sample_cache[ch][0] = sample * ((volume[ch] >> 4) & 0x0F);        \
	sample_cache[ch][1] = sample * ((volume[ch] >> 0) & 0x0F);        \
	}


#define SYNCSAMPLE(wt)	\
	{	\
	int32 left = sample_cache[ch][0], right = sample_cache[ch][1];	\
	WaveSynth.offset_inline(wt, left - last_val[ch][0], sbuf[0]);	\
	WaveSynth.offset_inline(wt, right - last_val[ch][1], sbuf[1]);	\
	last_val[ch][0] = left;	\
	last_val[ch][1] = right;	\
	}

#define SYNCSAMPLE_NOISE(wt)  \
	{    \
	int32 left = sample_cache[ch][0], right = sample_cache[ch][1];      \
	NoiseSynth.offset_inline(wt, left - last_val[ch][0], sbuf[0]);      \
	NoiseSynth.offset_inline(wt, right - last_val[ch][1], sbuf[1]);     \
	last_val[ch][0] = left;     \
	last_val[ch][1] = right;    \
	}

	void Sound::Update()
	{
		int32 run_time;
		const uint8 *ram = sys->memory.wsRAM;
		const uint32 current_ts = sys->cpu.timestamp;

		//printf("%d\n", v30mz_timestamp);
		//printf("%02x %02x\n", control, noise_control);
		run_time = current_ts - last_ts;

		for(unsigned int ch = 0; ch < 4; ch++)
		{
			// Channel is disabled?
			if(!(control & (1 << ch)))
				continue;

			if(ch == 1 && (control & 0x20)) // Direct D/A mode?
			{
				int32 neoval = (volume[ch] - 0x80) * voice_volume;

				VoiceSynth.offset(current_ts, neoval - last_v_val, sbuf[0]);
				VoiceSynth.offset(current_ts, neoval - last_v_val, sbuf[1]);

				last_v_val = neoval;
			}
			else if(ch == 2 && (control & 0x40) && sweep_value) // Sweep
			{
				uint32 tmp_pt = 2048 - period[ch];
				uint32 meow_timestamp = current_ts - run_time;
				uint32 tmp_run_time = run_time;

				while(tmp_run_time)
				{
					int32 sub_run_time = tmp_run_time;

					if(sub_run_time > sweep_8192_divider)
						sub_run_time = sweep_8192_divider;

					sweep_8192_divider -= sub_run_time;
					if(sweep_8192_divider <= 0)
					{
						sweep_8192_divider += 8192;
						sweep_counter--;
						if(sweep_counter <= 0)
						{
							sweep_counter = sweep_step + 1;
							period[ch] = (period[ch] + (int8)sweep_value) & 0x7FF;
						}
					}

					meow_timestamp += sub_run_time;
					if(tmp_pt > 4)
					{
						period_counter[ch] -= sub_run_time;
						while(period_counter[ch] <= 0)
						{
							sample_pos[ch] = (sample_pos[ch] + 1) & 0x1F;

							MK_SAMPLE_CACHE;
							SYNCSAMPLE(meow_timestamp + period_counter[ch]);
							period_counter[ch] += tmp_pt;
						}
					}
					tmp_run_time -= sub_run_time;
				}
			}
			else if(ch == 3 && (noise_control & 0x10)) //(control & 0x80)) // Noise
			{
				uint32 tmp_pt = 2048 - period[ch];

				period_counter[ch] -= run_time;
				while(period_counter[ch] <= 0)
				{
					static const uint8 stab[8] = { 14, 10, 13, 4, 8, 6, 9, 11 };
					nreg = ((nreg << 1) | ((1 ^ (nreg >> 7) ^ (nreg >> stab[noise_control & 0x7])) & 1)) & 0x7FFF;

					if(control & 0x80)
					{
						MK_SAMPLE_CACHE_NOISE;
						SYNCSAMPLE_NOISE(current_ts + period_counter[ch]);
					}
					else if(tmp_pt > 4)
					{
						sample_pos[ch] = (sample_pos[ch] + 1) & 0x1F;
						MK_SAMPLE_CACHE;
						SYNCSAMPLE(current_ts + period_counter[ch]);
					}
					period_counter[ch] += tmp_pt;
				}
			}
			else
			{
				uint32 tmp_pt = 2048 - period[ch];

				if(tmp_pt > 4)
				{
					period_counter[ch] -= run_time;
					while(period_counter[ch] <= 0)
					{
						sample_pos[ch] = (sample_pos[ch] + 1) & 0x1F;

						MK_SAMPLE_CACHE;
						SYNCSAMPLE(current_ts + period_counter[ch]); // - period_counter[ch]);
						period_counter[ch] += tmp_pt;
					}
				}
			}
		}

		{
			int32 tmphv = HyperVoice;

			if(tmphv - last_hv_val)
			{
				WaveSynth.offset_inline(current_ts, tmphv - last_hv_val, sbuf[0]);
				WaveSynth.offset_inline(current_ts, tmphv - last_hv_val, sbuf[1]);
				last_hv_val = tmphv;
			}
		}
		last_ts = current_ts;
	}

	void Sound::Write(uint32 A, uint8 V)
	{
		Update();

		if(A >= 0x80 && A <= 0x87)
		{
			int ch = (A - 0x80) >> 1;

