/* ownCloud Android client application
 *   Copyright (C) 2012-2014 ownCloud Inc.
 *
 *   This program is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License version 2,
 *   as published by the Free Software Foundation.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

package com.owncloud.android.services;

import java.io.IOException;
import java.util.Iterator;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.ConcurrentMap;

import com.owncloud.android.MainApp;
import com.owncloud.android.R;
import com.owncloud.android.datamodel.FileDataStorageManager;
import com.owncloud.android.datamodel.OCFile;
import com.owncloud.android.lib.common.OwnCloudAccount;
import com.owncloud.android.lib.common.OwnCloudClient;
import com.owncloud.android.lib.common.OwnCloudClientManagerFactory;
import com.owncloud.android.lib.common.OwnCloudCredentials;
import com.owncloud.android.lib.common.OwnCloudCredentialsFactory;
import com.owncloud.android.lib.common.accounts.AccountUtils.AccountNotFoundException;
import com.owncloud.android.lib.common.operations.OnRemoteOperationListener;
import com.owncloud.android.lib.common.operations.RemoteOperation;
import com.owncloud.android.lib.common.operations.RemoteOperationResult;
import com.owncloud.android.lib.common.utils.Log_OC;
import com.owncloud.android.lib.resources.files.ExistenceCheckRemoteOperation;
import com.owncloud.android.lib.resources.shares.ShareType;
import com.owncloud.android.lib.resources.users.GetRemoteUserNameOperation;
import com.owncloud.android.operations.common.SyncOperation;
import com.owncloud.android.operations.CreateFolderOperation;
import com.owncloud.android.operations.CreateShareOperation;
import com.owncloud.android.operations.GetServerInfoOperation;
import com.owncloud.android.operations.MoveFileOperation;
import com.owncloud.android.operations.OAuth2GetAccessToken;
import com.owncloud.android.operations.RemoveFileOperation;
import com.owncloud.android.operations.RenameFileOperation;
import com.owncloud.android.operations.SynchronizeFileOperation;
import com.owncloud.android.operations.SynchronizeFolderOperation;
import com.owncloud.android.operations.UnshareLinkOperation;

import android.accounts.Account;
import android.accounts.AccountsException;
import android.accounts.AuthenticatorException;
import android.accounts.OperationCanceledException;
import android.app.Service;
import android.content.Intent;
import android.net.Uri;
import android.os.Binder;
import android.os.Handler;
import android.os.HandlerThread;
import android.os.IBinder;
import android.os.Looper;
import android.os.Message;
import android.os.Process;
import android.util.Pair;

public class OperationsService extends Service {
    
    private static final String TAG = OperationsService.class.getSimpleName();
    
    public static final String EXTRA_ACCOUNT = "ACCOUNT";
    public static final String EXTRA_SERVER_URL = "SERVER_URL";
    public static final String EXTRA_OAUTH2_QUERY_PARAMETERS = "OAUTH2_QUERY_PARAMETERS";
    public static final String EXTRA_REMOTE_PATH = "REMOTE_PATH";
    public static final String EXTRA_SEND_INTENT = "SEND_INTENT";
    public static final String EXTRA_NEWNAME = "NEWNAME";
    public static final String EXTRA_REMOVE_ONLY_LOCAL = "REMOVE_LOCAL_COPY";
    public static final String EXTRA_CREATE_FULL_PATH = "CREATE_FULL_PATH";
    public static final String EXTRA_SYNC_FILE_CONTENTS = "SYNC_FILE_CONTENTS";
    public static final String EXTRA_RESULT = "RESULT";
    public static final String EXTRA_NEW_PARENT_PATH = "NEW_PARENT_PATH";
    
