#include <stdio.h>
#include <math.h>
#include <fcntl.h>
#include <string.h>
#include <math.h>

#include <sys/types.h>
#include <stdlib.h>

/* #define PI 3.141565 */

int fd;
FILE *fp;

int steps;
int cur_sampleid=0;

#define MAXLENGHT 10*44100         /* 10 sec. samples enough ? */
#define MAXNAMEL 32
#define MAXSAMPLEID 128

#define MSEC(t) (int)(t*44.1)


short os[MAXLENGHT];

struct sample {
   char  name[MAXNAMEL];
   int   id;
   int   samplerate;
   int   channels;
   int   length;
   short *data;
} ASAMPLE;

struct sample * samples[MAXSAMPLEID];

int consume_until(fd,str,len)
int fd, len;
char *str;
{
   int i;
   char b[4];
   read(fd,b,len);
   printf("[c,%s,%d]:%c%c%c%c,%d\n",str,len,b[0],b[1],b[2],b[3],
      strncmp(b,str,len));
   while (strncmp(b,str,len) != 0) {
      for (i=3; i>0; i--) b[i-1]=b[i];
      /* printf("[c ]:%d %d %d %d\n",(int) b[0],(int) b[1], (int) b[2], (int) b[3] ); */

      if (read(fd,b+3,1) != 1) {
         printf("Error: file format error\n");
         return(-1);
      }
   }
   return(0);                  /* match */
}

struct sample * readwav(s)                 /* Proto wav header, n=nnodes, filename */
char *s;
{
   char bb[4];
   short is, channels;
   int ii, length, samplerate;
   struct sample *p;
   fd = open(s,O_RDONLY|O_BINARY);
   if (fd < 0) return(NULL);

   /* read(fd,bb,4); */
   consume_until(fd,"RIFF",4);
   read(fd,&ii,4);
   consume_until(fd,"WAVE",4);

   consume_until(fd,"fmt ",4);
   read(fd,bb,4);   /* 0x10 */
   read(fd,bb,2);   /* 0x01 */
   read(fd,&channels,2);  /* (short) 1*/              /* Mono */
   if (channels != 1) {
      printf("Error: number of channels must be one.\n");
   }
   read(fd,&samplerate,4);
   if (samplerate != 44100) {
      printf("Error: Sample rate should be 44100 Hz\n");
   }
   read(fd,&ii,4);
   read(fd,&is,2);
   read(fd,&is,2);

   consume_until(fd,"data",4);
   read(fd,&length,4);  /* 2* steps (length of data) */

   if ((p= (struct sample *) malloc(sizeof(ASAMPLE) + length*sizeof(short))) == NULL ) {
      printf("Error: memory allocation failed.\n");
      exit(-3);
   }
   strncpy(p->name, s, MAXNAMEL);
   p->id = cur_sampleid;
   p->samplerate = samplerate;
   p->channels = (int) channels;
   p->data = (short *) (p+1);
   p->length = length/2;
   if (read(fd,p->data,length) != length) {
      printf("Error: not all data could be read of %s\n",s);
   }
   samples[p->id] = p;
   cur_sampleid++;
   return(p);
}


int print_sample(s1)
struct sample *s1;
{
   if (s1 != NULL) {
      printf("name=%s",s1->name);
      printf("  length: %d\n", s1->length);
      printf("  id=%d",s1->id);
      printf("  samplerate=%d",s1->samplerate);
      printf("  channels=%d",s1->channels);
      printf("  length=%d",s1->length);
      printf("  {%d %d %d %d}\n",s1->data[0],s1->data[1],s1->data[2],s1->data[3]);
   }
   return(0);
}





iwrite(fd,n,l)
int fd,l;
unsigned int n;
{
   write(fd,&n,l);
}

int initwav(s)                 /* Proto wav header, n=nnodes, filename */
char *s;
{
   fd = open(s,O_WRONLY|O_CREAT|O_TRUNC|O_BINARY);
   if (fd == NULL) return(-1);

   write(fd,"RIFF",4);
   iwrite(fd,(2*steps+36),4);
   write(fd,"WAVE",4);

   write(fd,"fmt ",4);
   iwrite(fd,(0x10),4);
   iwrite(fd,((short) 0x01),2);
   iwrite(fd,((short) 1),2);              /* Mono */
   iwrite(fd,(44100/1),4);                  /* Sample rate */
   iwrite(fd,(2*44100/1),4);
   iwrite(fd,((short) 2),2);
   iwrite(fd,((short) 16),2);

   write(fd,"data",4);
   iwrite(fd,(2*steps),4);
   return(0);
}


writewav(fd)
{
   int i;

   for (i=0; i<steps; i++)
      write(fd,&os[i],2);
   close(fd);
}

clear_os()
{
   int i;
   for (i=0; i<steps; i++)
       os[i] = 0;
}

struct sample * sample_exists(n)
char *n;
{
   struct sample * sp;
   int i;

   i=0;
   for (i=0; i<MAXSAMPLEID; i++) {
      sp = samples[i];
      if (sp != NULL)
         if (strcmp(sp->name,n) == 0) {
            return(sp);
            printf("Found loaded sample %d %s\n",i,n);
         }
   }
   return(NULL);
}

