#include "mds_reader.h"

session sessions[256];
int nsessions;

int flen(FILE*f)
{
	long lpos=ftell(f);
	long epos;

	fseek(f,0,SEEK_END);
	epos=ftell(f);
	fseek(f,lpos,SEEK_SET);
	return epos;
}

void byteswap(void *pbuffer,int bytes)
{
	char t;
	int p=0;
	int l=bytes-1;
	char *b=(char*)pbuffer;
	while(p<l)
	{
		t=b[p];b[p]=b[l];b[l]=t;
		p++;l--;
	}
}

int mds_mode(int mode)
{
	if(mode>0xa9)
		return mode - 0xa9;
	printf("unknown track mode %d , guessing audio ....\nPress Any Key To Continue\n",mode);
	//getchar();
	return 0;
}

int nrg_mode(int mode)
{
    if(mode == 0x07) return 0;//audio
    if(mode == 0x00) return 1;
	if(mode == 0x05) return 1;
    if(mode == 0x01) return 2;
	if(mode == 0x03) return 2;//mode2 form 1
	if(mode == 0x06) return 2;
	printf("unknown track mode %d , guessing audio ....\nPress Any Key To Continue\n",mode);
	//getchar();
	return 0;
} 


#define read_binary(type,source,offset) (*(type*)((source)+(offset)))

bool parse_mds(char *mds_filename,bool verbose)
{
    /*"returns the supposable bin_filename and raw entries, if something went \
    wrong it throws an exception"*/
    // read the file

	FILE*mds_file = fopen (mds_filename,"rb");
	if(!mds_file)
	{
        fprintf(stderr,"Could not open the mds-file <%s>\n",mds_filename);
		return false;
	}
    
    int  mds_size = flen(mds_file);

	//if its too small ..
	if (mds_size<16)
		return false;

	//do NOT load whole file to memory before checking ... cna be deadly for .nrg/.iso/ anything :p
	char mds_key[16];
	fseek(mds_file,0,SEEK_SET);
	fread(mds_key,16,1,mds_file);

    if(memcmp(mds_key,"MEDIA DESCRIPTOR",16)!=0)
	{
        fprintf(stderr,"Invalid data in <%s>. It is not an MDF/MDS file.\n",mds_filename);
		fclose(mds_file);
		return false;
	}

	fseek(mds_file,0,SEEK_SET);

	char *mds_content=(char*)malloc(mds_size);

    if(!mds_content)
	{
        fprintf(stderr,"Could not allocate a buffer to read <%s>\n",mds_filename);
		fclose(mds_file);
		return false;
	}

	fread(mds_content,mds_size,1,mds_file);
    
    if(memcmp(mds_content,"MEDIA DESCRIPTOR",16)!=0)
	{
        fprintf(stderr,"Invalid data in <%s>. It is not an MDF/MDS file.\n",mds_filename);
		free(mds_content);
		fclose(mds_file);
		return false;
	}

    // get some data from header
//    int mds_header_size = 0x70;
    int mds_datablock_size = 0x50;
    int mds_extrablock_size = 0x08;
//    int mds_footer_size = 0x16;
    int mds_version = read_binary(char, mds_content, 0x0010);
    int mds_revision = read_binary(char, mds_content, 0x0011);
    int mds_sessions = read_binary(unsigned char, mds_content, 0x0014);

	if(verbose)
	{
		printf("MDS/MDF version: %d.%d\n",mds_version, mds_revision);
	}

	nsessions=mds_sessions;

	int mds_session_offset = 0x58; 
	int mds_extrablocks_offset=0;

	for(int mds_current_session=0;mds_current_session<mds_sessions;mds_current_session++)
	{
		sessions[mds_current_session].pregap = read_binary(int, mds_content, mds_session_offset+0x0000);
		sessions[mds_current_session].sectors = read_binary(int, mds_content, mds_session_offset+0x0004);
		sessions[mds_current_session].something1 = read_binary(unsigned short, mds_content, mds_session_offset+0x0008);
		sessions[mds_current_session].datablocks = read_binary(unsigned char, mds_content, mds_session_offset+0x000a);
		sessions[mds_current_session].leadinblocks = read_binary(unsigned char, mds_content, mds_session_offset+0x000b);
		sessions[mds_current_session].session = read_binary(unsigned short, mds_content, mds_session_offset+0x000c);
		sessions[mds_current_session].last_track = read_binary(unsigned short, mds_content, mds_session_offset+0x000e);
		sessions[mds_current_session].something2 = read_binary(int, mds_content, mds_session_offset+0x0010);
		sessions[mds_current_session].datablocks_offset = read_binary(int, mds_content, mds_session_offset+0x0014);