    // TODO review if ALL OF THEM are necessary
    public static final String EXTRA_SUCCESS_IF_ABSENT = "SUCCESS_IF_ABSENT";
    public static final String EXTRA_USERNAME = "USERNAME";
    public static final String EXTRA_PASSWORD = "PASSWORD";
    public static final String EXTRA_AUTH_TOKEN = "AUTH_TOKEN";
    public static final String EXTRA_COOKIE = "COOKIE";
    
    public static final String ACTION_CREATE_SHARE = "CREATE_SHARE";
    public static final String ACTION_UNSHARE = "UNSHARE";
    public static final String ACTION_GET_SERVER_INFO = "GET_SERVER_INFO";
    public static final String ACTION_OAUTH2_GET_ACCESS_TOKEN = "OAUTH2_GET_ACCESS_TOKEN";
    public static final String ACTION_EXISTENCE_CHECK = "EXISTENCE_CHECK";
    public static final String ACTION_GET_USER_NAME = "GET_USER_NAME";
    public static final String ACTION_RENAME = "RENAME";
    public static final String ACTION_REMOVE = "REMOVE";
    public static final String ACTION_CREATE_FOLDER = "CREATE_FOLDER";
    public static final String ACTION_SYNC_FILE = "SYNC_FILE";
    public static final String ACTION_SYNC_FOLDER = "SYNC_FOLDER";  // for the moment, just to download
    public static final String ACTION_CANCEL_SYNC_FOLDER = "CANCEL_SYNC_FOLDER";  // for the moment, just to download
    public static final String ACTION_MOVE_FILE = "MOVE_FILE";
    
    public static final String ACTION_OPERATION_ADDED = OperationsService.class.getName() + ".OPERATION_ADDED";
    public static final String ACTION_OPERATION_FINISHED = OperationsService.class.getName() + ".OPERATION_FINISHED";


    private ConcurrentMap<Integer, Pair<RemoteOperation, RemoteOperationResult>> 
        mUndispatchedFinishedOperations =
            new ConcurrentHashMap<Integer, Pair<RemoteOperation, RemoteOperationResult>>();
    
    private static class Target {
        public Uri mServerUrl = null;
        public Account mAccount = null;
        public String mUsername = null;
        public String mPassword = null;
        public String mAuthToken = null;
        public String mCookie = null;
        
        public Target(Account account, Uri serverUrl, String username, String password, String authToken,
                String cookie) {
            mAccount = account;
            mServerUrl = serverUrl;
            mUsername = username;
            mPassword = password;
            mAuthToken = authToken;
            mCookie = cookie;
        }
    }

    private ServiceHandler mOperationsHandler;
    private OperationsServiceBinder mOperationsBinder;
    
    private SyncFolderHandler mSyncFolderHandler;
    
    /**
     * Service initialization
     */
    @Override
    public void onCreate() {
        super.onCreate();
        /// First worker thread for most of operations 
        HandlerThread thread = new HandlerThread("Operations thread", Process.THREAD_PRIORITY_BACKGROUND);
        thread.start();
        mOperationsHandler = new ServiceHandler(thread.getLooper(), this);
        mOperationsBinder = new OperationsServiceBinder(mOperationsHandler);
        
        /// Separated worker thread for download of folders (WIP)
        thread = new HandlerThread("Syncfolder thread", Process.THREAD_PRIORITY_BACKGROUND);
        thread.start();
        mSyncFolderHandler = new SyncFolderHandler(thread.getLooper(), this);
    }

    
    /**
     * Entry point to add a new operation to the queue of operations.
     * 
     * New operations are added calling to startService(), resulting in a call to this method. 
     * This ensures the service will keep on working although the caller activity goes away.
     */
    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        // WIP: for the moment, only SYNC_FOLDER and CANCEL_SYNC_FOLDER is expected here;
        // the rest of the operations are requested through the Binder
        if (ACTION_SYNC_FOLDER.equals(intent.getAction())) {
            if (!intent.hasExtra(EXTRA_ACCOUNT) || !intent.hasExtra(EXTRA_REMOTE_PATH)) {
                Log_OC.e(TAG, "Not enough information provided in intent");
                return START_NOT_STICKY;
            }
            Account account = intent.getParcelableExtra(EXTRA_ACCOUNT);
            String remotePath = intent.getStringExtra(EXTRA_REMOTE_PATH);

