/**

  * SQL-DK

  * Copyright © 2013 František Kučera (frantovo.cz)

  *

  * This program is free software: you can redistribute it and/or modify

  * it under the terms of the GNU General Public License as published by

  * the Free Software Foundation, either version 3 of the License, or

  * (at your option) any later version.

  *

  * This program is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

  * GNU General Public License for more details.

  *

  * You should have received a copy of the GNU General Public License

  * along with this program. If not, see <http://www.gnu.org/licenses/>.

  */

 package info.globalcode.sql.dk;

 import info.globalcode.sql.dk.configuration.Configuration;

 import info.globalcode.sql.dk.configuration.ConfigurationException;

 import info.globalcode.sql.dk.configuration.ConfigurationProvider;

 import info.globalcode.sql.dk.configuration.DatabaseDefinition;

 import info.globalcode.sql.dk.configuration.FormatterDefinition;

 import info.globalcode.sql.dk.configuration.Properties;

 import info.globalcode.sql.dk.configuration.Property;

 import info.globalcode.sql.dk.formatting.ColumnsHeader;

 import info.globalcode.sql.dk.formatting.FakeSqlArray;

 import info.globalcode.sql.dk.formatting.Formatter;

 import info.globalcode.sql.dk.formatting.FormatterContext;

 import info.globalcode.sql.dk.formatting.FormatterException;

 import java.io.BufferedReader;

 import java.io.ByteArrayOutputStream;

 import java.io.InputStreamReader;

 import java.io.PrintStream;

 import java.sql.Array;

 import java.sql.Driver;

 import java.sql.DriverManager;

 import java.sql.DriverPropertyInfo;

 import java.sql.SQLException;

 import java.util.ArrayList;

 import java.util.EnumSet;

 import java.util.HashSet;

 import java.util.List;

 import java.util.Map.Entry;

 import java.util.ServiceLoader;

 import java.util.Set;

 import java.util.concurrent.ExecutorService;

 import java.util.concurrent.Executors;

 import java.util.concurrent.TimeUnit;

 import java.util.logging.Level;

 import java.util.logging.LogRecord;

 import java.util.logging.Logger;

 import javax.sql.rowset.RowSetMetaDataImpl;

 /**

  * Displays info like help, version etc.

  *

  * @author Ing. František Kučera (frantovo.cz)

  */

 public class InfoLister {

 	private static final Logger log = Logger.getLogger(InfoLister.class.getName());

 	/**

 	 * Fake database name for output formatting

 	 */

 	public static final String CONFIG_DB_NAME = "sqldk_configuration";

 	private final PrintStream out;

 	private final ConfigurationProvider configurationProvider;

 	private final CLIOptions options;

 	private Formatter formatter;

 	public InfoLister(PrintStream out, ConfigurationProvider configurationProvider, CLIOptions options) {

 		this.out = out;

 		this.configurationProvider = configurationProvider;

 		this.options = options;

 	}

 	public void showInfo() throws ConfigurationException, FormatterException {

 		EnumSet<InfoType> commands = options.getShowInfo();

 		boolean formattinNeeded = false;

 		for (InfoType infoType : commands) {

 			switch (infoType) {

 				case CONNECTION:

 				case JDBC_DRIVERS:

 				case JDBC_PROPERTIES:

 				case DATABASES:

 				case FORMATTERS:

 				case TYPES:

 				case JAVA_PROPERTIES:

 				case ENVIRONMENT_VARIABLES:

 					formattinNeeded = true;

 					break;

 			}

 		}

 		if (formattinNeeded) {

 			try (Formatter f = getFormatter()) {

 				formatter = f;

 				formatter.writeStartBatch();

 				DatabaseDefinition dd = new DatabaseDefinition();

 				dd.setName(CONFIG_DB_NAME);

 				formatter.writeStartDatabase(dd);

 				showInfos(commands);

 				formatter.writeEndDatabase();

 				formatter.writeEndBatch();

 				formatter.close();

 			}

 		} else {

 			showInfos(commands);

 		}

 	}

 	private void showInfos(EnumSet<InfoType> commands) throws ConfigurationException, FormatterException {

 		for (InfoType infoType : commands) {

 			infoType.showInfo(this);

 		}

 	}

 	private void listJavaProperties() throws FormatterException, ConfigurationException {

 		ColumnsHeader header = constructHeader(new HeaderField("name", SQLType.VARCHAR), new HeaderField("value", SQLType.VARCHAR));

