/* $Id: ProgressCombinedImpl.h 30739 2010-07-08 12:27:42Z vboxsync $ */
/** @file
 *
 * VirtualBox COM class implementation
 */

/*
 * Copyright (C) 2006-2010 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 ____H_PROGRESSCOMBINEDIMPL
#define ____H_PROGRESSCOMBINEDIMPL

#include "ProgressImpl.h"
#include "AutoCaller.h"

#include <vector>

/**
 * The CombinedProgress class allows to combine several progress objects to a
 * single progress component. This single progress component will treat all
 * operations of individual progress objects as a single sequence of operations
 * that follow each other in the same order as progress objects are passed to
 * the #init() method.
 *
 * @note CombinedProgress is legacy code and deprecated. It does not support
 *       weighted operations, all suboperations are assumed to take the same
 *       amount of time. For new code, please use IProgress directly which
 *       has supported multiple weighted suboperations since VirtualBox 3.0.
 *
 * Individual progress objects are sequentially combined so that this progress
 * object:
 *
 *  -   is cancelable only if all progresses are cancelable.
 *  -   is canceled once a progress that follows next to successfully completed
 *      ones reports it was canceled.
 *  -   is completed successfully only after all progresses are completed
 *      successfully.
 *  -   is completed unsuccessfully once a progress that follows next to
 *      successfully completed ones reports it was completed unsuccessfully;
 *      the result code and error info of the unsuccessful progress
 *      will be reported as the result code and error info of this progress.
 *  -   returns N as the operation number, where N equals to the number of
 *      operations in all successfully completed progresses starting from the
 *      first one plus the operation number of the next (not yet complete)
 *      progress; the operation description of the latter one is reported as
 *      the operation description of this progress object.
 *  -   returns P as the percent value, where P equals to the sum of percents
 *      of all successfully completed progresses starting from the
 *      first one plus the percent value of the next (not yet complete)
 *      progress, normalized to 100%.
 *
 * @note It's the respoisibility of the combined progress object creator to
 *       complete individual progresses in the right order: if, let's say, the
 *       last progress is completed before all previous ones,
 *       #WaitForCompletion(-1) will most likely give 100% CPU load because it
 *       will be in a loop calling a method that returns immediately.
 */
class ATL_NO_VTABLE CombinedProgress :
    public Progress
{

public:
    VIRTUALBOXBASE_ADD_ERRORINFO_SUPPORT(CombinedProgress, IProgress)

    DECLARE_NOT_AGGREGATABLE(CombinedProgress)

    DECLARE_PROTECT_FINAL_CONSTRUCT()

    BEGIN_COM_MAP (CombinedProgress)
        COM_INTERFACE_ENTRY  (ISupportErrorInfo)
        COM_INTERFACE_ENTRY  (IProgress)
        COM_INTERFACE_ENTRY2 (IDispatch, IProgress)
    END_COM_MAP()

    HRESULT FinalConstruct();
    void FinalRelease();

    // public initializer/uninitializer for internal purposes only

    HRESULT init (
#if !defined (VBOX_COM_INPROC)
                  VirtualBox *aParent,
#endif
                  IUnknown *aInitiator,
                  CBSTR aDescription,
                  IProgress *aProgress1, IProgress *aProgress2,
                  OUT_GUID aId = NULL);

    /**
     * Initializes the combined progress object given the first and the last
     * normal progress object from the list.
     *
     * @param aParent       See ProgressBase::init().
     * @param aInitiator    See ProgressBase::init().
     * @param aDescription  See ProgressBase::init().
     * @param aFirstProgress Iterator of the first normal progress object.
     * @param aSecondProgress Iterator of the last normal progress object.
     * @param aId           See ProgressBase::init().
     */
    template <typename InputIterator>
    HRESULT init (
#if !defined (VBOX_COM_INPROC)
                  VirtualBox *aParent,
#endif
                  IUnknown *aInitiator,
                  CBSTR aDescription,
                  InputIterator aFirstProgress, InputIterator aLastProgress,
                  OUT_GUID aId = NULL)
    {
        /* Enclose the state transition NotReady->InInit->Ready */
        AutoInitSpan autoInitSpan (this);
        AssertReturn (autoInitSpan.isOk(), E_FAIL);

        mProgresses = ProgressVector (aFirstProgress, aLastProgress);

        HRESULT rc = protectedInit (autoInitSpan,
#if !defined (VBOX_COM_INPROC)
                                    aParent,
#endif
                                    aInitiator, aDescription, aId);

        /* Confirm a successful initialization when it's the case */
        if (SUCCEEDED(rc))
            autoInitSpan.setSucceeded();

        return rc;
    }

protected:

    HRESULT protectedInit (AutoInitSpan &aAutoInitSpan,
#if !defined (VBOX_COM_INPROC)
                           VirtualBox *aParent,
#endif
                           IUnknown *aInitiator,
                           CBSTR aDescription, OUT_GUID aId);

public:

    void uninit();

    // IProgress properties
    STDMETHOD(COMGETTER(Percent)) (ULONG *aPercent);
    STDMETHOD(COMGETTER(Completed)) (BOOL *aCompleted);
    STDMETHOD(COMGETTER(Canceled)) (BOOL *aCanceled);
    STDMETHOD(COMGETTER(ResultCode)) (LONG *aResultCode);
    STDMETHOD(COMGETTER(ErrorInfo)) (IVirtualBoxErrorInfo **aErrorInfo);
    STDMETHOD(COMGETTER(Operation)) (ULONG *aCount);
    STDMETHOD(COMGETTER(OperationDescription)) (BSTR *aOperationDescription);
    STDMETHOD(COMGETTER(OperationPercent)) (ULONG *aOperationPercent);
    STDMETHOD(COMSETTER(Timeout)) (ULONG aTimeout);
    STDMETHOD(COMGETTER(Timeout)) (ULONG *aTimeout);

    // IProgress methods
    STDMETHOD(WaitForCompletion) (LONG aTimeout);
    STDMETHOD(WaitForOperationCompletion) (ULONG aOperation, LONG aTimeout);
    STDMETHOD(Cancel)();

    STDMETHOD(SetCurrentOperationProgress)(ULONG aPercent)
    {
        NOREF(aPercent);
        return E_NOTIMPL;
    }

    STDMETHOD(SetNextOperation)(IN_BSTR bstrNextOperationDescription, ULONG ulNextOperationsWeight)
    {
        NOREF(bstrNextOperationDescription); NOREF(ulNextOperationsWeight);
        return E_NOTIMPL;
    }

    // public methods only for internal purposes

private:

    HRESULT checkProgress();

    typedef std::vector <ComPtr<IProgress> > ProgressVector;
    ProgressVector mProgresses;

    size_t mProgress;
    ULONG mCompletedOperations;
};

#endif /* ____H_PROGRESSCOMBINEDIMPL */