/*
 *  RapidMiner
 *
 *  Copyright (C) 2001-2011 by Rapid-I and the contributors
 *
 *  Complete list of developers available at our web site:
 *
 *       http://rapid-i.com
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Affero General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 Affero General Public License for more details.
 *
 *  You should have received a copy of the GNU Affero General Public License
 *  along with this program.  If not, see http://www.gnu.org/licenses/.
 */
package com.rapidminer.parameter;

import org.w3c.dom.Document;
import org.w3c.dom.Element;

import com.rapidminer.MacroHandler;
import com.rapidminer.tools.Tools;
import com.rapidminer.tools.XMLException;

/**
 * An abstract superclass for single, i.e. non-list, parameters.
 * 
 * @author Ingo Mierswa, Simon Fischer
 */
public abstract class ParameterTypeSingle extends ParameterType {

    private static final long serialVersionUID = 1144201124955949715L;

    public ParameterTypeSingle(Element element) throws XMLException {
        super(element);
    }

    public ParameterTypeSingle(String key, String description) {
        super(key, description);
    }

    @Override
    public Element getXML(String key, String value, boolean hideDefault, Document doc) {
        Element element = doc.createElement("parameter");
        element.setAttribute("key", key);
        if (value != null) {
            if (toString(value).equals(toString(getDefaultValue()))) {
                if (!hideDefault) {
                    element.setAttribute("value", value);
                } else {
                    return null;
                }
            } else {
                element.setAttribute("value", toXMLString(value));
            }
        } else {
            if (!hideDefault && getDefaultValue() != null) {
                element.setAttribute("value", getDefaultValue().toString());
            } else {
                return null;
            }
        }
        return element;
    }

    @Override
    public String getXML(String indent, String key, String value, boolean hideDefault) {
        if (value != null) {
            if (toString(value).equals(toString(getDefaultValue()))) {
                if (!hideDefault) {
                    return indent + "<parameter key=\"" + toXMLString(key) + "\"\tvalue=\"" + toXMLString(value) + "\"/>" + Tools.getLineSeparator();
                } else {
                    return "";
                }
            } else {
                return indent + "<parameter key=\"" + toXMLString(key) + "\"\tvalue=\"" + toXMLString(value) + "\"/>" + Tools.getLineSeparator();
            }
        } else {
            if (!hideDefault && getDefaultValue() != null) {
                return indent + "<parameter key=\"" + toXMLString(key) + "\"\tvalue=\"" + toXMLString(getDefaultValue()) + "\"/>" + Tools.getLineSeparator();
            } else {
                return "";
            }
        }
    }

    /** Subclasses may override this method to transform the string before
     *  writing it to XML. {@link ParameterTypePassword} uses this to encrypt the string. */
    public String toXMLString(String value) {
        return value;
    }


    @Override
    public String substituteMacros(String parameterValue, MacroHandler mh) {
        int startIndex = parameterValue.indexOf("%{");
        if (startIndex == -1) {
            return parameterValue;
        }
        try {
            StringBuffer result = new StringBuffer();
            while (startIndex >= 0) {
                result.append(parameterValue.substring(0, startIndex));
                int endIndex = parameterValue.indexOf("}", startIndex + 2);
                String macroString = parameterValue.substring(startIndex + 2, endIndex);
                String macroValue = mh.getMacro(macroString);
                if (macroValue != null) {
                    result.append(macroValue);
                } else {
                    result.append("%{" + macroString + "}");
                }
                parameterValue = parameterValue.substring(endIndex + 1);
                startIndex = parameterValue.indexOf("%{");
            }
            result.append(parameterValue);
            return result.toString();
        } catch (Exception e) {
            return parameterValue;
        }
    }
}