/*******************************************************************************
 * Copyright (c) 2011, 2014 Sierra Wireless and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Sierra Wireless - initial API and implementation
 *******************************************************************************/
package org.eclipse.ldt.ui.internal.editor.formatter;

import java.util.Map;

import org.eclipse.core.resources.IProject;
import org.eclipse.dltk.formatter.AbstractScriptFormatter;
import org.eclipse.dltk.ui.formatter.FormatterException;
import org.eclipse.dltk.ui.formatter.IScriptFormatterExtension;
import org.eclipse.dltk.ui.text.util.TabStyle;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.Document;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IRegion;
import org.eclipse.ldt.core.grammar.IGrammar;
import org.eclipse.ldt.core.grammar.ILuaSourceValidator;
import org.eclipse.ldt.core.internal.formatter.LuaFormatterException;
import org.eclipse.ldt.core.internal.formatter.LuaFormatterModule;
import org.eclipse.ldt.core.internal.grammar.LuaGrammarManager;
import org.eclipse.ldt.ui.internal.Activator;
import org.eclipse.swt.widgets.Display;
import org.eclipse.text.edits.ReplaceEdit;
import org.eclipse.text.edits.TextEdit;

public class LuaFormatter extends AbstractScriptFormatter implements IScriptFormatterExtension {
	static final String ID = "org.eclipse.ldt.formatter"; //$NON-NLS-1$
	private final TabStyle tabPolicy;
	private final int tabSize;
	private final int indentationSize;
	private final String delimiter;
	private final String tabulation;
	private final boolean formatTableValues;
	private IProject project;

	private static final LuaFormatterModule LUA_FORMAT_MODULE = new LuaFormatterModule();

	protected LuaFormatter(final String lineDelimiter, final Map<String, String> preferences) {
		super(preferences);
		delimiter = lineDelimiter;
		/*
		 * Get formatting constants from preferences
		 */
		tabPolicy = TabStyle.forName(preferences.get(LuaFormatterPreferenceConstants.FORMATTER_TAB_CHAR));
		String string = preferences.get(LuaFormatterPreferenceConstants.FORMATTER_TAB_SIZE);
		tabSize = (string == null || string.isEmpty()) ? 0 : Integer.parseInt(string);
		string = preferences.get(LuaFormatterPreferenceConstants.FORMATTER_INDENTATION_SIZE);
		indentationSize = (string == null || string.isEmpty()) ? 0 : Integer.parseInt(string);
		string = preferences.get(LuaFormatterPreferenceConstants.FORMATTER_INDENT_TABLE_VALUES);
		formatTableValues = (string == null || string.isEmpty()) ? false : Boolean.parseBoolean(string);

		/*
		 * Build separator character
		 */
		// Concatenate spaces
		if (tabPolicy == TabStyle.SPACES) {
			final char space = ' ';
			// Create tabulation
			final StringBuilder sb = new StringBuilder(tabSize);
			for (int k = 0; k < tabSize; k++) {
				sb.append(space);
			}
			tabulation = sb.toString();
		} else {
			// Use single tabulation
			tabulation = "\t"; //$NON-NLS-1$
		}
	}

	private ILuaSourceValidator getValidator() {
		// Get grammar
		IGrammar grammar = LuaGrammarManager.getDefaultGrammarFor(project);
		if (grammar != null)
			return grammar.getValidator();
		return null;
	}

	/**
	 * @see org.eclipse.dltk.ui.formatter.IScriptFormatter#format(String, int, int, int)
	 */
	@Override
	public TextEdit format(final String source, final int offset, final int length, final int indentationLevel) throws FormatterException {

		// valid lua code
		ILuaSourceValidator validator = getValidator();
		if (validator != null) {
			boolean valid = validator.valid(source);
			if (!valid) {
				throw new FormatterException("can not format file with error :" + validator.getErrorMessage()); //$NON-NLS-1$
			}
		}

		/*
		 * Format given source code
		 */
		final String formatted;
		try {
			// With mixed white spaces
			if (tabPolicy == TabStyle.MIXED) {
				formatted = LUA_FORMAT_MODULE.indent(source, delimiter, formatTableValues, tabSize, indentationSize);
			} else {
				// With one type of tabulation
				formatted = LUA_FORMAT_MODULE.indent(source, delimiter, formatTableValues, tabulation);
			}
		} catch (final LuaFormatterException e) {
			// TODO Show this to user
			throw new FormatterException(e);

		}

		if (length < source.length()) {
			final Document doc = new Document(source);
			try {
				// Get line change range form original source
				final int startLine = doc.getLineOfOffset(offset);
				final int endLine = doc.getLineOfOffset(offset + length);

				/*
				 * Get source code from those lines in formatted code
				 */
				final StringBuffer code = new StringBuffer();
				final Document formattedDoc = new Document(formatted);
				int lengthToReplace = 0;
				for (int line = startLine; line <= endLine; line++) {
					// Sum selected text length
					lengthToReplace += doc.getLineLength(line);

					// Retrieve formatted code
					final IRegion lineDescription = formattedDoc.getLineInformation(line);
					final String codeOnTheLine = formattedDoc.get(lineDescription.getOffset(), lineDescription.getLength());
					code.append(codeOnTheLine);

					// Append new line when needed
					final String lineEnd = formattedDoc.getLineDelimiter(line);
					if (lineEnd != null) {
						code.append(lineEnd);
					}
				}
				final int selectionStartOffset = doc.getLineOffset(startLine);
				return new ReplaceEdit(selectionStartOffset, lengthToReplace, code.toString());
			} catch (final BadLocationException e) {
				MessageDialog.openError(Display.getDefault().getActiveShell(), Messages.LuaFormatterErrorWhileFormattingTitle,
						Messages.LuaFormatterUnableToFormatSelection);
				Activator.logError(Messages.LuaFormatterUnableToFormatSelection, e);
			}
		} else if (source.equals(formatted)) {
			// If no modification have be done on the source code when formatting,
			// avoid the editor to be dirty/stale mode by returning null
			return null;
		}
		// Construct text edition
		return new ReplaceEdit(offset, length, formatted);
	}

	@Override
	public int detectIndentationLevel(final IDocument document, final int offset) {
		return 0;
	}

	/**
	 * @see org.eclipse.dltk.ui.formatter.IScriptFormatterExtension#initialize(org.eclipse.core.resources.IProject)
	 */
	@Override
	public void initialize(IProject p) {
		project = p;
	}
}