/*
 * Copyright 2005 the original author or authors.
 * 
 * Licensed 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.wamblee.crawler.kiss;

import java.io.InputStream;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.Iterator;
import java.util.List;

import javax.mail.internet.InternetAddress;

import org.apache.commons.mail.SimpleEmail;
import org.dom4j.Attribute;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;
import org.wamblee.conditions.AndCondition;
import org.wamblee.conditions.Condition;
import org.wamblee.conditions.PropertyRegexCondition;

/**
 * Parse the configuration of desired programs.
 */
class ProgramConfigurationParser {

    private static final String ELEM_PROGRAM = "program";

    private static final String ELEM_PATTERN = "match";

    private static final String ELEM_ACTION = "action";
    
    private static final String ELEM_CATEGORY = "category";

    private static final String ACTION_NOTIFY = "notify";
    
    private List<ProgramFilter> _filters; 
    
    private Notifier _notifier; 
    
    ProgramConfigurationParser() { 
        _filters = null; 
        _notifier = null; 
    }

    /**
     * Parses the condition used to match the desired programs.
     * 
     * @param aStream
     *            Input stream to parse from.
     * @return Condition.
     */
    void parse(InputStream aStream) {
        List<ProgramFilter> filters = new ArrayList<ProgramFilter>();
        try {
            SAXReader reader = new SAXReader();
            Document document = reader.read(aStream);

            Element root = document.getRootElement();

            for (Iterator i = root.elementIterator(ELEM_PROGRAM); i.hasNext();) {
                Element program = (Element) i.next();

                Element categoryElem = program.element(ELEM_CATEGORY);
                String category = "";
                if ( categoryElem != null ) { 
                    category = categoryElem.getText().trim(); 
                }
                
                Element actionElem = program.element(ELEM_ACTION);
                ProgramAction action = new RecordProgramAction();
                if (actionElem != null) {
                    if (actionElem.getText().equals(ACTION_NOTIFY)) {
                        action = new InterestingProgramAction(category);
                    }
                }
              
                List<Condition<Program>> regexConditions = 
                    new ArrayList<Condition<Program>>();
                for (Iterator j = program.elementIterator(ELEM_PATTERN); j.hasNext(); ) {
                    Element patternElem = (Element)j.next();
                    String fieldName = "name"; 
                    Attribute fieldAttribute = patternElem.attribute("field"); 
                    if ( fieldAttribute != null ) { 
                        fieldName = fieldAttribute.getText(); 
                    }
                    String pattern = ".*(" + patternElem.getText()
                    + ").*";
                    regexConditions.add(new PropertyRegexCondition<Program>(fieldName, pattern, true));
                }
                Condition<Program> condition = new AndCondition<Program>(regexConditions);
                filters.add(new ProgramFilter(condition, action));
            }
            _filters = filters;
            
            Element notifier = root.element("notification");
            _notifier = parseNotifier(notifier);
            
        } catch (DocumentException e) {
            throw new RuntimeException("Error parsing program configuraiton", e);
        }
    }
    
    /**
     * Parses the notifier
     * @return Notifier
     */
    private Notifier parseNotifier(Element aNotifier) { 
        String from = aNotifier.elementTextTrim("from");
        String to = aNotifier.elementTextTrim("to");
        String subject = aNotifier.elementTextTrim("subject");
        
        Element smtp = aNotifier.element("smtp");
        MailServer server = parseMailServer( smtp );
        
        Element format = aNotifier.element("format");
        String htmlXslt = format.elementTextTrim("html");
        String textXslt = format.elementTextTrim("text");
        
        return new MailNotifier(from, to, subject, htmlXslt, textXslt, server);
    }

    /**
     * @param smtp
     * @return
     */
    private MailServer parseMailServer( Element smtp ) {
        String host = smtp.elementTextTrim("host");
        Element portElem = smtp.element("port");
        int port = 25; 
        if ( portElem != null ) {
            port = Integer.valueOf(portElem.getTextTrim());
        }
        String username = smtp.elementTextTrim("username");
        String password = smtp.elementTextTrim("password");
        
        MailServer server = new MailServer(host, port, username, password);
        return server;
    }
    
    /**
     * Returns the list of program filters.
     * @return Filter list.
     */
    public List<ProgramFilter> getFilters() { 
        return _filters;
    }
    
    /**
     * Returns the notifier to use. 
     * @return Notifier.
     */
    public Notifier getNotifier() { 
        return _notifier; 
    }
}