using System;
using System.Data;
using System.Text.RegularExpressions;
using System.Web.UI;

namespace Sample
{
  /// <summary>
  /// PreviewResults class exstructs the contents of a document with a proper IFilter.
  /// </summary>
  public class PreviewResults : Control
  {
    /// <summary>
    /// path of the document.
    /// </summary>
    private string path;
    /// <summary>
    /// text contents of the document.
    /// </summary>
    private string contents;
    /// <summary>
    /// search text
    /// </summary>
    private string search_text;
    /// <summary>
    /// set path of the document.
    /// </summary>
    /// <param name="x">
    /// path
    /// </param>
    void SetPath(string x)
    {
      path = x;
    }
    public void SetSearchText(string x)
    {
      search_text = x;
    }
    /// <summary>
    /// clear text contents.
    /// </summary>
    void ClearContents()
    {
      contents = "";
    }
    /// <summary>
    /// constructor.
    /// </summary>
    public PreviewResults()
    {
      path = new String(' ', 0);
      search_text = new String(' ', 0);
      ClearContents();
    }
    public bool GetIFilterResults(string path_)
    {
      path = path_;
      try
      {
        IFilter ifilt = (IFilter)(new CFilter());
        System.Runtime.InteropServices.UCOMIPersistFile ipf = 
          (System.Runtime.InteropServices.UCOMIPersistFile)(ifilt);
        ipf.Load(path, 0);
        uint i = 0;
        STAT_CHUNK ps = new STAT_CHUNK();
        ifilt.Init(0, 0, null, ref i);
        int hr = 0;                   
        while (hr == 0)
        {
          ifilt.GetChunk(out ps);
          if (ps.flags == CHUNKSTATE.CHUNK_TEXT)
          {
            uint pcwcBuffer = 1000;
            int hr2 = 0;
            while (hr2 == Constants.FILTER_S_LAST_TEXT || hr2 == 0)
            {
              pcwcBuffer = 1000;
              System.Text.StringBuilder sbBuffer = new System.Text.StringBuilder((int)pcwcBuffer);
              hr2 = ifilt.GetText(ref pcwcBuffer, sbBuffer);
              //Console.Write(sbBuffer.ToString(0, (int)pcwcBuffer));
              contents += sbBuffer.ToString(0, (int)pcwcBuffer);
            }
          }
        }
      }
      catch (System.Exception /*ex*/)
      {
        //Console.WriteLine(ex.Message);
        return false;
      }
      return true;
    }
    /// <summary>
    /// render the HTML contents.
    /// </summary>
    /// <param name="writer"></param>
    protected override void Render(HtmlTextWriter writer)
    {
      writer.Write("<h1>");
      writer.Write(path);
      writer.Write("</h1>");
      writer.Write("<table bgcolor=\"#e8e8e8\">");
      writer.Write("<td>");
      RenderContents(writer);
      writer.Write("</td>");
      writer.Write("</table>");
    }
    protected void RenderContents(HtmlTextWriter writer)
    {
      string s1 = new String(' ', 0);
      s1 = contents;
      // .NETの文字列メソッドが遅いので配列を使って回避します。
      int s1_len = s1.Length;
      char[] x = new char[s1_len * 6 + 1];  // MAXで の6倍の長さに展開されるため
      int xi = 0;
      int n;
      bool top_p = true;
      for (n = 0; n < s1_len; n++)
      {
        char c = s1[n];
        switch (c)
        {
          case '&':  // -> "&"
            x[xi++] = '&';
            x[xi++] = 'a';
            x[xi++] = 'm';
            x[xi++] = 'p';
            x[xi++] = ';';
            break;
          case '<':  // -> "<"
            x[xi++] = '&';
            x[xi++] = 'l';
            x[xi++] = 't';
            x[xi++] = ';';
            break;
          case '>':  // -> ">"
            x[xi++] = '&';
            x[xi++] = 'g';
            x[xi++] = 't';
            x[xi++] = ';';
            break;
          case '\r':
            break;
          case '\n':  // -> "<br>\n"
            top_p = true;
            x[xi++] = '<';
            x[xi++] = 'b';
            x[xi++] = 'r';
            x[xi++] = '>';
            x[xi++] = '\n';
            break;
          case '\t':
          case ' ':
            if (top_p)
            {
              // -> " "
              x[xi++] = '&';
              x[xi++] = 'n';
              x[xi++] = 'b';
              x[xi++] = 's';
              x[xi++] = 'p';
              x[xi++] = ';';
            }
            else
            {
              // -> " "
              x[xi++] = ' ';
            }
            break;
          default:
            top_p = false;
            x[xi++] = c;
            break;
        }
      }
      x[xi] = '\0';
      char[] y = new char[xi];
      for (n = 0; n < xi; n++)
      {
        y[n] = x[n];
      }
      string s2 = new String(y);
      if (search_text.Length > 0)
      {
        s2 = s2.Replace(search_text, "<span style=\"color:red; font-weight:bold\">" + search_text + "</span>");
      }
      writer.Write(s2);      
    }
  }
}