/*
 * Created on Jun 6, 2008
 *
 */
package com.ecyrd.jspwiki.plugin;

import com.ecyrd.jspwiki.WikiContext;

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

import javax.servlet.http.HttpServletRequest;

import com.ecyrd.jspwiki.WikiEngine;

import com.ecyrd.jspwiki.WikiPage;

import com.ecyrd.jspwiki.providers.ProviderException;

import java.util.HashMap;
import java.util.Iterator;
import java.util.List;

/**
 * A simple calendar item container and HTML printer, used by WeblogCalendarPlugin.
 * The majority of this code is taken from the CalendarPrinter class written by 
 * Connie Chan.
 * 
 * <p>This particular formatter produces a div with a string that looks like the following:
 * <pre>
 * << <  OCT 2008  > >>
 * su mo tu we th fr sa
 *          01 02 03 04
 * 05 06 07 08 09 10 11
 * 12 13 14 15 16 17 18
 * 19 20 21 22 23 24 25
 * 26 27 28 29 30 31   
 * </pre>
 * 
 * 
 * <p>Each day is a link to a weblog entry using the http parameters weblog.startDate
 * and weblog.days
 * 
 * @author ebu
 */
public class WeblogCalendarPrinter
{
    private int m_dayMarker;
    private int m_dayPseudoMarker;
    private int m_monthMarker;
    private int m_yearMarker;
    private String CSS_SELECTED = "selected";
    private String CSS_EXISTINGENTRY = "exists";
    /** Stores the cached HTML string, to prevent needless rendering. */
    private String m_cached = null;
    /** The name of this calendar. Should correspond to a WikiPage, too. */
    private String m_calendarName;
    /** The CSS style prefix to use for DIVs in this calendar. Default is 'calendar'. */
    private String m_style = "calendar";
    private WikiEngine m_engine;
    private WikiContext m_context;
    /** The WikiPage that this calendar is displayed on. */
    private String m_owningPage;
    private boolean m_changed = false;   
    /** 
     * Linking mode; if LINK_TO_DAY, each day entry takes us to a day-specific WikiPage.
     * If LINK_TO_NAME, sets the date to the clicked day and takes us to the page
     * m_calendarName, which presumably contains a summary view to this calendar. 
     */
    private int m_linkMode = LINK_TO_DAY;
    private String m_handledQuery;

    // Utilities for HTML printing.
    private final String m_empty = "&nbsp;";
    private final String m_space = "</td>\n<td class=\"" + m_style + "\">";
//    private final String m_empty = "&nbsp;&nbsp;";
//    private final String m_space = "&nbsp;";
    // A nice up arrow / home mutant hybrid. Necessitates UTF-8, bad me.
    private final String m_today = "(Back to Today)";

    public static final int LINK_TO_DAY  = 0;
    public static final int LINK_TO_CURRENT = 1;


    /**
     * Creates a new calendar display object that uses the given name.
     * The name is free-form, but we expect it to also be an existant
     * WikiPage, and link to it accordingly.
     */
    public WeblogCalendarPrinter( WikiEngine wiki, WikiContext context, String name )
    {
        m_calendarName = name;
        m_owningPage = name;
        m_engine = wiki;
        m_context = context;
        Calendar cal = Calendar.getInstance();
        m_dayMarker = cal.get( Calendar.DAY_OF_MONTH );
        m_dayPseudoMarker = m_dayMarker;
        m_monthMarker = cal.get( Calendar.MONTH );
        m_yearMarker = cal.get( Calendar.YEAR );
        clear();
    }

    /**
     * Sets the linking mode of individual calendar days.
     */    
    public void setLinkingMode( int mode )
    {
        m_linkMode = mode;
        m_changed = true;
    }
    
    public void clear()
    {
        m_changed = true;
    }
    
    
    /**
     * Sets the unique name of the calendar. This is also presumed to be the name
     * of a WikiPage associated with this calendar.
     */
    public void setName( String name )
    {
        m_calendarName = name;
        m_changed = true;
    }
    

