#include "audio_stream_sample.h"

void AudioStreamPlaybackSample::start(float p_from_pos) {

	for(int i=0;i<2;i++) {
		ima_adpcm[i].step_index=0;
		ima_adpcm[i].predictor=0;
		ima_adpcm[i].loop_step_index=0;
		ima_adpcm[i].loop_predictor=0;
		ima_adpcm[i].last_nibble=-1;
		ima_adpcm[i].loop_pos=0x7FFFFFFF;
		ima_adpcm[i].window_ofs=0;
		ima_adpcm[i].ptr=(const uint8_t*)base->data;
		ima_adpcm[i].ptr+=AudioStreamSample::DATA_PAD;
	}

	seek_pos(p_from_pos);
	sign=1;
	active=true;
}

void AudioStreamPlaybackSample::stop() {

	active=false;
}

bool AudioStreamPlaybackSample::is_playing() const {

	return active;
}

int AudioStreamPlaybackSample::get_loop_count() const {

	return 0;
}

float AudioStreamPlaybackSample::get_pos() const {

	return float(offset>>MIX_FRAC_BITS)/base->mix_rate;
}
void AudioStreamPlaybackSample::seek_pos(float p_time) {

	if (base->format==AudioStreamSample::FORMAT_IMA_ADPCM)
		return; //no seeking in ima-adpcm

	float max=get_length();
	if (p_time<0) {
		p_time=0;
	} else if (p_time>=max) {
		p_time=max-0.001;
	}

	offset = uint64_t(p_time * base->mix_rate)<<MIX_FRAC_BITS;
}


template<class Depth,bool is_stereo,bool is_ima_adpcm>
void AudioStreamPlaybackSample::do_resample(const Depth* p_src, AudioFrame *p_dst,int64_t &offset,int32_t &increment,uint32_t amount,IMA_ADPCM_State *ima_adpcm) {

	// this function will be compiled branchless by any decent compiler

	int32_t final,final_r,next,next_r;
	while (amount--) {

		int64_t pos=offset >> MIX_FRAC_BITS;
		if (is_stereo && !is_ima_adpcm)
			pos<<=1;

		if (is_ima_adpcm) {

			int64_t sample_pos = pos + ima_adpcm[0].window_ofs;

			while(sample_pos>ima_adpcm[0].last_nibble) {


				static const int16_t _ima_adpcm_step_table[89] = {
					7, 8, 9, 10, 11, 12, 13, 14, 16, 17,
					19, 21, 23, 25, 28, 31, 34, 37, 41, 45,
					50, 55, 60, 66, 73, 80, 88, 97, 107, 118,
					130, 143, 157, 173, 190, 209, 230, 253, 279, 307,
					337, 371, 408, 449, 494, 544, 598, 658, 724, 796,
					876, 963, 1060, 1166, 1282, 1411, 1552, 1707, 1878, 2066,
					2272, 2499, 2749, 3024, 3327, 3660, 4026, 4428, 4871, 5358,
					5894, 6484, 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899,
					15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767
				};

				static const int8_t _ima_adpcm_index_table[16] = {
					-1, -1, -1, -1, 2, 4, 6, 8,
					-1, -1, -1, -1, 2, 4, 6, 8
				};

				for(int i=0;i<(is_stereo?2:1);i++) {


					int16_t nibble,diff,step;

					ima_adpcm[i].last_nibble++;
					const uint8_t *src_ptr=ima_adpcm[i].ptr;


					uint8_t nbb = src_ptr[ (ima_adpcm[i].last_nibble>>1) *  (is_stereo?2:1) + i ];
					nibble = (ima_adpcm[i].last_nibble&1)?(nbb>>4):(nbb&0xF);
					step=_ima_adpcm_step_table[ima_adpcm[i].step_index];


					ima_adpcm[i].step_index += _ima_adpcm_index_table[nibble];
					if (ima_adpcm[i].step_index<0)
						ima_adpcm[i].step_index=0;
					if (ima_adpcm[i].step_index>88)
						ima_adpcm[i].step_index=88;

					diff = step >> 3 ;
					if (nibble & 1)
						diff += step >> 2 ;
					if (nibble & 2)
						diff += step >> 1 ;
					if (nibble & 4)
						diff += step ;
					if (nibble & 8)
						diff = -diff ;

					ima_adpcm[i].predictor+=diff;
					if (ima_adpcm[i].predictor<-0x8000)
						ima_adpcm[i].predictor=-0x8000;
					else if (ima_adpcm[i].predictor>0x7FFF)
						ima_adpcm[i].predictor=0x7FFF;