            Pair<Account, String> itemSyncKey =  new Pair<Account , String>(account, remotePath);

            Pair<Target, RemoteOperation> itemToQueue = newOperation(intent);
            if (itemToQueue != null) {
                mSyncFolderHandler.add(account, remotePath, (SynchronizeFolderOperation)itemToQueue.second);
                Message msg = mSyncFolderHandler.obtainMessage();
                msg.arg1 = startId;
                msg.obj = itemSyncKey;
                mSyncFolderHandler.sendMessage(msg);
            }
        } else if (ACTION_CANCEL_SYNC_FOLDER.equals(intent.getAction())) {
            if (!intent.hasExtra(EXTRA_ACCOUNT) || !intent.hasExtra(EXTRA_REMOTE_PATH)) {
                Log_OC.e(TAG, "Not enough information provided in intent");
                return START_NOT_STICKY;
            }
            Account account = intent.getParcelableExtra(EXTRA_ACCOUNT);
            String remotePath = intent.getStringExtra(EXTRA_REMOTE_PATH);

            // Cancel operation
            mSyncFolderHandler.cancel(account,remotePath);
        } else {
            Message msg = mOperationsHandler.obtainMessage();
            msg.arg1 = startId;
            mOperationsHandler.sendMessage(msg);
        }
        
        return START_NOT_STICKY;
    }

    @Override
    public void onDestroy() {
        //Log_OC.wtf(TAG, "onDestroy init" );
        // Saving cookies
        try {
            OwnCloudClientManagerFactory.getDefaultSingleton().
                saveAllClients(this, MainApp.getAccountType());
            
            // TODO - get rid of these exceptions
        } catch (AccountNotFoundException e) {
            e.printStackTrace();
        } catch (AuthenticatorException e) {
            e.printStackTrace();
        } catch (OperationCanceledException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        
        //Log_OC.wtf(TAG, "Clear mUndispatchedFinisiedOperations" );
        mUndispatchedFinishedOperations.clear();
        
        //Log_OC.wtf(TAG, "onDestroy end" );
        super.onDestroy();
    }

    /**
     * Provides a binder object that clients can use to perform actions on the queue of operations, 
     * except the addition of new operations. 
     */
    @Override
    public IBinder onBind(Intent intent) {
        //Log_OC.wtf(TAG, "onBind" );
        return mOperationsBinder;
    }

    
    /**
     * Called when ALL the bound clients were unbound.
     */
    @Override
    public boolean onUnbind(Intent intent) {
        ((OperationsServiceBinder)mOperationsBinder).clearListeners();
        return false;   // not accepting rebinding (default behaviour)
    }


    /**
     *  Binder to let client components to perform actions on the queue of operations.
     * 
     *  It provides by itself the available operations.
     */
    public class OperationsServiceBinder extends Binder /* implements OnRemoteOperationListener */ {
        
        /** 
         * Map of listeners that will be reported about the end of operations from a {@link OperationsServiceBinder} instance 
         */
        private ConcurrentMap<OnRemoteOperationListener, Handler> mBoundListeners = 
                new ConcurrentHashMap<OnRemoteOperationListener, Handler>();
        
        private ServiceHandler mServiceHandler = null;   
        
        
        public OperationsServiceBinder(ServiceHandler serviceHandler) {
            mServiceHandler = serviceHandler;
        }


        /**
         * Cancels an operation
         *
         * TODO
         */
        public void cancel() {
            // TODO
        }
        
        
        public void clearListeners() {
            
            mBoundListeners.clear();
        }

        
        /**
         * Adds a listener interested in being reported about the end of operations.
         * 
         * @param listener          Object to notify about the end of operations.    
         * @param callbackHandler   {@link Handler} to access the listener without breaking Android threading protection.
         */
        public void addOperationListener (OnRemoteOperationListener listener, Handler callbackHandler) {
            synchronized (mBoundListeners) {
                mBoundListeners.put(listener, callbackHandler);
            }
        }
        