 		List<Object[]> data = new ArrayList<>();

 		for (Entry<Object, Object> e : System.getProperties().entrySet()) {

 			data.add(new Object[]{e.getKey(), e.getValue()});

 		}

 		printTable(formatter, header, "-- Java system properties", null, data);

 	}

 	private void listEnvironmentVariables() throws FormatterException, ConfigurationException {

 		ColumnsHeader header = constructHeader(new HeaderField("name", SQLType.VARCHAR), new HeaderField("value", SQLType.VARCHAR));

 		List<Object[]> data = new ArrayList<>();

 		for (Entry<String, String> e : System.getenv().entrySet()) {

 			data.add(new Object[]{e.getKey(), e.getValue()});

 		}

 		printTable(formatter, header, "-- environment variables", null, data);

 	}

 	private void listFormatters() throws ConfigurationException, FormatterException {

 		ColumnsHeader header = constructHeader(

 				new HeaderField("name", SQLType.VARCHAR),

 				new HeaderField("built_in", SQLType.BOOLEAN),

 				new HeaderField("default", SQLType.BOOLEAN),

 				new HeaderField("class_name", SQLType.VARCHAR),

 				new HeaderField("valid", SQLType.BOOLEAN));

 		List<Object[]> data = new ArrayList<>();

 		String defaultFormatter = configurationProvider.getConfiguration().getDefaultFormatter();

 		defaultFormatter = defaultFormatter == null ? Configuration.DEFAULT_FORMATTER : defaultFormatter;

 		for (FormatterDefinition fd : configurationProvider.getConfiguration().getBuildInFormatters()) {

 			data.add(new Object[]{fd.getName(), true, defaultFormatter.equals(fd.getName()), fd.getClassName(), isInstantiable(fd)});

 		}

 		for (FormatterDefinition fd : configurationProvider.getConfiguration().getFormatters()) {

 			data.add(new Object[]{fd.getName(), false, defaultFormatter.equals(fd.getName()), fd.getClassName(), isInstantiable(fd)});

 		}

 		printTable(formatter, header, "-- configured and built-in output formatters", null, data);

 	}

 	private boolean isInstantiable(FormatterDefinition fd) {

 		try {

 			try (ByteArrayOutputStream testStream = new ByteArrayOutputStream()) {

 				fd.getInstance(new FormatterContext(testStream, new Properties(0)));

 				return true;

 			}

 		} catch (Exception e) {

 			log.log(Level.SEVERE, "Unable to create an instance of formatter: " + fd.getName(), e);

 			return false;

 		}

 	}

 	public void listTypes() throws FormatterException, ConfigurationException {

 		ColumnsHeader header = constructHeader(new HeaderField("name", SQLType.VARCHAR), new HeaderField("code", SQLType.INTEGER));

 		List<Object[]> data = new ArrayList<>();

 		for (SQLType sqlType : SQLType.values()) {

 			data.add(new Object[]{sqlType.name(), sqlType.getCode()});

 		}

 		printTable(formatter, header, "-- data types", null, data);

 		log.log(Level.INFO, "Type names in --types option are case insensitive");

 	}

 	public void listDatabases() throws ConfigurationException, FormatterException {

 		ColumnsHeader header = constructHeader(

 				new HeaderField("database_name", SQLType.VARCHAR),

 				new HeaderField("user_name", SQLType.VARCHAR),

 				new HeaderField("database_url", SQLType.VARCHAR));

 		List<Object[]> data = new ArrayList<>();

 		final List<DatabaseDefinition> configuredDatabases = configurationProvider.getConfiguration().getDatabases();

 		if (configuredDatabases.isEmpty()) {

 			log.log(Level.WARNING, "No databases are configured.");

 		} else {

 			for (DatabaseDefinition dd : configuredDatabases) {

 				data.add(new Object[]{dd.getName(), dd.getUserName(), dd.getUrl()});

 			}

 		}

 		printTable(formatter, header, "-- configured databases", null, data);

 	}

 	public void listJdbcDrivers() throws FormatterException, ConfigurationException {

 		ColumnsHeader header = constructHeader(

 				new HeaderField("class", SQLType.VARCHAR),

 				new HeaderField("version", SQLType.VARCHAR),

 				new HeaderField("major", SQLType.INTEGER),

 				new HeaderField("minor", SQLType.INTEGER),

 				new HeaderField("jdbc_compliant", SQLType.BOOLEAN));

