package play.db;

import com.mchange.v2.c3p0.ComboPooledDataSource;
import java.io.File;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.sql.Connection;
import java.sql.Driver;
import java.sql.DriverManager;
import java.sql.DriverPropertyInfo;
import java.sql.SQLException;
import java.util.Properties;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.sql.DataSource;
import jregex.Matcher;
import play.Logger;
import play.Play;
import play.PlayPlugin;
import play.exceptions.DatabaseException;

/**
 * The DB plugin
 */
public class DBPlugin extends PlayPlugin {

    public static String url = "";

    @Override
    public void onApplicationStart() {
        if (changed()) {
            try {

                Properties p = Play.configuration;

                if (p.getProperty("db", "").startsWith("java:")) {

                    Context ctx = new InitialContext();
                    DB.datasource = (DataSource) ctx.lookup(p.getProperty("db"));

                } else {

                    // Try the driver
                    String driver = p.getProperty("db.driver");
                    try {
                        Driver d = (Driver) Class.forName(driver, true, Play.classloader).newInstance();
                        DriverManager.registerDriver(new ProxyDriver(d));
                    } catch (Exception e) {
                        throw new Exception("Driver not found (" + driver + ")");
                    }

                    // Try the connection
                    Connection fake = null;
                    try {
                        if (p.getProperty("db.user") == null) {
                            fake = DriverManager.getConnection(p.getProperty("db.url"));
                        } else {
                            fake = DriverManager.getConnection(p.getProperty("db.url"), p.getProperty("db.user"), p.getProperty("db.pass"));
                        }
                    } finally {
                        if (fake != null) {
                            fake.close();
                        }
                    }

                    System.setProperty("com.mchange.v2.log.MLog", "com.mchange.v2.log.FallbackMLog");
                    System.setProperty("com.mchange.v2.log.FallbackMLog.DEFAULT_CUTOFF_LEVEL", "OFF");
                    ComboPooledDataSource ds = new ComboPooledDataSource();
                    ds.setDriverClass(p.getProperty("db.driver"));
                    ds.setJdbcUrl(p.getProperty("db.url"));
                    ds.setUser(p.getProperty("db.user"));
                    ds.setPassword(p.getProperty("db.pass"));
                    ds.setAcquireRetryAttempts(10);
                    ds.setCheckoutTimeout(Integer.parseInt(p.getProperty("db.pool.timeout", "5000")));
                    ds.setBreakAfterAcquireFailure(false);
                    ds.setMaxPoolSize(Integer.parseInt(p.getProperty("db.pool.maxSize", "30")));
                    ds.setMinPoolSize(Integer.parseInt(p.getProperty("db.pool.minSize", "1")));
                    ds.setIdleConnectionTestPeriod(10);
                    ds.setTestConnectionOnCheckin(true);
                    DB.datasource = ds;
                    url = ds.getJdbcUrl();
                    Connection c = null;
                    try {
                        c = ds.getConnection();
                    } finally {
                        if (c != null) {
                            c.close();
                        }
                    }
                    Logger.info("Connected to %s", ds.getJdbcUrl());

                }

            } catch (Exception e) {
                DB.datasource = null;
                Logger.error(e, "Cannot connected to the database : %s", e.getMessage());
                if (e.getCause() instanceof InterruptedException) {
                    throw new DatabaseException("Cannot connected to the database. Check the configuration.", e);
                }
                throw new DatabaseException("Cannot connected to the database, " + e.getMessage(), e);
            }
        }
    }

    @Override
    public String getStatus() {
        StringWriter sw = new StringWriter();
        PrintWriter out = new PrintWriter(sw);
        if (DB.datasource == null || !(DB.datasource instanceof ComboPooledDataSource)) {
            out.println("Datasource:");
            out.println("~~~~~~~~~~~");
            out.println("(not yet connected)");
            return sw.toString();
        }
        ComboPooledDataSource datasource = (ComboPooledDataSource) DB.datasource;
        out.println("Datasource:");
        out.println("~~~~~~~~~~~");
        out.println("Jdbc url: " + datasource.getJdbcUrl());
        out.println("Jdbc driver: " + datasource.getDriverClass());
        out.println("Jdbc user: " + datasource.getUser());
        out.println("Jdbc password: " + datasource.getPassword());
        out.println("Min pool size: " + datasource.getMinPoolSize());
        out.println("Max pool size: " + datasource.getMaxPoolSize());
        out.println("Initial pool size: " + datasource.getInitialPoolSize());
        out.println("Checkout timeout: " + datasource.getCheckoutTimeout());
        return sw.toString();
    }

    @Override
    public void invocationFinally() {
        DB.close();
    }

    private static boolean changed() {
        Properties p = Play.configuration;

        if ("mem".equals(p.getProperty("db"))) {
            p.put("db.driver", "org.hsqldb.jdbcDriver");
            p.put("db.url", "jdbc:hsqldb:mem:playembed");
            p.put("db.user", "sa");
            p.put("db.pass", "");
        }

        if ("fs".equals(p.getProperty("db"))) {
            p.put("db.driver", "org.hsqldb.jdbcDriver");
            p.put("db.url", "jdbc:hsqldb:file:" + (new File(Play.applicationPath, "db/db").getAbsolutePath()));
            p.put("db.user", "sa");
            p.put("db.pass", "");
        }

        if (p.getProperty("db", "").startsWith("java:")) {
            if (DB.datasource == null) {
                return true;
            }
        }

        Matcher m = new jregex.Pattern("^mysql:(({user}[\\w]+)(:({pwd}[\\w]+))?@)?({name}[\\w]+)$").matcher(p.getProperty("db", ""));
        if (m.matches()) {
            String user = m.group("user");
            String password = m.group("pwd");
            String name = m.group("name");
            p.put("db.driver", "com.mysql.jdbc.Driver");
            p.put("db.url", "jdbc:mysql://localhost/" + name + "?useUnicode=yes&characterEncoding=UTF-8&connectionCollation=utf8_general_ci");
            if (user != null) {
                p.put("db.user", user);
            }
            if (password != null) {
                p.put("db.pass", password);
            }
        }

        if ((p.getProperty("db.driver") == null) || (p.getProperty("db.url") == null)) {
            return false;
        }
        if (DB.datasource == null) {
            return true;
        } else {
            ComboPooledDataSource ds = (ComboPooledDataSource) DB.datasource;
            if (!p.getProperty("db.driver").equals(ds.getDriverClass())) {
                return true;
            }
            if (!p.getProperty("db.url").equals(ds.getJdbcUrl())) {
                return true;
            }
            if (!p.getProperty("db.user", "").equals(ds.getUser())) {
                return true;
            }
            if (!p.getProperty("db.pass", "").equals(ds.getPassword())) {
                return true;
            }
        }
        return false;
    }

    /**
     * Needed because DriverManager will not load a driver ouside of the system classloader
     */
    public static class ProxyDriver implements Driver {

        private Driver driver;

        ProxyDriver(Driver d) {
            this.driver = d;
        }

        public boolean acceptsURL(String u) throws SQLException {
            return this.driver.acceptsURL(u);
        }

        public Connection connect(String u, Properties p) throws SQLException {
            return this.driver.connect(u, p);
        }

        public int getMajorVersion() {
            return this.driver.getMajorVersion();
        }

        public int getMinorVersion() {
            return this.driver.getMinorVersion();
        }

        public DriverPropertyInfo[] getPropertyInfo(String u, Properties p) throws SQLException {
            return this.driver.getPropertyInfo(u, p);
        }

        public boolean jdbcCompliant() {
            return this.driver.jdbcCompliant();
        }
    }
}