			if(A & 1)
				period[ch] = (period[ch] & 0x00FF) | ((V & 0x07) << 8);
			else
				period[ch] = (period[ch] & 0x0700) | ((V & 0xFF) << 0);
		}
		else if(A >= 0x88 && A <= 0x8B)
		{
			volume[A - 0x88] = V;
		}
		else if(A == 0x8C)
			sweep_value = V;
		else if(A == 0x8D)
		{
			sweep_step = V;
			sweep_counter = sweep_step + 1;
			sweep_8192_divider = 8192;
		}
		else if(A == 0x8E)
		{
			if(V & 0x8)
				nreg = 0;
			noise_control = V & 0x17;
			//printf("NOISECONTROL: %02x\n", V);
		}
		else if(A == 0x90)
		{
			for(int n = 0; n < 4; n++)
			{
				if(!(control & (1 << n)) && (V & (1 << n)))
				{
					period_counter[n] = 0;
					sample_pos[n] = 0x1F;
				}
			}
			control = V;
			//printf("Sound Control: %02x\n", V);
		}
		else if(A == 0x91)
		{
			output_control = V & 0xF;
			//printf("%02x, %02x\n", V, (V >> 1) & 3);
		}
		else if(A == 0x92)
			nreg = (nreg & 0xFF00) | (V << 0);
		else if(A == 0x93)
			nreg = (nreg & 0x00FF) | ((V & 0x7F) << 8);  
		else if(A == 0x94)
		{
			voice_volume = V & 0xF;
			//printf("%02x\n", V);
		}
		else switch(A)
		{
		case 0x8F: SampleRAMPos = V; break;
		case 0x95: HyperVoice = V; break; // Pick a port, any port?!
			//default: printf("%04x:%02x\n", A, V); break;
		}
		Update();
	}

	uint8 Sound::Read(uint32 A)
	{
		Update();

		if(A >= 0x80 && A <= 0x87)
		{
			int ch = (A - 0x80) >> 1;

			if(A & 1)
				return period[ch] >> 8;
			else
				return (uint8)period[ch];
		}
		else if(A >= 0x88 && A <= 0x8B)
			return(volume[A - 0x88]);
		else switch(A)
		{
		default:  /*printf("SoundRead: %04x\n", A);*/ return(0);
		case 0x8C: return(sweep_value);
		case 0x8D: return(sweep_step);
		case 0x8E: return(noise_control);
		case 0x8F: return(SampleRAMPos);
		case 0x90: return(control);
		case 0x91: return(output_control | 0x80);
		case 0x92: return((nreg >> 0) & 0xFF);
		case 0x93: return((nreg >> 8) & 0xFF);
		case 0x94: return(voice_volume);
		}
	}


	int32 Sound::Flush(int16 *SoundBuf, const int32 MaxSoundFrames)
	{
		int32 FrameCount = 0;

		Update();

		if(SoundBuf)
		{
			for(int y = 0; y < 2; y++)
			{
				sbuf[y]->end_frame(sys->cpu.timestamp);
				FrameCount = sbuf[y]->read_samples(SoundBuf + y, MaxSoundFrames, true);
			}
		}

		last_ts = 0;

		return(FrameCount);
	}

	// Call before wsRAM is updated
	void Sound::CheckRAMWrite(uint32 A)
	{
		if((A >> 6) == SampleRAMPos)
			Update();
	}

	Sound::Sound()
	{
		for(int i = 0; i < 2; i++)
		{
			sbuf[i] = new Blip_Buffer();

			sbuf[i]->set_sample_rate(0 ? 0 : 44100, 60);
			sbuf[i]->clock_rate((long)(3072000));
			sbuf[i]->bass_freq(20);
		}

		double eff_volume = 0.1; //TOOLOUD  1.0 / 4;

		WaveSynth.volume(eff_volume);
		NoiseSynth.volume(eff_volume);
		VoiceSynth.volume(eff_volume);

		SetRate(44100);
	}

	Sound::~Sound()
	{
		for(int i = 0; i < 2; i++)
		{
			if(sbuf[i])
			{
				delete sbuf[i];
				sbuf[i] = nullptr;
			}
		}

	}

	bool Sound::SetRate(uint32 rate)
	{
		for(int i = 0; i < 2; i++)
			sbuf[i]->set_sample_rate(rate?rate:44100, 60);

		return(TRUE);
	}

	void Sound::Reset()
	{
		std::memset(period, 0, sizeof(period));
		std::memset(volume, 0, sizeof(volume));
		voice_volume = 0;
		sweep_step = 0;
		sweep_value = 0;
		noise_control = 0;
		control = 0;
		output_control = 0;

		sweep_8192_divider = 8192;
		sweep_counter = 0;
		SampleRAMPos = 0;
		std::memset(period_counter, 0, sizeof(period_counter));
		std::memset(sample_pos, 0, sizeof(sample_pos));
		nreg = 0;

		std::memset(sample_cache, 0, sizeof(sample_cache));
		std::memset(last_val, 0, sizeof(last_val));
		last_v_val = 0;

		HyperVoice = 0;
		last_hv_val = 0;

		for(int y = 0; y < 2; y++)
			sbuf[y]->clear();
	}

	SYNCFUNC(Sound)
	{
		// don't need to save any of the blip stuff

		NSS(period);
		NSS(volume);
		NSS(voice_volume);

		NSS(sweep_step);
		NSS(sweep_value);
		NSS(noise_control);
		NSS(control);
		NSS(output_control);

		NSS(sweep_8192_divider);
		NSS(sweep_counter);
		NSS(SampleRAMPos);

		NSS(sample_cache);

		NSS(last_v_val);

		NSS(HyperVoice);
		NSS(last_hv_val);

		NSS(period_counter);
		NSS(last_val);
		NSS(sample_pos);
		NSS(nreg);
		NSS(last_ts);
	}
}