//CLI Midi file player based on libfluidsynth
//Midi file reading module
//Written by Chris Xiong, 2015
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cstdint>
#include <cstdarg>
#include <algorithm>
#include "qmpmidiplay.hpp"
const char* GM1SysX={"\xF0\x7E\x7F\x09\x01\xF7"};
const char* GM2SysX={"\xF0\x7E\x7F\x09\x03\xF7"};
const char* GSSysEx={"\xF0\x41\x10\x42\x12\x40\x00\x7F\x00\x41\xF7"};
const char* XGSysEx={"\xF0\x43\x10\x4C\x00\x00\x7E\x00\xF7"};
bool cmp(SEvent *a,SEvent *b){return a->time-b->time?a->time<b->time:a->iid<b->iid;}
void CMidiFile::error(int fatal,const char* format,...)
{
	va_list ap;
	va_start(ap,format);vfprintf(stderr,format,ap);va_end(ap);
	fprintf(stderr," at %#lx\n",ftell(f));
	if(fatal)throw std::runtime_error("fatal error");
}
uint32_t CMidiFile::readSW()
{
	byteread+=2;
	uint32_t ret=0;
	for(int i=0;i<2;++i){ret<<=8;ret|=((uint32_t)fgetc(f))&0xFF;}
	return ret;
}
uint32_t CMidiFile::readDW()
{
	byteread+=4;
	uint32_t ret=0;
	for(int i=0;i<4;++i){ret<<=8;ret|=((uint32_t)fgetc(f))&0xFF;}
	return ret;
}
uint32_t CMidiFile::readVL()
{
	uint32_t ret=0,t,c=0;
	do
	{
		t=fgetc(f);
		if(++c>4)error(1,"E: Variable length type overflow.");
		ret<<=7;ret|=(t&0x7F);
	}while(t&0x80);
	byteread+=c;
	return ret;
}
int CMidiFile::eventReader()//returns 0 if End of Track encountered
{
	uint32_t delta=readVL();curt+=delta;
	char type=fgetc(f);++byteread;uint32_t p1,p2;
	static char lasttype;eventdiscarded=0;
	if(!(type&0x80)){fseek(f,-1,SEEK_CUR);--byteread;type=lasttype;}
	switch(type&0xF0)
	{
		case 0x80://Note Off
			p1=fgetc(f);p2=fgetc(f);byteread+=2;
			eventList.push_back(new SEvent(curid,curt,type,p1,p2));
		break;
		case 0x90://Note On
			p1=fgetc(f);p2=fgetc(f);byteread+=2;
			if(p2)
			{
				++notes;
				eventList.push_back(new SEvent(curid,curt,type,p1,p2));
			}
			else
				eventList.push_back(new SEvent(curid,curt,(type&0x0F)|0x80,p1,p2));
		break;
		case 0xA0://Note Aftertouch
			p1=fgetc(f);p2=fgetc(f);byteread+=2;
			eventList.push_back(new SEvent(curid,curt,type,p1,p2));
		break;
		case 0xB0://Controller Change
			p1=fgetc(f);p2=fgetc(f);byteread+=2;
			eventList.push_back(new SEvent(curid,curt,type,p1,p2));
		break;
		case 0xC0://Patch Change
			p1=fgetc(f);++byteread;
			eventList.push_back(new SEvent(curid,curt,type,p1,0));
		break;
		case 0xD0://Channel Aftertouch
			p1=fgetc(f);++byteread;
			eventList.push_back(new SEvent(curid,curt,type,p1,0));
		break;
		case 0xE0://Pitch wheel
			p1=fgetc(f);p2=fgetc(f);byteread+=2;
			eventList.push_back(new SEvent(curid,curt,type,(p1|(p2<<7))&0x3FFF,0));
		break;
		case 0xF0:
			if((type&0x0F)==0x0F)//Meta Event
			{
				char metatype=fgetc(f);++byteread;
				switch(metatype)
				{
					case 0x00://Sequence Number
						fgetc(f);fgetc(f);fgetc(f);
						byteread+=3;
					break;
					case 0x20://Channel Prefix
						fgetc(f);fgetc(f);byteread+=2;
					break;
					case 0x2F://End of Track
						fgetc(f);++byteread;
						return 0;
					break;
					case 0x51://Set Tempo
						p1=readDW();p1&=0x00FFFFFF;
						eventList.push_back(new SEvent(curid,curt,type,metatype,p1));
					break;
					case 0x54://SMTPE offset, not handled.
