package geekblog;


import java.text.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.jsp.*;


public class Utils
{
  /**
   * Figure out what the root URL of the weblog is. Can't just use the name of
   * the servlet context, as we might be co-located deep inside another servlet
   * context.
   */
  public static String getRootURL(HttpServletRequest request)
  {
    String requestURL = request.getRequestURL().toString();
    return requestURL.substring(0, requestURL.lastIndexOf("/"));
  }


  /**
   * Scrub passed string (assumed to be HTML) for malicious tags; simply escape
   * the tag in the event it doesn't fit into the allowed set.
   *
   * TODO: In the future, allow the set to be user-configurable?
   */
  public static String scrubHTML(String html)
  {
    return html;
  }


  /**
   * Generate the HTML calendar text for the side panel.
   */
  private static final String placeholder = "<td align\"right\" class=\"calendar\"> </td>";
  private static final String dayPrefix = "<td align=\"right\" class=\"calendar\">";
  private static final String todayPrefix = "<td align\"right\" class=\"calendarcurrent\">";
  private static final String daySuffix = "</td>";
  public static String getCalendar(Calendar workingDate, DataManager dataMgr)
  {
    GregorianCalendar date = (GregorianCalendar)workingDate.clone();
    SimpleDateFormat datef = new SimpleDateFormat("yyyyMMdd");
    GregorianCalendar today = new GregorianCalendar();
    today.setTime(new Date());

    java.io.StringWriter writer = new java.io.StringWriter();
    java.io.PrintWriter out = new java.io.PrintWriter(writer);

    // Generate header
    //
    out.println("<center><span class=\"calendarhead\">" + 
                "<a href=\"index.jsp?month=" + new SimpleDateFormat("yyyyMM").format(workingDate.getTime()) + "\">" + 
                  new SimpleDateFormat("MMMM yyyy").format(workingDate.getTime()) + "</a>" +
                "</span></center>");
    out.println("<table border=\"0\" bgcolor=\"#FFFFFF\" cellpadding=\"2\" cellspacing=\"2\" class=\"border\">");
    out.println("<tr>");
    out.println("<th align=right class=\"calendarhead\">Sun</th>");
    out.println("<th align=right class=\"calendarhead\">Mon</th>");
    out.println("<th align=right class=\"calendarhead\">Tue</th>");
    out.println("<th align=right class=\"calendarhead\">Wed</th>");
    out.println("<th align=right class=\"calendarhead\">Thu</th>");
    out.println("<th align=right class=\"calendarhead\">Fri</th>");
    out.println("<th align=right class=\"calendarhead\">Sat</th>");
    out.println("</tr>");

    ArrayList weeksInMonth = new ArrayList();
    for (int i=1; i<=date.getActualMaximum(Calendar.WEEK_OF_MONTH); i++)
      weeksInMonth.add(new String[] { new String(placeholder), new String(placeholder), new String(placeholder), new String(placeholder), new String(placeholder), new String(placeholder), new String(placeholder) } );

    String todayStr = datef.format(today.getTime());
    int day = 1;
    do
    {
      date.set(Calendar.DAY_OF_MONTH, day++);
      int week = date.get(Calendar.WEEK_OF_MONTH);
      int dayOfWeek = date.get(Calendar.DAY_OF_WEEK);
      String dayStr = datef.format(date.getTime());

      String[] weekDays = (String[])weeksInMonth.get(week - 1);

      weekDays[dayOfWeek - 1] = 
        (dayStr.equals(todayStr) ? todayPrefix : dayPrefix) +
        ((dataMgr.getEntryCountForDate(date.getTime()) > 0) ? "<a href=\"index.jsp?date=" + datef.format(date.getTime()) + "\">" + date.get(Calendar.DAY_OF_MONTH) + "</a>" : "" + date.get(Calendar.DAY_OF_MONTH)) +
        daySuffix;

    } while (day <= date.getActualMaximum(Calendar.DAY_OF_MONTH));
    

    for (Iterator iter = weeksInMonth.iterator(); iter.hasNext(); )
    {
      out.println("<tr>");
      String[] weekDays = (String[])iter.next();
      for (int j=0; j<7; j++)
        out.println(weekDays[j]);
      out.println("</tr>");
    }

    out.println("</table>");

    return (writer.toString());
  }
}