					/* store loop if there */
					if (ima_adpcm[i].last_nibble==ima_adpcm[i].loop_pos) {

						ima_adpcm[i].loop_step_index = ima_adpcm[i].step_index;
						ima_adpcm[i].loop_predictor = ima_adpcm[i].predictor;
					}

					//printf("%i - %i - pred %i\n",int(ima_adpcm[i].last_nibble),int(nibble),int(ima_adpcm[i].predictor));

				}

			}

			final=ima_adpcm[0].predictor;
			if (is_stereo) {
				final_r=ima_adpcm[1].predictor;
			}

		} else {
			final=p_src[pos];
			if (is_stereo)
				final_r=p_src[pos+1];

			if (sizeof(Depth)==1) { /* conditions will not exist anymore when compiled! */
				final<<=8;
				if (is_stereo)
					final_r<<=8;
			}

			if (is_stereo) {

				next=p_src[pos+2];
				next_r=p_src[pos+3];
			} else {
				next=p_src[pos+1];
			}

			if (sizeof(Depth)==1) {
				next<<=8;
				if (is_stereo)
					next_r<<=8;
			}

			int32_t frac=int64_t(offset&MIX_FRAC_MASK);

			final=final+((next-final)*frac >> MIX_FRAC_BITS);
			if (is_stereo)
				final_r=final_r+((next_r-final_r)*frac >> MIX_FRAC_BITS);

		}


		if (!is_stereo) {
			final_r=final; //copy to right channel if stereo
		}

		p_dst->l=final/32767.0;
		p_dst->r=final_r/32767.0;
		p_dst++;

		offset+=increment;
	}
}

void AudioStreamPlaybackSample::mix(AudioFrame* p_buffer,float p_rate_scale,int p_frames) {

	if (!base->data || !active) {
		for(int i=0;i<p_frames;i++) {
			p_buffer[i]=AudioFrame(0,0);
		}
		return;
	}

	int len = base->data_bytes;
	switch(base->format) {
		case AudioStreamSample::FORMAT_8_BITS: len/=1; break;
		case AudioStreamSample::FORMAT_16_BITS: len/=2; break;
		case AudioStreamSample::FORMAT_IMA_ADPCM: len*=2; break;
	}

	if (base->stereo) {
		len/=2;
	}

	/* some 64-bit fixed point precaches */

	int64_t loop_begin_fp=((int64_t)len<< MIX_FRAC_BITS);
	int64_t loop_end_fp=((int64_t)base->loop_end << MIX_FRAC_BITS);
	int64_t length_fp=((int64_t)len << MIX_FRAC_BITS);
	int64_t begin_limit=(base->loop_mode!=AudioStreamSample::LOOP_DISABLED)?loop_begin_fp:0;
	int64_t end_limit=(base->loop_mode!=AudioStreamSample::LOOP_DISABLED)?loop_end_fp:length_fp;
	bool is_stereo=base->stereo;

	int32_t todo=p_frames;

	float base_rate = AudioServer::get_singleton()->get_mix_rate();
	float srate = base->mix_rate;
	srate*=p_rate_scale;
	float fincrement = srate / base_rate;
	int32_t increment = int32_t(fincrement * MIX_FRAC_LEN);
	increment*=sign;


	//looping

	AudioStreamSample::LoopMode loop_format=base->loop_mode;
	AudioStreamSample::Format format = base->format;


	/* audio data */

	uint8_t *dataptr=(uint8_t*)base->data;
	const void *data=dataptr+AudioStreamSample::DATA_PAD;
	AudioFrame *dst_buff=p_buffer;


	if (format==AudioStreamSample::FORMAT_IMA_ADPCM) {

		if (loop_format!=AudioStreamSample::LOOP_DISABLED) {
			ima_adpcm[0].loop_pos=loop_begin_fp>>MIX_FRAC_BITS;
			ima_adpcm[1].loop_pos=loop_begin_fp>>MIX_FRAC_BITS;
			loop_format=AudioStreamSample::LOOP_FORWARD;
		}
	}

	while (todo>0) {

		int64_t limit=0;
		int32_t target=0,aux=0;

