/*
 * Copyright (C) 2014 The Android Open Source Project
 *
 * 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 com.android.inputmethod.latin.accounts;

import android.accounts.AccountManager;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.preference.PreferenceManager;
import android.text.TextUtils;
import android.util.Log;

import com.android.inputmethod.annotations.UsedForTesting;
import com.android.inputmethod.latin.settings.LocalSettingsConstants;

/**
 * {@link BroadcastReceiver} for {@link AccountManager#LOGIN_ACCOUNTS_CHANGED_ACTION}.
 */
public class AccountsChangedReceiver extends BroadcastReceiver {
    static final String TAG = "AccountsChangedReceiver";

    @Override
    public void onReceive(Context context, Intent intent) {
        if (!AccountManager.LOGIN_ACCOUNTS_CHANGED_ACTION.equals(intent.getAction())) {
            Log.w(TAG, "Received unknown broadcast: " + intent);
            return;
        }

        // Ideally the account preference could live in a different preferences file
        // that wasn't being backed up and restored, however the preference fragments
        // currently only deal with the default shared preferences which is why
        // separating this out into a different file is not trivial currently.
        final SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
        final String currentAccount = prefs.getString(
                LocalSettingsConstants.PREF_ACCOUNT_NAME, null);
        removeUnknownAccountFromPreference(prefs, getAccountsForLogin(context), currentAccount);
    }

    /**
     * Helper method to help test this receiver.
     */
    @UsedForTesting
    protected String[] getAccountsForLogin(Context context) {
        return LoginAccountUtils.getAccountsForLogin(context);
    }

    /**
     * Removes the currentAccount from preferences if it's not found
     * in the list of current accounts.
     */
    private static void removeUnknownAccountFromPreference(final SharedPreferences prefs,
            final String[] accounts, final String currentAccount) {
        if (currentAccount == null) {
            return;
        }
        for (final String account : accounts) {
            if (TextUtils.equals(currentAccount, account)) {
                return;
            }
        }
        Log.i(TAG, "The current account was removed from the system: " + currentAccount);
        prefs.edit()
                .remove(LocalSettingsConstants.PREF_ACCOUNT_NAME)
                .apply();
    }
}