package no.uio.ifi.refaktor.analyze;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.eclipse.jdt.core.dom.ASTNode;
import org.eclipse.jdt.core.dom.ASTVisitor;
import org.eclipse.jdt.core.dom.IBinding;
import org.eclipse.jdt.core.dom.IVariableBinding;
import org.eclipse.jdt.core.dom.SimpleName;

public class VariableBindingFinder extends ASTVisitor {
	private final String bindingKey;
	private final Pattern pattern;
	private final String keyGroupOne;
	private final String keyGroupTwo;
	private boolean bindingFound;
	private IVariableBinding variableBinding;

	public VariableBindingFinder(String bindingKey) {
		this.bindingKey = bindingKey;
		bindingFound = false;
		pattern = Pattern.compile("^([^$]+)\\$\\d+[$;](.+)$");

		Matcher bindingKeyMatcher = pattern.matcher(bindingKey);

		if (bindingKeyMatcher.matches()) {
			keyGroupOne = bindingKeyMatcher.group(1);
			keyGroupTwo = bindingKeyMatcher.group(2);
		} else {
			keyGroupOne = "";
			keyGroupTwo = "";
		}
	}

	@Override
	public boolean visit(SimpleName node) {
		IBinding binding = node.resolveBinding();

		if (!(binding instanceof IVariableBinding))
			return false;

		if (perfectMatch(binding) || bindingPartiallyMatchesOriginalKey(binding)) {
			variableBinding = (IVariableBinding) binding;
			bindingFound = true;
		}

		return false;
	}

	private boolean perfectMatch(IBinding binding) {
		return binding.getKey().equals(bindingKey);
	}

	private boolean bindingPartiallyMatchesOriginalKey(IBinding binding) {
		Matcher matcher = pattern.matcher(binding.getKey());
		return matcher.matches() && keyGroupOne.equals(matcher.group(1)) && keyGroupTwo.equals(matcher.group(2));
	}

	@Override
	public boolean preVisit2(ASTNode node) {
		return !bindingFound;
	}

	public IVariableBinding getVariableBinding() {
		return variableBinding;
	}
}