		mds_extrablocks_offset=sessions[mds_current_session].datablocks_offset + mds_datablock_size*sessions[mds_current_session].datablocks;

		mds_session_offset = mds_session_offset + 0x18;
	}

	int mds_extrablocks_num=0;

	for(int mds_current_session=0;mds_current_session<mds_sessions;mds_current_session++)
	{
		sessions[mds_current_session].extrablocks_offset = mds_extrablocks_offset + mds_extrablock_size * mds_extrablocks_num;

		mds_extrablocks_num+=sessions[mds_current_session].datablocks;

	}

	for(int mds_current_session=0;mds_current_session<mds_sessions;mds_current_session++)
	{

		// making sure table is empty
		sessions[mds_current_session].ntracks=0;

		// read datablocks and extrablocks
		for(int datablock=0;datablock<sessions[mds_current_session].datablocks;datablock++)
		{
			int datablock_offset = sessions[mds_current_session].datablocks_offset+mds_datablock_size*datablock;
			int extrablock_offset = sessions[mds_current_session].extrablocks_offset+mds_extrablock_size*datablock;

			int mode = read_binary(unsigned char, mds_content, datablock_offset+0x0000);
			/*int smth1 = read_binary(unsigned char, mds_content, datablock_offset+0x0001);*/
			int flags = read_binary(unsigned short, mds_content, datablock_offset+0x0002);
			int track = read_binary(unsigned char, mds_content, datablock_offset+0x0004);
			/*int smth2 = read_binary(int, mds_content, datablock_offset+0x0005);*/
			int pmin = read_binary(unsigned char, mds_content, datablock_offset+0x0009);
			int psec = read_binary(unsigned char, mds_content, datablock_offset+0x000a);
			int pfrm = read_binary(unsigned char, mds_content, datablock_offset+0x000b);
			/*int smth3 = read_binary(int, mds_content, datablock_offset+0x000c);*/
			int sectorsize = read_binary(unsigned short, mds_content, datablock_offset+0x0010);
			/*int smth4 = read_binary(int, mds_content, datablock_offset+0x0014);*/
			/*int smth5 = read_binary(int, mds_content, datablock_offset+0x0018);*/
			/*int smth6 = read_binary(int, mds_content, datablock_offset+0x001c);*/
			/*int smth7 = read_binary(int, mds_content, datablock_offset+0x0020);*/
			int sector = read_binary(int, mds_content, datablock_offset+0x0024);
			__int64 offset = read_binary(__int64, mds_content, datablock_offset+0x0028);
			int pregap = read_binary(int, mds_content, extrablock_offset+0x0000);
			int sectors = read_binary(int, mds_content, extrablock_offset+0x0004);
			if(verbose)
				printf("datablock: %3d, track: %2x, mode: %2x, flags: %x, sector size: %d, MSF: %02d:%02d.%02d, sector: %d, offset: %d, pregap: %d, sectors: %d\n" ,
					datablock, track, mode, flags, sectorsize, pmin, psec, pfrm, sector, (int)offset, pregap, sectors);
			// writing data to entries
			if (track < 0xa0)
			{
				strack *t=&(sessions[mds_current_session].tracks[sessions[mds_current_session].ntracks]);
				t->track     =track;
				t->mode      =mds_mode(mode);
				t->flags     =flags;

				t->pmin      = pmin;
				t->psec      = psec;
				t->pfrm      = pfrm;

				t->sectorsize=sectorsize;
				t->pregap    =pregap;
				t->sector    =sector;
				t->sectors   =sectors;
				t->offset    =offset;
				sessions[mds_current_session].ntracks++;
			}
		}
	}

	free(mds_content);
	fclose(mds_file);

    return true;
}

bool parse_nrg(char*nrg_filename,bool verbose)
{
    /*"returns the supposable bin_filename and raw entries, if something went \
    wrong it throws an exception"*/
    // read the file
    FILE*nrg_file = fopen (nrg_filename,"rb");
	if(!nrg_file)
	{
        fprintf(stderr,"Could not open the nrg-file <%s>\n",nrg_filename);
		return false;
	}
    
