/*
    * 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.java.google;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.SortedSet;
  
  import org.apache.commons.collections4.CollectionUtils;
  import org.apache.commons.lang3.tuple.Pair;
  import org.netbeans.api.annotations.common.CheckForNull;
  
  import com.google.common.collect.Range;
  import com.google.googlejavaformat.java.Formatter;
  import com.google.googlejavaformat.java.FormatterException;
  import com.google.googlejavaformat.java.ImportOrderer;
  import com.google.googlejavaformat.java.JavaFormatterOptions;
  import com.google.googlejavaformat.java.RemoveUnusedImports;
  
  import de.funfried.netbeans.plugins.external.formatter.exceptions.FormattingFailedException;
  
  /**
   * Delegation class to the Google formatter implementation.
   *
   * @author bahlef
   */
  public final class GoogleJavaFormatterWrapper {
  	/**
  	 * Package private Constructor for creating a new instance of {@link GoogleJavaFormatterWrapper}.
  	 */
  	GoogleJavaFormatterWrapper() {
  	}
  
  	/**
  	 * Formats the given {@code code} with the given configurations and returns
  	 * the formatted code.
  	 *
  	 * @param code the unformatted code
  	 * @param codeStyle the code {@link JavaFormatterOptions.Style} to use,
  	 *        if {@code null} the {@link JavaFormatterOptions.Style#GOOGLE}
  	 *        style will be used
  	 * @param changedElements a {@link SortedSet} containing ranges as {@link Pair}
  	 *        objects defining the offsets which should be formatted
  	 *
  	 * @return the formatted code
  	 *
  	 * @throws FormattingFailedException if the external formatter failed to format the given code
  	 */
  	@CheckForNull
  	public String format(String code, JavaFormatterOptions.Style codeStyle, SortedSet<Pair<Integer, Integer>> changedElements)
  			throws FormattingFailedException {
  		if (code == null) {
  			return null;
  		}
  
  		if (codeStyle == null) {
  			codeStyle = JavaFormatterOptions.Style.GOOGLE;
  		}
  
  		Collection<Range<Integer>> characterRanges = new ArrayList<>();
  		if (changedElements == null) {
  			characterRanges.add(Range.closedOpen(0, code.length()));
  		} else if (!CollectionUtils.isEmpty(changedElements)) { // empty changed elements means nothing's left which can be formatted due to guarded sections
  			for (Pair<Integer, Integer> changedElement : changedElements) {
  				int start = changedElement.getLeft();
  				int end = changedElement.getRight();
  
  				if (start == end) {
  					end++;
  				}
  
  				characterRanges.add(Range.open(start, end));
  			}
  		}
  
  		if (changedElements == null || !CollectionUtils.isEmpty(changedElements)) {
  			try {
  				Formatter formatter = new Formatter(JavaFormatterOptions.builder().style(codeStyle).build());
  				code = formatter.formatSource(code, characterRanges);
  			} catch (FormatterException ex) {
  				throw new FormattingFailedException(ex);
  			}
  		}
  
  		return code;
  	}
  
  	@CheckForNull
  	public String organizeImports(String code, JavaFormatterOptions.Style codeStyle) throws FormattingFailedException {
  		if (code == null) {
  			return null;
  		}
 
 		if (codeStyle == null) {
 			codeStyle = JavaFormatterOptions.Style.GOOGLE;
 		}
 
 		try {
 			code = RemoveUnusedImports.removeUnusedImports(code);
 		} catch (FormatterException ex) {
 			throw new FormattingFailedException(ex);
 		}
 
 		try {
 			code = ImportOrderer.reorderImports(code, codeStyle);
 		} catch (FormatterException ex) {
 			throw new FormattingFailedException(ex);
 		}
 
 		return code;
 	}
 }