    /**
     * Returns the unique(?) name of the calendar.
     */
    public String getName()
    {
        return( m_calendarName );
    }


    /*
     * Sets the year to display.    
     * This is optimized to cause re-rendering only if the date has actually changed.
     */
    public void setYear( String y )
    {
        try {
            setYear( Integer.parseInt( y ) );
        } catch( NumberFormatException e ) {
        }
    }
    

    /*
     * Sets the year to display.    
     * This is optimized to cause re-rendering only if the date has actually changed.
     */
    public void setYear( int year )
    {
        if( m_yearMarker != year )
        {
            m_yearMarker = year;
            m_changed = true;
        }
    }

    public int getYear()
    {
        return( m_yearMarker );
    }
    
    public int getMonth()
    {
        return( m_monthMarker );
    }

    public int getDay()
    {
        return( m_dayMarker );
    }


    /*
     * Sets the css style to use for the calendar div.
     * If the style is x, the following CSS classes are used in the calendar view:
     * x, xtitle    
     */
    public void setCSSStyle( String cssStyle )
    {
        m_style = cssStyle;
        m_changed = true;
    }

    
    /*
     * Sets the month to display.    
     * This is optimized to cause re-rendering only if the date has actually changed.
     */
    public void setMonth( String m )
    {
        try {
            int month = Integer.parseInt( m );
            month = month % 12;
            setMonth( month );
        } catch( NumberFormatException e ) {
        }
    }

    /*
     * Sets the month to display.    
     * This is optimized to cause re-rendering only if the date has actually changed.
     */
    public void setMonth( int month )
    {
        if( m_monthMarker != month )
        {
            m_monthMarker = month;
            setDay( m_dayMarker ); // update in case of now.maxdate < previously.maxdate
            m_changed = true;
        }
    }


    /*
     * Sets the day to (maybe) display.    
     * This is optimized to cause re-rendering only if the date has actually changed.
     * Should be called after setMonth().
     */
    public void setDay( String d )
    {
        try {
            int day = Integer.parseInt( d );
            setDay( day );
        } catch( NumberFormatException e ) {
        }
    }

    /*
     * Sets the month to display.
     * Always causes a render update, because we're too lazy to check for an actual change.    
     */
    public void setDay( int d )
    {
        if( m_dayMarker != d )
        {
            m_dayMarker = d;
            m_changed = true;
        }
        Calendar cal = Calendar.getInstance();
        cal.set( Calendar.DAY_OF_MONTH, 1 );
        cal.set( Calendar.MONTH, m_monthMarker );
        int max = cal.getActualMaximum( Calendar.DAY_OF_MONTH );
        int p = (m_dayMarker > max ? max : m_dayMarker);
        if( p != m_dayPseudoMarker )
        {
            m_dayPseudoMarker = p;
            m_changed = true;
        }
    }



    /**
     * Sets page the calendar is displayed on. This information is used in generating
     * the next/previous month/year links, so that clicking on them brings us back to
     * the same page, but with new calendar date info.
     * This is optimized to cause re-rendering only if the date has actually changed.
     */
    public void setDisplayPage( String wikiPage )
    {
        if( wikiPage.equals( m_owningPage ) == false )
        {
            m_owningPage = wikiPage;
            m_changed = true;
        }
    }

    
    public String getDisplayPage()
    {
        return( m_owningPage );
    }
    
    
    
    protected void setHandledRequest( HttpServletRequest req )
    {
        m_handledQuery = req.getQueryString();
    }


    public boolean requestHandled( HttpServletRequest req )
    {
        if( req == null || m_handledQuery == null )
            return( false );
        String newQuery = req.getQueryString();
        if( m_handledQuery == newQuery )
            return( true );
        if( m_handledQuery.equals( newQuery ) )
            return( true );
            
        return( false );
    }


    SimpleDateFormat m_datefmt = new SimpleDateFormat( "ddMMyy" );
    /**
     * Return the filename this object would use for the given date in its html output.
     */    
    public String getEntryName( Calendar date )
    {
        return( m_calendarName + "_" + m_datefmt.format( date.getTime() ) );
    }