    // last 8 or 12 bytes gives us important information, like the signature
    // and where to find the rest of the image information.
    int nrg_filesize = flen(nrg_file);


    int nrg_signature;
	__int64 nrg_trailer_offset=0;
	int oldformat;

	fseek(nrg_file,-12,SEEK_END);
	fread(&nrg_signature,4,1,nrg_file);

#define NER5 0x3552454E
#define NERO 0x3552454E

    if(nrg_signature == NER5) // Nero 5.5.x or newer
	{
        if(verbose) printf("File format: NER5.\n");
        fread(&nrg_trailer_offset,8,1,nrg_file);
		byteswap(&nrg_trailer_offset,8);
        oldformat = 0; // Offsets are 64 bit.
	}
    else
	{
		fseek(nrg_file,-8,SEEK_END);
		fread(&nrg_signature,4,1,nrg_file);
        if(nrg_signature == NERO) // Nero older than 5.5.x
		{
            if(verbose) printf("File format: NERO.\n");
	        fread(&nrg_trailer_offset,4,1,nrg_file);
			byteswap(&nrg_trailer_offset,4);
            oldformat = 1; // Offsets are 32 bit.
		}
        else
		{
            fprintf(stderr,"Invalid data in <%s>. It is not an NRG file.",nrg_filename);
			return false;
		}
	}
    fseek(nrg_file,nrg_trailer_offset, SEEK_SET);
    
	char *nrg_content = (char*)malloc(nrg_filesize - nrg_trailer_offset);
    if(!nrg_content)
	{
        fprintf(stderr,"Could not allocate a buffer to read the nrg info from <%s>\n",nrg_filename);
		fclose(nrg_file);
		return false;
	}

	fread(nrg_content,(nrg_filesize - nrg_trailer_offset),1,nrg_file);

	nsessions=1;
    
    // find relative offsets for different blocks
    __int64 offs = 0;

    // CUEX is 64-bit variant of CUES, same goes for DAOX vs. DAOI and ETN2 vs. ETNF.
    // DAO is DiscAtOnce, ETN is TrackAtOnce. SINF is Session Information, and MTYP is Media Type.
    // CDTX is CD-Text. END! is a marker for the last block.
	char block_ids[10][5] = {"CUEX", "CUES", "DAOX", "DAOI", "CDTX", "ETNF", "ETN2", "SINF", "MTYP", "END!"};

	enum block_nums {CUEX, CUES, DAOX, DAOI, CDTX, ETNF, ETN2, SINF, MTYP, END};
    
	struct _block {
		struct info {
			__int64 offset;
			__int64 size;
		} infos[255];
		int found;
	} block[10];

	for(int block_num=0;block_num<10;block_num++)
		block[block_num].found=0;
    
	while(offs < (nrg_filesize - nrg_trailer_offset - 12))
	{
		bool found=false;
        for(int block_num=0;block_num<10;block_num++)
		{
			char *block_id = block_ids[block_num]; 
            if(memcmp(block_id,nrg_content+offs,4)==0)
			{
                int size = read_binary(unsigned int, nrg_content, offs+4);
				byteswap(&size,4);
				block[block_num].infos[block[block_num].found].offset=offs;
				block[block_num].infos[block[block_num].found].size=size;
                if(verbose) printf("%s [0x%x:0x%x]\n",block_id, offs, size);
                offs += size+8;
				block[block_num].found++;
				found=true;
                break;
			}
		}
		if(!found)
		{
			fprintf(stderr,"Error in parsing Nero CD-Image.\n");
			free(nrg_content);
			fclose(nrg_file);
			return false;
		}
	}

	bool is_dao;

