/* 
 * $Id$
 *
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <glib.h>

#include "config.h"
#include "libmpdclient.h"
#include "ncmpc.h"
#include "support.h"
#include "strfsong.h"

static char * 
skip(char * p) 
{
  int stack = 0;
 
  while (*p != '\0') {
    if(*p == '[') stack++;
    if(*p == '#' && p[1] != '\0') {
      /* skip escaped stuff */
      ++p;
    }
    else if(stack) {
      if(*p == ']') stack--;
    }
    else {
      if(*p == '&' || *p == '|' || *p == ']') {
	break;
      }
    }
    ++p;
  }

  return p;
}

static gsize
_strfsong(gchar *s, 
	  gsize max, 
	  const gchar *format, 
	  mpd_Song *song, 
	  gchar **last)
{
  gchar *p, *end;
  gchar *temp;
  gsize n, length = 0;
  gboolean found = FALSE;

  memset(s, 0, max);
  if( song==NULL )
    return 0;
  
  for( p=(gchar *) format; *p != '\0' && length<max; )
    {
      /* OR */
      if (p[0] == '|') 
	{
	  ++p;
	  if(!found) 
	    {
	      memset(s, 0, max);
	      length = 0;
	    }
	  else 
	    {
	      p = skip(p);
	    }
	  continue;
	}

      /* AND */
      if (p[0] == '&') 
	{
	  ++p;
	  if(!found) 
	    {
	      p = skip(p);
	    }
	  else 
	    {
	      found = FALSE;
	    }
	  continue;
	}

      /* EXPRESSION START */
      if (p[0] == '[')
	{
	  temp = g_malloc0(max);
	  if( _strfsong(temp, max, p+1, song, &p) >0 )
	    {
	      strncat(s, temp, max-length);
	      length = strlen(s);
	      found = TRUE;
	    }
	  g_free(temp);
	  continue;
	}

      /* EXPRESSION END */
      if (p[0] == ']')
	{
	  if(last) *last = p+1;
	  if(!found && length) 
	    {
	      memset(s, 0, max);
	      length = 0;
	    }
	  return length;
	}

      /* pass-through non-escaped portions of the format string */
      if (p[0] != '#' && p[0] != '%' && length<max)
	{
	  strncat(s, p, 1);
	  length++;
	  ++p;
	  continue;
	}

      /* let the escape character escape itself */
      if (p[0] == '#' && p[1] != '\0' && length<max)
	{
	  strncat(s, p+1, 1);
	  length++;
	  p+=2;
	  continue;
	}

      /* advance past the esc character */

      /* find the extent of this format specifier (stop at \0, ' ', or esc) */
      temp = NULL;
      end  = p+1;
      while(*end >= 'a' && *end <= 'z')
	{
	  end++;
	}
      n = end - p + 1;
      if(*end != '%')
	n--;
      else if (strncmp("%shortfile%", p, n) == 0)
	temp = utf8_to_locale(basename(song->file));
      else if (strncmp("%file%", p, n) == 0)
	temp = utf8_to_locale(song->file);
      else if (strncmp("%artist%", p, n) == 0)
	temp = song->artist ? utf8_to_locale(song->artist) : NULL;
      else if (strncmp("%title%", p, n) == 0)
	temp = song->title ? utf8_to_locale(song->title) : NULL;
      else if (strncmp("%album%", p, n) == 0)
	temp = song->album ? utf8_to_locale(song->album) : NULL;
      else if (strncmp("%track%", p, n) == 0)
	temp = song->track ? utf8_to_locale(song->track) : NULL;
      else if (strncmp("%name%", p, n) == 0)
	temp = song->name ? utf8_to_locale(song->name) : NULL;
      else if (strncmp("%time%", p, n) == 0)
	{
	  if (song->time != MPD_SONG_NO_TIME) {
	    gchar s[10];
	    snprintf(s, 9, "%d:%d", song->time / 60, 
		     song->time % 60 + 1);
	    /* nasty hack to use static buffer */
	    temp = g_strdup(s);
	  }
	}

      if( temp == NULL)
	{
	  gsize templen=n;
	  /* just pass-through any unknown specifiers (including esc) */
	  /* drop a null char in so printf stops at the end of this specifier,
	     but put the real character back in (pseudo-const) */
	  if( length+templen > max )
	    templen = max-length;
	  strncat(s, p, templen);
	  length+=templen;
	}
      else {
	gsize templen = strlen(temp);

	found = TRUE;
	if( length+templen > max )
	  templen = max-length;
	strncat(s, temp, templen);
	length+=templen;
	g_free(temp);
      }

      /* advance past the specifier */
      p += n;
    }

  if(last) *last = p;

  return length;
}


/* a modified version of mpc's songToFormatedString (util.c) 
 * added - %basename%
 */

gsize
strfsong(gchar *s, gsize max, const gchar *format, mpd_Song *song)
{
  return _strfsong(s, max, format, song, NULL);
}