        
        /**
         * Removes a listener from the list of objects interested in the being reported about the end of operations.
         * 
         * @param listener      Object to notify about progress of transfer.    
         */
        public void removeOperationListener (OnRemoteOperationListener listener) {
            synchronized (mBoundListeners) {
                mBoundListeners.remove(listener);
            }
        }


        /**
         * TODO - IMPORTANT: update implementation when more operations are moved into the service 
         * 
         * @return  'True' when an operation that enforces the user to wait for completion is in process.
         */
        public boolean isPerformingBlockingOperation() {
            return (!mServiceHandler.mPendingOperations.isEmpty());
        }


        /**
         * Creates and adds to the queue a new operation, as described by operationIntent.
         * 
         * Calls startService to make the operation is processed by the ServiceHandler.
         * 
         * @param operationIntent       Intent describing a new operation to queue and execute.
         * @return                      Identifier of the operation created, or null if failed.
         */
        public long queueNewOperation(Intent operationIntent) {
            Pair<Target, RemoteOperation> itemToQueue = newOperation(operationIntent);
            if (itemToQueue != null) {
                mServiceHandler.mPendingOperations.add(itemToQueue);
                startService(new Intent(OperationsService.this, OperationsService.class));
                return itemToQueue.second.hashCode();
                
            } else {
                return Long.MAX_VALUE;
            }
        }
        
        
        public boolean dispatchResultIfFinished(int operationId, OnRemoteOperationListener listener) {
            Pair<RemoteOperation, RemoteOperationResult> undispatched = 
                    mUndispatchedFinishedOperations.remove(operationId);
            if (undispatched != null) {
                listener.onRemoteOperationFinish(undispatched.first, undispatched.second);
                return true;
                //Log_OC.wtf(TAG, "Sending callback later");
            } else {
                if (!mServiceHandler.mPendingOperations.isEmpty()) {
                    return true;
                } else {
                    return false;
                }
                //Log_OC.wtf(TAG, "Not finished yet");
            }
        }

    }


    /**
     * SyncFolder worker. Performs the pending operations in the order they were requested.
     *
     * Created with the Looper of a new thread, started in {@link OperationsService#onCreate()}.
     */
    private static class SyncFolderHandler extends Handler {

        // don't make it a final class, and don't remove the static ; lint will warn about a possible memory leak

        OperationsService mService;

        private ConcurrentMap<String,SynchronizeFolderOperation> mPendingOperations =
                new ConcurrentHashMap<String,SynchronizeFolderOperation>();
        private OwnCloudClient mOwnCloudClient = null;
        private FileDataStorageManager mStorageManager;
        private SynchronizeFolderOperation mCurrentSyncOperation;


        public SyncFolderHandler(Looper looper, OperationsService service) {
            super(looper);
            if (service == null) {
                throw new IllegalArgumentException("Received invalid NULL in parameter 'service'");
            }
            mService = service;
        }

        @Override
        public void handleMessage(Message msg) {
            Pair<Account, String> itemSyncKey = (Pair<Account, String>) msg.obj;
            doOperation(itemSyncKey.first, itemSyncKey.second);
            mService.stopSelf(msg.arg1);
        }


        /**
         * Performs the next operation in the queue
         */
        private void doOperation(Account account, String remotePath) {

            String syncKey = buildRemoteName(account,remotePath);

            synchronized(mPendingOperations) {
                mCurrentSyncOperation = mPendingOperations.get(syncKey);
            }

            if (mCurrentSyncOperation != null) {

                try {

                    OwnCloudAccount ocAccount = new OwnCloudAccount(account, mService);
                    mOwnCloudClient = OwnCloudClientManagerFactory.getDefaultSingleton().
                            getClientFor(ocAccount, mService);
                    mStorageManager = new FileDataStorageManager(
                            account,
                            mService.getContentResolver()
                    );

                    mCurrentSyncOperation.execute(mOwnCloudClient, mStorageManager);

