package org.javasimon.jdbcx4;

import java.io.PrintWriter;
import java.lang.reflect.Method;
import java.sql.SQLException;
import java.util.Properties;

import org.javasimon.jdbc4.SimonConnectionConfiguration;

/**
 * SimonCommonDataSource is parent for all three datasource implementation classes.
 * <p/>
 * It contains getters and setters for basic properties which all three datasource types
 * needs to implement.
 *
 * @author Radovan Sninsky
 * @author <a href="mailto:virgo47@gmail.com">Richard "Virgo" Richter</a>
 * @since 2.4
 */
public abstract class AbstractSimonDataSource {
        protected transient PrintWriter logWriter;
        protected SimonConnectionConfiguration configuration;
        private String user;
        private String password;
        private int loginTimeout;

        private String realDataSourceClassName;
        private String prefix;
        /**
         * Properties specific to the real datasource
         */
        private Properties properties;

        /**
         * Retrieves the log writer for this <code>DataSource</code> object.
         *
         * @return the log writer for this data source or null if logging is disabled
         * @throws java.sql.SQLException if a database access error occurs
         * @see javax.sql.DataSource#getLogWriter()
         * @see #setLogWriter(java.io.PrintWriter)
         */
        public final PrintWriter getLogWriter() throws SQLException {
                return logWriter;
        }

        /**
         * Sets the log writer for this <code>DataSource</code> object to the given <code>java.io.PrintWriter</code> object.
         *
         * @param out the new log writer; to disable logging, set to null
         * @throws java.sql.SQLException if a database access error occurs
         * @see javax.sql.DataSource#setLogWriter(java.io.PrintWriter)
         * @see #getLogWriter
         */
        public final void setLogWriter(PrintWriter out) throws SQLException {
                this.logWriter = out;
        }

        /**
         * Returns JDBC connection URL.
         *
         * @return JDBC connection URL
         */
        public final String getUrl() {
                return configuration == null ? null : configuration.getSimonUrl();
        }

        /**
         * Setter for URL property.
         *
         * @param url JDBC connection URL
         */
        public final void setUrl(String url) {
                this.configuration = new SimonConnectionConfiguration(url);
        }

        /**
         * Returns real JDBC connection URL.
         *
         * @return real JDBC connection URL
         */
        public final String getRealUrl() {
                return configuration == null ? null : configuration.getRealUrl();
        }

        /**
         * Returns database user to authenticate connection.
         *
         * @return database user
         */
        public final String getUser() {
                return user;
        }

        /**
         * Setter for user property.
         *
         * @param user database user
         */
        public final void setUser(String user) {
                this.user = user;
        }

        /**
         * Returns database password to authenticate connection.
         *
         * @return database password
         */
        public final String getPassword() {
                return password;
        }

        /**
         * Setter for password property.
         *
         * @param password database password
         */
        public final void setPassword(String password) {
                this.password = password;
        }

        /**
         * Sets the maximum time in seconds that this data source will wait
         * while attempting to connect to a database.  A value of zero
         * specifies that the timeout is the default system timeout
         * if there is one; otherwise, it specifies that there is no timeout.
         * When a {@code DataSource} object is created, the login timeout is
         * initially zero.
         *
         * @param seconds the data source login time limit
         * @throws java.sql.SQLException if a database access error occurs.
         * @see #getLoginTimeout
         */
        public final void setLoginTimeout(int seconds) throws SQLException {
                this.loginTimeout = seconds;
        }

        /**
         * Gets the maximum time in seconds that this data source can wait
         * while attempting to connect to a database.  A value of zero
         * means that the timeout is the default system timeout
         * if there is one; otherwise, it means that there is no timeout.
         * When a {@code DataSource} object is created, the login timeout is
         * initially zero.
         *
         * @return the data source login time limit
         * @throws java.sql.SQLException if a database access error occurs.
         * @see #setLoginTimeout
         */
        public final int getLoginTimeout() throws SQLException {
                return loginTimeout;
        }

        /**
         * Returns real datasource class name.
         *
         * @return real datasource class name
         */
        public final String getRealDataSourceClassName() {
                if ((realDataSourceClassName == null || realDataSourceClassName.isEmpty()) && (configuration != null)) {
                        realDataSourceClassName = doGetRealDataSourceClassName();
                }
                return realDataSourceClassName;
        }