 		List<Object[]> data = new ArrayList<>();

 		final ServiceLoader<Driver> drivers = ServiceLoader.load(Driver.class);

 		for (Driver d : drivers) {

 			data.add(new Object[]{

 				d.getClass().getName(),

 				d.getMajorVersion() + "." + d.getMinorVersion(),

 				d.getMajorVersion(),

 				d.getMinorVersion(),

 				d.jdbcCompliant()

 			});

 		}

 		printTable(formatter, header, "-- discovered JDBC drivers (available on the CLASSPATH)", null, data);

 	}

 	public void listJdbcProperties() throws FormatterException, ConfigurationException {

 		for (String dbName : options.getDatabaseNamesToListProperties()) {

 			ColumnsHeader header = constructHeader(

 					new HeaderField("property_name", SQLType.VARCHAR),

 					new HeaderField("required", SQLType.BOOLEAN),

 					new HeaderField("choices", SQLType.ARRAY),

 					new HeaderField("configured_value", SQLType.VARCHAR),

 					new HeaderField("description", SQLType.VARCHAR));

 			List<Object[]> data = new ArrayList<>();

 			DatabaseDefinition dd = configurationProvider.getConfiguration().getDatabase(dbName);

 			Driver driver = findDriver(dd);

 			if (driver == null) {

 				log.log(Level.WARNING, "No JDBC driver was found for DB: {0} with URL: {1}", new Object[]{dd.getName(), dd.getUrl()});

 			} else {

 				log.log(Level.INFO, "For DB: {0} was found JDBC driver: {1}", new Object[]{dd.getName(), driver.getClass().getName()});

 				try {

 					DriverPropertyInfo[] propertyInfos = driver.getPropertyInfo(dd.getUrl(), dd.getProperties().getJavaProperties());

 					Set<String> standardProperties = new HashSet<>();

 					for (DriverPropertyInfo pi : propertyInfos) {

 						Array choices = new FakeSqlArray(pi.choices, SQLType.VARCHAR);

 						data.add(new Object[]{

 							pi.name,

 							pi.required,

 							choices.getArray() == null ? "" : choices,

 							pi.value == null ? "" : pi.value,

 							pi.description

 						});

 						standardProperties.add(pi.name);

 					}

 					for (Property p : dd.getProperties()) {

 						if (!standardProperties.contains(p.getName())) {

 							data.add(new Object[]{

 								p.getName(),

 								"",

 								"",

 								p.getValue(),

 								""

 							});

 							log.log(Level.WARNING, "Your configuration contains property „{0}“ not declared by the JDBC driver.", p.getName());

 						}

 					}

 				} catch (SQLException e) {

 					log.log(Level.WARNING, "Error during getting property infos.", e);

 				}

 				List<Parameter> parameters = new ArrayList<>();

 				parameters.add(new NamedParameter("database", dbName, SQLType.VARCHAR));

 				parameters.add(new NamedParameter("driver_class", driver.getClass().getName(), SQLType.VARCHAR));

 				parameters.add(new NamedParameter("driver_major_version", driver.getMajorVersion(), SQLType.INTEGER));

 				parameters.add(new NamedParameter("driver_minor_version", driver.getMinorVersion(), SQLType.INTEGER));

 				printTable(formatter, header, "-- configured and configurable JDBC driver properties", parameters, data);

 			}

 		}

 	}

 	private Driver findDriver(DatabaseDefinition dd) {

 		final ServiceLoader<Driver> drivers = ServiceLoader.load(Driver.class);

 		for (Driver d : drivers) {

 			try {

 				if (d.acceptsURL(dd.getUrl())) {

 					return d;

 				}

 			} catch (SQLException e) {

 				log.log(Level.WARNING, "Error during finding JDBC driver for: " + dd.getName(), e);

 			}

 		}

 		return null;

 	}

 	/**

 	 * Parallelism for connection testing – maximum concurrent database connections.

 	 */

 	private static final int TESTING_THREAD_COUNT = 64;

 	/**

 	 * Time limit for all connection testing threads – particular timeouts per connection will be

 	 * much smaller.

