/**
 * 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, version 3 of the License.
 *
 * 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.ConfigurationProvider;
import info.globalcode.sql.dk.CLIOptions.MODE;
import info.globalcode.sql.dk.batch.Batch;
import info.globalcode.sql.dk.batch.BatchDecoder;
import info.globalcode.sql.dk.batch.BatchException;
import info.globalcode.sql.dk.batch.BatchEncoder;
import info.globalcode.sql.dk.configuration.Configuration;
import info.globalcode.sql.dk.configuration.ConfigurationException;
import info.globalcode.sql.dk.configuration.DatabaseDefinition;
import info.globalcode.sql.dk.configuration.FormatterDefinition;
import info.globalcode.sql.dk.configuration.Loader;
import info.globalcode.sql.dk.configuration.NameIdentified;
import info.globalcode.sql.dk.configuration.PropertyDeclaration;
import info.globalcode.sql.dk.formatting.Formatter;
import info.globalcode.sql.dk.formatting.FormatterContext;
import info.globalcode.sql.dk.formatting.FormatterException;
import info.globalcode.sql.dk.jmx.ConnectionManagement;
import info.globalcode.sql.dk.jmx.ManagementUtils;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.PrintStream;
import java.io.PrintWriter;
import java.sql.SQLException;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.LogRecord;
import java.util.logging.Logger;

/**
 * Entry point of the command line interface of SQL-DK.
 *
 * @author Ing. František Kučera (frantovo.cz)
 */
public class CLIStarter implements ConfigurationProvider {

	// help:exit-codes
	public static final int EXIT_SUCCESS = 0; // doc:success
	public static final int EXIT_UNEXPECTED_ERROR = 1; // doc:unexpected error (probably bug)
	// 2 is reserved: http://www.tldp.org/LDP/abs/html/exitcodes.html#EXITCODESREF
	public static final int EXIT_SQL_ERROR = 3; // doc:SQL error
	public static final int EXIT_CLI_PARSE_ERROR = 4; // doc:CLI options parse error
	public static final int EXIT_CLI_VALIDATE_ERROR = 5; // doc:CLI options validation error
	public static final int EXIT_CONFIGURATION_ERROR = 6; // doc:configuration error
	public static final int EXIT_FORMATTING_ERROR = 7; // doc:formatting error
	public static final int EXIT_BATCH_ERROR = 8; // doc:batch error
	private static final Logger log = Logger.getLogger(CLIStarter.class.getName());
	private final CLIOptions options;
	private final Loader configurationLoader = new Loader();
	private Configuration configuration;

	public static void main(String[] args) {
		log.log(Level.FINE, "Starting " + Constants.PROGRAM_NAME);
		int exitCode;

		if (args.length == 0) {
			args = new String[]{CLIParser.Tokens.INFO_HELP};
		}

		try {
			CLIParser parser = new CLIParser();
			CLIOptions options = parser.parseOptions(args, System.in);
			options.validate();
			CLIStarter starter = new CLIStarter(options);
			starter.installDefaultConfiguration();
			starter.process();
			log.log(Level.FINE, "All done");
			exitCode = EXIT_SUCCESS;
		} catch (CLIParserException e) {
			log.log(Level.SEVERE, "Unable to parse CLI options", e);
			exitCode = EXIT_CLI_PARSE_ERROR;
		} catch (InvalidOptionsException e) {
			log.log(Level.SEVERE, "Invalid CLI options", e);
			for (InvalidOptionsException.OptionProblem p : e.getProblems()) {
				LogRecord r = new LogRecord(Level.SEVERE, "Option problem: {0}");
				r.setThrown(p.getException());
				r.setParameters(new Object[]{p.getDescription()});
				log.log(r);
			}
			exitCode = EXIT_CLI_VALIDATE_ERROR;
		} catch (ConfigurationException e) {
			log.log(Level.SEVERE, "Configuration problem", e);
			exitCode = EXIT_CONFIGURATION_ERROR;
		} catch (SQLException e) {
			log.log(Level.SEVERE, "SQL problem", e);
			exitCode = EXIT_SQL_ERROR;
		} catch (FormatterException e) {
			log.log(Level.SEVERE, "Formatting problem", e);
			exitCode = EXIT_FORMATTING_ERROR;
		} catch (BatchException e) {
			log.log(Level.SEVERE, "Batch problem", e);
			exitCode = EXIT_BATCH_ERROR;
		}

		System.exit(exitCode);
	}

	public CLIStarter(CLIOptions options) {
		this.options = options;
	}

	private void process() throws ConfigurationException, SQLException, FormatterException, BatchException {
		MODE mode = options.getMode();

		/** Show info */
		if (!options.getShowInfo().isEmpty()) {
			PrintStream infoOut = mode == MODE.JUST_SHOW_INFO ? System.out : System.err;
			InfoLister infoLister = new InfoLister(infoOut, this, options);
			infoLister.showInfo();
		}

		switch (mode) {
			case QUERY_NOW:
				processQueryNow();
				break;
			case PREPARE_BATCH:
				processPrepareBatch();
				break;
			case EXECUTE_BATCH:
				processExecuteBatch();
				break;
			case JUST_SHOW_INFO:
				// already done above
				break;
			default:
				log.log(Level.SEVERE, "Unsupported mode: {0}", mode);
				break;
		}