                } catch (AccountsException e) {
                    Log_OC.e(TAG, "Error while trying to get autorization", e);
                } catch (IOException e) {
                    Log_OC.e(TAG, "Error while trying to get autorization", e);
                } finally {
                    synchronized(mPendingOperations) {
                        mPendingOperations.remove(syncKey);
                    }
                }
            }
        }

        public void add(Account account, String remotePath, SynchronizeFolderOperation syncFolderOperation){
            String syncKey = buildRemoteName(account,remotePath);
            mPendingOperations.putIfAbsent(syncKey,syncFolderOperation);
        }


        /**
         * Cancels a pending or current sync operation.
         *
         * @param account       Owncloud account where the remote file is stored.
         * @param remotePath    A remote file path
         */
        public void cancel(Account account, String remotePath) {
            SynchronizeFolderOperation syncOperation = null;
            synchronized (mPendingOperations) {
                syncOperation = mPendingOperations.remove(buildRemoteName(account, remotePath));
            }
            if (syncOperation != null) {
                syncOperation.cancel();
            }
        }

        /**
         * Builds a key from the account and file to download
         *
         * @param account   Account where the file to download is stored
         * @param path      File path
         */
        private String buildRemoteName(Account account, String path) {
            return account.name + path;
        }
    }


    /** 
     * Operations worker. Performs the pending operations in the order they were requested. 
     * 
     * Created with the Looper of a new thread, started in {@link OperationsService#onCreate()}. 
     */
    private static class ServiceHandler extends Handler {
        // don't make it a final class, and don't remove the static ; lint will warn about a possible memory leak
        
        
        OperationsService mService;
        
        
        private ConcurrentLinkedQueue<Pair<Target, RemoteOperation>> mPendingOperations =
                new ConcurrentLinkedQueue<Pair<Target, RemoteOperation>>();
        private RemoteOperation mCurrentOperation = null;
        private Target mLastTarget = null;
        private OwnCloudClient mOwnCloudClient = null;
        private FileDataStorageManager mStorageManager;
        
        
        public ServiceHandler(Looper looper, OperationsService service) {
            super(looper);
            if (service == null) {
                throw new IllegalArgumentException("Received invalid NULL in parameter 'service'");
            }
            mService = service;
        }

        @Override
        public void handleMessage(Message msg) {
            nextOperation();
            mService.stopSelf(msg.arg1);
        }
        
        
        /**
         * Performs the next operation in the queue
         */
        private void nextOperation() {
            
            //Log_OC.wtf(TAG, "nextOperation init" );
            
            Pair<Target, RemoteOperation> next = null;
            synchronized(mPendingOperations) {
                next = mPendingOperations.peek();
            }

            if (next != null) {
                
                mCurrentOperation = next.second;
                RemoteOperationResult result = null;
                try {
                    /// prepare client object to send the request to the ownCloud server
                    if (mLastTarget == null || !mLastTarget.equals(next.first)) {
                        mLastTarget = next.first;
                        if (mLastTarget.mAccount != null) {
                            OwnCloudAccount ocAccount = new OwnCloudAccount(mLastTarget.mAccount, mService);
                            mOwnCloudClient = OwnCloudClientManagerFactory.getDefaultSingleton().
                                    getClientFor(ocAccount, mService);
                            mStorageManager = new FileDataStorageManager(
                                    mLastTarget.mAccount, 
                                    mService.getContentResolver()
                            );
                        } else {
                            OwnCloudCredentials credentials = null;
                            if (mLastTarget.mUsername != null && 
                                    mLastTarget.mUsername.length() > 0) {
                                credentials = OwnCloudCredentialsFactory.newBasicCredentials(
                                        mLastTarget.mUsername, 
                                        mLastTarget.mPassword);  // basic
                                
