/**

 * 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.formatting;

import info.globalcode.sql.dk.Parameter;

import info.globalcode.sql.dk.Xmlns;

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

import static info.globalcode.sql.dk.Functions.notNull;

import info.globalcode.sql.dk.NamedParameter;

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

import java.sql.Array;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.SQLXML;

import java.sql.Types;

import java.util.ArrayList;

import java.util.Collections;

import java.util.HashMap;

import java.util.LinkedHashMap;

import java.util.List;

import java.util.Map;

import java.util.logging.Level;

import java.util.logging.Logger;

import javax.xml.namespace.QName;

/**

 * <p>

 * Prints machine-readable output – XML document containing resultsets and updates count. Good

 * choice for further processing – e.g. XSL transformation.</p>

 *

 * <p>

 * XML format is defined in the <a href="https://relational-pipes.globalcode.info/">Relational

 * pipes</a> specification.

 * </p>

 *

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

 */

@PropertyDeclaration(name = XmlFormatter.PROPERTY_LABELED_COLUMNS, defaultValue = "false", type = Boolean.class, description = "whether to add 'label' attribute to each 'column' element")

public class XmlFormatter extends AbstractXmlFormatter {

	private static final String XML_ELEMENT_RELATION = "relation";

	private static final String XML_ELEMENT_NAME = "name";

	private static final String XML_ELEMENT_RECORD = "record";

	private static final String XML_ELEMENT_ATTRIBUTE = "attribute";

	private static final String XML_ATTRIBUTE_NAME = "name";

	private static final String XML_ATTRIBUTE_TYPE = "type";

	private static final String XML_ATTRIBUTE_STATEMENT = "statement";

	private static final String XML_NS_PREFIX_SQLDK = "sql-dk";

	private static final String RELPIPE_TYPE_BOOLEAN = "boolean";

	private static final String RELPIPE_TYPE_INTEGER = "integer";

	private static final String RELPIPE_TYPE_STRING = "string";

	private static final Map<Integer, String> RELPIPE_TYPES;

	static {

		Map<Integer, String> m = new HashMap<>();

		m.put(Types.BOOLEAN, RELPIPE_TYPE_BOOLEAN);

		m.put(Types.BIT, RELPIPE_TYPE_BOOLEAN); // TODO: relpipe "boolean" can not be null in the current version

		// m.put(Types.INTEGER, RELPIPE_TYPE_INTEGER); // relpipe "integer" is unsigned

		// TODO: add more types when supported in Relational pipes

		m.put(Types.CHAR, RELPIPE_TYPE_STRING);

		m.put(Types.VARCHAR, RELPIPE_TYPE_STRING);

		RELPIPE_TYPES = Collections.unmodifiableMap(m);

	}

	public static final String NAME = "xml"; // bash-completion:formatter

	public static final String PROPERTY_LABELED_COLUMNS = "labeledColumns";

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

	private final boolean labeledColumns;

	private String currentDatabaseName;

	private int statementCounter;

	public XmlFormatter(FormatterContext formatterContext) {

		super(formatterContext);

		labeledColumns = formatterContext.getProperties().getBoolean(PROPERTY_LABELED_COLUMNS, false);

	}

	private QName qname(String localPart) {

		return new QName(Xmlns.RELPIPE, localPart);

	}

	private QName qnameDK(String localPart) {

		return new QName(Xmlns.SQLDK, localPart, XML_NS_PREFIX_SQLDK);

	}

	@Override

	public void writeStartBatch() {

		super.writeStartBatch();

		printStartDocument();

		Map<QName, String> attributes = new LinkedHashMap<>(2);

		attributes.put(qname("xmlns"), Xmlns.RELPIPE);

		attributes.put(new QName(null, XML_NS_PREFIX_SQLDK, "xmlns"), Xmlns.SQLDK);

		printStartElement(qname("relpipe"), attributes);

		statementCounter = 0;

	}

	@Override

	public void writeEndBatch() {

		super.writeEndBatch();

		printEndElement();

		printEndDocument();

