/**

* Copyright (c) 2010 Sasken Communication Technologies Ltd.

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the "{License}"

* which accompanies  this distribution, and is available

* at the URL "{LicenseUrl}".

*

* Initial Contributors:

* Narasimhulu Kavadapu, Sasken Communication Technologies Ltd - Initial contribution

*

* Contributors:

*

* Description:

* class to handle calls to rest Server API's

*/

#ifndef FBREQUEST_H

#define FBREQUEST_H

#include <QObject>

#include <QString>

#include <QDateTime>

#include <QHttp>

#include <QHash>

#include <QNetworkAccessManager>

#include <QNetworkReply>

#include "progressbar.h"

#include "authAppConstants.h"

#include "xmlParser.h"

// FORWARD DECLARATIONS

class FBSession;

class FBError;

///////////////////////////////////////////////////////////////////////////////////////////////////

class  FBRequest : public QObject

{

    Q_OBJECT

private:

    /* pointer to the session that owns this request */

    FBSession*  iSession;

    /**

     * The URL which will be contacted to execute the request.

     */

    QString iUrl;

    /**

     * The API method which will be called.

     */

    QString iMethod;

    /**

     * An object used by the user of the request to help identify the meaning of the request.

     */

    void*   iUserInfo;

    /**

     * The dictionary of parameters to pass to the method.

     *

     * These values in the dictionary will be converted to strings using the

     * standard Objective-C object-to-string conversion facilities.

     */

    Dictionary  iParams;

    /**

     * A data parameter.

     *

     * Used for methods such as photos.upload, video.upload, events.create, and

     * events.edit.

     */

    QByteArray  iDataParam;

    /**

      * true if iDataParam holds picture data

      */

    bool        iDataParamPicture;

    /**

     * The timestamp of when the request was sent to the server.

     */

    QDateTime   iTimestamp;

    QHttp       iConnection;

    QByteArray  iResponseText;

    QNetworkAccessManager iNetworkAccessManager;

    progressbar* pbar;

signals: /* the signals ommitted by FBRequest */

    /**

     * Called just before the request is sent to the server.

     */

    void requestLoading();

    /**

     * Called when the server responds and begins to send back data.

     */

    //todo: void requestDidReceiveResponse (FBRequest* aRequest, NSURLResponse* aResponse);

    /**

     * Called when an error prevents the request from completing successfully.

     */

    void requestFailedWithNetworkError( QNetworkReply::NetworkError code );

    void requestFailedWithFacebookError ( const FBError& aError );

    /**

     * Called when a request returns and its response has been parsed into an object.

     *

     * The resulting object may be a dictionary, an array, a string, or a number, depending

     * on thee format of the API response.

     */

    void requestDidLoad ( const QVariant& aResult);

    /**

     * Called when the request was cancelled.

     */

    void requestWasCancelled ();

private slots:

    void networkReplyError ( QNetworkReply::NetworkError code );

    void networkReplyFinished ();

public: /* class functions */

    /**

     * Creates a new API request for the global session.

     */

    static FBRequest* request();

    /**

     * Creates a new API request for a particular session.

     */

    static FBRequest* requestWithSession (FBSession* aSession);

public: /* instance functions */

    /**

     * Creates a new request paired to a session.

     */

    FBRequest (FBSession* aSession);

    /**

     * Calls a method on the server asynchronously.

     *

     * The delegate will be called for each stage of the loading process.

     */

    void call (const QString& aMethod, const Dictionary& aParams);

    /**

     * Calls a method on the server asynchronously, with a file upload component.

     *

     * The delegate will be called for each stage of the loading process.

     */

    void callWithDataParams (const QString& aMethod, const Dictionary& aParams, const QByteArray& aDataParam, bool aDataParamPicture);

    /**

     * Calls a URL on the server asynchronously.

     *

     * The delegate will be called for each stage of the loading process.

     */

    void post( const QString& aUrl, const Dictionary& aParams);

    /**

     * Stops an active request before the response has returned.

     */

    void cancel();

    /**

      * returns the time stamp of when the request was sent to the server

      */

    const QDateTime& timeStamp() const;

    void connect();

private:

    /**

      * Given a string returns its hex coded md5 hash

      */

    static QString md5(const QString&);

    /**

      * @return true if the current request method is a special method

      */

    bool isSpecialMethod() const;

    /**

      * @return QString a url to use for the given method

      */

    QString urlForMethod (const QString& aMethod) const;

    /**

      * @return the Get Url for the request

      */

    QString generateGetURL() const;

    QString generateCallId() const;

    QString generateSig();

    void generatePostBody(QByteArray& body);

    /**

      * handles the data received from the server

      * @param aResponseData is the data received from the server

      */

    void handleResponseData( const QByteArray& aResponseData );

    /**

      * @param aResponseData is the data received from the server

      * @param aError will get error codes if any error occurs ( this will change in the future )

      * @return a void* pointer, this will change

      */

    QVariant parseXMLResponse ( const QByteArray& aResponseData, FBError& aError);

};

#endif // FBREQUEST_H