package org.madore.damlengine;

import java.util.Properties;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.io.BufferedReader;
import java.io.IOException;
import java.sql.Connection;
import java.sql.SQLException;
import org.postgresql.Driver;

public final class WeblogDatabaseConnection {

    private WeblogDatabaseConnection() { // Forbid instantiation
	throw new AssertionError("WeblogDatabaseConnection cannot be instantiated");
    }

    public static Connection conn;

    public static Connection getConnection()
        throws SQLException {
	if ( conn == null ) {
	    String dbHost = System.getenv("PGHOST");
	    if ( dbHost == null )
		dbHost = "localhost";
	    String dbPort = System.getenv("PGPORT");
	    if ( dbPort == null )
		dbPort = "5432";
	    String dbName = "weblog";
	    String dbUser = System.getenv("PGUSER");
	    if ( dbUser == null )
		dbUser = System.getenv("USER");
	    if ( dbUser == null )
		dbUser = System.getProperty("user.name");
	    if ( dbUser == null )
		dbUser = dbName;
	    String dbPass = System.getenv("PGPASSWORD");
	    if ( dbPass == null )
		try {
		    String dbPassFile = System.getenv("PGPASSFILE");
		    if ( dbPassFile == null )
			dbPassFile = System.getProperty("user.home")
			    + "/.pgpass";
		    BufferedReader buf
			= new BufferedReader(new InputStreamReader(new FileInputStream(dbPassFile)));
		    String line;
		    while ( ( line = buf.readLine() ) != null ) {
			String[] elts = line.split(":");
			if ( elts.length == 5 
			     && ( elts[0].equals("*") || elts[0].equals(dbHost) )
			     && ( elts[1].equals("*") || elts[1].equals(dbPort) )
			     && ( elts[2].equals("*") || elts[2].equals(dbName) )
			     && ( elts[3].equals("*") || elts[3].equals(dbUser) ) ) {
			    dbPass = elts[4];
			    break;
			}
		    }
		} catch (IOException e) {
		    // Ignore
		}
	    if ( dbPass == null )
		dbPass = "";
	    final String dbUrl
		= "jdbc:postgresql://"+dbHost+":"+dbPort+"/"+dbName;
	    final Properties dbProps = new Properties();
	    dbProps.setProperty("user", dbUser);
	    dbProps.setProperty("password", dbPass);
	    dbProps.setProperty("ssl", "true");
	    dbProps.setProperty("sslfactory", "org.postgresql.ssl.NonValidatingFactory");
	    conn = (new Driver()).connect(dbUrl, dbProps);
	    conn.createStatement().execute("SET TIME ZONE 0");
	}
	return conn;
    }

}