/**

 * 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.formatting.ColumnsHeader;

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.InputStreamReader;

import java.io.PrintStream;

import java.sql.SQLException;

import java.util.ArrayList;

import java.util.EnumSet;

import java.util.List;

import java.util.logging.Level;

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());

	private PrintStream out;

	private ConfigurationProvider configurationProvider;

	private 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();

		for (InfoType infoType : commands) {

			switch (infoType) {

				// only these need formatted output

				case CONNECTION:

				case DATABASES:

				case FORMATTERS:

				case TYPES:

					formatter = getFormatter();

					formatter.writeStartBatch();

					formatter.writeStartDatabase(new DatabaseDefinition());

			}

		}

		for (InfoType infoType : commands) {

			infoType.showInfo(this);

		}

		if (formatter != null) {

			formatter.writeEndDatabase();

			formatter.writeEndBatch();

		}

	}

	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));

		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()});

		}

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

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

		}

		printTable(formatter, header, data);

	}

	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);

	}

	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, data);

	}

	public void testConnection() throws FormatterException, ConfigurationException {

		ColumnsHeader header = constructHeader(

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

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

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

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

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

			data.add(testConnection(dbName));

		}

		printTable(formatter, header, data);

	}

	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()) {

				succesfullyConnected = dc.test();

			}

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

		} catch (ConfigurationException | SQLException e) {

			log.log(Level.SEVERE, "Error during testing connection", 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, List<Object[]> data) throws ConfigurationException, FormatterException {

		formatter.writeStartResultSet();

		formatter.writeColumnsHeader(header);

		for (Object[] row : data) {

			formatter.writeStartRow();

			for (Object cell : row) {

				formatter.writeColumnValue(cell);

			}

			formatter.writeEndRow();

		}

		formatter.writeEndResultSet();

	}

	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);

		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);

			}

		},

		FORMATTERS {

			@Override

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

				infoLister.listFormatters();

			}

		},

		TYPES {

			@Override

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

				infoLister.listTypes();

			}

		},

		DATABASES {

			@Override

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

				infoLister.listDatabases();

			}

		},

		CONNECTION {

			@Override

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

				infoLister.testConnection();

			}

		};

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

	}

}