/*
 * Copyright 2022 Olaf Wintermann
 *
 * Permission is hereby granted, free of charge, to any person obtaining a 
 * copy of this software and associated documentation files (the "Software"), 
 * to deal in the Software without restriction, including without limitation 
 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 
 * and/or sell copies of the Software, and to permit persons to whom the 
 * Software is furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in 
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
 * DEALINGS IN THE SOFTWARE.
 */

#include "nfont.h"


/* font list functions */

NFont *FontCreate(Display *dp, FcPattern *pattern)
{
    if(!pattern) {
        return NULL;
    }
    FcResult result;
    pattern = FcPatternDuplicate(pattern);
    FcPattern *match = XftFontMatch(dp, DefaultScreen(dp), pattern, &result);
    
    double sz = 0;
    result = FcPatternGetDouble (pattern, FC_SIZE, 0, &sz);
    if(result != FcResultMatch) {
        FcPatternGetDouble (match, FC_SIZE, 0, &sz);
    }
    
    XftFont *defaultFont = XftFontOpenPattern(dp, match);
    if(!defaultFont) {
        FcPatternDestroy(match);
        return NULL;
    }
    
    NFont *font = malloc(sizeof(NFont));
    font->display = dp;
    font->pattern = pattern;
    font->fail = NULL;
    font->size = sz;
    font->ref = 1;

    NFontList *list = malloc(sizeof(NFontList));
    list->font = defaultFont;
    list->next = NULL;
    font->fonts = list;
    
    return font;
}

NFont *FontFromName(Display *dp, const char *name)
{
    FcPattern *pattern = FcNameParse((FcChar8*)name);
    if(!pattern) {
        return NULL;
    }
    NFont *font = FontCreate(dp, pattern);
    FcPatternDestroy(pattern);
    return font;
}

XftFont *FontListAddFontForChar(NFont *f, FcChar32 c)
{
    /* charset for char c */
    FcCharSet *charset = FcCharSetCreate();
    FcValue value;
    value.type = FcTypeCharSet;
    value.u.c = charset;
    FcCharSetAddChar(charset, c);
    if(!FcCharSetHasChar(charset, c)) {
        FcCharSetDestroy(charset);
        return f->fonts->font;
    }
    
    /* font lookup based on the NFont pattern */ 
    FcPattern *pattern = FcPatternDuplicate(f->pattern);
    FcPatternAdd(pattern, FC_CHARSET, value, 0);
    FcResult result;
    FcPattern *match = XftFontMatch (
            f->display, DefaultScreen(f->display), pattern, &result);
    if(!match) {
        FcPatternDestroy(pattern);
        FontAddFail(f, charset);
        return f->fonts->font;
    }
    
    XftFont *newFont = XftFontOpenPattern(f->display, match);   
    if(!newFont || !FcCharSetHasChar(newFont->charset, c)) {
        FcPatternDestroy(pattern);
        FcPatternDestroy(match);
        if(newFont) {
            XftFontClose(f->display, newFont);
        }
        FontAddFail(f, charset);
        return f->fonts->font;
    }
    
    FcCharSetDestroy(charset);
    
    NFontList *newElm = malloc(sizeof(NFontList));
    newElm->font = newFont;
    newElm->next = NULL;
    
    NFontList *elm = f->fonts;
    NFontList *last = NULL;
    while(elm) {
        last = elm;
        elm = elm->next;
    }
    last->next = newElm;
    
    
    return newFont;
}

XftFont *FindFont(NFont *f, FcChar32 c)
{
    if(c < 128) {
        return f->fonts->font;
    }
    
    /* make sure the char is not in the fail list, because we don't
     * want to retry font lookups */
    NCharSetList *fail = f->fail;
    while(fail) {
        if(FcCharSetHasChar(fail->charset, c)) {
            return f->fonts->font;
        }
        fail = fail->next;
        
    }
    
    /* find a font that has this char */
    NFontList *elm = f->fonts;
    while(elm) {
        if(FcCharSetHasChar(elm->font->charset, c)) {
            return elm->font;
        }
        elm = elm->next;
    }
    
    /* open a new font for this char */
    return FontListAddFontForChar(f, c);
}

XftFont *FontDefault(NFont *f) {
    return f->fonts->font;
}

void FontAddFail(NFont *f, FcCharSet *c)
{
    NCharSetList *elm = f->fail;
    NCharSetList *last = elm;
    while(elm) {
        last = elm;
        elm = elm->next;
    }
    
    NCharSetList *newElm = malloc(sizeof(NCharSetList));
    newElm->charset = c;
    newElm->next = NULL;
    if(last) {
        last->next = newElm;
    } else {
        f->fail = newElm;
    }
}

void FontDestroy(NFont *f)
{
    NCharSetList *c = f->fail;
    NCharSetList *nc;
    while(c) {
        FcCharSetDestroy(c->charset);
        nc = c->next;
        free(c);
        c = nc;
    }
    
    NFontList *l = f->fonts;
    NFontList *nl;
    while(l) {
        XftFontClose(f->display, l->font);
        nl = l->next;
        free(nl);
        l = nl;
    }
    
    FcPatternDestroy(f->pattern);
    free(f);
}

NFont *FontRef(NFont *font)  {
    font->ref++;
    return font;
}

void FontUnref(NFont *font) {
    if(--font->ref == 0) {
        FontDestroy(font);
    }
}