                            } else if (mLastTarget.mAuthToken != null && 
                                    mLastTarget.mAuthToken.length() > 0) {
                                credentials = OwnCloudCredentialsFactory.newBearerCredentials(
                                        mLastTarget.mAuthToken);  // bearer token
                                
                            } else if (mLastTarget.mCookie != null &&
                                    mLastTarget.mCookie.length() > 0) {
                                credentials = OwnCloudCredentialsFactory.newSamlSsoCredentials(
                                        mLastTarget.mCookie); // SAML SSO
                            }
                            OwnCloudAccount ocAccount = new OwnCloudAccount(
                                    mLastTarget.mServerUrl, credentials);
                            mOwnCloudClient = OwnCloudClientManagerFactory.getDefaultSingleton().
                                    getClientFor(ocAccount, mService);
                            mStorageManager = null;
                        }
                    }

                    /// perform the operation
                    if (mCurrentOperation instanceof SyncOperation) {
                        result = ((SyncOperation)mCurrentOperation).execute(mOwnCloudClient, mStorageManager);
                    } else {
                        result = mCurrentOperation.execute(mOwnCloudClient);
                    }
                    
                } catch (AccountsException e) {
                    if (mLastTarget.mAccount == null) {
                        Log_OC.e(TAG, "Error while trying to get authorization for a NULL account", e);
                    } else {
                        Log_OC.e(TAG, "Error while trying to get authorization for " + mLastTarget.mAccount.name, e);
                    }
                    result = new RemoteOperationResult(e);
                    
                } catch (IOException e) {
                    if (mLastTarget.mAccount == null) {
                        Log_OC.e(TAG, "Error while trying to get authorization for a NULL account", e);
                    } else {
                        Log_OC.e(TAG, "Error while trying to get authorization for " + mLastTarget.mAccount.name, e);
                    }
                    result = new RemoteOperationResult(e);
                } catch (Exception e) {
                    if (mLastTarget.mAccount == null) {
                        Log_OC.e(TAG, "Unexpected error for a NULL account", e);
                    } else {
                        Log_OC.e(TAG, "Unexpected error for " + mLastTarget.mAccount.name, e);
                    }
                    result = new RemoteOperationResult(e);
                
                } finally {
                    synchronized(mPendingOperations) {
                        mPendingOperations.poll();
                    }
                }
                
                //sendBroadcastOperationFinished(mLastTarget, mCurrentOperation, result);
                mService.dispatchResultToOperationListeners(mLastTarget, mCurrentOperation, result);
            }
        }


        
    }
    

    /**
     * Creates a new operation, as described by operationIntent.
     * 
     * TODO - move to ServiceHandler (probably)
     * 
     * @param operationIntent       Intent describing a new operation to queue and execute.
     * @return                      Pair with the new operation object and the information about its target server.
     */
    private Pair<Target , RemoteOperation> newOperation(Intent operationIntent) {
        RemoteOperation operation = null;
        Target target = null;
        try {
            if (!operationIntent.hasExtra(EXTRA_ACCOUNT) && 
                    !operationIntent.hasExtra(EXTRA_SERVER_URL)) {
                Log_OC.e(TAG, "Not enough information provided in intent");
                
            } else {
                Account account = operationIntent.getParcelableExtra(EXTRA_ACCOUNT);
                String serverUrl = operationIntent.getStringExtra(EXTRA_SERVER_URL);
                String username = operationIntent.getStringExtra(EXTRA_USERNAME);
                String password = operationIntent.getStringExtra(EXTRA_PASSWORD);
                String authToken = operationIntent.getStringExtra(EXTRA_AUTH_TOKEN);
                String cookie = operationIntent.getStringExtra(EXTRA_COOKIE);
                target = new Target(
                        account, 
                        (serverUrl == null) ? null : Uri.parse(serverUrl),
                        username,
                        password,
                        authToken,
                        cookie
                );
                
