package dk.thoerup.traininfoservice;

import java.io.IOException;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.Statement;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class DumpResultSet extends HttpServlet {

    public DumpResultSet() {
        super();
    }


	private static final long serialVersionUID = 1L;

	String dumpResultset(String sql) throws ServletException {
		StringBuilder sb = new StringBuilder();
		
		Connection conn = null;
		Statement stmt = null;
		ResultSet rs = null;
		
		try {
			conn =  DBConnection.getConnection();
			stmt = conn.createStatement();
			
			rs = stmt.executeQuery(sql);
			ResultSetMetaData meta = rs.getMetaData();
			int columns = meta.getColumnCount();
			
			sb.append("<h2>").append(sql).append("</h2>");
			sb.append("<table border=1><tr>");
			for (int i=1; i<=columns; i++) {
				sb.append("<th>").append( meta.getColumnName(i)).append("</th>");
			}
			sb.append("</tr>");
			while(rs.next())
			{
				sb.append("<tr>");
				for (int i=1; i<=columns; i++) {
					sb.append("<td>").append(rs.getString(i)).append("</td>");
				}
				sb.append("</tr>");
			}
			sb.append("</table>");
		} catch (Exception e) { 
			throw new ServletException(e);
		} finally {

			try {
				if (rs != null && !rs.isClosed())
					rs.close();
			} catch (Exception e) {}
			try {
				if (stmt != null && !stmt.isClosed())
					stmt.close();
			} catch (Exception e) {}
			
			try {
				if (conn != null && !conn.isClosed())
					conn.close();
			} catch (Exception e) {}
		}
		
		return sb.toString();
	}
	
	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		String dump = req.getParameter("dump");
		
		String res = null;
	
		if (dump != null) {
			if (dump.equals("all")) {
				res = dumpResultset("SELECT * FROM trainstations");
			} else if (dump.equals("coords")) {
				res = dumpResultset("SELECT * FROM trainstations WHERE latitude IS NULL OR longitude IS NULL");			
			} else if (dump.equals("duplicate")) {
				res = dumpResultset("SELECT name,count(*) FROM trainstations GROUP BY name HAVING count(*) > 1"); 
			}
		}
		if (res == null) {
			res = "<a href=DumpResultSet?dump=all>All</a><br><a href=DumpResultSet?dump=coords>Missing coords</a><br><a href=DumpResultSet?dump=duplicate>Duplicate stations</a>";
		}
		
		resp.setContentType("text/html");
		resp.getWriter().println(res);
	}

}