 	 */

 	private static final long TESTING_AWAIT_LIMIT = 1;

 	private static final TimeUnit TESTING_AWAIT_UNIT = TimeUnit.DAYS;

 	public void testConnections() throws FormatterException, ConfigurationException {

 		ColumnsHeader header = constructHeader(

 				new HeaderField("database_name", SQLType.VARCHAR),

 				new HeaderField("configured", SQLType.BOOLEAN),

 				new HeaderField("connected", SQLType.BOOLEAN));

 		log.log(Level.FINE, "Testing DB connections in {0} threads", TESTING_THREAD_COUNT);

 		ExecutorService es = Executors.newFixedThreadPool(TESTING_THREAD_COUNT);

 		final Formatter currentFormatter = formatter;

 		printHeader(currentFormatter, header, "-- database configuration and connectivity test", null);

 		for (final String dbName : options.getDatabaseNamesToTest()) {

 			preloadDriver(dbName);

 		}

 		for (final String dbName : options.getDatabaseNamesToTest()) {

 			es.submit(new Runnable() {

 				// TODO: Java 8 – lambda

 				@Override

 				public void run() {

 					final Object[] row = testConnection(dbName);

 					synchronized (currentFormatter) {

 						printRow(currentFormatter, row);

 					}

 				}

 			});

 		}

 		es.shutdown();

 		try {

 			log.log(Level.FINEST, "Waiting for test results: {0} {1}", new Object[]{TESTING_AWAIT_LIMIT, TESTING_AWAIT_UNIT.name()});

 			boolean finished = es.awaitTermination(TESTING_AWAIT_LIMIT, TESTING_AWAIT_UNIT);

 			if (finished) {

 				log.log(Level.FINEST, "All testing threads finished in time limit.");

 			} else {

 				throw new FormatterException("Exceeded total time limit for test threads – this should never happen");

 			}

 		} catch (InterruptedException e) {

 			throw new FormatterException("Interrupted while waiting for test results", e);

 		}

 		printFooter(currentFormatter);

 	}

 	/**

 	 * JDBC driver classes should be preloaded in single thread to avoid deadlocks while doing

 	 * {@linkplain DriverManager#registerDriver(java.sql.Driver)} during parallel connections.

 	 *

 	 * @param dbName

 	 */

 	private void preloadDriver(String dbName) {

 		try {

 			DatabaseDefinition dd = configurationProvider.getConfiguration().getDatabase(dbName);

 			Driver driver = findDriver(dd);

 			if (driver == null) {

 				log.log(Level.WARNING, "No Driver found for DB: {0}", dbName);

 			} else {

 				log.log(Level.FINEST, "Driver preloading for DB: {0} was successfull", dbName);

 			}

 		} catch (Exception e) {

 			LogRecord r = new LogRecord(Level.WARNING, "Failed to preload the Driver for DB: {0}");

 			r.setParameters(new Object[]{dbName});

 			r.setThrown(e);

 			log.log(r);

 		}

 	}

 	public Object[] testConnection(String dbName) {

 		log.log(Level.FINE, "Testing connection to database: {0}", dbName);

 		boolean succesfullyConnected = false;

 		boolean succesfullyConfigured = false;

 		try {

 			DatabaseDefinition dd = configurationProvider.getConfiguration().getDatabase(dbName);

 			log.log(Level.FINE, "Database definition was loaded from configuration");

 			succesfullyConfigured = true;

 			try (DatabaseConnection dc = dd.connect(options.getDatabaseProperties())) {

 				succesfullyConnected = dc.test();

 			}

 			log.log(Level.FINE, "Database connection test was successful");

 		} catch (ConfigurationException | SQLException | RuntimeException e) {

 			log.log(Level.SEVERE, "Error during testing connection " + dbName, e);

 		}

 		return new Object[]{dbName, succesfullyConfigured, succesfullyConnected};

 	}

 	public void printResource(String fileName) {

 		try (BufferedReader reader = new BufferedReader(new InputStreamReader(getClass().getClassLoader().getResourceAsStream(fileName)))) {

 			while (true) {

 				String line = reader.readLine();

 				if (line == null) {

 					break;

 				} else {

 					println(line);

 				}

 			}

 		} catch (Exception e) {

 			log.log(Level.SEVERE, "Unable to print this info. Please see our website for it: " + Constants.WEBSITE, e);

 		}

 	}

 	private void println(String line) {

 		out.println(line);

 	}

 	private void printTable(Formatter formatter, ColumnsHeader header, String sql, List<Parameter> parameters, List<Object[]> data) throws ConfigurationException, FormatterException {

 		printHeader(formatter, header, sql, parameters);

 		for (Object[] row : data) {

 			printRow(formatter, row);

 		}

 		printFooter(formatter);

