/*
 * 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.royale.compiler.internal.css;

import org.antlr.runtime.TokenStream;
import org.antlr.runtime.tree.CommonTree;

import org.apache.royale.compiler.css.ICSSProperty;
import org.apache.royale.compiler.css.ICSSPropertyValue;

import com.google.common.base.Joiner;
import com.google.common.base.Strings;

/**
 * Implementation for a CSS property.
 */
public class CSSProperty extends CSSNodeBase implements ICSSProperty
{
    protected CSSProperty(final String name, final CSSPropertyValue value, final CommonTree tree, final TokenStream tokenStream)
    {
        super(tree, tokenStream, CSSModelTreeType.PROPERTY);
        assert !Strings.isNullOrEmpty(name) : "CSS property name can't be empty.";
        assert value != null : "CSS property name can't be null.";
        this.rawName = name;
        this.normalizedName = normalize(name);
        this.value = value;
    }

    private final String normalizedName;
    private final String rawName;
    private final CSSPropertyValue value;

    @Override
    public String getName()
    {
        return normalizedName;
    }

    @Override
    public ICSSPropertyValue getValue()
    {
        return value;
    }

    @Override
    public String toString()
    {
        if (rawName.equalsIgnoreCase("border"))
        {
            CSSArrayPropertyValue borderValues = (CSSArrayPropertyValue)value;
            return String.format("%s: %s;", rawName, Joiner.on(" ").join(borderValues.getElements()));
        }
        return String.format("%s: %s;", rawName, value.toString());
    }

    public String toCSSString()
    {
        String cssName = rawName;
        if (!rawName.equals(rawName.toLowerCase()))
        {
            cssName = cssName.replaceAll("[A-Z]", "-$0").toLowerCase();
        }
        if (cssName.equals("content") && value instanceof CSSStringPropertyValue)
        {
            return String.format("%s: \"%s\";", cssName, escape(((CSSStringPropertyValue)value).getValue()));            
        }
        if (value instanceof CSSStringPropertyValue)
        {
            return String.format("%s: %s;", cssName, ((CSSStringPropertyValue)value).getValue());
        }
        if (value instanceof CSSFunctionCallPropertyValue)
        {
            return String.format("%s: %s;", cssName, ((CSSFunctionCallPropertyValue)value).toString());
        }
        return String.format("%s: %s;", cssName, value.toString());
    }


    /**
     * Normalize CSS property names to camel-case style names. Names alread in
     * camel-cases will be returned as-is.
     * <p>
     * For example:<br>
     * {@code normalize("font-family")} returns {@code "fontFamily"}.<br>
     * {@code normalize("fontFamily")} returns {@code "fontFamily"}.
     * 
     * @param name CSS property name
     * @return Camel-case style name.
     */
    protected static String normalize(final String name)
    {
        if (name == null)
            return null;

        final StringBuilder result = new StringBuilder();

        boolean lastCharIsHyphen = false;
        boolean isFirstChar = true;
        for (int i = 0; i < name.length(); i++)
        {
            final char c = name.charAt(i);
            if ('-' == c)
            {
                lastCharIsHyphen = true;
            }
            else if (lastCharIsHyphen)
            {
                result.append(Character.toUpperCase(c));
                lastCharIsHyphen = false;
            }
            else if (isFirstChar)
            {
                result.append(Character.toLowerCase(c));
                isFirstChar = false;
            }
            else
            {
                result.append(c);
            }
        }

        return result.toString();
    }

    private String escape(String content)
    {
        if (content.length() == 1 && content.codePointAt(0) > 255)
        {
            int code = content.codePointAt(0);
            content = Integer.toHexString(code);
            return "\\" + content;
        }
        return content;
    }
}