/** @file
 * Drag and Drop manager.
 */

/*
 * Copyright (C) 2011-2012 Oracle Corporation
 *
 * This file is part of VirtualBox Open Source Edition (OSE), as
 * available from http://www.virtualbox.org. This file is free software;
 * you can redistribute it and/or modify it under the terms of the GNU
 * General Public License (GPL) as published by the Free Software
 * Foundation, in version 2 as it comes in the "COPYING" file of the
 * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
 * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
 */

#ifndef ___VBox_HostService_DnD_dndmanager_h
#define ___VBox_HostService_DnD_dndmanager_h

#include <VBox/HostServices/Service.h>
#include <VBox/HostServices/DragAndDropSvc.h>

#include <iprt/cpp/ministring.h>
#include <iprt/cpp/list.h>

typedef DECLCALLBACK(int) FNDNDPROGRESS(unsigned uPercentage, uint32_t uState, void *pvUser);
typedef FNDNDPROGRESS *PFNDNDPROGRESS;

/**
 * DnD message class. This class forms the base of all other more specialized
 * message classes.
 */
class DnDMessage
{
public:
    DnDMessage()
      : m_pNextMsg(NULL)
    {
    }
    virtual ~DnDMessage()
    {
        clearNextMsg();
    }

    virtual HGCM::Message* nextHGCMMessage()
    {
        return m_pNextMsg;
    }
    virtual int currentMessageInfo(uint32_t *puMsg, uint32_t *pcParms)
    {
        AssertPtrReturn(puMsg, VERR_INVALID_POINTER);
        AssertPtrReturn(pcParms, VERR_INVALID_POINTER);

        if (!m_pNextMsg)
            return VERR_NO_DATA;

        *puMsg = m_pNextMsg->message();
        *pcParms = m_pNextMsg->paramsCount();

        return VINF_SUCCESS;
    }
    virtual int currentMessage(uint32_t uMsg, uint32_t cParms, VBOXHGCMSVCPARM paParms[])
    {
        if (!m_pNextMsg)
            return VERR_NO_DATA;

        int rc = m_pNextMsg->getData(uMsg, cParms, paParms);

        clearNextMsg();

        return rc;
    }
    virtual void clearNextMsg()
    {
        if (m_pNextMsg)
        {
            delete m_pNextMsg;
            m_pNextMsg = NULL;
        }
    }

    virtual bool isMessageWaiting() const { return m_pNextMsg != NULL; }

protected:
    HGCM::Message *m_pNextMsg;
};

/**
 * DnD message class for generic messages which didn't need any special
 * handling.
 */
class DnDGenericMessage: public DnDMessage
{
public:
    DnDGenericMessage(uint32_t uMsg, uint32_t cParms, VBOXHGCMSVCPARM paParms[])
    {
        m_pNextMsg = new HGCM::Message(uMsg, cParms, paParms);
    }
};

/**
 * DnD message class for informing the guest about a new drop data event.
 */
class DnDHGSendDataMessage: public DnDMessage
{
public:
    DnDHGSendDataMessage(uint32_t uMsg, uint32_t cParms, VBOXHGCMSVCPARM paParms[], PFNDNDPROGRESS pfnProgressCallback, void *pvProgressUser);
    ~DnDHGSendDataMessage();

    HGCM::Message* nextHGCMMessage();
    int currentMessageInfo(uint32_t *puMsg, uint32_t *pcParms);
    int currentMessage(uint32_t uMsg, uint32_t cParms, VBOXHGCMSVCPARM paParms[]);

    bool isMessageWaiting() const { return !!m_pNextPathMsg; }

protected:
    struct PathEntry
    {
        PathEntry(const RTCString &strHostPath, const RTCString &strGuestPath, uint32_t fMode, uint64_t cbSize)
          : m_strHostPath(strHostPath)
          , m_strGuestPath(strGuestPath)
          , m_fMode(fMode)
          , m_cbSize(cbSize) {}
        RTCString m_strHostPath;
        RTCString m_strGuestPath;
        uint32_t  m_fMode;
        uint64_t  m_cbSize;
    };

    bool hasFileUrls(const char *pcszFormat, size_t cbMax) const;
    int buildFileTree(const char *pcszPath, size_t cbBaseLen);
    static DECLCALLBACK(int) progressCallback(size_t cbDone, void *pvUser);

    RTCList<PathEntry>  m_uriList;
    DnDMessage         *m_pNextPathMsg;

    /* Progress stuff */
    size_t              m_cbAll;
    size_t              m_cbTransfered;
    PFNDNDPROGRESS      m_pfnProgressCallback;
    void               *m_pvProgressUser;
};

/**
 * DnD message class for informing the guest to cancel any currently and
 * pending activities.
 */
class DnDHGCancelMessage: public DnDMessage
{
public:
    DnDHGCancelMessage()
    {
        m_pNextMsg = new HGCM::Message(DragAndDropSvc::HOST_DND_HG_EVT_CANCEL, 0, 0);
    }
};

/**
 * DnD manager. Manage creation and queuing of messages for the various DnD
 * messages types.
 */
class DnDManager
{
public:
    DnDManager(PFNDNDPROGRESS pfnProgressCallback, void *pvProgressUser)
      : m_pCurMsg(0)
      , m_fOpInProcess(false)
      , m_pfnProgressCallback(pfnProgressCallback)
      , m_pvProgressUser(pvProgressUser)
    {}
    ~DnDManager()
    {
        clear();
    }

    int addMessage(uint32_t uMsg, uint32_t cParms, VBOXHGCMSVCPARM paParms[]);

    HGCM::Message *nextHGCMMessage();
    int nextMessageInfo(uint32_t *puMsg, uint32_t *pcParms);
    int nextMessage(uint32_t uMsg, uint32_t cParms, VBOXHGCMSVCPARM paParms[]);

    void clear();

    bool hasActiveOperation() const { return m_fOpInProcess; }

private:
    DnDMessage           *m_pCurMsg;
    RTCList<DnDMessage*>  m_dndMessageQueue;

    bool                  m_fOpInProcess;

    /* Progress stuff */
    PFNDNDPROGRESS        m_pfnProgressCallback;
    void                 *m_pvProgressUser;
};

#endif /* ___VBox_HostService_DnD_dndmanager_h */