package com.ustc.dystu.dandelion.atk;

import android.content.Context;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;

import com.sina.weibo.sdk.auth.Oauth2AccessToken;

/**
 * ���ඨ����΢����Ȩʱ����Ҫ�IJ�����
 * 
 * @author SINA
 * @since 2013-10-07
 */
public class AccessTokenKeeper {
    private static final String PREFERENCES_NAME = "com_weibo_sdk_android";

    private static final String KEY_UID           = "uid";
    private static final String KEY_ACCESS_TOKEN  = "access_token";
    private static final String KEY_EXPIRES_IN    = "expires_in";
    
    /**
     * ���� Token ���� SharedPreferences��
     * 
     * @param context Ӧ�ó��������Ļ���
     * @param token   Token ����
     */
    public static void writeAccessToken(Context context, Oauth2AccessToken token) {
        if (null == context || null == token) {
            return;
        }
        
        SharedPreferences pref = context.getSharedPreferences(PREFERENCES_NAME, Context.MODE_APPEND);
        Editor editor = pref.edit();
        editor.putString(KEY_UID, token.getUid());
        editor.putString(KEY_ACCESS_TOKEN, token.getToken());
        editor.putLong(KEY_EXPIRES_IN, token.getExpiresTime());
        editor.commit();
    }

    /**
     * �� SharedPreferences ��ȡ Token ��Ϣ��
     * 
     * @param context Ӧ�ó��������Ļ���
     * 
     * @return ���� Token ����
     */
    public static Oauth2AccessToken readAccessToken(Context context) {
        if (null == context) {
            return null;
        }
        
        Oauth2AccessToken token = new Oauth2AccessToken();
        SharedPreferences pref = context.getSharedPreferences(PREFERENCES_NAME, Context.MODE_APPEND);
        token.setUid(pref.getString(KEY_UID, ""));
        token.setToken(pref.getString(KEY_ACCESS_TOKEN, ""));
        token.setExpiresTime(pref.getLong(KEY_EXPIRES_IN, 0));
        return token;
    }

    /**
     * ��� SharedPreferences �� Token��Ϣ��
     * 
     * @param context Ӧ�ó��������Ļ���
     */
    public static void clear(Context context) {
        if (null == context) {
            return;
        }
        
        SharedPreferences pref = context.getSharedPreferences(PREFERENCES_NAME, Context.MODE_APPEND);
        Editor editor = pref.edit();
        editor.clear();
        editor.commit();
    }
}