	}

	@Override

	public void writeStartDatabase(DatabaseDefinition databaseDefinition) {

		super.writeStartDatabase(databaseDefinition);

		currentDatabaseName = databaseDefinition.getName();

		Map<QName, String> attributes = databaseDefinition.getName() == null ? null : singleAttribute(qname("name"), databaseDefinition.getName());

		printEmptyElement(qnameDK("database-start"), attributes);

	}

	@Override

	public void writeEndDatabase() {

		super.writeEndDatabase();

		Map<QName, String> attributes = currentDatabaseName == null ? null : singleAttribute(qname("name"), currentDatabaseName);

		printEmptyElement(qnameDK("database-end"), attributes);

	}

	private String getCurrentStatementName() {

		return "s" + statementCounter;

	}

	@Override

	public void writeStartStatement() {

		super.writeStartStatement();

		statementCounter++;

		printEmptyElement(qnameDK("statement-start"), singleAttribute(qname("id"), getCurrentStatementName()));

	}

	@Override

	public void writeEndStatement() {

		super.writeEndStatement();

		printEmptyElement(qnameDK("statement-end"), singleAttribute(qname("id"), getCurrentStatementName()));

	}

	@Override

	public void writeQuery(String sql) {

		super.writeQuery(sql);

		printTextElement(qnameDK("sql"), singleAttribute(qname(XML_ATTRIBUTE_STATEMENT), getCurrentStatementName()), sql);

	}

	@Override

	public void writeParameters(List<? extends Parameter> parameters) {

		super.writeParameters(parameters);

		if (parameters != null && parameters.size() > 0) {

			printStartElement(qnameDK("parameters"), singleAttribute(qname(XML_ATTRIBUTE_STATEMENT), getCurrentStatementName()));

			for (Parameter p : notNull(parameters)) {

				Map<QName, String> attributes = new LinkedHashMap<>(2);

				if (p instanceof NamedParameter) {

					attributes.put(qname(XML_ATTRIBUTE_NAME), ((NamedParameter) p).getName());

				}

				attributes.put(qname(XML_ATTRIBUTE_TYPE), p.getType().name());

				printTextElement(qnameDK("parameter"), attributes, String.valueOf(p.getValue()));

			}

			printEndElement();

		}

	}

	@Override

	public void writeStartResultSet(ColumnsHeader header) {

		super.writeStartResultSet(header);

		printStartElement(qname(XML_ELEMENT_RELATION), singleAttribute(qnameDK(XML_ATTRIBUTE_STATEMENT), getCurrentStatementName()));

		printTextElement(qname(XML_ELEMENT_NAME), null, getCurrentRelationName());

		printStartElement(qname("attributes-metadata"));

		for (ColumnDescriptor cd : header.getColumnDescriptors()) {

			Map<QName, String> attributes = new LinkedHashMap<>(6);

			attributes.put(qname(XML_ATTRIBUTE_NAME), cd.getLabel());

			attributes.put(qname(XML_ATTRIBUTE_TYPE), toRelpipeType(cd.getType()));

			attributes.put(qnameDK("tableName"), cd.getTableName());

			attributes.put(qnameDK("columnName"), cd.getName());

			attributes.put(qnameDK("jdbcTypeName"), cd.getTypeName());

			attributes.put(qnameDK("jdbcType"), String.valueOf(cd.getType()));

			printEmptyElement(qname("attribute-metadata"), attributes);

		}

		printEndElement();

	}

	/**

	 * @param jdbcType value from {@linkplain Types}

	 * @return

	 */

	private String toRelpipeType(int jdbcType) {

		return RELPIPE_TYPES.getOrDefault(jdbcType, RELPIPE_TYPE_STRING);

	}

	@Override

	public void writeEndResultSet() {

		super.writeEndResultSet();

		printEndElement();

	}

	@Override

	public void writeStartRow() {

		super.writeStartRow();

		printStartElement(qname(XML_ELEMENT_RECORD));

