/*

   Licensed to the Apache Software Foundation (ASF) under one or more
   contributor license agreements.  See the NOTICE file distributed with
   this work for additional information regarding copyright ownership.
   The ASF licenses this file to You under the Apache License, Version 2.0
   (the "License"); you may not use this file except in compliance with
   the License.  You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.

 */
package org.apache.batik.bridge;

import java.awt.font.TextAttribute;
import java.util.ArrayList;
import java.util.StringTokenizer;

import org.apache.batik.css.engine.SVGCSSEngine;
import org.apache.batik.css.engine.value.Value;
import org.apache.batik.util.CSSConstants;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.css.CSSPrimitiveValue;

/**
 * A collection of utility method for text.
 *
 * @author <a href="mailto:stephane@hillion.org">Stephane Hillion</a>
 * @author <a href="mailto:bill.haneman@ireland.sun.com">Bill Haneman</a>
 * @version $Id$
 */
public abstract class TextUtilities implements CSSConstants, ErrorConstants {

    /**
     * Returns the content of the given element.
     */
    public static String getElementContent(Element e) {
        StringBuffer result = new StringBuffer();
        for (Node n = e.getFirstChild();
             n != null;
             n = n.getNextSibling()) {
            switch (n.getNodeType()) {
            case Node.ELEMENT_NODE:
                result.append(getElementContent((Element)n));
                break;
            case Node.CDATA_SECTION_NODE:
            case Node.TEXT_NODE:
                result.append(n.getNodeValue());
            }
        }
        return result.toString();
    }

    /**
     * Returns the float list that represents a set of horizontal
     * values or percentage.
     *
     * @param element the element that defines the specified coordinates
     * @param attrName the name of the attribute (used by error handling)
     * @param valueStr the delimited string containing values of the coordinate
     * @param ctx the bridge context
     */
    public static
        ArrayList svgHorizontalCoordinateArrayToUserSpace(Element element,
                                                          String attrName,
                                                          String valueStr,
                                                          BridgeContext ctx) {

        UnitProcessor.Context uctx = UnitProcessor.createContext(ctx, element);
        ArrayList values = new ArrayList();
        StringTokenizer st = new StringTokenizer(valueStr, ", ", false);
        while (st.hasMoreTokens()) {
            values.add
                (UnitProcessor.svgHorizontalCoordinateToUserSpace
                        (st.nextToken(), attrName, uctx));
        }
        return values;
    }

    /**
     * Returns the float list that represents a set of values or percentage.
     *
     *
     * @param element the element that defines the specified coordinates
     * @param attrName the name of the attribute (used by error handling)
     * @param valueStr the delimited string containing values of the coordinate
     * @param ctx the bridge context
     */
    public static
        ArrayList svgVerticalCoordinateArrayToUserSpace(Element element,
                                                        String attrName,
                                                        String valueStr,
                                                        BridgeContext ctx) {

        UnitProcessor.Context uctx = UnitProcessor.createContext(ctx, element);
        ArrayList values = new ArrayList();
        StringTokenizer st = new StringTokenizer(valueStr, ", ", false);
        while (st.hasMoreTokens()) {
            values.add
                (UnitProcessor.svgVerticalCoordinateToUserSpace
                        (st.nextToken(), attrName, uctx));
        }
        return values;
    }


    public static ArrayList svgRotateArrayToFloats(Element element,
                                                   String attrName,
                                                   String valueStr,
                                                   BridgeContext ctx) {

        StringTokenizer st = new StringTokenizer(valueStr, ", ", false);
        ArrayList values = new ArrayList();
        String s;
        while (st.hasMoreTokens()) {
            try {
                s = st.nextToken();
                values.add
                    ((float) Math.toRadians
                            (SVGUtilities.convertSVGNumber(s)));
            } catch (NumberFormatException nfEx ) {
                throw new BridgeException
                    (ctx, element, nfEx, ERR_ATTRIBUTE_VALUE_MALFORMED,
                     new Object [] {attrName, valueStr});
            }
        }
        return values;
    }

    /**
     * Converts the font-size CSS value to a float value.
     * @param e the element
     */
    public static Float convertFontSize(Element e) {
        Value v = CSSUtilities.getComputedStyle
            (e, SVGCSSEngine.FONT_SIZE_INDEX);
        return v.getFloatValue();
    }

    /**
     * Converts the font-style CSS value to a float value.
     * @param e the element
     */
    public static Float convertFontStyle(Element e) {
        Value v = CSSUtilities.getComputedStyle
            (e, SVGCSSEngine.FONT_STYLE_INDEX);
        switch (v.getStringValue().charAt(0)) {
        case 'n':
            return TextAttribute.POSTURE_REGULAR;
        default:
            return TextAttribute.POSTURE_OBLIQUE;
        }
    }