 	}

 	private void printHeader(Formatter formatter, ColumnsHeader header, String sql, List<Parameter> parameters) {

 		formatter.writeStartStatement();

 		if (sql != null) {

 			formatter.writeQuery(sql);

 			if (parameters != null) {

 				formatter.writeParameters(parameters);

 			}

 		}

 		formatter.writeStartResultSet(header);

 	}

 	private void printRow(Formatter formatter, Object[] row) {

 		formatter.writeStartRow();

 		for (Object cell : row) {

 			formatter.writeColumnValue(cell);

 		}

 		formatter.writeEndRow();

 	}

 	private void printFooter(Formatter formatter) {

 		formatter.writeEndResultSet();

 		formatter.writeEndStatement();

 	}

 	private Formatter getFormatter() throws ConfigurationException, FormatterException {

 		String formatterName = options.getFormatterName();

 		formatterName = formatterName == null ? Configuration.DEFAULT_FORMATTER_PREFETCHING : formatterName;

 		FormatterDefinition fd = configurationProvider.getConfiguration().getFormatter(formatterName);

 		FormatterContext context = new FormatterContext(out, options.getFormatterProperties());

 		return fd.getInstance(context);

 	}

 	private ColumnsHeader constructHeader(HeaderField... fields) throws FormatterException {

 		try {

 			RowSetMetaDataImpl metaData = new RowSetMetaDataImpl();

 			metaData.setColumnCount(fields.length);

 			for (int i = 0; i < fields.length; i++) {

 				HeaderField hf = fields[i];

 				int sqlIndex = i + 1;

 				metaData.setColumnName(sqlIndex, hf.name);

 				metaData.setColumnLabel(sqlIndex, hf.name);

 				metaData.setColumnType(sqlIndex, hf.type.getCode());

 				metaData.setColumnTypeName(sqlIndex, hf.type.name());

 			}

 			return new ColumnsHeader(metaData);

 		} catch (SQLException e) {

 			throw new FormatterException("Error while constructing table headers", e);

 		}

 	}

 	private static class HeaderField {

 		String name;

 		SQLType type;

 		public HeaderField(String name, SQLType type) {

 			this.name = name;

 			this.type = type;

 		}

 	}

 	public enum InfoType {

 		HELP {

 					@Override

 					public void showInfo(InfoLister infoLister) {

 						infoLister.printResource(Constants.HELP_FILE);

 					}

 				},

 		VERSION {

 					@Override

 					public void showInfo(InfoLister infoLister) {

 						infoLister.printResource(Constants.VERSION_FILE);

 					}

 				},

 		LICENSE {

 					@Override

 					public void showInfo(InfoLister infoLister) {

 						infoLister.printResource(Constants.LICENSE_FILE);

 					}

 				},

 		JAVA_PROPERTIES {

 					@Override

 					public void showInfo(InfoLister infoLister) throws FormatterException, ConfigurationException {

 						infoLister.listJavaProperties();

 					}

 				},

 		ENVIRONMENT_VARIABLES {

 					@Override

 					public void showInfo(InfoLister infoLister) throws FormatterException, ConfigurationException {

 						infoLister.listEnvironmentVariables();

 					}

 				},

 		FORMATTERS {

 					@Override

 					public void showInfo(InfoLister infoLister) throws FormatterException, ConfigurationException {

 						infoLister.listFormatters();

 					}

 				},

 		TYPES {

 					@Override

 					public void showInfo(InfoLister infoLister) throws FormatterException, ConfigurationException {

 						infoLister.listTypes();

 					}

 				},

 		JDBC_DRIVERS {

 					@Override

 					public void showInfo(InfoLister infoLister) throws ConfigurationException, FormatterException {

 						infoLister.listJdbcDrivers();

 					}

 				},

 		JDBC_PROPERTIES {

 					@Override

 					public void showInfo(InfoLister infoLister) throws ConfigurationException, FormatterException {

 						infoLister.listJdbcProperties();

 					}

 				},

 		DATABASES {

 					@Override

 					public void showInfo(InfoLister infoLister) throws FormatterException, ConfigurationException {

 						infoLister.listDatabases();

 					}

 				},

 		CONNECTION {

 					@Override

 					public void showInfo(InfoLister infoLister) throws FormatterException, ConfigurationException {

 						infoLister.testConnections();

 					}

 				};

 		public abstract void showInfo(InfoLister infoLister) throws ConfigurationException, FormatterException;

 	}

 }