/*
 * 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.exchange.service;

import android.app.Service;
import android.content.Intent;
import android.content.SyncResult;
import android.database.Cursor;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.IBinder;
import android.provider.CalendarContract;
import android.provider.ContactsContract;
import android.text.TextUtils;

import com.android.emailcommon.provider.HostAuth;
import com.android.emailcommon.service.IEmailService;
import com.android.emailcommon.service.IEmailServiceCallback;
import com.android.emailcommon.service.SearchParams;
import com.android.emailcommon.service.ServiceProxy;
import com.android.exchange.Eas;
import com.android.exchange.eas.EasFolderSync;
import com.android.exchange.eas.EasOperation;
import com.android.mail.utils.LogUtils;

/**
 * Service to handle all communication with the EAS server. Note that this is completely decoupled
 * from the sync adapters; sync adapters should make blocking calls on this service to actually
 * perform any operations.
 */
public class EasService extends Service {

    private static final String TAG = Eas.LOG_TAG;

    /**
     * The content authorities that can be synced for EAS accounts. Initialization must wait until
     * after we have a chance to call {@link EmailContent#init} (and, for future content types,
     * possibly other initializations) because that's how we can know what the email authority is.
     */
    private static String[] AUTHORITIES_TO_SYNC;

    /** Bookkeeping for ping tasks & sync threads management. */
    private final PingSyncSynchronizer mSynchronizer;

    /**
     * Implementation of the IEmailService interface.
     * For the most part these calls should consist of creating the correct {@link EasOperation}
     * class and calling {@link #doOperation} with it.
     */
    private final IEmailService.Stub mBinder = new IEmailService.Stub() {
        @Override
        public void sendMail(final long accountId) {}

        @Override
        public void loadAttachment(final IEmailServiceCallback callback, final long attachmentId,
                final boolean background) {
            LogUtils.d(TAG, "IEmailService.loadAttachment: %d", attachmentId);
        }

        @Override
        public void updateFolderList(final long accountId) {
            final EasFolderSync operation = new EasFolderSync(EasService.this, accountId);
            doOperation(operation, null, "IEmailService.updateFolderList");
        }

        @Override
        public Bundle validate(final HostAuth hostAuth) {
            final EasFolderSync operation = new EasFolderSync(EasService.this, hostAuth);
            doOperation(operation, null, "IEmailService.validate");
            return operation.getValidationResult();
        }

        @Override
        public int searchMessages(final long accountId, final SearchParams searchParams,
                final long destMailboxId) {
            LogUtils.d(TAG, "IEmailService.searchMessages");
            return 0;
        }

        @Override
        public void sendMeetingResponse(final long messageId, final int response) {
            LogUtils.d(TAG, "IEmailService.sendMeetingResponse: %d, %d", messageId, response);
        }

        @Override
        public Bundle autoDiscover(final String username, final String password) {
            LogUtils.d(TAG, "IEmailService.autoDiscover");
            return null;
        }

        @Override
        public void setLogging(final int flags) {
            LogUtils.d(TAG, "IEmailService.setLogging");
        }

        @Override
        public void deleteAccountPIMData(final String emailAddress) {
            LogUtils.d(TAG, "IEmailService.deleteAccountPIMData");
        }
    };

    /**
     * Content selection string for getting all accounts that are configured for push.
     * TODO: Add protocol check so that we don't get e.g. IMAP accounts here.
     * (Not currently necessary but eventually will be.)
     */
    private static final String PUSH_ACCOUNTS_SELECTION =
            EmailContent.AccountColumns.SYNC_INTERVAL +
                    "=" + Integer.toString(Account.CHECK_INTERVAL_PUSH);

    /** {@link AsyncTask} to restart pings for all accounts that need it. */
    private class RestartPingsTask extends AsyncTask<Void, Void, Void> {
        private boolean mHasRestartedPing = false;

        @Override
        protected Void doInBackground(Void... params) {
            final Cursor c = EasService.this.getContentResolver().query(Account.CONTENT_URI,
                    Account.CONTENT_PROJECTION, PUSH_ACCOUNTS_SELECTION, null, null);
            if (c != null) {
                try {
                    while (c.moveToNext()) {
                        final Account account = new Account();
                        account.restore(c);
                        if (EasService.this.pingNeededForAccount(account)) {
                            mHasRestartedPing = true;
                            EasService.this.mSynchronizer.pushModify(account.mId);
                        }
                    }
                } finally {
                    c.close();
                }
            }
            return null;
        }

        @Override
        protected void onPostExecute(Void result) {
            if (!mHasRestartedPing) {
                LogUtils.d(TAG, "RestartPingsTask did not start any pings.");
                EasService.this.mSynchronizer.stopServiceIfIdle();
            }
        }
    }

    public EasService() {
        super();
        mSynchronizer = new PingSyncSynchronizer(this);
    }

    @Override
    public void onCreate() {
<<<<<<< HEAD
        // TODO: Restart all pings that are needed.
=======
        super.onCreate();
        EmailContent.init(this);
        AUTHORITIES_TO_SYNC = new String[] {
                EmailContent.AUTHORITY,
                CalendarContract.AUTHORITY,
                ContactsContract.AUTHORITY
        };

        // Restart push for all accounts that need it. Because this requires DB loads, we do it in
        // an AsyncTask, and we startService to ensure that we stick around long enough for the
        // task to complete. The task will stop the service if necessary after it's done.
        startService(new Intent(this, EasService.class));
        new RestartPingsTask().executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
>>>>>>> c3ad5a3... Flesh out EasService some, and start using it.
    }

    @Override
    public void onDestroy() {
        mSynchronizer.stopAllPings();
    }

    @Override
    public IBinder onBind(final Intent intent) {
        return mBinder;
    }

    @Override
    public int onStartCommand(final Intent intent, final int flags, final int startId) {
        if (intent != null &&
                TextUtils.equals(Eas.EXCHANGE_SERVICE_INTENT_ACTION, intent.getAction())) {
            if (intent.getBooleanExtra(ServiceProxy.EXTRA_FORCE_SHUTDOWN, false)) {
                // We've been asked to forcibly shutdown. This happens if email accounts are
                // deleted, otherwise we can get errors if services are still running for
                // accounts that are now gone.
                // TODO: This is kind of a hack, it would be nicer if we could handle it correctly
                // if accounts disappear out from under us.
                LogUtils.d(TAG, "Forced shutdown, killing process");
                System.exit(-1);
            }
        }
        return START_STICKY;
    }

    public int doOperation(final EasOperation operation, final SyncResult syncResult,
            final String loggingName) {
        final long accountId = operation.getAccountId();
        LogUtils.d(TAG, "%s: %d", loggingName, accountId);
        mSynchronizer.syncStart(accountId);
        // TODO: Do we need a wakelock here? For RPC coming from sync adapters, no -- the SA
        // already has one. But for others, maybe? Not sure what's guaranteed for AIDL calls.
        // If we add a wakelock (or anything else for that matter) here, must remember to undo
        // it in the finally block below.
        // On the other hand, even for SAs, it doesn't hurt to get a wakelock here.
        try {
            return operation.performOperation(syncResult);
        } finally {
            // TODO: Fix pushEnabled param
            mSynchronizer.syncEnd(accountId, false);
        }
    }
}