/*

* Copyright (c) 2005-2006 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the License "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description: 

*

*/

#ifndef WEBCLIENTENGINE_H

#define WEBCLIENTENGINE_H

// INCLUDES

#include <coecntrl.h>

#include <http.h>

#include <http/mhttpauthenticationcallback.h>

#include <es_sock.h>

// CONSTANTS

const TInt KMaxHeaderNameLength     = 32;

const TInt KMaxHeaderValueLength    = 128;

const TInt KMaxAuthTypeLength       = 128;

const TInt KMaxDateTimeStringLength = 40;

const TInt KMaxStatusTextLength     = 32;

const TInt KMaxUserNameLength       = 128;

const TInt KMaxPasswordLength       = 128;

// Used user agent for requests

_LIT8( KUserAgent, "WebClient 1.0" );

// This client accepts all content types.

// (change to e.g. "text/plain" for plain text only)

_LIT8( KAccept, "*/*" );

// Format for output of data/time values

_LIT( KDateFormat,"%D%M%Y%/0%1%/1%2%/2%3%/3 %:0%H%:1%T%:2%S.%C%:3" );

// Some texts for header output

_LIT( KColon, ": " );

_LIT( Krealm, "Realm: " );

class CWebClientEngine;

// CLASS DECLARATION

/**

* MWebClientObserver

* CWebClientEngine passes events and responses body data with this interface. 

* An instance of this class must be provided for construction of CWebClientEngine.

*/

class MWebClientObserver 

    {

    public:

    	/**

    	 * ClientOpenSessionFailedL( CWebClientEngine& anEngine )

    	 * An error occurred opening the HTTP session. The calling code

    	 * will leave after this method returns.

    	 * @param anError: the error code

    	 * Most common error; no access point configured, and session creation

         * leaves with KErrNotFound.

    	 */

    	virtual void ClientOpenSessionFailedL( CWebClientEngine& anEngine, TInt anError ) = 0;

 		/**

         * ClientConnectingL()

         * Called to notify that a connection was initiated

         */

        virtual void ClientConnectingL( CWebClientEngine& anEngine ) = 0;

		/**

        * ClientHeaderReceivedL()

        * Called when HTTP header is received.

        * @param aHeaderData: Header field name and value

        */

        virtual void ClientHeaderReceivedL( CWebClientEngine& anEngine, const TDesC& aHeaderData ) = 0;

 		/**

        * ClientBodyReceivedL()

        * Called when a part of the HTTP body is received.

        * @param aBodyData:  Part of the body data received. (e.g. part of

        *                    the received HTML page)

        */

        virtual void ClientBodyReceivedL( CWebClientEngine& anEngine, const TDesC8& aBodyData ) = 0;

 		/**

         * ClientConnectionCanceledL()

         * Called to notify that a connection attempt has been canceled

         */

        virtual void ClientConnectionCanceledL( CWebClientEngine& anEngine ) = 0;

 		/**

         * ClientResponseCompleteL

         * Called to notify that a transaction's response is complete.

         * See TTransactionEvent::EResponseComplete

         */

        virtual void ClientResponseCompleteL( CWebClientEngine& anEngine ) = 0;

 		/**

         * ClientTransactionSucceeded()

         * Called to notify that a transaction completed successfully

         * See TTransactionEvent::ESucceeded

         */

        virtual void ClientTransactionSucceededL( CWebClientEngine& anEngine ) = 0;

 		/** 

         * ClientTransactionFailed()

         * Catch-all for failure. 

         * See TTransactionEvent::EFailed

         */

         virtual void ClientTransactionFailedL( CWebClientEngine& anEngine ) = 0;

  		/**

          * ClientUnknownEventL()

          * Called to notify that an unknown HTTP event has

          * been received.

          * @param aStatus: the iStatus field of the event

          * See THTTPEvent::iStatus

          */

         virtual void ClientUnknownEventL( CWebClientEngine& anEngine , TInt aStatus ) = 0;

 		/**

         * ClientRunErrorL()

         * Called when a error occurs in the handling of a transaction event.

         * @param anError: the error code

         */

        virtual void ClientRunErrorL( CWebClientEngine& anEngine , TInt anError) = 0;

 		/**

         * ClientGetCredentialsL()

         * Called when authentication has been requested by the server.

         * Return EFalse for no authentication or e.g. the user cancels

         * an input dialog. Otherwise return the user name and password 

         * as out parameters along with an ETrue result.

         * @param aUri: the current URI

         * @param aRealm: the realm associated with the request

         * @param aUserName: the returned user name

         * @param aPassword: the returned password

         */

        virtual TBool ClientGetCredentialsL( CWebClientEngine& anEngine, const TUriC8& aUri, 

                                const TDesC8& aRealm, 

                                TDes& aUsername, 

                                TDes& aPassword ) = 0;

    };

/**

* CWebClientEngine

* Provides simple interface to HTTP Client API.