    // DiscAtOnce or TrackAtOnce?
    if(oldformat)
	{
        if(block[DAOI].found && (block[DAOI].found==block[CUES].found)) 
		{
			is_dao = true;
			nsessions=block[DAOI].found;
		}
        else 
		if(block[ETNF].found && (block[SINF].found==block[ETNF].found))
		{
			is_dao = false;
			nsessions=block[ETNF].found;
		}
        else
		{
			fprintf(stderr,"Error in checking for DAO / TAO.\n");
			free(nrg_content);
			fclose(nrg_file);
			return false;
		}
	}
    else
	{
        if(block[DAOX].found && (block[DAOX].found==block[CUEX].found)) 
		{
			is_dao = true;
			nsessions=block[DAOX].found;
		}
        else 
		if(block[ETN2].found && (block[SINF].found==block[ETN2].found))
		{
			is_dao = false;
			nsessions=block[ETN2].found;
		}
        else
		{
			fprintf(stderr,"Error in checking for DAO / TAO.\n");
			free(nrg_content);
			fclose(nrg_file);
			return false;
		}
	}
    if(verbose)
	{
        if(is_dao) printf("CD-Image is Disc-At-Once.\n");
        else printf("CD-Image is Track-At-Once.\n");
	}       

	// Got CD-Text? Parse it.
	/* nah why?
    if(block[4].found)
        if(verbose) print("CD-TEXT:");
        int entry = 0
        char cdtext_song[256] = "";
		char cdtext_artist[256] = "";
        char cdtext_compilation[256] = "";

        while(entry*18+8 < block[4].size) 
		{
            int cdtext_1 = read_binary(unsigned short, nrg_content, block[4].offset+8+entry*18+0);
            int cdtext_2 = read_binary(unsigned short, nrg_content, block[4].offset+8+entry*18+2)
            char cdtext_3[13];
			cdtext_3[12]=0;
			memcpy(cdtext_3,nrg_content+block[4].offset+8+entry*18+4,12);
            int cdtext_4 = read_binary(unsigned short, nrg_content, block[4].offset+8+entry*18+0)
            cdtext_entry = cdtext_2 >> 8;
            cdtext_type = cdtext_1 >> 8;
            if(((entry == 0)&&(cdtext_entry == 0))||(cdtext_entry != 0))
			{
                switch(cdtext_type)
				{
					case 0x80: strcat(cdtext_song,cdtext_3); break;
					case 0x81: strcat(cdtext_artist,cdtext_3); break;
					case 0x8f: strcat(cdtext_compilation,cdtext_3); break;
					default:
						printf("NOTE: Unrecognized cd-text type found while parsing Nero CD-Image.");
				}
			}
			entry++;
		}
        cdtext_song = string.split(cdtext_song, "\0")
        cdtext_artist = string.split(cdtext_artist, "\0")
        while len(cdtext_song[-1]) == 0: del cdtext_song[-1]
        while len(cdtext_artist[-1]) == 0: del cdtext_artist[-1]
        if verbose:
            for entry in range(0, len(cdtext_song)):
                print "Artist: %s   Song: %s" % (cdtext_artist[entry], cdtext_song[entry])
	}
	*/
    // making sure table is empty
	int entry=0;
	int sess=0;
    
	if(verbose) printf("TRACK ENTRIES:");

	for(sess=0;sess<nsessions;sess++)
	{
		sessions[sess].session=sess+1;

		if(is_dao) // Read DAO information.
		{
			entry = 1; // entry 0 is block-header entry so we start on entry 1
			for(;;)
			{
				__int64 cue_offset;
				__int64 dao_offset;
				if(oldformat)
				{
					cue_offset = block[CUES].infos[sess].offset;
					dao_offset = block[DAOI].infos[sess].offset;
				}
				else
				{
					cue_offset = block[CUEX].infos[sess].offset;
					dao_offset = block[DAOX].infos[sess].offset;
				}
	    
				// tracktype. 0x40 = datatrack, 0x01 = copyright?
				int tracktype = read_binary(unsigned char, nrg_content, cue_offset+8+entry*16+0);
				int track_raw = read_binary(unsigned char, nrg_content, cue_offset+8+entry*16+1);
				int track = (track_raw >> 4) * 10 + (track_raw & 0x0f);

				// addr_ctrl. addresstype MSF or LBA in lower 4 bits, Q-channel control field in upper 4 bits.
				int addr_ctrl = read_binary(unsigned char, nrg_content, cue_offset+8+entry*16+2);
				int start_sector = read_binary(int, nrg_content, cue_offset+8+entry*16+4);
				byteswap(&start_sector,4);
				int nexttrack_raw = read_binary(unsigned char, nrg_content, cue_offset+8+entry*16+9);
				int nexttrack = (nexttrack_raw >> 4) * 10 + (nexttrack_raw & 0x0f);
				int end_sector = read_binary(int, nrg_content, cue_offset+8+entry*16+12);
				byteswap(&end_sector,4);
	            
				char isrc[12];
				memcpy(isrc,nrg_content+dao_offset-12+entry*42,12);

				int sector_size = read_binary(unsigned short, nrg_content, dao_offset-12+entry*42+12);
				byteswap(&sector_size,2);
				int mode = read_binary(unsigned char, nrg_content, dao_offset-12+entry*42+14);

