/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1999
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
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 * ***** END LICENSE BLOCK ***** */

/* 
*/

#ifndef nsDocLoader_h__
#define nsDocLoader_h__

#include "nsIDocumentLoader.h"
#include "nsIWebProgress.h"
#include "nsIWebProgressListener.h"
#include "nsIRequestObserver.h"
#include "nsWeakReference.h"
#include "nsILoadGroup.h"
#include "nsCOMArray.h"
#include "nsVoidArray.h"
#include "nsString.h"
#include "nsIChannel.h"
#include "nsIProgressEventSink.h"
#include "nsIInterfaceRequestor.h"
#include "nsIInterfaceRequestorUtils.h"
#include "nsIChannelEventSink.h"
#include "nsISecurityEventSink.h"
#include "nsISupportsPriority.h"
#include "nsInt64.h"
#include "nsCOMPtr.h"
#include "pldhash.h"

struct nsRequestInfo;
struct nsListenerInfo;

/****************************************************************************
 * nsDocLoader implementation...
 ****************************************************************************/

#define NS_THIS_DOCLOADER_IMPL_CID                    \
 { /* b4ec8387-98aa-4c08-93b6-6d23069c06f2 */         \
     0xb4ec8387,                                      \
     0x98aa,                                          \
     0x4c08,                                          \
     {0x93, 0xb6, 0x6d, 0x23, 0x06, 0x9c, 0x06, 0xf2} \
 }

class nsDocLoader : public nsIDocumentLoader, 
                    public nsIRequestObserver,
                    public nsSupportsWeakReference,
                    public nsIProgressEventSink,
                    public nsIWebProgress,
                    public nsIInterfaceRequestor,
                    public nsIChannelEventSink,
                    public nsISecurityEventSink,
                    public nsISupportsPriority
{
public:
    NS_DECLARE_STATIC_IID_ACCESSOR(NS_THIS_DOCLOADER_IMPL_CID)

    nsDocLoader();

    virtual nsresult Init();

    static already_AddRefed<nsDocLoader> GetAsDocLoader(nsISupports* aSupports);
    // Needed to deal with ambiguous inheritance from nsISupports...
    static nsISupports* GetAsSupports(nsDocLoader* aDocLoader) {
        return static_cast<nsIDocumentLoader*>(aDocLoader);
    }

    // Add aDocLoader as a child to the docloader service.
    static nsresult AddDocLoaderAsChildOfRoot(nsDocLoader* aDocLoader);

    NS_DECL_ISUPPORTS
    NS_DECL_NSIDOCUMENTLOADER
    
    // nsIProgressEventSink
    NS_DECL_NSIPROGRESSEVENTSINK

    NS_DECL_NSISECURITYEVENTSINK

    // nsIRequestObserver methods: (for observing the load group)
    NS_DECL_NSIREQUESTOBSERVER
    NS_DECL_NSIWEBPROGRESS

    NS_DECL_NSIINTERFACEREQUESTOR
    NS_DECL_NSICHANNELEVENTSINK
    NS_DECL_NSISUPPORTSPRIORITY

    // Implementation specific methods...

    // Remove aChild from our childlist.  This nulls out the child's mParent
    // pointer.
    nsresult RemoveChildLoader(nsDocLoader *aChild);
    // Add aChild to our child list.  This will set aChild's mParent pointer to
    // |this|.
    nsresult AddChildLoader(nsDocLoader* aChild);
    nsDocLoader* GetParent() const { return mParent; }

protected:
    virtual ~nsDocLoader();

    virtual nsresult SetDocLoaderParent(nsDocLoader * aLoader);

    PRBool IsBusy();

    void Destroy();
    virtual void DestroyChildren();

    nsIDocumentLoader* ChildAt(PRInt32 i) {
        return static_cast<nsDocLoader*>(mChildList[i]);
    }

    nsIDocumentLoader* SafeChildAt(PRInt32 i) {
        return static_cast<nsDocLoader*>(mChildList.SafeElementAt(i));
    }

    void FireOnProgressChange(nsDocLoader* aLoadInitiator,
                              nsIRequest *request,
                              PRInt64 aProgress,
                              PRInt64 aProgressMax,
                              PRInt64 aProgressDelta,
                              PRInt64 aTotalProgress,
                              PRInt64 aMaxTotalProgress);

    void FireOnStateChange(nsIWebProgress *aProgress,
                           nsIRequest* request,
                           PRInt32 aStateFlags,
                           nsresult aStatus);

    void FireOnStatusChange(nsIWebProgress *aWebProgress,
                            nsIRequest *aRequest,
                            nsresult aStatus,
                            const PRUnichar* aMessage);

    void FireOnLocationChange(nsIWebProgress* aWebProgress,
                              nsIRequest* aRequest,
                              nsIURI *aUri);

