/*
    Android Asynchronous Http Client
    Copyright (c) 2011 James Smith <[email protected]>
    http://loopj.com

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

        http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
*/

package cn.rongcloud.im.server.network.http;

import android.content.Context;
import android.content.SharedPreferences;
import android.text.TextUtils;

import org.apache.http.client.CookieStore;
import org.apache.http.cookie.Cookie;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.concurrent.ConcurrentHashMap;

/**
 * A persistent cookie store which implements the Apache HttpClient {@link CookieStore} interface.
 * Cookies are stored and will persist on the user's device between application sessions since they
 * are serialized and stored in {@link SharedPreferences}. <p>&nbsp;</p> Instances of this class are
 * designed to be used with {@link AsyncHttpClient#setCookieStore}, but can also be used with a
 * regular old apache HttpClient/HttpContext if you prefer.
 */
public class PersistentCookieStore implements CookieStore {
    private static final String COOKIE_PREFS = "CookiePrefsFile";
    private static final String COOKIE_NAME_STORE = "names";
    private static final String COOKIE_NAME_PREFIX = "cookie_";

    private final ConcurrentHashMap<String, Cookie> cookies;
    private final SharedPreferences cookiePrefs;

    /**
     * Construct a persistent cookie store.
     *
     * @param context Context to attach cookie store to
     */
    public PersistentCookieStore(Context context) {
        cookiePrefs = context.getSharedPreferences(COOKIE_PREFS, 0);
        cookies = new ConcurrentHashMap<String, Cookie>();

        // Load any previously stored cookies into the store
        String storedCookieNames = cookiePrefs.getString(COOKIE_NAME_STORE, null);
        if (storedCookieNames != null) {
            String[] cookieNames = TextUtils.split(storedCookieNames, ",");
            for (String name : cookieNames) {
                String encodedCookie = cookiePrefs.getString(COOKIE_NAME_PREFIX + name, null);
                if (encodedCookie != null) {
                    Cookie decodedCookie = decodeCookie(encodedCookie);
                    if (decodedCookie != null) {
                        cookies.put(name, decodedCookie);
                    }
                }
            }

            // Clear out expired cookies
            clearExpired(new Date());
        }
    }

    @Override
    public void addCookie(Cookie cookie) {
        String name = cookie.getName() + cookie.getDomain();

        // Save cookie into local store, or remove if expired
        if (!cookie.isExpired(new Date())) {
            cookies.put(name, cookie);
        } else {
            cookies.remove(name);
        }

        // Save cookie into persistent store
        SharedPreferences.Editor prefsWriter = cookiePrefs.edit();
        prefsWriter.putString(COOKIE_NAME_STORE, TextUtils.join(",", cookies.keySet()));
        prefsWriter.putString(COOKIE_NAME_PREFIX + name, encodeCookie(new SerializableCookie(cookie)));
        prefsWriter.apply();
    }

    @Override
    public void clear() {
        // Clear cookies from persistent store
        SharedPreferences.Editor prefsWriter = cookiePrefs.edit();
        for (String name : cookies.keySet()) {
            prefsWriter.remove(COOKIE_NAME_PREFIX + name);
        }
        prefsWriter.remove(COOKIE_NAME_STORE);
        prefsWriter.apply();

        // Clear cookies from local store
        cookies.clear();
    }

    @Override
    public boolean clearExpired(Date date) {
        boolean clearedAny = false;
        SharedPreferences.Editor prefsWriter = cookiePrefs.edit();

        for (ConcurrentHashMap.Entry<String, Cookie> entry : cookies.entrySet()) {
            String name = entry.getKey();
            Cookie cookie = entry.getValue();
            if (cookie.isExpired(date)) {
                // Clear cookies from local store
                cookies.remove(name);

                // Clear cookies from persistent store
                prefsWriter.remove(COOKIE_NAME_PREFIX + name);

                // We've cleared at least one
                clearedAny = true;
            }
        }

        // Update names in persistent store
        if (clearedAny) {
            prefsWriter.putString(COOKIE_NAME_STORE, TextUtils.join(",", cookies.keySet()));
        }
        prefsWriter.apply();

        return clearedAny;
    }

    @Override
    public List<Cookie> getCookies() {
        return new ArrayList<Cookie>(cookies.values());
    }


    //
    // Cookie serialization/deserialization
    //

    protected String encodeCookie(SerializableCookie cookie) {
        ByteArrayOutputStream os = new ByteArrayOutputStream();
        try {
            ObjectOutputStream outputStream = new ObjectOutputStream(os);
            outputStream.writeObject(cookie);
        } catch (Exception e) {
            return null;
        }

        return byteArrayToHexString(os.toByteArray());
    }

    protected Cookie decodeCookie(String cookieStr) {
        byte[] bytes = hexStringToByteArray(cookieStr);
        ByteArrayInputStream is = new ByteArrayInputStream(bytes);
        Cookie cookie = null;
        try {
            ObjectInputStream ois = new ObjectInputStream(is);
            cookie = ((SerializableCookie) ois.readObject()).getCookie();
        } catch (Exception e) {
            e.printStackTrace();
        }

        return cookie;
    }

    // Using some super basic byte array <-> hex conversions so we don't have
    // to rely on any large Base64 libraries. Can be overridden if you like!
    protected String byteArrayToHexString(byte[] b) {
        StringBuilder sb = new StringBuilder(b.length * 2);
        for (byte element : b) {
            int v = element & 0xff;
            if (v < 16) {
                sb.append('0');
            }
            sb.append(Integer.toHexString(v));
        }
        return sb.toString().toUpperCase();
    }

    protected byte[] hexStringToByteArray(String s) {
        int len = s.length();
        byte[] data = new byte[len / 2];
        for (int i = 0; i < len; i += 2) {
            data[i / 2] = (byte) ((Character.digit(s.charAt(i), 16) << 4) + Character.digit(s.charAt(i + 1), 16));
        }
        return data;
    }
}