#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <string.h>
#include <strings.h>
#include <stdlib.h>
#include "myc_err.h"
#include "myc_str.h"
#include "myc_buf.h"

char *StrNGet(StrBuf *buf, char *result, int reslen, int sep) {
  char *b, *f, *e, quote;
  int res, l, ll;

  if (buf->rdpos < 0 || buf->rdpos >= buf->dsize || buf->buf==NULL)
      ERR_MSG("buffer corrupt");
  b=buf->buf + buf->rdpos;
  if (*b=='"' || *b=='\'') { /* take string within quotes (single or double) */
    quote=*b; b++;
    f=strchr(b, quote);
    if (f==NULL)
        ERR_MSG("missing '""'");
    l=f-b;
    if (sep == StrNONE) {
      buf->rdpos=f - buf->buf + 1;
      buf->seen = 0;
    } else {
      e=strchr(f+1, sep);
      if (e==NULL) {
        buf->rdpos = f - buf->buf + 1 + strlen(f+1);
        buf->seen=0;
      } else {
        buf->rdpos = e - buf->buf + 1;
        buf->seen=1;
      }
    }
  } else {
    f=strchr(b, sep);
    if (f==NULL) {
      l=strlen(b);
      f=b+l;
      buf->rdpos+=l;
      buf->seen=0;
    } else {
      l=f-b;
      buf->rdpos+=l+1;
      buf->seen=1;
    }
  }
  if (result==NULL) {
    if (reslen==-1) { /* special case for StrGetBuf */
      return(f);
    }
    *f='\0';
    return(b);
  } else {
    if (l>=reslen) l=reslen-1; /* ERR_MSG("result too short"); */
    strncpy(result, b, l);
    result[l]='\0';
    return(result);
  }
  OnError:
    buf->rdpos=buf->dsize; /* illegal value */
    return(NULL);
}

int StrGetBuf(StrBuf *buf, StrBuf *res, int sep) {
  char *b, *f;

  b = buf->buf + buf->rdpos;
  ERR_P(f=StrNGet(buf, NULL, -1, sep));
  res->buf   = b;
  res->wrpos = f-b;
  res->rdpos = 0;
  res->dsize = f-b;
  return(0);
  OnError:
    buf->rdpos=buf->dsize; /* illegal value */
    return(-1);
}

int StrGetInt(StrBuf *buf, int *res, int sep) {
  char num[32];
  int i, l, p;

  p=buf->rdpos;
  ERR_P(StrGet(buf, num, sep));
  i=sscanf(num, "%d%n", res, &l);
  if (i==0)
      ERR_MSG("illegal number");
  if (sep==StrNONE) {
    buf->rdpos=p+l;
  }
  return(0);
  OnError:
    buf->rdpos=buf->dsize; /* illegal value */
    return(0);
}

int StrGetFloat(StrBuf *buf, float *res, int sep) {
  char num[32];
  int i, l, p;

  p=buf->rdpos;
  ERR_P(StrGet(buf, num, sep));
  if (num[0]=='N' && num[1]=='a' && num[2]=='N') {
    l=3;
    *res = MYC_NAN;
  } else {
    i=sscanf(num, "%f%n", res, &l);
    if (i==0) {
      ERR_MSG("illegal number");
    }
  }
  if (sep==StrNONE) {
    buf->rdpos=p+l;
  }
  return(0);
  OnError:
    buf->rdpos=buf->dsize; /* illegal value */
    return(-1);
}

int StrGetEnd(StrBuf *buf) {
  if (buf->buf!=NULL) {
    if (buf->rdpos < 0 || buf->rdpos >= buf->dsize)
        ERR_MSG("buffer corrupt");
    if (buf->rdpos != buf->wrpos)
        ERR_MSG("superflous content in buffer");
  }
  return(0);
  OnError:
    return(-1);
}

int StrPut(StrBuf *buf, const char *str, int sep) {
  int l, pos;
  char quote;

  pos=buf->wrpos;
  if (pos < 0 || pos >= buf->dsize || buf->buf==NULL)
      ERR_MSG("buffer corrupt");
  l=strlen(str);
  quote='\0';
  if (sep>0) {
    if (strchr(str, sep)!=NULL) {
      if (strchr(str, '"')!=NULL) {
        quote='"'; l+=2;
      }
      if (strchr(str, '\'')!=NULL) {
        if (quote!='\0')
            ERR_MSG("str must not contain separator and both kind of quotes");
        quote='\''; l+=2;
      }
    }
  }
  if (pos+l >= buf->dsize) {
    ERR_MSG("buffer too short");
  }
  if (quote!='\0') {
    buf->buf[pos]=quote; pos++;
    strcpy(buf->buf + pos, str);
    buf->buf[pos]=quote; pos++;
  } else {
    strcpy(buf->buf + pos, str);
  }
  pos+=l;
  if (sep!=StrNONE) {
    buf->buf[pos]=sep;
    pos++;
  } else {
    buf->buf[pos]='\0';    
  }
  buf->wrpos=pos;
  return(0);
  OnError:
    buf->wrpos=-1;
    return(-1);
}

