/*
 * This file is part of the CSS implementation for KDE.
 *
 * Copyright (C) 1999-2003 Lars Knoll (knoll@kde.org)
 *           (C) David Carson  <dacarson@gmail.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 */
#include "helper.h"
#include "khtmllayout.h"
#include <QtCore/QMap>
#include <QPainter>
#include <dom/dom_string.h>
#include <xml/dom_stringimpl.h>
#include <rendering/render_object.h>
#include <kconfig.h>
#include <kcolorscheme.h>
#include <ksharedconfig.h>
#include <kconfiggroup.h>
#include <QToolTip>
#include "css/cssvalues.h"

using namespace DOM;
using namespace khtml;

namespace khtml
{

QPainter *printpainter;

void setPrintPainter(QPainter *printer)
{
    printpainter = printer;
}

void findWordBoundary(QChar *chars, int len, int position, int *start, int *end)
{
    if (chars[position].isSpace()) {
        int pos = position;
        while (pos >= 0 && chars[pos].isSpace()) {
            pos--;
        }
        *start = pos + 1;
        pos = position;
        while (pos < (int)len && chars[pos].isSpace()) {
            pos++;
        }
        *end = pos;
    } else if (chars[position].isPunct()) {
        int pos = position;
        while (pos >= 0 && chars[pos].isPunct()) {
            pos--;
        }
        *start = pos + 1;
        pos = position;
        while (pos < (int)len && chars[pos].isPunct()) {
            pos++;
        }
        *end = pos;
    } else {
        int pos = position;
        while (pos >= 0 && !chars[pos].isSpace() && !chars[pos].isPunct()) {
            pos--;
        }
        *start = pos + 1;
        pos = position;
        while (pos < (int)len && !chars[pos].isSpace() && !chars[pos].isPunct()) {
            pos++;
        }
        *end = pos;
    }
}

}

// color mapping code
struct colorMap {
    int css_value;
    QRgb color;
};

static const colorMap cmap[] = {
    { CSS_VAL_AQUA, 0xFF00FFFF },
    { CSS_VAL_BLACK, 0xFF000000 },
    { CSS_VAL_BLUE, 0xFF0000FF },
    { CSS_VAL_CRIMSON, 0xFFDC143C },
    { CSS_VAL_FUCHSIA, 0xFFFF00FF },
    { CSS_VAL_GRAY, 0xFF808080 },
    { CSS_VAL_GREEN, 0xFF008000  },
    { CSS_VAL_INDIGO, 0xFF4B0082 },
    { CSS_VAL_LIME, 0xFF00FF00 },
    { CSS_VAL_MAROON, 0xFF800000 },
    { CSS_VAL_NAVY, 0xFF000080 },
    { CSS_VAL_OLIVE, 0xFF808000  },
    { CSS_VAL_ORANGE, 0xFFFFA500 },
    { CSS_VAL_PURPLE, 0xFF800080 },
    { CSS_VAL_RED, 0xFFFF0000 },
    { CSS_VAL_SILVER, 0xFFC0C0C0 },
    { CSS_VAL_TEAL, 0xFF008080  },
    { CSS_VAL_WHITE, 0xFFFFFFFF },
    { CSS_VAL_YELLOW, 0xFFFFFF00 },
    { CSS_VAL_TRANSPARENT, transparentColor },
    { CSS_VAL_GREY, 0xff808080 },
    { 0, 0 }
};

struct uiColors {
    int css_value;
    QPalette::ColorGroup group;
    QPalette::ColorRole role;
};