		/** LOOP CHECKING **/

		if ( increment < 0 ) {
			/* going backwards */

			if (  loop_format!=AudioStreamSample::LOOP_DISABLED && offset < loop_begin_fp ) {
				/* loopstart reached */
				if ( loop_format==AudioStreamSample::LOOP_PING_PONG ) {
					/* bounce ping pong */
					offset= loop_begin_fp + ( loop_begin_fp-offset );
					increment=-increment;
					sign*=-1;
				} else {
					/* go to loop-end */
					offset=loop_end_fp-(loop_begin_fp-offset);
				}
			} else {
				/* check for sample not reaching begining */
				if(offset < 0) {

					active=false;
					break;
				}
			}
		} else {
			/* going forward */
			if(  loop_format!=AudioStreamSample::LOOP_DISABLED && offset >= loop_end_fp ) {
				/* loopend reached */

				if ( loop_format==AudioStreamSample::LOOP_PING_PONG ) {
					/* bounce ping pong */
					offset=loop_end_fp-(offset-loop_end_fp);
					increment=-increment;
					sign*=-1;
				} else {
					/* go to loop-begin */

					if (format==AudioStreamSample::FORMAT_IMA_ADPCM) {
						for(int i=0;i<2;i++) {
							ima_adpcm[i].step_index=ima_adpcm[i].loop_step_index;
							ima_adpcm[i].predictor=ima_adpcm[i].loop_predictor;
							ima_adpcm[i].last_nibble=loop_begin_fp>>MIX_FRAC_BITS;
						}
						offset=loop_begin_fp;
					} else {
						offset=loop_begin_fp+(offset-loop_end_fp);
					}

				}
			} else {
				/* no loop, check for end of sample */
				if(offset >= length_fp) {

					active=false;
					break;
				}
			}
		}

		/** MIXCOUNT COMPUTING **/

		/* next possible limit (looppoints or sample begin/end */
		limit=(increment < 0) ?begin_limit:end_limit;

		/* compute what is shorter, the todo or the limit? */
		aux=(limit-offset)/increment+1;
		target=(aux<todo)?aux:todo; /* mix target is the shorter buffer */

		/* check just in case */
		if ( target<=0 ) {
			active=false;
			break;
		}

		todo-=target;

		switch(base->format) {
			case AudioStreamSample::FORMAT_8_BITS: {

				if (is_stereo)
					do_resample<int8_t,true,false>((int8_t*)data,dst_buff,offset,increment,target,ima_adpcm);
				else
					do_resample<int8_t,false,false>((int8_t*)data,dst_buff,offset,increment,target,ima_adpcm);
			} break;
			case AudioStreamSample::FORMAT_16_BITS: {
				if (is_stereo)
					do_resample<int16_t,true,false>((int16_t*)data,dst_buff,offset,increment,target,ima_adpcm);
				else
					do_resample<int16_t,false,false>((int16_t*)data,dst_buff,offset,increment,target,ima_adpcm);

			} break;
			case AudioStreamSample::FORMAT_IMA_ADPCM: {
				if (is_stereo)
					do_resample<int8_t,true,true>((int8_t*)data,dst_buff,offset,increment,target,ima_adpcm);
				else
					do_resample<int8_t,false,true>((int8_t*)data,dst_buff,offset,increment,target,ima_adpcm);

			} break;
		}

		dst_buff+=target;

	}


}

float AudioStreamPlaybackSample::get_length() const {

	int len = base->data_bytes;
	switch(base->format) {
		case AudioStreamSample::FORMAT_8_BITS: len/=1; break;
		case AudioStreamSample::FORMAT_16_BITS: len/=2; break;
		case AudioStreamSample::FORMAT_IMA_ADPCM: len*=2; break;
	}

	if (base->stereo) {
		len/=2;
	}


	return float(len)/base->mix_rate;
}


AudioStreamPlaybackSample::AudioStreamPlaybackSample() {

	active=false;
	offset=0;
	sign=1;
}


/////////////////////


void AudioStreamSample::set_format(Format p_format) {

	format=p_format;
}

AudioStreamSample::Format AudioStreamSample::get_format() const{

	return format;
}

void AudioStreamSample::set_loop_mode(LoopMode p_loop_mode){

	loop_mode=p_loop_mode;
}
AudioStreamSample::LoopMode AudioStreamSample::get_loop_mode() const{

	return loop_mode;
}

void AudioStreamSample::set_loop_begin(int p_frame){

	loop_begin=p_frame;
}
int AudioStreamSample::get_loop_begin() const{

	return loop_begin;
}

void AudioStreamSample::set_loop_end(int p_frame){

	loop_end=p_frame;
}
int AudioStreamSample::get_loop_end() const{

	return loop_end;
}


void AudioStreamSample::set_mix_rate(int p_hz){

	mix_rate=p_hz;
}
int AudioStreamSample::get_mix_rate() const{

	return mix_rate;
}
void AudioStreamSample::set_stereo(bool p_enable){

	stereo=p_enable;
}
bool AudioStreamSample::is_stereo() const{

	return stereo;
}

void AudioStreamSample::set_data(const PoolVector<uint8_t>& p_data) {

	AudioServer::get_singleton()->lock();
	if (data) {
		AudioServer::get_singleton()->audio_data_free(data);
		data=NULL;
		data_bytes=0;
	}

	int datalen = p_data.size();
	if (datalen) {

		PoolVector<uint8_t>::Read r = p_data.read();
		int alloc_len = datalen+DATA_PAD*2;
		data = AudioServer::get_singleton()->audio_data_alloc(alloc_len); //alloc with some padding for interpolation
		zeromem(data,alloc_len);
		uint8_t *dataptr=(uint8_t*)data;
		copymem(dataptr+DATA_PAD,r.ptr(),datalen);
		data_bytes=datalen;
	}