#define FRAC 0x10000
#define SINCR(i,fi,di) fi+=di; i+= fi/FRAC; fi=fi%FRAC;

int sample_copy(to, from, len, ampl, tune)
short to[], from[];
int len;
float ampl, tune;
{
   int i, j, fi, di;
/*   printf("%ld %ld %d  %d %d\n",(int)to,(int)from,(int)len,
      (int) to[0], (int) from[0]); */
   j = 0;
   fi = 0;
   di = (int) ((float) FRAC *tune);
   for (i=0; j<len;) { SINCR(i,fi,di)

      to[j]+=(short) (ampl* (float) from[i]);
      j++;
   }
   return(0);
}

int gen_sample(name,start,length,ampl,tune)
char *name;
int start, length;
float ampl, tune;
{
   struct sample *sp;
   int alength;
   if ((sp=sample_exists(name)) == NULL ) {
      sp = readwav(name);
   }
   if (sp == NULL) {
      printf("Error: sample %s not found.\n");
      return(-1);
   }
   print_sample(sp);
   if (length == 0) {
      alength = sp->length;
   } else {
      if (length > sp->length)
         alength = sp->length;
      else
         alength = length;
   }
   printf("alength = %d\n",alength);
   sample_copy(
      os+start, sp->data, alength, ampl, tune
   );
   return(0);
}

gen_bd(start,length,ampl,tune)
int start, length;
float ampl, tune;
{
   int i;
   short t;

   /* printf("start= %d length = %d\n",start, length); */
   for (i=0; i<length; i++) {
      t = (short)
      ( (double) ampl*32000*
         (2.0/PI) * 5 * atan( 0.2 *
              ( (2.0/PI) *5 * atan( .2 *
                 sin(2*PI*50*(double)i/44100.0) )
              )
              * pow(.5,4* 6.0 * (double) i/ (double) (length)
            )
         )
      );
      /* printf("%d\n",(int) t); */
      os[i+start]+=t;
   }
}

gen_sd(start,length,ampl, tune)
int start, length;
float ampl, tune;
{
   int i;
   short t;
   double t1,t2,t3,t4;

   t1=t2=t3=t4=0.0;
   /* printf("start= %d length = %d\n",start, length); */
   for (i=0; i<length; i++) {
      t1 = (-1.0+2.0* ((double) rand()) /(double) RAND_MAX );
      t = (short)
      ( (double) ampl*32000*
         (2.0/PI) * 5 * atan( 0.2 *
              ( (2.0/PI) *10 * atan( .1 * 0.5 *
                 (
                    sin(2*PI*120*((double)i+5*t1)/44100.0) + 0.4 * t1
                 ) )
              )
              * pow(.5,3* 6.0 * (double) i/ (double) (length)
            )
         )
      );
      /* printf("%d\n",(int) t); */
      os[i+start]+=t;
      t2=t1;t3=t2;t4=t3;
   }
}

gen_hhc(start,length,ampl, tune)
int start, length;
float ampl, tune;
{
   int i;
   short t,t1,t2;

   t1=t2=0;

   /* printf("start= %d length = %d\n",start, length); */
   for (i=0; i<length; i++) {
      t = (int)
      ( (double) ampl*32000*
         (-1.0+2.0* ((double) rand()) /(double) RAND_MAX )
         /* sin(2*PI*50*(double)i/44100.0) */
      )
      * pow(.5,4* 6.0 * (double) i/ (double) (length) );
      /* printf("%d\n",(int) t); */
      t /= 3;
      os[i+start]+=t+t1+t2;
      t1 = t; t2 = t1;
   }
}

gen_hho(start,length,ampl, tune)
int start, length;
float ampl, tune;
{
   int i;
   short t,t1,t2;

   t1=t2=0;

   /* printf("start= %d length = %d\n",start, length); */
   for (i=0; i<0.9*length; i++) {
      t = (int)
      ( (double) ampl*32000*
         (-1.0+2.0* ((double) rand()) /(double) RAND_MAX )
         /* sin(2*PI*50*(double)i/44100.0) */
      )
      * pow(.5,4* .6 * (double) i/ (double) (length) );
      /* printf("%d\n",(int) t); */
      t /= 3;
      os[i+start]+=t+t1+t2;
      t1 = t; t2 = t1;
   }
   t1=t2=0;
   for (i=0; i<(1-0.9)*length; i++) {
      t = (int)
      ( (double) ampl*32000*
         (-1.0+2.0* ((double) rand()) /(double) RAND_MAX )
         /* sin(2*PI*50*(double)i/44100.0) */
      )
      * pow(.5,4* .6 * (double) (0.9 *(length-1))/ (double) (length) )
      * pow(.5,4* 6.0 * (double) i/ (double) (length) );
      /* printf("%d\n",(int) t); */
      t /= 3;
      os[i+start+(int) ((0.9) * length)]+=t+t1+t2;
      t1 = t; t2 = t1;
   }
}


