import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.sql.*;

public class Artist extends HttpServlet
{
    private HTMLParser html;
    private DBUtil db;
    private PrintWriter out;
    private String artist;
    private String content;

    public void doGet(HttpServletRequest request,
		      HttpServletResponse response)
	throws IOException, ServletException
    {
	artist = request.getParameter("name");
	out = response.getWriter();
	html = new HTMLParser();

	try { db = new DBUtil(); }
	catch (Exception e) { html.outputError(e, out); }

	response.setContentType("text/html");

	if(artist == null) {
	    html.setContent(printLinks());
	    html.parse(out, null, "Listing of all Artists");
	}
	else {
	    artist = artist.replace('_', ' ');
	    html.setContent(getArtistInfo(artist, html));
	    html.parse(out, null, artist);
	}
	
	db.close();
    }

    private String printLinks()
    {
	ResultSet rs = db.execQuery("SELECT name FROM Artist ORDER BY name");

	String links = "";
	try {
	    while(rs.next())
		{
		    String name = rs.getString("name");
		    String _name = name.replace(' ', '_');
		    links += ("<a href=\"Artist?name=" + _name + "\">" +
			  name + "</a><br>\n");
		}
	    rs.close();
	    db.closeQuery();  // has to come after rs processing...
	}
	catch (SQLException e) { html.outputError(e, out); }
	
	links += "<p><p><a href=\"Edit?edit=Add+an+Artist+Entry\">" +
	    "Add a new Artist</a><p>\n";
	links += "<a href=\"Edit?edit=Delete+an+Artist+Entry\">" +
	    "Delete an Artist</a>\n";

	return links;
    }

    private String getArtistInfo(String artist, HTMLParser html)
    {
	String info = "", query;

	query = "SELECT * FROM Artist WHERE name='" + artist + "'";
	ResultSet groupInfo = db.execQuery(query);

	query = "SELECT * FROM Musician WHERE name IN " +
	    "(SELECT musicianName FROM InGroup WHERE groupName='" + 
	    artist + "')";
	ResultSet members = db.execQuery(query);

	query = "SELECT * FROM album WHERE groupName='"+artist+"'"
	    + " ORDER BY year";
	ResultSet albums = db.execQuery(query);
	
	info += "<table width=\"100%\">\n<tr>\n<td valign=\"top\">\n";

	try {
	    // the groupInfo should only have one entry...
	    if(groupInfo.next()) {
		info += ("<h1>"+groupInfo.getString("name")+"</h1>\n");
		info += "<p>\n";
		info += "Genre: " + groupInfo.getString("genre") + "\n<p>";
		info += "Hometown: " + groupInfo.getString("hometown") + "\n";
		String homepage = groupInfo.getString("homepage");
		info += "<p>Homepage: <a href=\"" + homepage + "\">";
		info += homepage + "</a>\n";
		info += "<p>" + groupInfo.getString("bio") + "\n";
		info += "</td>\n";

		info += html.insertPic(artist.replace(' ', '_'), "band");
		
		info += "</tr>\n</table>\n";
	    }
	    else {
		return ("Artist: '" + artist + "' not found");
	    }
		
	    info += "<h2>Members:</h2>\n";
	    info += "<table width=\"100%\">\n<tr>\n";
	    info += "<th align=\"left\">Name</th>\n";
	    info += "<th align=\"left\">Instrument</th>\n";
	    info += "<th align=\"left\">Hometown</th>\n</tr>\n";
	 
	    while(members.next()) {
		info += "<tr>\n";
		
		String memberName = members.getString("name");
		info += "<td><a href=\"Musician?name=" +
		    memberName.replace(' ', '_') + "\">" + memberName +
		    "</a></td>\n";
		info += 
		    "<td>"+members.getString("instrument")+"</td>\n";
		info += "<td>"+members.getString("hometown")+"</td>\n";
		
		info += "</tr>\n";
	    }
	    
	    info += "</table>\n";

	    info += "<h2>Discography</h2><p>\n";
	    info += "<table width=\"100%\">\n<tr>\n";
	    info += "<th align=\"left\">Album</th>\n";
	    info += "<th align=\"left\">Date Released</th>\n";
	    info += "<th align=\"left\">Tracks</th>\n</tr>\n";

	    while(albums.next()) {
		info += "<tr>\n";
		
		String albumName = albums.getString("albumName");

		info += "<td><a href=\"Album?artist=" +
		    artist.replace(' ', '_') + "&album=" +
		    albumName.replace(' ', '_') + "\">"+albumName+"</td>\n";
		info += "<td>"+albums.getDate("year")+"</td>\n";
		info += "<td>"+albums.getInt("numTracks")+"</td>\n";
		
		String pic = artist.replace(' ', '_') + "-" +
		    albumName.replace(' ', '_');
		info += html.insertPic(pic, "album");

		info += "</tr>\n";
	    }

	    info += "</table>\n";
	}
	catch (SQLException e) { html.outputError(e, out); }
    
	info += "<tr><p>\n<td align=\"center\">\n";
	info += "<a href=\"Edit?edit=Update+an+Artist+Entry"
	    + "&oldName="+ artist.replace(' ', '+') +
	    "\">Update this Artist</a></td>\n";
	info += "<td><a href=\"Tab?group=" + artist.replace(' ', '_') +
	    "\">Get Tablature for this Artist</a></td>\n</tr>\n";
	info += /*"<a href=\"Artist\"><p>Back</a>\n*/"\n";
	info += "\n</table>\n";
	
	return info;
    }

}