        /**
         * Setter for realDataSourceClassName property.
         *
         * @param className class name of real datasource
         */
        public final void setRealDataSourceClassName(String className) {
                this.realDataSourceClassName = className;
        }

        /**
         * Instantiates the DataSource.
         *
         * @param dataSourceClass Expected DataSource class
         * @param <T> DataSource type
         * @return Create DataSource
         * @throws SQLException
         */
        protected final <T> T createDataSource(Class<T> dataSourceClass) throws SQLException {
                if (getRealDataSourceClassName() == null) {
                        throw new SQLException("Property realDataSourceClassName is not set");
                }
                try {
                        T ds = dataSourceClass.cast(Class.forName(realDataSourceClassName).newInstance());
                        for (Method m : ds.getClass().getMethods()) {
                                String methodName = m.getName();
                                if (methodName.startsWith("set") && m.getParameterTypes().length == 1) {
                                        final Object propertyValue;
                                        if (methodName.equals("setUser")) {
                                                propertyValue = getUser();
                                        } else if (methodName.equals("setPassword")) {
                                                propertyValue = getPassword();
                                        } else if (methodName.equalsIgnoreCase("setUrl")) {
                                                propertyValue = getRealUrl();
                                        } else if (methodName.equals("setLogWriter")) {
                                                propertyValue = getLogWriter();
                                        } else if (methodName.equals("setLoginTimeout")) {
                                                propertyValue = getLoginTimeout();
                                        } else {
                                                String propertyName = methodName.substring(3, 4).toLowerCase();
                                                if (methodName.length() > 4) {
                                                        propertyName += methodName.substring(4);
                                                }
                                                final Class<?> propertyType = m.getParameterTypes()[0];
                                                propertyValue = getPropertyAs(propertyName, propertyType);
                                        }
                                        if (propertyValue != null) {
                                                m.invoke(ds, propertyValue);
                                        }
                                }
                        }
                        return ds;

                } catch (Exception e) {
                        throw new SQLException(e);
                }
        }

        /**
         * Reads DataSource class name from configuration.
         */
        protected abstract String doGetRealDataSourceClassName();

        /**
         * Returns Simon prefix for constructing names of Simons.
         *
         * @return Simon prefix
         */
        public final String getPrefix() {
                if ((prefix == null || prefix.isEmpty()) && (configuration != null)) {
                        prefix = configuration.getPrefix();
                }
                return prefix;
        }

        /**
         * Sets Simon prefix for constructing names of Simons.
         *
         * @param prefix Simon prefix
         */
        public final void setPrefix(String prefix) {
                this.prefix = prefix;
        }

        /**
         * Get properties specific to the real datasource.
         *
         * @return Properties
         */
        public Properties getProperties() {
                return properties;
        }

        /**
         * Set properties specific to the real datasource.
         */
        public void setProperties(Properties properties) {
                this.properties = properties;
        }

        /**
         * Returns property from {@link #properties} and convert it to given type.
         *
         * @param <T> property type
         * @param propertyName property name
         * @param propertyType property type
         * @return property value
         */
        @SuppressWarnings("unchecked")
        private <T> T getPropertyAs(String propertyName, Class<T> propertyType) {
                final String sValue = properties == null ? null : properties.getProperty(propertyName);
                final T value;
                if (sValue == null) {
                        value = null;
                } else if (propertyType.equals(String.class)) {
                        value = propertyType.cast(sValue);
                } else if (propertyType.equals(Integer.class)) {
                        value = propertyType.cast(Integer.valueOf(sValue));
                } else if (propertyType.equals(int.class)) {
                        value = (T) Integer.valueOf(sValue);
                } else if (propertyType.equals(Long.class)) {
                        value = propertyType.cast(Long.valueOf(sValue));
                } else if (propertyType.equals(long.class)) {
                        value = (T) Long.valueOf(sValue);
                } else if (propertyType.equals(Boolean.class)) {
                        value = propertyType.cast(Boolean.valueOf(sValue));
                } else if (propertyType.equals(boolean.class)) {
                        value = (T) Boolean.valueOf(sValue);
                } else {
                        value = null;
                }
                return value;
        }
}