// CSS 2.1 system color mapping
static const uiColors uimap[] = {
    // MDI background color
    { CSS_VAL_APPWORKSPACE, QPalette::Normal, QPalette::Mid },
    // Button colors
    { CSS_VAL_BUTTONFACE, QPalette::Normal, QPalette::Button },
    { CSS_VAL_BUTTONHIGHLIGHT, QPalette::Normal, QPalette::Light },
    { CSS_VAL_BUTTONSHADOW, QPalette::Normal, QPalette::Dark },
    { CSS_VAL_BUTTONTEXT, QPalette::Normal, QPalette::ButtonText },
    // Disabled text
    { CSS_VAL_GRAYTEXT, QPalette::Disabled, QPalette::Text },
    // Selected items
    { CSS_VAL_HIGHLIGHTTEXT, QPalette::Normal, QPalette::HighlightedText },
    { CSS_VAL_HIGHLIGHT, QPalette::Normal, QPalette::Highlight },
    // Tooltips
    { CSS_VAL_INFOBACKGROUND, QPalette::Normal, QPalette::ToolTipBase },
    { CSS_VAL_INFOTEXT, QPalette::Normal, QPalette::ToolTipText },
    // Menu colors
    { CSS_VAL_MENU, QPalette::Normal, QPalette::Window },
    { CSS_VAL_MENUTEXT, QPalette::Normal, QPalette::Text },
    // Scroll bar color
    { CSS_VAL_SCROLLBAR, QPalette::Normal, QPalette::Window },
    // 3D elements
    { CSS_VAL_THREEDDARKSHADOW, QPalette::Normal, QPalette::Dark },
    { CSS_VAL_THREEDFACE, QPalette::Normal, QPalette::Button },
    { CSS_VAL_THREEDHIGHLIGHT, QPalette::Normal, QPalette::Light },
    { CSS_VAL_THREEDLIGHTSHADOW, QPalette::Normal, QPalette::Midlight },
    { CSS_VAL_THREEDSHADOW, QPalette::Normal, QPalette::Mid },
    // Window background
    { CSS_VAL_WINDOW, QPalette::Normal, QPalette::Base },
    // Window frame
    { CSS_VAL_WINDOWFRAME, QPalette::Normal, QPalette::Window },
    // WindowText
    { CSS_VAL_WINDOWTEXT, QPalette::Normal, QPalette::Text },
    { CSS_VAL_TEXT, QPalette::Normal, QPalette::Text },
    { 0, QPalette::NColorGroups, QPalette::NColorRoles }
};

QColor khtml::colorForCSSValue(int css_value)
{
    // try the regular ones first
    const colorMap *col = cmap;
    while (col->css_value && col->css_value != css_value) {
        ++col;
    }
    if (col->css_value) {
        return QColor::fromRgba(col->color);
    } else if (css_value == CSS_VAL_INVERT) {
        return QColor();
    }

    const uiColors *uicol = uimap;
    while (uicol->css_value && uicol->css_value != css_value) {
        ++uicol;
    }
#ifndef APPLE_CHANGES
    if (!uicol->css_value) {
        switch (css_value) {
        case CSS_VAL_ACTIVEBORDER:
            return qApp->palette().color(QPalette::Normal, QPalette::Window);
        case CSS_VAL_ACTIVECAPTION:
            return KColorScheme(QPalette::Active, KColorScheme::Window).background(KColorScheme::ActiveBackground).color();
        case CSS_VAL_CAPTIONTEXT:
            return KColorScheme(QPalette::Active, KColorScheme::Window).foreground(KColorScheme::ActiveText).color();
        case CSS_VAL_INACTIVEBORDER:
            return qApp->palette().color(QPalette::Inactive, QPalette::Window);
        case CSS_VAL_INACTIVECAPTION:
            return KColorScheme(QPalette::Inactive, KColorScheme::Window).background().color();
        case CSS_VAL_INACTIVECAPTIONTEXT:
            return KColorScheme(QPalette::Inactive, KColorScheme::Window).foreground().color();
        case CSS_VAL_BACKGROUND: // Desktop background - no way to get this information from Plasma
            return qApp->palette().color(QPalette::Normal, QPalette::Highlight);
        default:
            return QColor();
        }
    }
#endif

    const QPalette &pal = qApp->palette();
    return pal.color(uicol->group, uicol->role);
}

double calcHue(double temp1, double temp2, double hueVal)
{
    if (hueVal < 0) {
        hueVal++;
    } else if (hueVal > 1) {
        hueVal--;
    }
    if (hueVal * 6 < 1) {
        return temp1 + (temp2 - temp1) * hueVal * 6;
    }
    if (hueVal * 2 < 1) {
        return temp2;
    }
    if (hueVal * 3 < 2) {
        return temp1 + (temp2 - temp1) * (2.0 / 3.0 - hueVal) * 6;
    }
    return temp1;
}