	AudioServer::get_singleton()->unlock();

}
PoolVector<uint8_t> AudioStreamSample::get_data() const{

	PoolVector<uint8_t> pv;

	if (data) {
		pv.resize(data_bytes);
		{

			PoolVector<uint8_t>::Write w =pv.write();
			copymem(w.ptr(),data,data_bytes);
		}
	}

	return pv;
}


Ref<AudioStreamPlayback> AudioStreamSample::instance_playback() {

	Ref<AudioStreamPlaybackSample> sample;
	sample.instance();
	sample->base=Ref<AudioStreamSample>(this);
	return sample;
}

String AudioStreamSample::get_stream_name() const {

	return "";
}

void AudioStreamSample::_bind_methods() {

	ClassDB::bind_method(D_METHOD("set_format","format"),&AudioStreamSample::set_format);
	ClassDB::bind_method(D_METHOD("get_format"),&AudioStreamSample::get_format);

	ClassDB::bind_method(D_METHOD("set_loop_mode","loop_mode"),&AudioStreamSample::set_loop_mode);
	ClassDB::bind_method(D_METHOD("get_loop_mode"),&AudioStreamSample::get_loop_mode);

	ClassDB::bind_method(D_METHOD("set_loop_begin","loop_begin"),&AudioStreamSample::set_loop_begin);
	ClassDB::bind_method(D_METHOD("get_loop_begin"),&AudioStreamSample::get_loop_begin);

	ClassDB::bind_method(D_METHOD("set_loop_end","loop_end"),&AudioStreamSample::set_loop_end);
	ClassDB::bind_method(D_METHOD("get_loop_end"),&AudioStreamSample::get_loop_end);

	ClassDB::bind_method(D_METHOD("set_mix_rate","mix_rate"),&AudioStreamSample::set_mix_rate);
	ClassDB::bind_method(D_METHOD("get_mix_rate"),&AudioStreamSample::get_mix_rate);

	ClassDB::bind_method(D_METHOD("set_stereo","stereo"),&AudioStreamSample::set_stereo);
	ClassDB::bind_method(D_METHOD("is_stereo"),&AudioStreamSample::is_stereo);

	ClassDB::bind_method(D_METHOD("set_data","data"),&AudioStreamSample::set_data);
	ClassDB::bind_method(D_METHOD("get_data"),&AudioStreamSample::get_data);

	ADD_PROPERTY(PropertyInfo(Variant::INT,"format",PROPERTY_HINT_ENUM,"8-Bit,16-Bit,IMA-ADPCM"),"set_format","get_format");
	ADD_PROPERTY(PropertyInfo(Variant::INT,"loop_mode",PROPERTY_HINT_ENUM,"Disabled,Forward,Ping-Pong"),"set_loop_mode","get_loop_mode");
	ADD_PROPERTY(PropertyInfo(Variant::INT,"loop_begin"),"set_loop_begin","get_loop_begin");
	ADD_PROPERTY(PropertyInfo(Variant::INT,"loop_end"),"set_loop_end","get_loop_end");
	ADD_PROPERTY(PropertyInfo(Variant::INT,"mix_rate"),"set_mix_rate","get_mix_rate");
	ADD_PROPERTY(PropertyInfo(Variant::BOOL,"stereo"),"set_stereo","is_stereo");
	ADD_PROPERTY(PropertyInfo(Variant::POOL_BYTE_ARRAY,"data",PROPERTY_HINT_NONE,"",PROPERTY_USAGE_NOEDITOR),"set_data","get_data");

}

AudioStreamSample::AudioStreamSample()
{
	format=FORMAT_8_BITS;
	loop_mode=LOOP_DISABLED;
	stereo=false;
	loop_begin=0;
	loop_end=0;
	mix_rate=44100;
	data=NULL;
	data_bytes=0;
}
AudioStreamSample::~AudioStreamSample() {


	if (data) {
		AudioServer::get_singleton()->audio_data_free(data);
		data=NULL;
		data_bytes=0;
	}
}