    /**
     * Produces HTML output for a monthly view, tailored for the given page.
     */
    public String printMonthView(WikiContext context) throws Exception {
        if( m_changed ) {
            m_context = context;
            Calendar marker = Calendar.getInstance();
            marker.setFirstDayOfWeek( Calendar.SUNDAY );
            int realMonth = marker.get( Calendar.MONTH );
            int realYear  = marker.get( Calendar.YEAR );
            int realDay   = marker.get( Calendar.DAY_OF_MONTH );
            
            // Currently displayed month/year/day. Get before clone(), in case we did stupidities...    
            int currMonth = m_monthMarker;
            int currYear  = m_yearMarker;
            int currDay   = m_dayPseudoMarker;
            marker.set( Calendar.MONTH, currMonth );
            marker.set( Calendar.DAY_OF_MONTH, currDay );
            marker.set( Calendar.YEAR, currYear );
            int maxDays   = marker.getActualMaximum( Calendar.DAY_OF_MONTH );
            int yearDays  = marker.getActualMaximum( Calendar.DAY_OF_YEAR );    

            // Scrollers for iterating through the days of the month.
            Calendar cal = (Calendar)marker.clone();
            Calendar scroller = (Calendar)marker.clone();
            Calendar scroller2 = (Calendar)marker.clone();
            scroller2.set(Calendar.DAY_OF_MONTH, maxDays);
            String lastDayOfMonth = m_datefmt.format(scroller2.getTime());            
            scroller2.set(Calendar.MONTH, 11);
            scroller2.set(Calendar.DAY_OF_MONTH, 31);
            String lastDayOfYear = m_datefmt.format(scroller2.getTime()); 
            cal.set( Calendar.DAY_OF_MONTH, 1 ); // 1 is start date
            int firstDayOfWeek = cal.get( Calendar.DAY_OF_WEEK ); // 1 is Monday.
            if( firstDayOfWeek < 1 )
                firstDayOfWeek += 7;

            // Formatting for month/year in title, and days in table    
            SimpleDateFormat monthfmt = new SimpleDateFormat( "MMM" );
            SimpleDateFormat yearfmt = new SimpleDateFormat( "yyyy" );
            SimpleDateFormat dayfmt = new SimpleDateFormat( "dd" );
            SimpleDateFormat simpleMonthfmt = new SimpleDateFormat( "MM" );
            
            // Shortcuts for already too long HTML string nasties.
            String cy = WeblogCalendarPlugin.EXT_YEAR;
            String cm = WeblogCalendarPlugin.EXT_MONTH;
            String cd = WeblogCalendarPlugin.EXT_DAY;

