/*
 * font.c
 *
 * map dvi fonts to X fonts
 */
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <X11/Xos.h>
#include <X11/IntrinsicP.h>
#include <X11/StringDefs.h>
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include "DviP.h"
#include "XFontName.h"

static char *
savestr(const char *s)
{
    size_t len;
    char * n;

    if (!s)
        return NULL;
    len = strlen(s) + 1;
    n = XtMalloc (len);
    if (n)
        memcpy(n, s, len);
    return n;
}

static DviFontList *
LookupFontByPosition(DviWidget dw, int position)
{
    DviFontList *f;

    for (f = dw->dvi.fonts; f; f = f->next) {
        if (f->dvi_number == position)
            break;
    }
    return f;
}

static DviFontSizeList *
LookupFontSizeBySize(DviWidget dw, DviFontList *f, int size)
{
    DviFontSizeList *best = NULL;

    if (f->scalable) {
        char            fontNameString[2048];
        XFontName       fontName;
        unsigned int    fontNameAttributes;

        for (best = f->sizes; best; best = best->next) {
            if (best->size == size)
                return best;
        }
        best = (DviFontSizeList *) XtMalloc(sizeof *best);
        best->next = f->sizes;
        best->size = size;
        XParseFontName(f->x_name, &fontName, &fontNameAttributes);
        fontNameAttributes &= ~(FontNamePixelSize | FontNameAverageWidth);
        fontNameAttributes |= FontNameResolutionX;
        fontNameAttributes |= FontNameResolutionY;
        fontNameAttributes |= FontNamePointSize;
        fontName.ResolutionX = dw->dvi.screen_resolution;
        fontName.ResolutionY = dw->dvi.screen_resolution;
        fontName.PointSize = size * 10 / dw->dvi.size_scale;
        XFormatFontName(&fontName, fontNameAttributes, fontNameString);
        best->x_name = savestr(fontNameString);
#ifdef USE_XFT
        /*
         * Force a match of a core font for adobe-fontspecific
         * encodings; we don't have a scalable font in
         * the right encoding
         */
        best->core = False;
        if (!strcmp(fontName.CharSetRegistry, "adobe") &&
            !strcmp(fontName.CharSetEncoding, "fontspecific")) {
            best->core = True;
        }
#endif
        best->doesnt_exist = 0;
        best->font = NULL;
        f->sizes = best;
    }
    else {
        int bestdist = 65536;

        for (DviFontSizeList * fs = f->sizes; fs; fs = fs->next) {
            int dist = size - fs->size;

            if (dist < 0)
                dist = -dist * 16;
            if (dist < bestdist) {
                best = fs;
                bestdist = dist;
            }
        }
    }
    return best;
}

static const char *
SkipFontNameElement(const char *n)
{
    while (*n != '-') {
        if (!*++n)
            return NULL;
    }
    return n + 1;
}

#define SizePosition		8
#define EncodingPosition	13

#ifndef USE_XFT
static int
ConvertFontNameToSize(const char *n)
{
    int i, size;

    for (i = 0; i < SizePosition; i++) {
        n = SkipFontNameElement(n);
        if (!n)
            return -1;
    }
    size = atoi(n);
    return size / 10;
}
#endif

static const char *
ConvertFontNameToEncoding(const char *n)
{
    for (int i = 0; i < EncodingPosition; i++) {
        n = SkipFontNameElement(n);
        if (!n)
            return NULL;
    }
    return n;
}

static void
DisposeFontSizes(DviWidget dw, DviFontSizeList *fs)
{
    DviFontSizeList *next;

    for (; fs; fs = next) {
        next = fs->next;
        if (fs->x_name)
            XtFree(fs->x_name);
        if (fs->font) {
#ifdef USE_XFT
            XftFontClose(XtDisplay(dw), fs->font);
#else
            XUnloadFont(XtDisplay(dw), fs->font->fid);
            XFree((char *) fs->font);
#endif
        }
        XtFree((char *) fs);
    }
}