                String action = operationIntent.getAction();
                if (action.equals(ACTION_CREATE_SHARE)) {  // Create Share
                    String remotePath = operationIntent.getStringExtra(EXTRA_REMOTE_PATH);
                    Intent sendIntent = operationIntent.getParcelableExtra(EXTRA_SEND_INTENT);
                    if (remotePath.length() > 0) {
                        operation = new CreateShareOperation(remotePath, ShareType.PUBLIC_LINK, 
                                "", false, "", 1, sendIntent);
                    }
                    
                } else if (action.equals(ACTION_UNSHARE)) {  // Unshare file
                    String remotePath = operationIntent.getStringExtra(EXTRA_REMOTE_PATH);
                    if (remotePath.length() > 0) {
                        operation = new UnshareLinkOperation(
                                remotePath, 
                                OperationsService.this);
                    }
                    
                } else if (action.equals(ACTION_GET_SERVER_INFO)) { 
                    // check OC server and get basic information from it
                    operation = new GetServerInfoOperation(serverUrl, OperationsService.this);
                    
                } else if (action.equals(ACTION_OAUTH2_GET_ACCESS_TOKEN)) {
                    /// GET ACCESS TOKEN to the OAuth server
                    String oauth2QueryParameters =
                            operationIntent.getStringExtra(EXTRA_OAUTH2_QUERY_PARAMETERS);
                    operation = new OAuth2GetAccessToken(
                            getString(R.string.oauth2_client_id), 
                            getString(R.string.oauth2_redirect_uri),       
                            getString(R.string.oauth2_grant_type),
                            oauth2QueryParameters);
                    
                } else if (action.equals(ACTION_EXISTENCE_CHECK)) {
                    // Existence Check 
                    String remotePath = operationIntent.getStringExtra(EXTRA_REMOTE_PATH);
                    boolean successIfAbsent = operationIntent.getBooleanExtra(EXTRA_SUCCESS_IF_ABSENT, false);
                    operation = new ExistenceCheckRemoteOperation(remotePath, OperationsService.this, successIfAbsent);
                    
                } else if (action.equals(ACTION_GET_USER_NAME)) {
                    // Get User Name
                    operation = new GetRemoteUserNameOperation();
                    
                } else if (action.equals(ACTION_RENAME)) {
                    // Rename file or folder
                    String remotePath = operationIntent.getStringExtra(EXTRA_REMOTE_PATH);
                    String newName = operationIntent.getStringExtra(EXTRA_NEWNAME);
                    operation = new RenameFileOperation(remotePath, newName);
                    
                } else if (action.equals(ACTION_REMOVE)) {
                    // Remove file or folder
                    String remotePath = operationIntent.getStringExtra(EXTRA_REMOTE_PATH);
                    boolean onlyLocalCopy = operationIntent.getBooleanExtra(EXTRA_REMOVE_ONLY_LOCAL, false);
                    operation = new RemoveFileOperation(remotePath, onlyLocalCopy);
                    
                } else if (action.equals(ACTION_CREATE_FOLDER)) {
                    // Create Folder
                    String remotePath = operationIntent.getStringExtra(EXTRA_REMOTE_PATH);
                    boolean createFullPath = operationIntent.getBooleanExtra(EXTRA_CREATE_FULL_PATH, true);
                    operation = new CreateFolderOperation(remotePath, createFullPath);
                    
                } else if (action.equals(ACTION_SYNC_FILE)) {
                    // Sync file
                    String remotePath = operationIntent.getStringExtra(EXTRA_REMOTE_PATH);
                    boolean syncFileContents = operationIntent.getBooleanExtra(EXTRA_SYNC_FILE_CONTENTS, true);
                    operation = new SynchronizeFileOperation(
                            remotePath, account, syncFileContents, getApplicationContext()
                    );
                    
                } else if (action.equals(ACTION_SYNC_FOLDER)) {
                    // Sync file
                    String remotePath = operationIntent.getStringExtra(EXTRA_REMOTE_PATH);
                    operation = new SynchronizeFolderOperation(
                            this,                       // TODO remove this dependency from construction time 
                            remotePath,
                            account, 
                            System.currentTimeMillis()  // TODO remove this dependency from construction time
                    );
                    