		generateBashCompletion();
	}

	private void processQueryNow() throws ConfigurationException, SQLException, FormatterException {
		DatabaseDefinition dd = getConfiguration().getDatabase(options.getDatabaseName());
		FormatterDefinition fd = configuration.getFormatter(options.getFormatterName());
		ConnectionManagement jmxBean = ManagementUtils.registerMBean(dd.getName());

		try (DatabaseConnection c = dd.connect(options.getDatabaseProperties(), jmxBean)) {
			log.log(Level.FINE, "Database connected");
			try (Formatter f = fd.getInstance(new FormatterContext(options.getOutputStream(), options.getFormatterProperties(), options.getRelationNames()))) {
				c.executeQuery(options.getSQLCommand(), f);
			}
		}
	}

	private void processPrepareBatch() throws BatchException {
		BatchEncoder enc = new BatchEncoder();
		int length = enc.encode(options.getSQLCommand(), options.getOutputStream());
		log.log(Level.FINE, "Prepared batch size: {0} bytes", length);
	}

	private void processExecuteBatch() throws ConfigurationException, SQLException, FormatterException, BatchException {
		BatchDecoder dec = new BatchDecoder();
		Batch b = dec.decode(options.getInputStream());

		DatabaseDefinition dd = getConfiguration().getDatabase(options.getDatabaseName());
		FormatterDefinition fd = configuration.getFormatter(options.getFormatterName());
		ConnectionManagement jmxBean = ManagementUtils.registerMBean(dd.getName());

		try (DatabaseConnection c = dd.connect(options.getDatabaseProperties(), jmxBean)) {
			log.log(Level.FINE, "Database connected");
			try (Formatter f = fd.getInstance(new FormatterContext(options.getOutputStream(), options.getFormatterProperties(), options.getRelationNames()))) {
				c.executeBatch(b, f);
			}
		}
	}

	@Override
	public Configuration getConfiguration() throws ConfigurationException {
		if (configuration == null) {
			configuration = configurationLoader.loadConfiguration();
		}
		return configuration;
	}

	private void installDefaultConfiguration() throws ConfigurationException {
		Constants.DIR.mkdir();

		if (Constants.CONFIG_FILE.exists()) {
			log.log(Level.FINER, "Config file already exists: {0}", Constants.CONFIG_FILE);
		} else {
			try {
				Functions.installResource(Constants.EXAMPLE_CONFIG_FILE, Constants.CONFIG_FILE);
				log.log(Level.FINE, "Installing default config file: {0}", Constants.CONFIG_FILE);
			} catch (IOException e) {
				throw new ConfigurationException("Unable to write example configuration to " + Constants.CONFIG_FILE, e);
			}
		}
	}

	private void generateBashCompletion() {
		if (configuration == null) {
			log.log(Level.FINER, "Not writing Bash completion helper files. In order to generate these files please run some command which requires configuration.");
		} else {
			try {
				File dir = new File(Constants.DIR, "bash-completion");
				dir.mkdir();
				writeBashCompletionHelperFile(configuration.getDatabases(), new File(dir, "databases"));
				writeBashCompletionHelperFile(configuration.getAllFormatters(), new File(dir, "formatters"));
				writeBashCompletionHelperFileForFormatterProperties(new File(dir, "formatter-properties"));
			} catch (Exception e) {
				log.log(Level.WARNING, "Unable to generate Bash completion helper files", e);
			}
		}
	}

	private void writeBashCompletionHelperFile(Collection<? extends NameIdentified> items, File target) throws FileNotFoundException {
		if (Constants.CONFIG_FILE.lastModified() > target.lastModified()) {
			try (PrintWriter fw = new PrintWriter(target)) {
				for (NameIdentified dd : items) {
					fw.println(dd.getName());
				}
				fw.close();
				log.log(Level.FINE, "Bash completion helper file was written: {0}", target);
			}
		} else {
			log.log(Level.FINER, "Not writing Bash completion helper file: {0} because configuration {1} has not been changed", new Object[]{target, Constants.CONFIG_FILE});
		}
	}

	private void writeBashCompletionHelperFileForFormatterProperties(File formattersDir) throws ClassNotFoundException, FileNotFoundException {
		if (Constants.CONFIG_FILE.lastModified() > formattersDir.lastModified()) {
			// TODO: delete old directory
			formattersDir.mkdir();
			for (FormatterDefinition fd : configuration.getAllFormatters()) {
				File formatterDir = new File(formattersDir, fd.getName());
				formatterDir.mkdir();

				Class<Formatter> formatterClass = (Class<Formatter>) Class.forName(fd.getClassName());
				List<Class<? extends Formatter>> hierarchy = Functions.getClassHierarchy(formatterClass, Formatter.class);
				Collections.reverse(hierarchy);
				for (Class<? extends Formatter> c : hierarchy) {
					for (PropertyDeclaration p : Functions.getPropertyDeclarations(c)) {
						File propertyDir = new File(formatterDir, p.name());
						propertyDir.mkdir();
						File choicesFile = new File(propertyDir, "choices");
						try (PrintWriter fw = new PrintWriter(choicesFile)) {
							// TODO: refactor, move
							if (p.type() == Boolean.class) {
								fw.println("true");
								fw.println("false");
							}
						}
					}
				}
			}
			log.log(Level.FINE, "Bash completion helper files was written in: {0}", formattersDir);
		} else {
			log.log(Level.FINER, "Not writing Bash completion helper directory: {0} because configuration {1} has not been changed", new Object[]{formattersDir, Constants.CONFIG_FILE});
		}

	}
}