add_sample(name,start,length, ampl, tune)
char *name;
float start, length, ampl, tune;
{
   char t[128];
   if (strcmp(name,"s_bd") == 0) {
      gen_bd(MSEC(start),MSEC(length),ampl,tune);
   } else
   if (strcmp(name,"s_hhc") == 0) {
      gen_hhc(MSEC(start),MSEC(length),ampl,tune);
   } else
   if (strcmp(name,"s_hho") == 0) {
      gen_hho(MSEC(start),MSEC(length),ampl,tune);
   } else
   if (strcmp(name,"s_sd") == 0) {
      gen_sd(MSEC(start),MSEC(length),ampl,tune);
   } else
   if (strcmp(name,"len") == 0) {
      steps = MSEC(start);
      clear_os();
   } else {
      strcpy(t,name);
      strcat(t,".wav");
      gen_sample(t,MSEC(start),MSEC(length),ampl,tune);
   }
/*   if (strcmp(name,"s_bd") == 0) {
      gen_sample("kick.wav",MSEC(start),MSEC(length),ampl);
   }
   if (strcmp(name,"s_hhc") == 0) {
      gen_sample("chh.wav",MSEC(start),MSEC(length),ampl);
   }
   if (strcmp(name,"s_sd") == 0) {
      gen_sample("sd.wav",MSEC(start),MSEC(length),ampl);
   }
   if (strcmp(name,"s_hho") == 0) {
      gen_sample("ohh.wav",MSEC(start),MSEC(length),ampl);
   }
   if (strcmp(name,"s_ride") == 0) {
      gen_sample("ride.wav",MSEC(start),MSEC(length),ampl);
   }
   if (strcmp(name,"s_crash") == 0) {
      gen_sample("crash.wav",MSEC(start),MSEC(length),ampl);
   }
   if (strcmp(name,"s_tamb") == 0) {
      gen_sample("tamb.wav",MSEC(start),MSEC(length),ampl);
   }
*/
}

/*    gen_bd(MSEC(   0),MSEC(200),0.9); */


#define MAXCOM 16*1024

read_com()
{
   int i;
   float t,l,a,d;

   static char b[MAXCOM];
   while (!feof(stdin) && fgets(b,MAXCOM,stdin) != NULL) {
      i=0;
      if (b[0] != '\n')
      {
         while (b[i] != ' ' && i<MAXCOM) i++;
         if (i>=MAXCOM) {write_com("error : data missing"); exit(-1); }
         if (sscanf(b+i+1,"%f %f %f %f",&t,&l,&a,&d) == 4) {
            b[i] = '\0';
            add_sample(b,t,l,a,d);
         }
      }
   }

}

write_com(s)
char s[];
{
   printf("%s\n",s);
}



create_sample()            /* 120 BPM. 16th Quantized basic track */
{ /*************** NO TUNE PARA YET ***************/
   int t, n16;
   steps = MSEC(2000.0);
   clear_os();
   gen_bd(MSEC(   0),MSEC(200),0.9);
   gen_bd(MSEC( 750),MSEC(200),0.45);
   gen_bd(MSEC(1000),MSEC(200),0.9);
   n16=0;
   for (t=0; t<MSEC(2000); t+=MSEC(1000/8)) {
      if ((n16%16) == 10) {
         gen_hho(t,MSEC(240),.15);
      } else
         if ((n16%8) == 0)
            gen_hhc(t,MSEC(100),.4);
         else {
            if ((n16%2) == 0)
               gen_hhc(t,MSEC(100),.2);
         }
      if (n16 == 1)
         gen_hhc(t,MSEC(50),.3);
      n16++;
   }
   gen_sd(MSEC( 500),MSEC(300),0.8);
   gen_sd(MSEC(1500),MSEC(300),0.8);
}

init_samples()
{
   int i;
   for (i=0; i<MAXSAMPLEID; i++)
      samples[i] = NULL;
}

int main(argc,argv)
int argc;
char *argv[];
{
   if (argc != 2) {
      printf("Usage: %s <outfile.wav>\n",argv[0]);
      exit(-1);
   }
   init_samples();
   read_com();
   /* create_sample(); */
   /* clear_os(); */
   if (initwav(argv[1]) != 0) {
      printf("Cannot open output file %s.\n", argv[2]);
      exit(-3);
   }
   writewav(fd);
   write_com("end\n");
   return(0);
}

trymain()
{
   init_samples();
   add_sample("len",2000,0,0, 1.0);
   add_sample("s_bd",0,0,0.9, 1.0);
   add_sample("s_bd",500,0,0.9, 1.0);
}