            
            // Target page time scroller links take to (the page this calendar is shown on). 
            String currentURL = m_engine.getViewURL( m_owningPage );
            HashMap blogEntries = getBlogEntries(context, m_owningPage);
            String blogParams = "";
            String selectedDate = "";
            try {
                if (m_context.getHttpParameter("weblog.startDate") != null && m_context.getHttpParameter("weblog.days") != null) {
                    selectedDate = m_context.getHttpParameter("weblog.startDate");
                    blogParams = "&weblog.startDate=" + m_context.getHttpParameter("weblog.startDate") + "&weblog.days=" + m_context.getHttpParameter("weblog.days");
                }
            } catch (Exception e) {
                // do nothing because http parameters must be null
            }
            StringBuffer buf = new StringBuffer();
            // Start calendar div. Date-change-info is encoded in HTTP params, so the CalendarPlugin can figure them out.
//            buf.append( "<div class=\"" + m_style + "\">\n" );
            buf.append( "<table border=\"0\">\n" );
            buf.append( "<tr><td colspan=\"7\" class=\"" + m_style + "title\">\n" );
            // '<<', with link to current page, previous year in this calendar
            buf.append( "<a class=\"calendartitle\" href=\"" + currentURL + "&" + m_calendarName + cy + "=" + (currYear - 1) + blogParams + "\">&lt;&lt;</a>&nbsp;" );
            // '<', with link to current page, previous month in this calendar
            scroller.add( Calendar.MONTH, -1 );
            buf.append( "<a class=\"calendartitle\" href=\"" + currentURL + "&" + m_calendarName + cy + "=" + scroller.get( Calendar.YEAR ) + "&" + m_calendarName + cm + "=" + scroller.get( Calendar.MONTH ) +  blogParams + "\">&lt;</a>&nbsp;&nbsp;" );
            // month, with link to WikiPage m_calendarName, last day of this month, maxDays days
            buf.append( "<a class=\"calendartitle\" href=\"" + m_engine.getViewURL( m_calendarName ) + "&" + m_calendarName + cy + "=" + currYear + "&" + m_calendarName + cm + "=" + currMonth + "&" + m_calendarName + cd + "=" + maxDays + "&" + WeblogCalendarPlugin.PLUGINPARAM_DAYS + "=" + maxDays + "&weblog.startDate=" + lastDayOfMonth + "&weblog.days="+ maxDays + "\">" + monthfmt.format( cal.getTime() ) + "</a> " );  
            // year, with link to WikiPage m_calendarName, last day of year, about 365 days
            buf.append( "<a class=\"calendartitle\" href=\"" + m_engine.getViewURL( m_calendarName ) + "&" + m_calendarName + cy + "=" + currYear + "&" + m_calendarName + cm + "=11" + "&" + m_calendarName + cd + "=" + maxDays + "&" + WeblogCalendarPlugin.PLUGINPARAM_DAYS + "=" + yearDays +  "&weblog.startDate=" + lastDayOfYear + "&weblog.days="+ yearDays + "\">" + yearfmt.format( cal.getTime() ) + "</a>" );
            // '>', next month, this page  
            scroller.add( Calendar.MONTH, 2 );
            buf.append( "&nbsp;&nbsp;<a class=\"calendartitle\" href=\"" + currentURL + "&" + m_calendarName + cy + "=" + scroller.get( Calendar.YEAR ) + "&" + m_calendarName + cm + "=" + scroller.get( Calendar.MONTH ) +  blogParams + "\">&gt;</a>" );
            // '>>', next year, this page
            buf.append( "&nbsp;<a class=\"calendartitle\" href=\"" + currentURL + "&" + m_calendarName + cy + "=" + (currYear + 1) +  blogParams + "\">&gt;&gt;</a>" );
            buf.append( "<br>\n" );
            //FIX: hard-coding:
            buf.append( "</td></tr>\n" );
            buf.append( "<tr><td class=\"" + m_style + "title\">su</td><td class=\"" + m_style + "title\">mo</td><td class=\"" + m_style + "title\">tu</td><td class=\"" + m_style + "title\">we</td><td class=\"" + m_style + "title\">th</td><td class=\"" + m_style + "title\">fr</td><td class=\"" + m_style + "title\">sa</td></tr>\n" );
            //buf.append( "<tr><td colspan=\"7\" class=\"" + m_style + "\">&nbsp;</td></tr>" );
            // Start date table. Add empty days. We don't show the previous month's days.
            buf.append( "<tr><td class=\"" + m_style + "\">" );
            for( int i = Calendar.SUNDAY; i < firstDayOfWeek; i++ )  // 1 for first day, again. Argh.
                buf.append( m_empty + m_space );
            // Add dates, with style (if set), link (if set), and remember
            // a newline and break when the week ends (on sundays).
            int row = 0;  // Tracks the week row we're doing.
            int col = 0;  // Tracks the day column we're doing.
            while( cal.get( Calendar.MONTH ) == currMonth ) 
            {
                int d = cal.get(Calendar.DAY_OF_MONTH);
                //String targetPageName = getEntryName( cal );
                String targetPageName = m_owningPage;
                // By default, link to a daily entry (LINK_TO_DAY). LINK_TO_NAME provides a navigation mode, instead.
                if( m_linkMode == LINK_TO_CURRENT )
                    targetPageName = m_owningPage;
                String pageUrl = m_engine.getViewURL( targetPageName );

