/*
 * 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.
 */

/* $Id$ */

package org.apache.fop.events.model;

import java.io.Serializable;
import java.util.Collections;
import java.util.List;

import org.xml.sax.ContentHandler;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.AttributesImpl;

import org.apache.xmlgraphics.util.XMLizable;

/**
 * Represents an event method. Each method in an event producer interface will result in one
 * instance of <code>EventMethodModel</code>.
 */
public class EventMethodModel implements Serializable, XMLizable {

    private static final long serialVersionUID = -7548882973341444354L;

    private String methodName;
    private EventSeverity severity;
    private List params = new java.util.ArrayList();
    private String exceptionClass;

    /**
     * Creates an new instance.
     * @param methodName the event method's name
     * @param severity the event severity
     */
    public EventMethodModel(String methodName, EventSeverity severity) {
        this.methodName = methodName;
        this.severity = severity;
    }

    /**
     * Adds a method parameter.
     * @param param the method parameter
     */
    public void addParameter(Parameter param) {
        this.params.add(param);
    }

    /**
     * Adds a method parameter.
     * @param type the type of the parameter
     * @param name the name of the parameter
     * @return the resulting Parameter instance
     */
    public Parameter addParameter(Class type, String name) {
        Parameter param = new Parameter(type, name);
        addParameter(param);
        return param;
    }

    /**
     * Sets the event method name.
     * @param name the event name
     */
    public void setMethodName(String name) {
        this.methodName = name;
    }

    /**
     * Returns the event method name
     * @return the event name
     */
    public String getMethodName() {
        return this.methodName;
    }

    /**
     * Sets the event's severity level.
     * @param severity the severity
     */
    public void setSeverity(EventSeverity severity) {
        this.severity = severity;
    }

    /**
     * Returns the event's severity level.
     * @return the severity
     */
    public EventSeverity getSeverity() {
        return this.severity;
    }

    /**
     * Returns an unmodifiable list of parameters for this event method.
     * @return the list of parameters
     */
    public List getParameters() {
        return Collections.unmodifiableList(this.params);
    }

    /**
     * Sets the primary exception class for this event method. Note: Not all event methods throw
     * exceptions!
     * @param exceptionClass the exception class
     */
    public void setExceptionClass(String exceptionClass) {
        this.exceptionClass = exceptionClass;
    }

    /**
     * Returns the primary exception class for this event method. This method returns null if
     * the event is only informational or just a warning.
     * @return the primary exception class or null
     */
    public String getExceptionClass() {
        return this.exceptionClass;
    }

    /** {@inheritDoc} */
    public void toSAX(ContentHandler handler) throws SAXException {
        AttributesImpl atts = new AttributesImpl();
        atts.addAttribute("", "name", "name", "CDATA", getMethodName());
        atts.addAttribute("", "severity", "severity", "CDATA", getSeverity().getName());
        if (getExceptionClass() != null) {
            atts.addAttribute("", "exception", "exception", "CDATA", getExceptionClass());
        }
        String elName = "method";
        handler.startElement("", elName, elName, atts);
        for (Object param : this.params) {
            ((XMLizable) param).toSAX(handler);
        }
        handler.endElement("", elName, elName);
    }

    /**
     * Represents an event parameter.
     */
    public static class Parameter implements Serializable, XMLizable {

        private static final long serialVersionUID = 6062500277953887099L;

        private Class type;
        private String name;

        /**
         * Creates a new event parameter.
         * @param type the parameter type
         * @param name the parameter name
         */
        public Parameter(Class type, String name) {
            this.type = type;
            this.name = name;
        }

        /**
         * Returns the parameter type.
         * @return the parameter type
         */
        public Class getType() {
            return this.type;
        }

        /**
         * Returns the parameter name.
         * @return the parameter name
         */
        public String getName() {
            return this.name;
        }

        /** {@inheritDoc} */
        public void toSAX(ContentHandler handler) throws SAXException {
            AttributesImpl atts = new AttributesImpl();
            atts.addAttribute("", "type", "type", "CDATA", getType().getName());
            atts.addAttribute("", "name", "name", "CDATA", getName());
            String elName = "parameter";
            handler.startElement("", elName, elName, atts);
            handler.endElement("", elName, elName);
        }

    }
}
