/**

 * 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.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.NameIdentified;

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

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

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

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.logging.Level;

import java.util.logging.LogRecord;

import java.util.logging.Logger;

import javax.xml.bind.JAXBContext;

import javax.xml.bind.Unmarshaller;

/**

 * 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 CLIOptions options;

	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());

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

			log.log(Level.FINE, "Database connected");

			try (Formatter f = fd.getInstance(new FormatterContext(options.getOutputStream(), options.getFormatterProperties()))) {

				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());

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

			log.log(Level.FINE, "Database connected");

			try (Formatter f = fd.getInstance(new FormatterContext(options.getOutputStream(), options.getFormatterProperties()))) {

				c.executeBatch(b, f);

			}

		}

	}

	@Override

	public Configuration getConfiguration() throws ConfigurationException {

		if (configuration == null) {

			configuration = 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 Configuration loadConfiguration() throws ConfigurationException {

		try {

			JAXBContext jaxb = JAXBContext.newInstance(Configuration.class);

			Unmarshaller u = jaxb.createUnmarshaller();

			return (Configuration) u.unmarshal(Constants.CONFIG_FILE);

		} catch (Exception e) {

			throw new ConfigurationException("Unable to load configuration from " + 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"));

			} 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});

		}

	}

}