void
ResetFonts(DviWidget dw)
{
    for (DviFontList *f = dw->dvi.fonts; f; f = f->next) {
        if (f->initialized) {
            DisposeFontSizes(dw, f->sizes);
            f->sizes = NULL;
            f->initialized = FALSE;
            f->scalable = FALSE;
        }
    }
    /* 
     * force requery of fonts
     */
    dw->dvi.font = NULL;
    dw->dvi.font_number = -1;
    dw->dvi.cache.font = NULL;
    dw->dvi.cache.font_number = -1;
}

static DviFontSizeList *
InstallFontSizes(DviWidget dw, const char *x_name, Boolean *scalablep)
{
#ifndef USE_XFT
    char fontNameString[2048];
    char **fonts;
    int count;
    XFontName fontName;
    unsigned int fontNameAttributes;
#endif
    DviFontSizeList *sizes = NULL;

#ifdef USE_XFT
    *scalablep = TRUE;
#else
    *scalablep = FALSE;
    if (!XParseFontName(x_name, &fontName, &fontNameAttributes))
        return NULL;

    fontNameAttributes &= ~(FontNamePixelSize | FontNamePointSize);
    fontNameAttributes |= FontNameResolutionX;
    fontNameAttributes |= FontNameResolutionY;
    fontName.ResolutionX = dw->dvi.screen_resolution;
    fontName.ResolutionY = dw->dvi.screen_resolution;
    XFormatFontName(&fontName, fontNameAttributes, fontNameString);
    fonts = XListFonts(XtDisplay(dw), fontNameString, 10000000, &count);
    for (int i = 0; i < count; i++) {
        int size = ConvertFontNameToSize(fonts[i]);

        if (size == 0) {
            DisposeFontSizes(dw, sizes);
            *scalablep = TRUE;
            sizes = NULL;
            break;
        }
        if (size != -1) {
            DviFontSizeList *new = (DviFontSizeList *) XtMalloc(sizeof *new);

            new->next = sizes;
            new->size = size;
            new->x_name = savestr(fonts[i]);
            new->doesnt_exist = 0;
            new->font = NULL;
            sizes = new;
        }
    }
    XFreeFontNames(fonts);
#endif
    return sizes;
}

static DviFontList *
InstallFont(DviWidget dw, int position, const char *dvi_name,
            const char *x_name)
{
    DviFontList *f = LookupFontByPosition(dw, position);

    if (f) {
        /*
         * ignore gratuitous font loading
         */
        if (!strcmp(f->dvi_name, dvi_name) && !strcmp(f->x_name, x_name))
            return f;

        DisposeFontSizes(dw, f->sizes);
        if (f->dvi_name)
            XtFree(f->dvi_name);
        if (f->x_name)
            XtFree(f->x_name);
    }
    else {
        f = (DviFontList *) XtMalloc(sizeof(*f));
        f->next = dw->dvi.fonts;
        dw->dvi.fonts = f;
    }
    f->initialized = FALSE;
    f->dvi_name = savestr(dvi_name);
    f->x_name = savestr(x_name);
    f->dvi_number = position;
    f->sizes = NULL;
    f->scalable = FALSE;
    if (f->x_name) {
        const char *encoding = ConvertFontNameToEncoding(f->x_name);

        f->char_map = DviFindMap(encoding);
    }
    else
        f->char_map = NULL;
    /* 
     * force requery of fonts
     */
    dw->dvi.font = NULL;
    dw->dvi.font_number = -1;
    dw->dvi.cache.font = NULL;
    dw->dvi.cache.font_number = -1;
    return f;
}

static const char *
MapDviNameToXName(DviWidget dw, const char *dvi_name)
{
    DviFontMap *fm;

