/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * The contents of this file are subject to the Netscape Public License
 * Version 1.0 (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/NPL/
 *
 * 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 Communicator client code.
 *
 * The Initial Developer of the Original Code is Netscape Communications
 * Corporation.  Portions created by Netscape are Copyright (C) 1998
 * Netscape Communications Corporation.  All Rights Reserved.
 */

#include "nscore.h"
#include "nsCRT.h"
#include "nsString.h"
#include "nsISupports.h"
#include "nsIContentViewerContainer.h"
#include "nsIDocumentViewer.h"

#include "nsIDocument.h"
#include "nsIPresContext.h"
#include "nsIPresShell.h"
#include "nsIStyleSet.h"
#include "nsIStyleSheet.h"

#include "nsIScriptContextOwner.h"
#include "nsIScriptGlobalObject.h"
#include "nsILinkHandler.h"
#include "nsIDOMDocument.h"

#include "nsViewsCID.h"
#include "nsWidgetsCID.h"
#include "nsIDeviceContext.h"
#include "nsIViewManager.h"
#include "nsIView.h"

#include "nsIURL.h"

class DocumentViewerImpl : public nsIDocumentViewer
{
public:
    DocumentViewerImpl();
    
    void* operator new(size_t sz) {
        void* rv = new char[sz];
        nsCRT::zero(rv, sz);
        return rv;
    }

    // nsISupports interface...
    NS_DECL_ISUPPORTS

    // nsIContentViewer interface...
    NS_IMETHOD Init(nsNativeWidget aParent,
                    nsIDeviceContext* aDeviceContext,
                    nsIPref* aPrefs,
                    const nsRect& aBounds,
                    nsScrollPreference aScrolling = nsScrollPreference_kAuto);
    
    NS_IMETHOD BindToDocument(nsISupports* aDoc, const char* aCommand);
    NS_IMETHOD SetContainer(nsIContentViewerContainer* aContainer);
    NS_IMETHOD GetContainer(nsIContentViewerContainer*& aContainerResult);

    virtual nsRect GetBounds();
    virtual void SetBounds(const nsRect& aBounds);
    virtual void Move(PRInt32 aX, PRInt32 aY);
    virtual void Show();
    virtual void Hide();


    // nsIDocumentViewer interface...
    NS_IMETHOD Init(nsNativeWidget aParent,
                    const nsRect& aBounds,
                    nsIDocument* aDocument,
                    nsIPresContext* aPresContext,
                    nsScrollPreference aScrolling = nsScrollPreference_kAuto);

    NS_IMETHOD SetUAStyleSheet(nsIStyleSheet* aUAStyleSheet);
  
    NS_IMETHOD GetDocument(nsIDocument*& aResult);
  
    NS_IMETHOD GetPresShell(nsIPresShell*& aResult);
  
    NS_IMETHOD GetPresContext(nsIPresContext*& aResult);

protected:
    virtual ~DocumentViewerImpl();

private:
    void ForceRefresh(void);
    nsresult CreateStyleSet(nsIDocument* aDocument, nsIStyleSet** aStyleSet);
    nsresult MakeWindow(nsNativeWidget aNativeParent,
                        const nsRect& aBounds,
                        nsScrollPreference aScrolling);

protected:
    nsIViewManager* mViewManager;
    nsIView*        mView;
    nsIWidget*      mWindow;
    nsIContentViewerContainer* mContainer;

    nsIDocument*    mDocument;
    nsIPresContext* mPresContext;
    nsIPresShell*   mPresShell;
    nsIStyleSheet*  mUAStyleSheet;

};

//Class IDs
static NS_DEFINE_IID(kViewManagerCID,       NS_VIEW_MANAGER_CID);
static NS_DEFINE_IID(kScrollingViewCID,     NS_SCROLLING_VIEW_CID);
static NS_DEFINE_IID(kWidgetCID,            NS_CHILD_CID);


// Interface IDs
static NS_DEFINE_IID(kIScriptContextOwnerIID, NS_ISCRIPTCONTEXTOWNER_IID);
static NS_DEFINE_IID(kISupportsIID,         NS_ISUPPORTS_IID);
static NS_DEFINE_IID(kIDocumentIID,         NS_IDOCUMENT_IID);
static NS_DEFINE_IID(kIDOMDocumentIID,      NS_IDOMDOCUMENT_IID);
static NS_DEFINE_IID(kIViewManagerIID,      NS_IVIEWMANAGER_IID);
static NS_DEFINE_IID(kIViewIID,             NS_IVIEW_IID);
static NS_DEFINE_IID(kScrollViewIID,        NS_ISCROLLABLEVIEW_IID);
static NS_DEFINE_IID(kIContentViewerIID,    NS_ICONTENT_VIEWER_IID);
static NS_DEFINE_IID(kIDocumentViewerIID,   NS_IDOCUMENT_VIEWER_IID);
static NS_DEFINE_IID(kILinkHandlerIID,      NS_ILINKHANDLER_IID);


