package br.gov.serpro.security;

import java.io.Serializable;
import java.security.Principal;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.UUID;

import br.gov.frameworkdemoiselle.security.TokenManager;

public class AppTokenManager implements TokenManager {

	private TokenStore store = new TokenStore();

	@Override
	public String persist(Principal user) throws Exception {
		String token = store.get(user);

		if (token == null) {
			token = store.put(user);
		}

		return token;
	}

	@Override
	public Principal load(String token) throws Exception {
		return store.get(token);
	}

	public static class TokenStore implements Serializable {

		private static final long serialVersionUID = 1L;

		private Map<String, Principal> map = Collections.synchronizedMap(new HashMap<String, Principal>());

		public String put(Principal user) {
			String token = UUID.randomUUID().toString();

			if (map.containsValue(user)) {
				map.remove(token);
			}

			map.put(token, user);

			return token;
		}

		public String get(Principal user) {
			String result = null;

			if (map.containsValue(user)) {
				for (String key : map.keySet()) {
					if (map.get(key).equals(user)) {
						result = key;
						break;
					}
				}
			}

			return result;
		}

		public Principal get(String token) {
			return map.get(token);
		}
	}
}