// Explanation of this algorithm can be found in the CSS3 Color Module
// specification at http://www.w3.org/TR/css3-color/#hsl-color with further
// explanation available at http://en.wikipedia.org/wiki/HSL_color_space

// all values are in the range of 0 to 1.0
QRgb khtml::qRgbaFromHsla(double h, double s, double l, double a)
{
    double temp2 = l < 0.5 ? l * (1.0 + s) : l + s - l * s;
    double temp1 = 2.0 * l - temp2;

    return qRgba(static_cast<int>(calcHue(temp1, temp2, h + 1.0 / 3.0) * 255),
                 static_cast<int>(calcHue(temp1, temp2, h) * 255),
                 static_cast<int>(calcHue(temp1, temp2, h - 1.0 / 3.0) * 255),
                 static_cast<int>(a * 255));
}

/** finds out the background color of an element
 * @param obj render object
 * @return the background color. It is guaranteed that a valid color is returned.
 */
QColor khtml::retrieveBackgroundColor(const RenderObject *obj)
{
    QColor result;
    while (!obj->isCanvas()) {
        result = obj->style()->backgroundColor();
        if (result.isValid()) {
            return result;
        }

        obj = obj->container();
    }/*wend*/

    // everything transparent? Use base then.
    return obj->style()->palette().color(QPalette::Active, QPalette::Base);
}

/** checks whether the given colors have enough contrast
 * @returns @p true if contrast is ok.
 */
bool khtml::hasSufficientContrast(const QColor &c1, const QColor &c2)
{
// New version from Germain Garand, better suited for contrast measurement
#if 1

#define HUE_DISTANCE 40
#define CONTRAST_DISTANCE 10

    int h1, s1, v1, h2, s2, v2;
    int hdist = -CONTRAST_DISTANCE;
    c1.getHsv(&h1, &s1, &v1);
    c2.getHsv(&h2, &s2, &v2);
    if (h1 != -1 && h2 != -1) { // grey values have no hue
        hdist = qAbs(h1 - h2);
        if (hdist > 180) {
            hdist = 360 - hdist;
        }
        if (hdist < HUE_DISTANCE) {
            hdist -= HUE_DISTANCE;
            // see if they are high key or low key colours
            bool hk1 = h1 >= 45 && h1 <= 225;
            bool hk2 = h2 >= 45 && h2 <= 225;
            if (hk1 && hk2) {
                hdist = (5 * hdist) / 3;
            } else if (!hk1 && !hk2) {
                hdist = (7 * hdist) / 4;
            }
        }
        hdist = qMin(hdist, HUE_DISTANCE * 2);
    }
    return hdist + (qAbs(s1 - s2) * 128) / (160 + qMin(s1, s2)) + qAbs(v1 - v2) > CONTRAST_DISTANCE;

#undef CONTRAST_DISTANCE
#undef HUE_DISTANCE

#else   // orginal fast but primitive version by me (LS)

// ### arbitrary value, to be adapted if necessary (LS)
#define CONTRAST_DISTANCE 32

    if (qAbs(c1.Qt::red() - c2.Qt::red()) > CONTRAST_DISTANCE) {
        return true;
    }
    if (qAbs(c1.Qt::green() - c2.Qt::green()) > CONTRAST_DISTANCE) {
        return true;
    }
    if (qAbs(c1.Qt::blue() - c2.Qt::blue()) > CONTRAST_DISTANCE) {
        return true;
    }

    return false;

#undef CONTRAST_DISTANCE

#endif
}
