/*
 *                 Sun Public License Notice
 *
 * The contents of this file are subject to the Sun Public License
 * Version 1.0 (the "License"). You may not use this file except in
 * compliance with the License. A copy of the License is available at
 * http://www.sun.com/
 *
 * The Original Code is NetBeans. The Initial Developer of the Original
 * Code is Sun Microsystems, Inc. Portions Copyright 1997-2003 Sun
 * Microsystems, Inc. All Rights Reserved.
 */

package org.netbeans.modules.tasklist.usertasks.ics;

import java.io.Reader;
import java.io.Writer;
import java.util.ArrayList;
import java.util.List;
import org.netbeans.modules.tasklist.usertasks.ics.parser.*;

/**
 * Reads ics files
 */
public class ICalReader {
    /**
     * A parameter in a content line
     */
    public static class Param {
        /** name of the parameter */
        public String name;
        
        /** parameter values */
        public String[] values;
    }
    
    /**
     * A property in a content line
     */
    public static class Property {
        /** name of a property */
        public String name;
        
        /** parameters */
        public Param[] params;
        
        /** value */
        public String value;
    }
    
    private static final int CONTEXT_FILE = 0;
    private static final int CONTEXT_VCALENDAR = 1;
    private static final int CONTEXT_VEVENT = 2;
    
    private int context = CONTEXT_FILE;
    
    private boolean calendarPropsSection = false;
    private ICalendar calendar;
    private ICalEvent event;
    
    /**
     * Creates a new instance of ICalReader
     */
    public ICalReader() {
    }
    
    /**
     * Read the content from the specified Reader
     *
     * @param r input
     * @return read content
     */
    public ICalFile read(Reader r) throws ICalParseException {
        try {            
            Node n = new IcsParser(r).File();
            if (n.jjtGetNumChildren() == 0)
                throw new ICalParseException("VCALENDAR section expected");
            
            // for each content line
            for (int i = 0; i < n.jjtGetNumChildren(); i++) {
                SimpleNode lineNode = (SimpleNode) n.jjtGetChild(i);
                String name = lineNode.firstToken.image;
                String value = lineNode.lastToken.image;
                List params = new ArrayList();
                
                // for each parameter
                for (int j = 0; j < lineNode.jjtGetNumChildren(); j++) {
                    SimpleNode paramNode = (SimpleNode) lineNode.jjtGetChild(j);
                    Param p = new Param();
                    p.name = paramNode.firstToken.image;
                    List values = new ArrayList();
                    
                    // for each parameter value
                    for (int k = 0; k < paramNode.jjtGetNumChildren(); k++) {
                        SimpleNode valueNode = 
                            (SimpleNode) paramNode.jjtGetChild(k);
                        values.add(valueNode.firstToken.image);
                    }
                    p.values = (String[]) values.toArray(new String[values.size()]);
                    params.add(p);
                }
                Param[] parameters = 
                    (Param[]) params.toArray(new Param[params.size()]);
                Property p = new Property();
                p.name = name;
                p.value = value;
                p.params = parameters;
                handleContentLine(p);
            }
        } catch (ParseException e) {
            throw new ICalParseException(e.getMessage());
        }
        return null; // TODO
    }
    
    /**
     * Handles one line in an ics file
     *
     * @param p a content line
     */
    private void handleContentLine(Property p) throws ICalParseException {
        switch (context) {
            case CONTEXT_FILE:
                if (isBegin(p, "VCALENDAR")) {
                    calendar = new ICalendar();
                    context = CONTEXT_VCALENDAR;
                    calendarPropsSection = true;
                } else {
                    throw new ICalParseException("Unexpected line: " + p.name);
                }
                break;
            case CONTEXT_VCALENDAR:
                if (isEnd(p, "VCALENDAR")) {
                    calendar = null;
                    context = CONTEXT_FILE;
                } else if (p.name.equals("END")) {
                    throw new ICalParseException("END:VCALENDAR expected");
                } else if (p.name.equals("PRODID")) {
                    if (!calendarPropsSection)
                        throw new ICalParseException("Unexpected line:" + p.name);
                    if (calendar.prodid != null) 
                        throw new ICalParseException("Duplicate PRODID");
                    calendar.prodid = p;
                } else if (p.name.equals("VERSION")) {
                    if (!calendarPropsSection)
                        throw new ICalParseException("Unexpected line:" + p.name);
                    if (calendar.version != null) 
                        throw new ICalParseException("Duplicate VERSION");
                    calendar.version = p;
                } else if (p.name.equals("CALSCALE")) {
                    if (!calendarPropsSection)
                        throw new ICalParseException("Unexpected line:" + p.name);
                    if (calendar.scale != null) 
                        throw new ICalParseException("Duplicate CALSCALE");
                    calendar.scale = p;
                } else if (p.name.equals("METHOD")) {
                    if (!calendarPropsSection)
                        throw new ICalParseException("Unexpected line:" + p.name);
                    if (calendar.method != null) 
                        throw new ICalParseException("Duplicate METHOD");
                    calendar.method = p;
                } else if (isBegin(p, "VEVENT")) {
                    event = new ICalEvent();
                    calendar.components.add(event);
                    context = CONTEXT_VEVENT;
                    calendarPropsSection = false;
                } else if (isBegin(p, "dddddd")) {
                    calendar.props.add(p);
                } else {
                    throw new ICalParseException("Unexpected line: " + p.name);
                }
                break;
            case CONTEXT_VEVENT:
                if (isEnd(p, "VEVENT")) {
                    event = null;
                    context = CONTEXT_VCALENDAR;
                } else if (p.name.equals("CLASS")) {
                    event.class_ = p;
                }
                break;
            default:
                throw new InternalError("Unexpected context");
        }
    }

    /**
     * Test for BEGIN:SOMETHING
     *
     * @param p a content line
     * @param n expected value (name of the section)
     */
    private static boolean isBegin(Property p, String n) {
        return p.name.equals("BEGIN") && p.params.length == 0 && p.value.equals(n);
    }

    /**
     * Test for END:SOMETHING
     *
     * @param p a content line
     * @param n expected value (name of the section)
     */
    private static boolean isEnd(Property p, String n) {
        return p.name.equals("END") && p.params.length == 0 && p.value.equals(n);
    }    
    
    public void write(Writer w) {
        // TODO
    }
}