/*
    * Copyright (c) 2020 bahlef.
    * All rights reserved. This program and the accompanying materials
    * are made available under the terms of the Eclipse Public License v2.0
    * which accompanies this distribution, and is available at
    * http://www.eclipse.org/legal/epl-v20.html
    * Contributors:
    * bahlef - initial API and implementation and/or initial documentation
    */
  package de.funfried.netbeans.plugins.external.formatter.javascript.eclipse;
  
  import java.util.Map;
  import java.util.Objects;
  
  import org.apache.commons.lang3.tuple.Pair;
  import org.eclipse.jface.text.Document;
  import org.eclipse.jface.text.IDocument;
  import org.eclipse.text.edits.TextEdit;
  import org.eclipse.wst.jsdt.core.ToolFactory;
  import org.eclipse.wst.jsdt.core.formatter.CodeFormatter;
  import org.netbeans.api.annotations.common.CheckForNull;
  import org.netbeans.api.annotations.common.NonNull;
  
  import de.funfried.netbeans.plugins.external.formatter.exceptions.CannotLoadConfigurationException;
  import de.funfried.netbeans.plugins.external.formatter.exceptions.ConfigReadException;
  import de.funfried.netbeans.plugins.external.formatter.exceptions.FormattingFailedException;
  import de.funfried.netbeans.plugins.external.formatter.exceptions.ProfileNotFoundException;
  
  /**
   * Wrapper class to the Eclipse formatter implementation.
   *
   * @author bahlef
   */
  public final class EclipseJavascriptFormatterWrapper {
  	/** Use to specify the kind of the code snippet to format. */
  	private static final int FORMATTER_OPTS = CodeFormatter.K_JAVASCRIPT_UNIT;
  
  	/**
  	 * Package private Constructor for creating a new instance of {@link EclipseJavascriptFormatterWrapper}.
  	 */
  	EclipseJavascriptFormatterWrapper() {
  	}
  
  	/**
  	 * Formats the given {@code code} with the given configurations and returns
  	 * the formatted code.
  	 *
  	 * @param formatterFile the path to the formatter configuration file
  	 * @param formatterProfile the name of the formatter configuration profile
  	 * @param code the unformatted code
  	 * @param lineFeed the line feed to use for formatting
  	 * @param changedElement an optional range as a {@link Pair} object defining the offsets which should be formatted
  	 *
  	 * @return the formatted code
  	 *
  	 * @throws ConfigReadException if there is an issue parsing the formatter configuration
  	 * @throws ProfileNotFoundException if the given {@code profile} could not be found
  	 * @throws CannotLoadConfigurationException if there is any issue accessing or reading the formatter configuration
  	 * @throws FormattingFailedException if the external formatter failed to format the given code
  	 */
  	@CheckForNull
  	public String format(String formatterFile, String formatterProfile, String code, String lineFeed, Pair<Integer, Integer> changedElement)
  			throws ConfigReadException, ProfileNotFoundException, CannotLoadConfigurationException, FormattingFailedException {
  		if (code == null) {
  			return null;
  		}
  
  		Map<String, String> allConfig = EclipseFormatterConfig.parseConfig(formatterFile, formatterProfile);
  
  		CodeFormatter formatter = ToolFactory.createCodeFormatter(allConfig, ToolFactory.M_FORMAT_EXISTING);
  
  		int codeLength = code.length();
  
  		int offset = 0;
  		int length = codeLength;
  
  		if (changedElement != null && changedElement.getLeft() != null && changedElement.getRight() != null) {
  			offset = changedElement.getLeft();
  			if (offset < 0) {
  				offset = 0;
  			}
  
  			length = (changedElement.getRight() - changedElement.getLeft()) + 1;
  			if (length > codeLength) {
  				length = codeLength;
  			}
  		}
  
  		return format(formatter, code, offset, length, lineFeed);
  	}
  
  	/**
  	 * Formats the given {@code code} with the given configurations and returns
  	 * the formatted code.
  	 *
  	 * @param formatter the {@link CodeFormatter}
  	 * @param code the unformatted code
  	 * @param offset the offset where to start formatting the given code
  	 * @param length the length where to stop formatting the given code
 	 * @param lineFeed the line feed to use for formatting
 	 *
 	 * @return the formatted code
 	 *
 	 * @throws FormattingFailedException if the external formatter failed to format the given code
 	 */
 	@CheckForNull
 	private String format(@NonNull CodeFormatter formatter, @NonNull String code, int offset, int length, String lineFeed) throws FormattingFailedException {
 		String formattedCode = null;
 
 		try {
 			TextEdit te = formatter.format(FORMATTER_OPTS, code, offset, length, 0, lineFeed);
 			if (te != null && te.getChildrenSize() > 0) {
 				IDocument dc = new Document(code);
 				te.apply(dc);
 
 				formattedCode = dc.get();
 
 				if (Objects.equals(code, formattedCode)) {
 					return null;
 				}
 			}
 		} catch (FormattingFailedException | IllegalArgumentException ex) {
 			throw ex;
 		} catch (Exception ex) {
 			throw new FormattingFailedException(ex);
 		}
 
 		return formattedCode;
 	}
 }