    for (fm = dw->dvi.font_map; fm; fm = fm->next)
        if (!strcmp(fm->dvi_name, dvi_name))
            return fm->x_name;
    ++dvi_name;
    for (fm = dw->dvi.font_map; fm; fm = fm->next)
        if (!strcmp(fm->dvi_name, "R"))
            return fm->x_name;
    if (dw->dvi.font_map->x_name)
        return dw->dvi.font_map->x_name;
    return "-*-*-*-*-*-*-*-*-*-*-*-*-iso8859-1";
}

void
ParseFontMap(DviWidget dw)
{
    char *m;
    DviFontMap *fm;

    if (dw->dvi.font_map)
        DestroyFontMap(dw->dvi.font_map);
    fm = NULL;
    m = dw->dvi.font_map_string;
    while (*m) {
        char dvi_name[1024];
        char x_name[2048];
        char *s = m;

        while (*m && !isspace(*m))
            ++m;
        strncpy(dvi_name, s, m - s);
        dvi_name[m - s] = '\0';
        while (isspace(*m))
            ++m;
        s = m;
        while (*m && *m != '\n')
            ++m;
        strncpy(x_name, s, m - s);
        x_name[m - s] = '\0';

        DviFontMap *new = (DviFontMap *) XtMalloc(sizeof *new);
        new->x_name = savestr(x_name);
        new->dvi_name = savestr(dvi_name);
        new->next = fm;
        fm = new;
        ++m;
    }
    dw->dvi.font_map = fm;
}

void
DestroyFontMap(DviFontMap *font_map)
{
    DviFontMap *next;

    for (; font_map; font_map = next) {
        next = font_map->next;
        if (font_map->x_name)
            XtFree(font_map->x_name);
        if (font_map->dvi_name)
            XtFree(font_map->dvi_name);
        XtFree((char *) font_map);
    }
}

 /*ARGSUSED*/ void
SetFontPosition(DviWidget dw, int position, const char *dvi_name,
                const char *extra)
{
    const char *x_name;

    x_name = MapDviNameToXName(dw, dvi_name);
    (void) InstallFont(dw, position, dvi_name, x_name);
}

#ifdef USE_XFT
XftFont *
#else
XFontStruct *
#endif
QueryFont(DviWidget dw, int position, int size)
{
    DviFontList *f;
    DviFontSizeList *fs;

    f = LookupFontByPosition(dw, position);
    if (!f)
        return dw->dvi.default_font;
    if (!f->initialized) {
        f->sizes = InstallFontSizes(dw, f->x_name, &f->scalable);
        f->initialized = TRUE;
    }
    fs = LookupFontSizeBySize(dw, f, size);
    if (!fs)
        return dw->dvi.default_font;
    if (!fs->font) {
        if (fs->x_name) {
#ifdef USE_XFT
            XftPattern *pat;
            XftPattern *match;
            XftResult result;

            pat = XftXlfdParse(fs->x_name, False, False);
            XftPatternAddBool(pat, XFT_CORE, fs->core);
            match = XftFontMatch(XtDisplay(dw),
                                 XScreenNumberOfScreen(dw->core.screen),
                                 pat, &result);
            XftPatternDestroy(pat);
            if (match) {
                fs->font = XftFontOpenPattern(XtDisplay(dw), match);
                if (!fs->font)
                    XftPatternDestroy(match);
            }
            else
                fs->font = 0;
#else
            fs->font = XLoadQueryFont(XtDisplay(dw), fs->x_name);
#endif
        }
        if (!fs->font)
            fs->font = dw->dvi.default_font;
    }
    return fs->font;
}

DviCharNameMap *
QueryFontMap(DviWidget dw, int position)
{
    DviFontList *f = LookupFontByPosition(dw, position);

    if (f)
        return f->char_map;
    else
        return NULL;
}

unsigned char *
DviCharIsLigature(DviCharNameMap *map, const char *name)
{
    for (int i = 0; i < DVI_MAX_LIGATURES; i++) {
        if (!map->ligatures[i][0])
            break;
        if (!strcmp(name, map->ligatures[i][0]))
            return (unsigned char *) map->ligatures[i][1];
    }
    return NULL;
}