/*
 * This file is part of firk's window manager for x11 (fwm)
 * Copyright (C) 2016-2021 firk <firk@cantconnect.ru>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/Xatom.h>
#include "main.h"
#include "base.h"
#include "xkrap.h"

/* weird and bad code in this file */
static XFontStruct * fs = NULL;
static void init_fs(GC gc) { if(!fs) fs=XQueryFont(display,XGContextFromGC(gc)); }
extern int text_width(GC gc, char const * str, int count) {
  int res;
  init_fs(gc);
  if(fs) {
    res = XTextWidth(fs, str, count);
    return res;
  } else return count*8;
}


extern void getwintitle(Window w, char * dest, unsigned int destsize) {
  XTextProperty tp;
  char * * list;
  int n;
  if(!dest || destsize<1) return;
  dest[0] = 0;
  if(!XGetWMName(display, w, &tp)) return;
  if(tp.nitems) {
    if(tp.encoding==XA_STRING) {
      snprintf(dest, destsize, "%s", tp.value);
    } else {
      if(Xutf8TextPropertyToTextList(display, &tp, &list, &n)>=Success &&
         n>0 && *list) {
        snprintf(dest, destsize, "%s", *list);
        XFreeStringList(list);
      }
    }
  }
  if(tp.value) XFree(tp.value);
}

static XChar2b * convert_to_utf8(char const * s, size_t n, size_t * rn) {
  XChar2b *tmp;
  size_t pos, outpos;
  unsigned char c, c2, c3;
  unsigned int uc;

  if(n<1) return NULL;
  if(n>10000) n=10000; // dirty hack; but really we never need to out strings > 10000 bytes
  tmp = malloc(sizeof(*tmp)*n);
  if(!tmp) return NULL;
  
#define SP(X) (*(unsigned char*)(s+(X)))
  for(outpos=pos=0; pos<n; ) {
    c = SP(pos);
    if(!(c&0x80)) { uc = c; pos++; }
    else if(n-pos>=2 && (c&0xE0)==0xC0 && ((c2=SP(pos+1))&0xC0)==0x80) { uc = ((c&0x1F)<<6) | (c2&0x3F); pos+=2; }
    else if(n-pos>=3 && (c&0xF0)==0xE0 && ((c2=SP(pos+1))&0xC0)==0x80 && ((c3=SP(pos+2))&0xC0)==0x80) { uc = ((c&0xF)<<12) | ((c2&0x3F)<<6) | (c3&0x3F); pos+=3; }
    else { uc='?'; pos++; }
    tmp[outpos].byte1 = (unsigned char)(uc>>8);
    tmp[outpos].byte2 = (unsigned char)(uc);
    outpos++;
  }
#undef SP

  *rn = outpos;
  return tmp;
}

extern void draw_string_utf8(Display *dis, Drawable d, GC gc, int x, int y, char const * s, size_t n) {
  XChar2b *tmp;
  size_t rn;

  if(n<1) return;
  if(n>10000) n=10000; // dirty hack; but really we never need to out strings > 10000 bytes
  tmp = convert_to_utf8(s, n, &rn);
  if(!tmp) {
    XDrawString(dis, d, gc, x, y, s, n); // fallback and don't care about minor problems; we can't fail
    return;
  }

  XDrawString16(dis, d, gc, x, y, tmp, rn);
  free(tmp);
}


extern int text_width_utf8(GC gc, char const * str, int count) {
  int res;
  XChar2b *tmp;
  size_t rn;

  init_fs(gc);
  if(fs) {
    tmp = convert_to_utf8(str, count, &rn);
    if(!tmp) {
      res = XTextWidth(fs, str, count);
    } else {
      res = XTextWidth16(fs, tmp, rn); free(tmp);
    }
    return res;
  } else return count*8;
}