    PRBool RefreshAttempted(nsIWebProgress* aWebProgress,
                            nsIURI *aURI,
                            PRInt32 aDelay,
                            PRBool aSameURI);

    // this function is overridden by the docshell, it is provided so that we
    // can pass more information about redirect state (the normal OnStateChange
    // doesn't get the new channel).
    // @param aRedirectFlags The flags being sent to OnStateChange that
    //                       indicate the type of redirect.
    // @param aStateFlags    The channel flags normally sent to OnStateChange.
    virtual void OnRedirectStateChange(nsIChannel* aOldChannel,
                                       nsIChannel* aNewChannel,
                                       PRUint32 aRedirectFlags,
                                       PRUint32 aStateFlags) {}

    void doStartDocumentLoad();
    void doStartURLLoad(nsIRequest *request);
    void doStopURLLoad(nsIRequest *request, nsresult aStatus);
    void doStopDocumentLoad(nsIRequest *request, nsresult aStatus);

    // Inform a parent docloader that aChild is about to call its onload
    // handler.
    PRBool ChildEnteringOnload(nsIDocumentLoader* aChild) {
        // It's ok if we're already in the list -- we'll just be in there twice
        // and then the RemoveObject calls from ChildDoneWithOnload will remove
        // us.
        return mChildrenInOnload.AppendObject(aChild);
    }

    // Inform a parent docloader that aChild is done calling its onload
    // handler.
    void ChildDoneWithOnload(nsIDocumentLoader* aChild) {
        mChildrenInOnload.RemoveObject(aChild);
        DocLoaderIsEmpty(PR_TRUE);
    }        

protected:
    // IMPORTANT: The ownership implicit in the following member
    // variables has been explicitly checked and set using nsCOMPtr
    // for owning pointers and raw COM interface pointers for weak
    // (ie, non owning) references. If you add any members to this
    // class, please make the ownership explicit (pinkerton, scc).
  
    nsCOMPtr<nsIRequest>       mDocumentRequest;       // [OWNER] ???compare with document

    nsDocLoader*               mParent;                // [WEAK]

    nsVoidArray                mListenerInfoList;

    nsCOMPtr<nsILoadGroup>        mLoadGroup;
    // We hold weak refs to all our kids
    nsVoidArray                   mChildList;

    // The following member variables are related to the new nsIWebProgress 
    // feedback interfaces that travis cooked up.
    PRInt32 mProgressStateFlags;

    nsInt64 mCurrentSelfProgress;
    nsInt64 mMaxSelfProgress;

    nsInt64 mCurrentTotalProgress;
    nsInt64 mMaxTotalProgress;

    PLDHashTable mRequestInfoHash;

    /*
     * This flag indicates that the loader is loading a document.  It is set
     * from the call to LoadDocument(...) until the OnConnectionsComplete(...)
     * notification is fired...
     */
    PRPackedBool mIsLoadingDocument;

    /* Flag to indicate that we're in the process of restoring a document. */
    PRPackedBool mIsRestoringDocument;

    /* Flag to indicate that we're in the process of flushing layout
       undere DocLoaderIsEmpty() */
    PRPackedBool mIsFlushingLayout;

private:
    // A list of kids that are in the middle of their onload calls and will let
    // us know once they're done.  We don't want to fire onload for "normal"
    // DocLoaderIsEmpty calls (those coming from requests finishing in our
    // loadgroup) unless this is empty.
    nsCOMArray<nsIDocumentLoader> mChildrenInOnload;
    
    // DocLoaderIsEmpty should be called whenever the docloader may be empty.
    // This method is idempotent and does nothing if the docloader is not in
    // fact empty.  This method _does_ make sure that layout is flushed if our
    // loadgroup has no active requests before checking for "real" emptiness if
    // aFlushLayout is true.
    void DocLoaderIsEmpty(PRBool aFlushLayout);

    nsListenerInfo *GetListenerInfo(nsIWebProgressListener* aListener);

    PRInt64 GetMaxTotalProgress();

    nsresult AddRequestInfo(nsIRequest* aRequest);
    nsRequestInfo *GetRequestInfo(nsIRequest* aRequest);
    void ClearRequestInfoHash();
    PRInt64 CalculateMaxProgress();
///    void DumpChannelInfo(void);

    // used to clear our internal progress state between loads...
    void ClearInternalProgress(); 
};

NS_DEFINE_STATIC_IID_ACCESSOR(nsDocLoader, NS_THIS_DOCLOADER_IMPL_CID)

#endif /* nsDocLoader_h__ */