*/

class CWebClientEngine : public CBase, 

                         public MHTTPTransactionCallback,

                         public MHTTPAuthenticationCallback

    {

    public:

 		/**

        * NewL()

        * Create a CWebClientEngine object.

        * @param  iObserver: 

        * @return A pointer to the created instance of CWebClientEngine

        */

        static CWebClientEngine* NewL( MWebClientObserver& aObserver );

 		/**

        * NewLC()

        * Create a CWebClientEngine object.

        * @param  iObserver:

        * @return A pointer to the created instance of CWebClientEngine

        */

        static CWebClientEngine* NewLC( MWebClientObserver& aObserver );

 		/**

        * ~CWebClientEngine()

        * Destroy the object

        */

        ~CWebClientEngine();

 		/**

         * Opens the HTTP session. Automatically called when a session is initiated,

         * or can be called separately.

         */

        void OpenSessionL();

 		/**

        * IssueHTTPGetL()

        * Starts a new HTTP GET transaction.

        * @param aUri: URI to get. (e.g. http://host.org")

        */

        void IssueHTTPGetL( const TDesC8& aUri );

 		/**

        * CancelTransactionL()

        * Closes currently running transaction and frees resources related to it.

        */

        void CancelTransactionL();

 		/**

        * IsRunning()

        * Checks if the transaction is running.

        * @return ETrue, if transaction is currently running.

        */

        inline TBool IsRunning() { return iRunning; };

    private:

 		/**

        * ConstructL()

        * Perform the second phase construction of a CWebClientEngine object.

        */

        void ConstructL();

 		/**

        * CWebClientEngine()

        * Perform the first phase of two phase construction.

        * @param iObserver: 

        */

        CWebClientEngine( MWebClientObserver& iObserver );

 		/**

        * SetHeaderL()

        * Sets header value of an HTTP request.

        * @param aHeaders:  Headers of the HTTP request

        * @param aHdrField: Enumerated HTTP header field, e.g. HTTP::EUserAgent

        * @param aHdrValue: New value for header field

        */

        void SetHeaderL( RHTTPHeaders aHeaders, TInt aHdrField, 

                         const TDesC8& aHdrValue );

 		/**

        * DumpRespHeadersL()

        * Called when HTTP header is received.

        * Displays HTTP header field names and values

        * @param aTransaction: The transaction that is processed.

        */

        void DumpRespHeadersL( RHTTPTransaction& aTransantion );

 		/**

        * HandleRunErrorL()

        * Called from MHFRunError() when *leave* occurs in handling of transaction event. 

        * @param aError:       The leave code that occured.

        */

        void HandleRunErrorL( TInt aError );

    /**

    * From MHTTPSessionEventCallback

    */

    private:

 		/**

        * MHFRunL()

        * Called by framework to notify about transaction events.

        * @param aTransaction: Transaction, where the event occured.

        * @param aEvent:       Occured event.

        */

        void MHFRunL( RHTTPTransaction aTransaction, const THTTPEvent& aEvent );

 		/**

        * MHFRunError()

        * Called by framework when *leave* occurs in handling of transaction event. 

        * @param aError:       The leave code that occured.

        * @param aTransaction: The transaction that was being processed when leave occured.

        * @param aEvent:       The event that was being processed when leave occured.

        * @return KErrNone,    if the error was handled. Otherwise the value of aError, or

        *                      some other error value. Returning error value causes causes 

        *                      HTTP-CORE 6 panic.

        */

        TInt MHFRunError( TInt aError, 

                          RHTTPTransaction aTransaction, 

                          const THTTPEvent& aEvent );

    /**

    * From MHTTPAuthenticationCallback (needed for HTTP authentication)

    */

    private:

 		/**

        * GetCredentialsL()

        * Called by framework when username and password for requested URI is 

        * needed.

        * @param aURI: The URI being requested (e.g. "http://host.org")

        * @param aRealm: The realm being requested (e.g. "user@host.org")

        * @param aAuthenticationType: Authentication type. (e.g. "Basic")

        * @param aUsername: Given user name.

        * @param aPassword: Given password.

        * @return A pointer to the created document

        */

        TBool GetCredentialsL(  const TUriC8& aUri, 

                                RString aRealm, 

                                RStringF aAuthenticationType, 

                                RString& aUsername, 

                                RString& aPassword );

    private: // Data

        RHTTPSession            iSession;

        RHTTPTransaction        iTransaction;

        RSocketServ 			iSocketServ;

		RConnection 			iConnection;

        MWebClientObserver&     iObserver;      // Used for passing body data and

                                                // events to UI.

        TBool					iSessionOpened; // ETrue, if session successfully opened

        TBool                   iRunning;       // ETrue, if transaction running

    };

#endif // WEBCLIENTENGINE_H