/**

 * SQL-DK

 * Copyright © 2014 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.formatting;

import info.globalcode.sql.dk.ColorfulPrintWriter;

import info.globalcode.sql.dk.Constants;

import java.util.Collections;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

/**

 * Outputs result sets in (La)TeX format.

 *

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

 */

public class TeXFormatter extends AbstractFormatter {

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

	public static final String PROPERTY_COLORFUL = "color";

	private static final ColorfulPrintWriter.TerminalColor COMMAND_COLOR = ColorfulPrintWriter.TerminalColor.Magenta;

	private static final ColorfulPrintWriter.TerminalColor OPTIONS_COLOR = ColorfulPrintWriter.TerminalColor.Yellow;

	private static final Map<Character, String> TEX_ESCAPE_MAP;

	private final ColorfulPrintWriter out;

	static {

		Map<Character, String> replacements = new HashMap<>();

		replacements.put('\\', "\\textbackslash{}");

		replacements.put('{', "\\{{}");

		replacements.put('}', "\\}{}");

		replacements.put('_', "\\_{}");

		replacements.put('^', "\\textasciicircum{}");

		replacements.put('#', "\\#{}");

		replacements.put('&', "\\&{}");

		replacements.put('$', "\\${}");

		replacements.put('%', "\\%{}");

		replacements.put('~', "\\textasciitilde{}");

		replacements.put('-', "{-}");

		TEX_ESCAPE_MAP = Collections.unmodifiableMap(replacements);

	}

	public TeXFormatter(FormatterContext formatterContext) {

		super(formatterContext);

		boolean colorful = formatterContext.getProperties().getBoolean(PROPERTY_COLORFUL, false);

		out = new ColorfulPrintWriter(formatterContext.getOutputStream(), false, colorful);

	}

	@Override

	public void writeStartBatch() {

		super.writeStartBatch();

		printCommand("documentclass", "a4paper,twoside", "article", true);

		printCommand("usepackage", "T1", "fontenc", true);

		printCommand("usepackage", "utf8x", "inputenc", true);

		printCommand("usepackage", "pdfauthor={" + Constants.WEBSITE + "}, bookmarks=true,unicode,colorlinks=true,linkcolor=black,urlcolor=blue,citecolor=blue", "hyperref", true);

		printBegin("document");

	}

	@Override

	public void writeEndBatch() {

		super.writeEndBatch();

		printEnd("document");

	}

	@Override

	public void writeColumnValue(Object value) {

		super.writeColumnValue(value);

		// TODO: arrays, numbers, booleans, nulls etc.:

		out.print(escapeTex(toString(value)));

		if (!isCurrentColumnLast()) {

			printColumnSeparator();

		}

	}

	@Override

	public void writeEndRow() {

		super.writeEndRow();

		printEndRow();

	}

	@Override

	public void writeStartResultSet(ColumnsHeader header) {

		super.writeStartResultSet(header);

		printCommand("begin", null, "tabular", false);

		List<ColumnDescriptor> columnDescriptors = header.getColumnDescriptors();

		StringBuilder columnAlignments = new StringBuilder();

		for (ColumnDescriptor cd : columnDescriptors) {

			if (cd.isNumeric() || cd.isBoolean()) {

				columnAlignments.append('r');

			} else {

				columnAlignments.append('l');

			}

		}

		printCommand(null, null, columnAlignments.toString(), true);

		printCommand("hline", null, null, true);

		for (ColumnDescriptor cd : columnDescriptors) {

			printCommand("textbf", null, cd.getLabel(), false);

			if (cd.isLastColumn()) {

				printEndRow();

			} else {

				printColumnSeparator();

			}

		}

		printCommand("hline", null, null, true);

	}

	@Override

	public void writeEndResultSet() {

		super.writeEndResultSet();

		printCommand("hline", null, null, true);

		printEnd("tabular");

	}

	private String escapeTex(String text) {

		if (text == null) {

			return null;

		} else {

			StringBuilder result = new StringBuilder(text.length() * 2);

			for (char ch : text.toCharArray()) {

				String replacement = TEX_ESCAPE_MAP.get(ch);

				result.append(replacement == null ? ch : replacement);

			}

			return result.toString();

		}

	}

	protected String toString(Object value) {

		return String.valueOf(value);

	}

	private void printColumnSeparator() {

		out.print(COMMAND_COLOR, " & ");

	}

	private void printEndRow() {

		out.println(COMMAND_COLOR, " \\\\");

		out.flush();

	}

	/**

	 *

	 * @param command will not be escaped – should contain just a valid TeX command name

	 * @param options will not be escaped – should be properly formatted to be printed inside [

	 * and ]

	 * @param value will be escaped

	 * @param println whether to print line end and flush

	 */

	private void printCommand(String command, String options, String value, boolean println) {

		if (command != null) {

			out.print(COMMAND_COLOR, "\\" + command);

		}

		if (options != null) {

			out.print(COMMAND_COLOR, "[");

			out.print(OPTIONS_COLOR, options);

			out.print(COMMAND_COLOR, "]");

		}

		if (value != null) {

			out.print(COMMAND_COLOR, "{");

			out.print(escapeTex(value));

			out.print(COMMAND_COLOR, "}");

		}

		if (println) {

			out.println();

			out.flush();

		}

	}

	private void printBegin(String environment) {

		printCommand("begin", null, environment, true);

	}

	private void printEnd(String environment) {

		printCommand("end", null, environment, true);

	}

}