Adding test for PropertyExtractorExecutor.

[ifi-stolz-refaktor.git] / software / no.uio.ifi.refaktor / src / no / uio / ifi / refaktor / extractors / LongestCommonPrefixExtractor.java

package no.uio.ifi.refaktor.extractors;

import no.uio.ifi.refaktor.utils.ParseUtils;
import no.uio.ifi.refaktor.utils.SmartTextSelection;

import org.eclipse.jdt.core.dom.QualifiedName;

public class LongestCommonPrefixExtractor extends PropertyExtractor {
	
	protected String property;

	public LongestCommonPrefixExtractor(SmartTextSelection selection) {
		super(selection);
	}
	
	//TODO: what about simple names?

	@Override
	public boolean visit(QualifiedName node) {
		if (!nodeInSelection(node))
			return false;
		
		String nodeText = ParseUtils.getNodeText(node, getSelection().getDocument()).trim();
		
		if (property == null) {
			property = nodeText;
		} else {
			property = longestCommonPrefix(property, nodeText);
		}
		return false;
	}

	private String longestCommonPrefix(String attribute, String nodeText) {
		String commonPrefix = attribute.substring(0, numberOfCommonCharacters(attribute, nodeText));
		if (commonPrefix.endsWith(".")) {
			return stripLastChar(commonPrefix);
		}
		return commonPrefix;
	}

	private String stripLastChar(String commonPrefix) {
		return commonPrefix.substring(0, commonPrefix.length() - 1);
	}

	private int numberOfCommonCharacters(String attribute, String nodeText) {
		int charCount = 0;
		while (belowStringLengths(charCount, attribute, nodeText) && charsMatchingAt(attribute, nodeText, charCount))
			charCount++;
		return charCount;
	}

	private boolean belowStringLengths(int index, String attribute, String nodeText) {
		return index < attribute.length() && index < nodeText.length();
	}
	
	private boolean charsMatchingAt(String attribute, String nodeText, int index) {
		return attribute.charAt(index) == nodeText.charAt(index);
	}

	public String stringProperty() {
		return property;
	}
}