/*
 *  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.Element;

import com.rapidminer.tools.XMLException;


/**
 * This parameter type allows to select either Operator Values or
 * Parameters for logging purposes.
 * 
 * @author Ingo Mierswa, Simon Fischer
 */
public class ParameterTypeValue extends ParameterTypeSingle {

    public static class OperatorValueSelection {
        private String operatorName;
        private String valueParameterName;
        private boolean isValue;

        public OperatorValueSelection() {}

        public OperatorValueSelection(String operatorName, boolean isValue, String valueOrParameterName) {
            this.operatorName = operatorName;
            this.valueParameterName = valueOrParameterName;
            this.isValue = isValue;
        }

        public String getOperator() {
            return operatorName;
        }

        public String getParameterName() {
            if (!isValue)
                return valueParameterName;
            return null;
        }
        public String getValueName() {
            if (isValue)
                return valueParameterName;
            return null;
        }
        public boolean isValue() {
            return isValue;
        }
    }

    private static final long serialVersionUID = -5863628921324775010L;

    // only one character allowed
    private static final String ESCAPE_CHAR = "\\";
    private static final String ESCAPE_CHAR_REGEX = "\\\\";
    // only one character allowed
    private static final String SEPERATOR_CHAR_REGEX = "\\.";
    private static final String SEPERATOR_CHAR = ".";

    public ParameterTypeValue(Element element) throws XMLException {
        super(element);
        setOptional(false);
    }

    public ParameterTypeValue(String key, String description) {
        super(key, description);
        setOptional(false);
    }

    /** Returns null. */
    @Override
    public Object getDefaultValue() {
        return null;
    }

    /** Does nothing. */
    @Override
    public void setDefaultValue(Object defaultValue) {}

    @Override
    public String getRange() {
        return "values";
    }

    /** Returns false. */
    @Override
    public boolean isNumerical() { return false; }

    @Override
    public String notifyOperatorRenaming(String oldOperatorName, String newOperatorName, String parameterValue) {
        OperatorValueSelection selection = transformString2OperatorValueSelection(parameterValue);
        if (selection != null) {
            if (selection.getOperator().equals(oldOperatorName)) {
                selection.operatorName = newOperatorName;
            }
            return transformOperatorValueSelection2String(selection);
        }
        return parameterValue;
    }


    public static OperatorValueSelection transformString2OperatorValueSelection(String parameterValue) {
        String[] unescaped = parameterValue.split("(?<=[^"+ ESCAPE_CHAR_REGEX + "])" + SEPERATOR_CHAR_REGEX, -1);
        for (int i = 0; i < unescaped.length; i++) {
            unescaped[i] = unescape(unescaped[i]);
        }
        OperatorValueSelection selection = new OperatorValueSelection();
        if (unescaped.length == 4) {
            selection.operatorName = unescaped[1];
            selection.valueParameterName = unescaped[3];
            selection.isValue = unescaped[2].equals("value");
            return selection;
        }
        return null;
    }

    private static String unescape(String escapedString) {
        escapedString = escapedString.replace(ESCAPE_CHAR + SEPERATOR_CHAR, SEPERATOR_CHAR);
        escapedString = escapedString.replace(ESCAPE_CHAR + ESCAPE_CHAR, ESCAPE_CHAR);
        return escapedString;
    }

    public static String transformOperatorValueSelection2String(OperatorValueSelection selection) {
        String operator = selection.operatorName != null ? selection.getOperator().replace(ESCAPE_CHAR, ESCAPE_CHAR + ESCAPE_CHAR) : "";
        operator = operator.replace(SEPERATOR_CHAR, ESCAPE_CHAR + SEPERATOR_CHAR);
        String value = selection.valueParameterName != null ? selection.valueParameterName.replace(ESCAPE_CHAR, ESCAPE_CHAR + ESCAPE_CHAR) : "";
        value = value.replace(SEPERATOR_CHAR, ESCAPE_CHAR + SEPERATOR_CHAR);
        return "operator"+ SEPERATOR_CHAR + operator + SEPERATOR_CHAR + (selection.isValue? "value" : "parameter")+ SEPERATOR_CHAR + value;
    }

    @Override
    protected void writeDefinitionToXML(Element typeElement) {
    }
}