				__int64 start_offset;
				__int64 end_offset;
	    
				if(oldformat)
				{
					start_offset = read_binary(unsigned int, nrg_content, dao_offset-12+entry*42+22);
					end_offset = read_binary(unsigned int, nrg_content, dao_offset-12+entry*42+26);
					byteswap(&start_offset,4);
					byteswap(&end_offset,4);
				}
				else
				{
					start_offset = read_binary(__int64, nrg_content, dao_offset-12+entry*42+26);
					end_offset = read_binary(__int64, nrg_content, dao_offset-12+entry*42+34);
					byteswap(&start_offset,8);
					byteswap(&end_offset,8);
				}

				if(verbose)
				{
					printf("[%3i] track: %3i, next track: %3i, start sector: %8i, end sector: %8i\n      sector size: %i, mode: %i, start: 0x%08x, end: 0x%08x.\n",
							entry, track, nexttrack, start_sector, end_sector, sector_size, mode, start_offset, end_offset);
					printf("      tracktype: 0x%x, addr_ctrl: 0x%x, isrc: %s.\n",tracktype, addr_ctrl, isrc);
				}
	            
				sessions[sess].tracks[entry-1].mode=nrg_mode(mode);
				sessions[sess].tracks[entry-1].track=track;
				sessions[sess].tracks[entry-1].sectorsize=sector_size;
				sessions[sess].tracks[entry-1].sector=start_sector;
				sessions[sess].tracks[entry-1].sectors=end_sector-start_sector;
				sessions[sess].tracks[entry-1].offset=start_offset;

				entry += 1;
				if(nexttrack_raw == 0xAA) break; // lead-out
			}
			sessions[sess].ntracks=entry-1;
		}
		else // Read TAO information.
		{
			int tracks_in_session = read_binary(int, nrg_content, block[SINF].infos[sess].offset+8+0);
			byteswap(&tracks_in_session,4);
			if(verbose) printf("Tracks in Session %i: %i.\n",sess,tracks_in_session);
	                        
			for(entry=0;entry<tracks_in_session;entry++)
			{
				__int64 offset;
				__int64 size;
				int mode;
				int sector;

				if(oldformat)
				{
					offset = read_binary(unsigned int, nrg_content, block[ETNF].infos[sess].offset+8+entry*20+0);
					size = read_binary(unsigned int, nrg_content, block[ETNF].infos[sess].offset+8+entry*20+4);
					mode = read_binary(unsigned char, nrg_content, block[ETNF].infos[sess].offset+8+entry*20+11);
					sector = read_binary(int, nrg_content, block[ETNF].infos[sess].offset+8+entry*20+12);
					byteswap(&size,4);
					byteswap(&offset,4);
					byteswap(&sector,4);
				}
				else
				{
					offset = read_binary(__int64, nrg_content, block[ETN2].infos[sess].offset+8+entry*32+0);
					size = read_binary(__int64, nrg_content, block[ETN2].infos[sess].offset+8+entry*32+8);
					mode = read_binary(unsigned char, nrg_content, block[ETN2].infos[sess].offset+8+entry*32+19);
					sector = read_binary(int, nrg_content, block[ETN2].infos[sess].offset+8+entry*32+20);
					byteswap(&size,8);
					byteswap(&offset,8);
					byteswap(&sector,4);
				}
				if(verbose)
					printf("[%3i] offset: 0x%08I64x, size: 0x%08I64x, sector: %i, mode: %x\n",entry+1, offset, size, sector, mode);

				sessions[sess].tracks[entry].mode=nrg_mode(mode);
				sessions[sess].tracks[entry].track=entry+1;
				sessions[sess].tracks[entry].sector=sector;
				sessions[sess].tracks[entry].sectorsize=2048;
				sessions[sess].tracks[entry].sectors=(s32)(size>>11); // size/2048 (user data sectors)
				sessions[sess].tracks[entry].offset=offset;
			}
			sessions[sess].ntracks=tracks_in_session;
		}
	}

    return true;
}