	}

	@Override

	public void writeColumnValue(Object value) {

		super.writeColumnValue(value);

		Map<QName, String> attributes = null;

		if (labeledColumns) {

			attributes = new LinkedHashMap<>(2);

			attributes.put(qname(XML_ATTRIBUTE_NAME), getCurrentColumnsHeader().getColumnDescriptors().get(getCurrentColumnsCount() - 1).getLabel());

			attributes.put(qname(XML_ATTRIBUTE_TYPE), toRelpipeType(getCurrentColumnsHeader().getColumnDescriptors().get(getCurrentColumnsCount() - 1).getType()));

		}

		if (value == null) {

			if (attributes == null) {

				attributes = new LinkedHashMap<>(2);

			}

			// TODO: synchronize syntax with Relational pipes (after adding support of null values)

			attributes.put(qnameDK("null"), "true");

			printEmptyElement(qname(XML_ELEMENT_ATTRIBUTE), attributes);

		} else if (value instanceof Array) {

			Array sqlArray = (Array) value;

			try {

				Object[] array = (Object[]) sqlArray.getArray();

				printStartElement(qname(XML_ELEMENT_ATTRIBUTE), attributes);

				printArray(array);

				printEndElement();

			} catch (SQLException e) {

				// FIXME: rewrite array formatting, remember array mode, don't try sqlArray.getArray() again and again if it has failed

				log.log(Level.SEVERE, "Unable to format array", e);

				try {

					ResultSet arrayResultSet = sqlArray.getResultSet();

					//int columnCount = arrayResultSet.getMetaData().getColumnCount();

					ArrayList<Object> arrayList = new ArrayList<>();

					while (arrayResultSet.next()) {

						arrayList.add(arrayResultSet.getObject(2));

						// for (int i = 1; i <= columnCount; i++) {

						// 	log.log(Level.INFO, "Array column {0} = {1}", new Object[]{i, arrayResultSet.getObject(i)});

						// }

					}

					printStartElement(qname(XML_ELEMENT_ATTRIBUTE), attributes);

					// FIXME: instanceof SQLXML, see below

					printArray(arrayList.toArray());

					printEndElement();

				} catch (SQLException e2) {

					// FIXME: fix logging, error recovery

					log.log(Level.SEVERE, "Second level fuck up !!!", e2);

				}

				writeColumnValue(String.valueOf(value));

			}

		} else if (value instanceof SQLXML) { // FIXME: move to separate method, to AbstractFormatter?

			SQLXML xml = (SQLXML) value;

			// TODO: parse DOM/SAX and transplant XML, don't escape (optional)

			try {

				printTextElement(qname(XML_ELEMENT_ATTRIBUTE), attributes, xml.getString());

			} catch (SQLException e) {

				log.log(Level.SEVERE, "Unable to format XML", e);

				writeColumnValue(String.valueOf(value));

			}

		} else {

			printTextElement(qname(XML_ELEMENT_ATTRIBUTE), attributes, toString(value));

		}

	}

	private void printArray(Object[] array) {

		// TODO: synchronize array syntax with Relational pipes

		printStartElement(qnameDK("array"));

		for (Object o : array) {

			if (o instanceof Object[]) {

				printStartElement(qnameDK("item"));

				printArray((Object[]) o);

				printEndElement();

			} else {

				printTextElement(qnameDK("item"), null, String.valueOf(o));

			}

		}

		printEndElement();

	}

	@Override

	public void writeEndRow() {

		super.writeEndRow();

		printEndElement();

	}

	@Override

	public void writeUpdatesResult(int updatedRowsCount) {

		super.writeUpdatesResult(updatedRowsCount);

		printTextElement(qnameDK("updatedRecords"), singleAttribute(qnameDK(XML_ATTRIBUTE_STATEMENT), getCurrentStatementName()), String.valueOf(updatedRowsCount));

	}

	protected String toString(Object value) {

		return String.valueOf(value);

	}

}