    /**
     * Converts the font-stretch CSS value to a float value.
     * @param e the element
     */
    public static Float convertFontStretch(Element e) {
        Value v = CSSUtilities.getComputedStyle
            (e, SVGCSSEngine.FONT_STRETCH_INDEX);
        String s = v.getStringValue();
        switch (s.charAt(0)) {
        case 'u':
            if (s.charAt(6) == 'c') {
                return TextAttribute.WIDTH_CONDENSED;
            } else {
                return TextAttribute.WIDTH_EXTENDED;
            }

        case 'e':
            if (s.charAt(6) == 'c') {
                return TextAttribute.WIDTH_CONDENSED;
            } else {
                if (s.length() == 8) {
                    return TextAttribute.WIDTH_SEMI_EXTENDED;
                } else {
                    return TextAttribute.WIDTH_EXTENDED;
                }
            }

        case 's':
            if (s.charAt(6) == 'c') {
                return TextAttribute.WIDTH_SEMI_CONDENSED;
            } else {
                return TextAttribute.WIDTH_SEMI_EXTENDED;
            }

        default:
            return TextAttribute.WIDTH_REGULAR;
        }
    }

    /**
     * Converts the font-weight CSS value to a float value.
     * @param e the element
     */
    public static Float convertFontWeight(Element e) {
        Value v = CSSUtilities.getComputedStyle
            (e, SVGCSSEngine.FONT_WEIGHT_INDEX);
        int weight = (int)v.getFloatValue();
        //Note: the mapping from CSS2 to TextAttribute's weights is somewhat arbitrary.
        //Important is to map 400/normal to REGULAR and 700/bold to BOLD.
        switch (weight) {
        case 100:
            return TextAttribute.WEIGHT_EXTRA_LIGHT;
        case 200:
            return TextAttribute.WEIGHT_LIGHT;
        case 300:
            return TextAttribute.WEIGHT_DEMILIGHT;
        case 400:
            return TextAttribute.WEIGHT_REGULAR;
        case 500:
            return TextAttribute.WEIGHT_SEMIBOLD;
        default:
            String javaVersionString = System.getProperty("java.specification.version");
            float javaVersion = (javaVersionString != null
                    ? Float.parseFloat(javaVersionString) : 1.5f);
            if (javaVersion < 1.5) {
                // Would like to do this but the JDK 1.3 & 1.4
                // seems to drop back to 'REGULAR' instead of 'BOLD'
                // if there is not a match.
                return TextAttribute.WEIGHT_BOLD;
            }
            switch (weight) {
            case 600:
                return TextAttribute.WEIGHT_MEDIUM;
            case 700:
                return TextAttribute.WEIGHT_BOLD;
            case 800:
                return TextAttribute.WEIGHT_HEAVY;
            case 900:
                return TextAttribute.WEIGHT_ULTRABOLD;
            default:
                return TextAttribute.WEIGHT_REGULAR; //No matching CSS value (probably illegal)
            }
        }
    }

    /**
     * Converts the text-anchor CSS value to a TextNode.Anchor.
     * @param e the element
     */
    public static TextNode.Anchor convertTextAnchor(Element e) {
        Value v = CSSUtilities.getComputedStyle
            (e, SVGCSSEngine.TEXT_ANCHOR_INDEX);
        switch (v.getStringValue().charAt(0)) {
        case 's':
            return TextNode.Anchor.START;
        case 'm':
            return TextNode.Anchor.MIDDLE;
        default:
            return TextNode.Anchor.END;
        }
    }

    /**
     * Converts a baseline-shift CSS value to a value usable as a text
     * attribute, or null.
     * @param e the element
     */
    public static Object convertBaselineShift(Element e) {
        Value v = CSSUtilities.getComputedStyle
            (e, SVGCSSEngine.BASELINE_SHIFT_INDEX);
        if (v.getPrimitiveType() == CSSPrimitiveValue.CSS_IDENT) {
            String s = v.getStringValue();
            switch (s.charAt(2)) {
            case 'p': //suPerscript
                return TextAttribute.SUPERSCRIPT_SUPER;

            case 'b': //suBscript
                return TextAttribute.SUPERSCRIPT_SUB;

            default:
                return null;
            }
        } else {
            return v.getFloatValue();
        }
    }

    /**
     * Converts a kerning CSS value to a value usable as a text
     * attribute, or null.
     * @param e the element
     */
    public static Float convertKerning(Element e) {
        Value v = CSSUtilities.getComputedStyle
            (e, SVGCSSEngine.KERNING_INDEX);
        if (v.getPrimitiveType() == CSSPrimitiveValue.CSS_IDENT) {
            return null;
        }
        return v.getFloatValue();
    }

    /**
     * Converts a letter-spacing CSS value to a value usable as a text
     * attribute, or null.
     * @param e the element
     */
    public static Float convertLetterSpacing(Element e) {
        Value v = CSSUtilities.getComputedStyle
            (e, SVGCSSEngine.LETTER_SPACING_INDEX);
        if (v.getPrimitiveType() == CSSPrimitiveValue.CSS_IDENT) {
            return null;
        }
        return v.getFloatValue();
    }

    /**
     * Converts a word-spacing CSS value to a value usable as a text
     * attribute, or null.
     * @param e the element
     */
    public static Float convertWordSpacing(Element e) {
        Value v = CSSUtilities.getComputedStyle
            (e, SVGCSSEngine.WORD_SPACING_INDEX);
        if (v.getPrimitiveType() == CSSPrimitiveValue.CSS_IDENT) {
            return null;
        }
        return v.getFloatValue();
    }
}