package com.xtremelabs.robolectric.shadows;

import java.util.Arrays;
import java.util.HashMap;
import java.util.List;

import android.content.UriMatcher;
import android.net.Uri;

import com.xtremelabs.robolectric.internal.Implementation;
import com.xtremelabs.robolectric.internal.Implements;

@Implements(UriMatcher.class)
public class ShadowUriMatcher {

	public static class MatchNode {
		public int code = UriMatcher.NO_MATCH;
		public HashMap<String, MatchNode> map = new HashMap<String, ShadowUriMatcher.MatchNode>();
		public MatchNode number;
		public MatchNode text;

		public MatchNode(int code) {
			this.code = code;
		}
	}

	public MatchNode rootNode;

	public void __constructor__(int code) {
		rootNode = new MatchNode(code);
	}

	@Implementation
	public void addURI(String authority, String path, int code) {
		MatchNode authNode = rootNode.map.get(authority);
		if (authNode == null) {
			authNode = new MatchNode(rootNode.code);
			rootNode.map.put(authority, authNode);
		}

		String[] segments = path.split("/");
		addNodes(authNode, Arrays.asList(segments), code);
	}

	@Implementation
	public int match(Uri uri) {
		String auth = uri.getAuthority();
		List<String> segments = uri.getPathSegments();

		if (!rootNode.map.containsKey(auth)) {
			return rootNode.code;
		}

		return matchSegments(rootNode.map.get(auth), segments);
	}

	private int matchSegments(MatchNode node, List<String> segments) {
		if (segments.isEmpty()) return node.code;
		String segment = segments.get(0);
		segments = segments.subList(1, segments.size());

		if (node.map.containsKey(segment)) {
			return matchSegments(node.map.get(segment), segments);
		}
		if (node.number != null) {
			long id;
			try {
				id = Long.parseLong(segment);
				if (id >= 0) {
					return matchSegments(node.number, segments);
				}
			}
			catch (NumberFormatException e) {}
		}
		if (node.text != null) {
			return matchSegments(node.text, segments);
		}

		return rootNode.code;
	}

	private void addNodes(MatchNode baseNode, List<String> segments, int code) {
		MatchNode nextNode = null;
		String segment = segments.get(0);

		if (segment.equals("#")) {
			nextNode = baseNode.number;
			if (nextNode == null) {
				nextNode = new MatchNode(rootNode.code);
				baseNode.number = nextNode;
			}
		}
		else if (segment.equals("*")) {
			nextNode = baseNode.text;
			if (nextNode == null) {
				nextNode = new MatchNode(rootNode.code);
				baseNode.text = nextNode;
			}
		}
		else {
			nextNode = baseNode.map.get(segment);
			if (nextNode == null) {
				nextNode = new MatchNode(rootNode.code);
				baseNode.map.put(segment, nextNode);
			}
		}

		if (segments.size() > 1) {
			addNodes(nextNode, segments.subList(1, segments.size()), code);
		}
		else {
			nextNode.code = code;
		}
	}

}