                String cssClass = "";
                if (blogEntries.containsKey(m_datefmt.format(cal.getTime())))
                    cssClass = "class=\"" + CSS_EXISTINGENTRY + "\" ";            
                if (selectedDate.equals(m_datefmt.format(cal.getTime())))
                    cssClass = "class=\"" + CSS_SELECTED + "\" ";

                if ( cal.get( Calendar.DAY_OF_WEEK ) == Calendar.SUNDAY ) {
                    buf.append( "<tr><td class=\"" + m_style + "\">" );
                    col = 0;
                }

                buf.append( "<a " + cssClass + "href=\"" + pageUrl );
                buf.append( "&" + m_calendarName + cy + "=" + currYear + "&" + m_calendarName + cm + "=" + currMonth + "&" + m_calendarName + cd + "=" + d + "&weblog.days=1&weblog.startDate="  +  m_datefmt.format(cal.getTime()) + "\">" + dayfmt.format( cal.getTime() ) + "</a>" );

                // Advance row counter on sunday. Need to keep track of row and col, though.
                if( cal.get( Calendar.DAY_OF_WEEK ) == Calendar.SATURDAY ) {
                    row++;
                    buf.append( "</td></tr>\n" );
                    col++;
                } else {
                    buf.append( m_space );
                    col++;
                }
                cal.add( Calendar.DAY_OF_MONTH, 1 );
            } 

            // Move to the end of the last row.
            while (col < 6)
            {
                buf.append( "&nbsp;" + m_space );
                col++;
            }
            
            if( cal.get( Calendar.DAY_OF_WEEK ) != Calendar.SUNDAY ) { 
            	buf.append( "&nbsp;</td></tr>\n" );
            }
            
            // A bit of finery: always pad to the full 6 rows (the 6th will also get a today link).
           // while( row++ < 5 )
           // {
           // 	buf.append( "<tr><td colspan=7 class=\"" + m_style + "\">&nbsp;</td></tr>\n" );
           //     col = 0;
           // }

        	buf.append( "<tr><td colspan=7 align=\"right\" class=\"" + m_style + "title\"><a href=\"" + currentURL + "&" + m_calendarName + cy + "=" + realYear + "&" + m_calendarName + cm + "=" + realMonth + "&" + m_calendarName + cd + "=" + realDay + "\">" + m_today + "</a></td></tr>\n" );
        	buf.append( "</table>\n" );
      	
//            buf.append( "</div>\n" );
            
            m_cached = buf.toString();
            m_changed = false;
        }
        return( m_cached );
    }
    
    private HashMap getBlogEntries (WikiContext context, String page) throws Exception{
        // Used HashMap for faster searching.
        HashMap blogEntriesMap = new HashMap();
        WeblogPlugin pl = new WeblogPlugin();

        List blogEntries;

        try {
            blogEntries = 
                    pl.findBlogEntries( context.getEngine().getPageManager(),
                                               page, new Date(0L), new Date() );
        } catch (ProviderException e) {
            throw e;
        }
        for (Iterator i = blogEntries.iterator(); i.hasNext(); ) {
            WikiPage p = (WikiPage) i.next();
            String dateStr = p.getName().substring(p.getName().indexOf("_blogentry_") + "_blogentry_".length(), p.getName().lastIndexOf("_"));
            blogEntriesMap.put(dateStr,dateStr);
        }
        
        return blogEntriesMap;
    }
    
    public static void main (String[] args) {
        String p = "SamBurdenBlog_blogentry_300508_2";
        System.out.println(p.substring(p.indexOf("_blogentry_") + "_blogentry_".length(), p.lastIndexOf("_")));
    }
}