                } else if (action.equals(ACTION_MOVE_FILE)) {
                    // Move file/folder
                    String remotePath = operationIntent.getStringExtra(EXTRA_REMOTE_PATH);
                    String newParentPath = operationIntent.getStringExtra(EXTRA_NEW_PARENT_PATH);
                    operation = new MoveFileOperation(remotePath,newParentPath,account);
                }
                
            }
                
        } catch (IllegalArgumentException e) {
            Log_OC.e(TAG, "Bad information provided in intent: " + e.getMessage());
            operation = null;
        }

        if (operation != null) {
            return new Pair<Target , RemoteOperation>(target, operation);  
        } else {
            return null;
        }
    }
    

    /**
     * Sends a broadcast when a new operation is added to the queue.
     * 
     * Local broadcasts are only delivered to activities in the same process, but can't be done sticky :\
     * 
     * @param target            Account or URL pointing to an OC server.
     * @param operation         Added operation.
     */
    private void sendBroadcastNewOperation(Target target, RemoteOperation operation) {
        Intent intent = new Intent(ACTION_OPERATION_ADDED);
        if (target.mAccount != null) {
            intent.putExtra(EXTRA_ACCOUNT, target.mAccount);    
        } else {
            intent.putExtra(EXTRA_SERVER_URL, target.mServerUrl);    
        }
        //LocalBroadcastManager lbm = LocalBroadcastManager.getInstance(this);
        //lbm.sendBroadcast(intent);
        sendStickyBroadcast(intent);
    }

    
    // TODO - maybe add a notification for real start of operations
    
    /**
     * Sends a LOCAL broadcast when an operations finishes in order to the interested activities can update their view
     * 
     * Local broadcasts are only delivered to activities in the same process.
     * 
     * @param target            Account or URL pointing to an OC server.
     * @param operation         Finished operation.
     * @param result            Result of the operation.
     */
    private void sendBroadcastOperationFinished(Target target, RemoteOperation operation, RemoteOperationResult result) {
        Intent intent = new Intent(ACTION_OPERATION_FINISHED);
        intent.putExtra(EXTRA_RESULT, result);
        if (target.mAccount != null) {
            intent.putExtra(EXTRA_ACCOUNT, target.mAccount);    
        } else {
            intent.putExtra(EXTRA_SERVER_URL, target.mServerUrl);    
        }
        //LocalBroadcastManager lbm = LocalBroadcastManager.getInstance(this);
        //lbm.sendBroadcast(intent);
        sendStickyBroadcast(intent);
    }

    
    /**
     * Notifies the currently subscribed listeners about the end of an operation.
     * 
     * @param target            Account or URL pointing to an OC server.
     * @param operation         Finished operation.
     * @param result            Result of the operation.
     */
    private void dispatchResultToOperationListeners(
            Target target, final RemoteOperation operation, final RemoteOperationResult result) {
        int count = 0;
        Iterator<OnRemoteOperationListener> listeners = mOperationsBinder.mBoundListeners.keySet().iterator();
        while (listeners.hasNext()) {
            final OnRemoteOperationListener listener = listeners.next();
            final Handler handler = mOperationsBinder.mBoundListeners.get(listener);
            if (handler != null) { 
                handler.post(new Runnable() {
                    @Override
                    public void run() {
                        listener.onRemoteOperationFinish(operation, result);
                    }
                });
                count += 1;
            }
        }
        if (count == 0) {
            //mOperationResults.put(operation.hashCode(), result);
            Pair<RemoteOperation, RemoteOperationResult> undispatched = 
                    new Pair<RemoteOperation, RemoteOperationResult>(operation, result);
            mUndispatchedFinishedOperations.put(operation.hashCode(), undispatched);
        }
        Log_OC.d(TAG, "Called " + count + " listeners");
    }
}