						fgetc(f);fgetc(f);fgetc(f);
						fgetc(f);fgetc(f);fgetc(f);
						byteread+=6;
					break;
					case 0x58://Time signature
						fgetc(f);++byteread;
						p1=readDW();
						eventList.push_back(new SEvent(curid,curt,type,metatype,p1));
					break;
					case 0x59://Key signature
						fgetc(f);++byteread;
						p1=readSW();
						eventList.push_back(new SEvent(curid,curt,type,metatype,p1));
					break;
					case 0x01:case 0x02:case 0x03:
					case 0x04:case 0x05:case 0x06:
					case 0x07:case 0x7F:default://text-like meta
					{
						uint32_t len=readVL(),c;char* str=NULL;
						if(len<=1024&&len>0)str=new char[len+8];
						for(c=0;c<len;++c)
						{
							++byteread;if(str)str[c]=fgetc(f);else fgetc(f);
						}
						if(str)str[c]='\0';eventList.push_back(new SEvent(curid,curt,type,metatype,0,str));
						if(str&&metatype==0x03&&!title)
						{
							title=new char[len+8];
							strcpy(title,str);
						}
						if(str&&metatype==0x02&&!copyright)
						{
							copyright=new char[len+8];
							strcpy(copyright,str);
						}
						if(len<=1024&&len>0)delete[] str;
					}
				}
			}
			else if((type&0x0F)==0x00||(type&0x0F)==0x07)//SysEx
			{
				uint32_t len=readVL(),c;char* str=NULL;
				str=new char[len+8];
				if((type&0x0F)==0x00)
				{
					str[0]=0xF0;++len;
					for(c=1;c<len;++c){++byteread;str[c]=fgetc(f);}
				}
				else for(c=0;c<len;++c){++byteread;str[c]=fgetc(f);}
				eventList.push_back(new SEvent(curid,curt,type,len,0,str));
				if(!strcmp(str,GM1SysX))std=1;
				if(!strcmp(str,GM2SysX))std=2;
				if(!strcmp(str,GSSysEx))std=3;
				if(!strcmp(str,XGSysEx))std=4;
				delete[] str;
			}
			else error(0,"W: Unknown event type %#x",type);
		break;
		default:
			error(0,"W: Unknown event type %#x",type);
	}
	lasttype=type;++curid;
	if(eventList.size())
	{
		SEvent* le=eventList[eventList.size()-1];
		SEventCallBackData cbd(le->type,le->p1,le->p2,le->time);
		for(int i=0;i<16;++i)if(eventReaderCB[i])
			eventReaderCB[i]->callBack(&cbd,eventReaderCBuserdata[i]);
	}
	return 1;
}
void CMidiFile::trackChunkReader()
{
	int chnklen=readDW();byteread=0;curt=0;curid=0;
	while(/*byteread<chnklen&&*/eventReader());
	if(byteread<chnklen)
	{
		error(0,"W: Extra bytes after EOT event.");
		while(byteread<chnklen){fgetc(f);++byteread;}
	}
	/*if(byteread>chnklen)
	{
		error(1,"E: Read past end of track.");
	}*/
}
void CMidiFile::headerChunkReader()
{
	int chnklen=readDW();byteread=0;
	if(chnklen<6)error(1,"E: Header chunk too short.");
	if(chnklen>6)error(0,"W: Header chunk length longer than expected. Ignoring extra bytes.");
	fmt=readSW();trk=readSW();divs=readSW();
	if(divs&0x8000)error(1,"E: SMTPE format is not supported.");
	for(;byteread<chnklen;++byteread){fgetc(f);}
}
int CMidiFile::chunkReader(int hdrXp)
{
	char hdr[6];
	if(!fgets(hdr,5,f))error(1,"E: Unexpected EOF.");
	if(hdrXp)
		if(strncmp(hdr,"MThd",4)){error(1,"E: Wrong MIDI header.");throw std::runtime_error("Wrong MIDI header");}
		else return headerChunkReader(),0;
	else
		if(strncmp(hdr,"MTrk",4))
		{
			error(0,"W: Wrong track chunk header. Ignoring the whole chunk.");
			for(int chnklen=readDW();chnklen>0;--chnklen)fgetc(f);return 0;
		}
		else return trackChunkReader(),1;
}
void CMidiFile::dumpEvents()
{
	for(uint32_t i=0;i<eventList.size();++i)
	if(eventList[i]->str)
		printf("type %x #%d @%d p1 %d p2 %d str %s\n",eventList[i]->type,
		eventList[i]->iid,eventList[i]->time,eventList[i]->p1,eventList[i]->p2,eventList[i]->str);
	else
		printf("type %x #%d @%d p1 %d p2 %d\n",eventList[i]->type,
		eventList[i]->iid,eventList[i]->time,eventList[i]->p1,eventList[i]->p2);
}
CMidiFile::CMidiFile(const char* fn,CMidiPlayer* par)
{
	title=copyright=NULL;notes=0;std=0;valid=1;
	memcpy(eventReaderCB,par->eventReaderCB,sizeof(eventReaderCB));
	memcpy(eventReaderCBuserdata,par->eventReaderCBuserdata,sizeof(eventReaderCBuserdata));
	try
	{
		if(!(f=fopen(fn,"rb")))throw (fprintf(stderr,"E: file %s doesn't exist!\n",fn),std::runtime_error("File doesn't exist"));
		chunkReader(1);
		for(uint32_t i=0;i<trk;i+=chunkReader(0));
		fclose(f);
		std::sort(eventList.begin(),eventList.end(),cmp);
		par->maxtk=eventList[eventList.size()-1]->time;
	}
	catch(std::runtime_error&){fprintf(stderr,"E: %s is not a supported file.\n",fn);valid=0;}
}
CMidiFile::~CMidiFile()
{
	for(uint32_t i=0;i<eventList.size();++i)delete eventList[i];eventList.clear();
	if(title)delete[] title;if(copyright)delete[] copyright;
}
const SEvent* CMidiFile::getEvent(uint32_t id){return id<eventList.size()?eventList[id]:NULL;}
uint32_t CMidiFile::getEventCount(){return eventList.size();}
uint32_t CMidiFile::getDivision(){return divs;}
uint32_t CMidiFile::getNoteCount(){return notes;}
uint32_t CMidiFile::getStandard(){return std;}
bool CMidiFile::isValid(){return valid;}
const char* CMidiFile::getTitle(){return title;}
const char* CMidiFile::getCopyright(){return copyright;}

void CMidiFile::discardLastEvent()
{
	if(eventdiscarded)return;eventdiscarded=1;
	delete eventList[eventList.size()-1];eventList.pop_back();
}
void CMidiFile::commitEventChange(SEventCallBackData d)
{
	eventList[eventList.size()-1]->time=d.time;
	eventList[eventList.size()-1]->type=d.type;
	eventList[eventList.size()-1]->p1=d.p1;
	eventList[eventList.size()-1]->p2=d.p2;
}