int StrPutInt(StrBuf *buf, int val, int sep) {
  char num[32];

  sprintf(num, "%d", val);
  ERR_I(StrPut(buf, num, sep));
  return(0);
  OnError:
    return(-1);
}

int StrPutFloat(StrBuf *buf, float val, int sep) {
  char num[32];
  int l;

  if (val == MYC_NAN) {
    ERR_I(StrPut(buf, "NaN", sep));
  } else {
    sprintf(num, "%g", val);
    ERR_I(StrPut(buf, num, sep));
  }
  return(0);
  OnError:
    return(-1);
}

void StrReset(StrBuf *buf) {
  buf->rdpos=0;
}

void StrClear(StrBuf *buf) {
  buf->rdpos=0;
  buf->wrpos=0;
}

void StrNLink(StrBuf *buf, char *str, int length) {
  int l;
  buf->buf=str;
  buf->rdpos=0;
  l=strlen(str);
  if (l<length) l=length;
  buf->wrpos=l;
  buf->dsize=buf->wrpos;
}

#define TWO_23 8388608
#define EXP_OFFS 128

void flt_to_char4(double f, char buf[4]) {
  double m;
  int e, res, ir;

  m=frexp(f, &e);
  e=e+EXP_OFFS;
  if (e<0 || m==0) {
    res=0; m=0;
  } else {
    if (e>255) {
      res=255*TWO_23+(TWO_23-1); /* max. representable number */
    } else {
      res=e*TWO_23+(int)(0.5+(fabs(m*2)-1.0)*TWO_23);
    }
  }
  buf[0]=res % 256; res=res/256;
  buf[1]=res % 256; res=res/256;
  buf[2]=res % 256; res=res/256;
  if (m<0) {
    buf[3]=res-128;
  } else {
    buf[3]=res;
  }
}

double flt_from_char4(char buf[4]) {
  int s, i, b0, b1, b2, b3;
  
  b0=buf[0]; if (b0<0) b0+=256;
  b1=buf[1]; if (b1<0) b1+=256;
  b2=buf[2]; if (b2<0) b2+=256;
  b3=buf[3]; if (b3<0) b3+=256;
  if (b3>=128) {
    i=(b3-128)*(256*65536)+b2*65536+b1*256+b0;
    if (i==0) return 0.0;
    return -ldexp((i % TWO_23)*1.0/(TWO_23)*0.5+0.5, i/TWO_23-EXP_OFFS);
  } else {
    i=b3*(256*65536)+b2*65536+b1*256+b0;
    if (i==0) return 0.0;
    return ldexp((i % TWO_23)*1.0/(TWO_23)*0.5+0.5, i/TWO_23-EXP_OFFS);
  }
}

int StrPutArray(StrBuf *buf, float val[], int size) {
  int i, pos;
  char *b;

  pos=buf->wrpos;
  if (pos < 0 || pos >= buf->dsize || buf->buf==NULL)
      ERR_MSG("buffer corrupt");
  if (pos+4*size >= buf->dsize)
      ERR_MSG("buffer too short");
  b=buf->buf+pos;
  flt_to_char4((float)size, b);
  b+=4;
  for (i=0; i<size; i++) {
    flt_to_char4(val[i], b);
    b+=4;
  }
  buf->wrpos=b - buf->buf;
  return(0);
  OnError:
    buf->wrpos=-1;
    return(-1);
}

int StrGetArray(StrBuf *buf, float val[], int maxsize) {
  int size, i;
  char *b;
  double gg;

  if (buf->rdpos < 0 || buf->rdpos >= buf->dsize || buf->buf==NULL)
      ERR_MSG("buffer corrupt");
  b=buf->buf + buf->rdpos;
  size=flt_from_char4(b);  b+=4;
  buf->rdpos+=4*(size+1);
  if (maxsize<size) size=maxsize;
  for (i=0; i<size; i++) {
    gg=flt_from_char4(b); b+=4;
    val[i]=gg;
  }
  return size;
  OnError:
    buf->rdpos=buf->dsize; /* illegal value */
    return(-1);
}