/******************************************************
 *
 * zexy - implementation file
 *
 * copyleft (c) Franz Zotter
 *
 *   2105:forum::für::umläute:2007
 *
 *   institute of electronic music and acoustics (iem)
 *
 ******************************************************
 *
 * license: GNU General Public License v.2
 *
 ******************************************************/

#include "zexy.h"

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

#ifdef __WIN32__
# include <io.h>
#else
# include <sys/types.h>
# include <unistd.h>
#endif

#define MIN_FREADLN_LENGTH 10

/* freadln: reads messages continuously from the lines of 
 * a file that doesn't necessarily need to fit 
 * into the RAM of your system
 *
 * Franz Zotter zotter@iem.at, 2007
 * Institute of Electronic Music and Acoustics
 *
 */

static t_class *freadln_class;

typedef struct freadln
{
   t_object x_ob;
   FILE *x_file;
   char *x_filename;
   char *x_textbuf;
   int x_textbuf_length;
   t_outlet *x_message_outlet;
   t_outlet *x_readybang_outlet;
} t_freadln;


static void freadln_close (t_freadln *x)
{
   if(x->x_file) 
      fclose(x->x_file);
   x->x_file=0;
   if(x->x_filename)
      freebytes(x->x_filename, sizeof(char)*MAXPDSTRING);
   x->x_filename=0;
   if(x->x_textbuf)
      freebytes(x->x_textbuf, sizeof(char)*x->x_textbuf_length);
   x->x_textbuf=0;
   x->x_textbuf_length=0;
}

static void freadln_open (t_freadln *x, t_symbol *s, t_symbol*type)
{
   char filenamebuf[MAXPDSTRING], *filenamebufptr;
   int fd;
   freadln_close(x);

   if(type!=gensym("cr")) {
     pd_error(x, "currently only 'cr' type files are implemented!");
     return;
   }

   // directory, filename, extension, dirresult, nameresult, unsigned int size, int bin
   if ((fd=open_via_path("",s->s_name,"", filenamebuf, &filenamebufptr, MAXPDSTRING,0))==-1) {
      pd_error(x, "failed to open %128s", filenamebuf);
      close(fd);
      return;
   }
   close(fd);
   if (!(x->x_file=fopen(filenamebuf, "r"))) {
      pd_error(x, "failed to open %128s",filenamebuf);
      return;
   }
   if (!(x->x_filename=(char*)getbytes(sizeof(char)*strlen(filenamebuf)))) {
      pd_error(x, "out of memory");
      freadln_close(x);
      return;
   }
   strcpy(x->x_filename,filenamebuf);
   if (!(x->x_textbuf = (char *) getbytes (MIN_FREADLN_LENGTH * sizeof(char)))) {
      pd_error(x, "out of memory");
      freadln_close(x);
      return;
   }
   x->x_textbuf_length=MIN_FREADLN_LENGTH;
}

static int enlarge_cstr_if_required(const char **c_str, int *len, const int desired_min_length) 
{
   if ((!(*c_str))||*len==0) {
      *c_str = (char*) calloc (1,sizeof(char));
      return 1;
   }
   if (len[0]<desired_min_length) {
      do {
         len[0]<<=1;
      } while ((len[0]<desired_min_length)&&(len[0]!=0));
      freebytes((char*)*c_str, sizeof(char)*len[0]);
      if (!(*c_str=(char*)calloc(len[0],sizeof(char))))
         len[0]=0;
   } 
   return len[0];
}

static int cstr_char_pos(const char *c_str, const char c) 
{
   int cnt=1;
   if (c_str) {
      do {
         if (*c_str==c)
            return cnt;
         cnt++;
      } while (*c_str++!='\0');
   }
   return -1;
}

static void freadln_readline (t_freadln *x)
{
   int min_length=(x->x_textbuf_length < 1)?1:x->x_textbuf_length;
   int ret_pos=0;
   t_binbuf *bbuf;
   t_atom *abuf;
   int abuf_length;
   t_symbol *s;

   if (!x->x_file) {
      pd_error(x, "no file opened for reading");
      return;
   }

   do {
      if (ret_pos==-1) {
	 min_length++;
	 fseek(x->x_file,-(long)(x->x_textbuf_length-1),SEEK_CUR);
      }
      if (!enlarge_cstr_if_required((const char**) &x->x_textbuf, &x->x_textbuf_length, min_length)) {
         pd_error(x, "out of memory");
         x->x_textbuf_length=0;
         freadln_close(x);
         return;
      }
      if (!(fgets(x->x_textbuf, x->x_textbuf_length, x->x_file))) {
         freadln_close(x);
         outlet_bang(x->x_readybang_outlet);
         return;
      }
   } while ((ret_pos=cstr_char_pos(x->x_textbuf,'\n'))==-1);
   x->x_textbuf[ret_pos-1]='\0';
   //post("analyzing \"%s\"",x->x_textbuf);
   if (!(bbuf=binbuf_new())) {
      pd_error(x, "out of memory");
      freadln_close(x);
      return;
   }
   binbuf_text(bbuf, x->x_textbuf, ret_pos-1);
   abuf = binbuf_getvec(bbuf);
   abuf_length = binbuf_getnatom(bbuf);
   if (abuf_length>0) {
      if (abuf->a_type==A_SYMBOL) {
         outlet_anything(x->x_message_outlet, atom_getsymbol(abuf), abuf_length-1, abuf+1);
      }
      else {
         outlet_list(x->x_message_outlet, gensym("list"), abuf_length, abuf);
      }
   } 
   else {
      outlet_list(x->x_message_outlet, atom_getsymbol(abuf), 0, abuf);
   }
   // NOTE: the following line might be a problem in recursions
   // and could be performed before to outlet_* as well,
   // but(!) atom buffer abuf must be copied if doing so.
   binbuf_free(bbuf);

}
static void freadln_free (t_freadln *x)
{
   freadln_close(x);
   outlet_free (x->x_message_outlet);
   outlet_free (x->x_readybang_outlet);
}

static void *freadln_new(void)
{
   t_freadln *x = (t_freadln *)pd_new(freadln_class);
   x->x_message_outlet = outlet_new(&x->x_ob, &s_list);
   x->x_readybang_outlet = outlet_new(&x->x_ob, &s_bang);
   x->x_filename=0;
   x->x_file=0;
   x->x_textbuf=0;
   return (void *)x;
}

void freadln_setup(void)
{
   freadln_class = class_new(gensym("freadln"), (t_newmethod)freadln_new, 
         (t_method) freadln_free, sizeof(t_freadln), 0, 0);
   class_addmethod(freadln_class, (t_method)freadln_open, gensym("open"), A_SYMBOL, A_DEFSYM, 0);
   class_addmethod(freadln_class, (t_method)freadln_close, gensym("close"), A_NULL, 0);
   class_addbang(freadln_class, (t_method)freadln_readline);

   zexy_register("freadln");
}