// Note: operator new zeros our memory
DocumentViewerImpl::DocumentViewerImpl()
{
    NS_INIT_REFCNT();
}

// ISupports implementation...
NS_IMPL_ADDREF(DocumentViewerImpl)
NS_IMPL_RELEASE(DocumentViewerImpl)

nsresult DocumentViewerImpl::QueryInterface(REFNSIID aIID, void** aInstancePtr)
{
    if (NULL == aInstancePtr) {
        return NS_ERROR_NULL_POINTER;
    }

    if (aIID.Equals(kIContentViewerIID)) {
        *aInstancePtr = (void*)(nsIContentViewer*)this;
        NS_ADDREF_THIS();
        return NS_OK;
    }
    if (aIID.Equals(kIDocumentViewerIID)) {
        *aInstancePtr = (void*)(nsIDocumentViewer*)this;
        NS_ADDREF_THIS();
        return NS_OK;
    }
    if (aIID.Equals(kISupportsIID)) {
        *aInstancePtr = (void*)(nsISupports*)(nsIContentViewer*)this;
        NS_ADDREF_THIS();
        return NS_OK;
    }
    return NS_NOINTERFACE;
}


DocumentViewerImpl::~DocumentViewerImpl()
{
    // Release windows and views
    NS_IF_RELEASE(mViewManager);
    NS_IF_RELEASE(mWindow);

    if (nsnull != mDocument) {
      //Break global object circular reference on the document
      //created in the DocViewer Init
      nsIScriptContextOwner *mOwner = mDocument->GetScriptContextOwner();
      if (nsnull != mOwner) {
        nsIScriptGlobalObject *mGlobal;
        mOwner->GetScriptGlobalObject(&mGlobal);
        if (nsnull != mGlobal) {
          mGlobal->SetNewDocument(nsnull);
          NS_RELEASE(mGlobal);
        }
        NS_RELEASE(mOwner);

        mDocument->SetScriptContextOwner(nsnull);
      }
      NS_RELEASE(mDocument);
    }
    
    // Note: release context then shell
    NS_IF_RELEASE(mPresContext);
    if (nsnull != mPresShell) {
        // Break circular reference first
        mPresShell->EndObservingDocument();

        // Then release the shell
        NS_RELEASE(mPresShell);
    }
    
    NS_IF_RELEASE(mUAStyleSheet);
    NS_IF_RELEASE(mContainer);
}



/*
 * This method is called by the Document Loader once a document has
 * been created for a particular data stream...  The content viewer
 * must cache this document for later use when Init(...) is called.
 */
NS_IMETHODIMP
DocumentViewerImpl::BindToDocument(nsISupports *aDoc, const char *aCommand)
{
    nsresult rv;

    NS_PRECONDITION(nsnull == mDocument, "Viewer is already bound to a document!");

#ifdef NS_DEBUG
    printf("DocumentViewerImpl::BindToDocument\n");
#endif

    rv = aDoc->QueryInterface(kIDocumentIID, (void**)&mDocument);
    if (nsnull != mDocument) {
    }
    return rv;
}

NS_IMETHODIMP
DocumentViewerImpl::SetContainer(nsIContentViewerContainer* aContainer)
{
    NS_IF_RELEASE(mContainer);
    mContainer = aContainer;

    if (nsnull != aContainer) {
        if (nsnull != mPresContext) {
            mPresContext->SetContainer(aContainer);
        }
        NS_ADDREF(mContainer);
    }

    return NS_OK;
}

NS_IMETHODIMP
DocumentViewerImpl::GetContainer(nsIContentViewerContainer*& aResult)
{
    aResult = mContainer;
    NS_IF_ADDREF(mContainer);
    return NS_OK;
}


NS_IMETHODIMP
DocumentViewerImpl::Init(nsNativeWidget aNativeParent,
                         nsIDeviceContext* aDeviceContext,
                         nsIPref* aPrefs,
                         const nsRect& aBounds,
                         nsScrollPreference aScrolling)
{
    nsresult rv;

    if (nsnull == mDocument) {
        return NS_ERROR_NULL_POINTER;
    }

    // Create presentation context
    rv = NS_NewGalleyContext(&mPresContext);
    if (NS_OK != rv) {
        return rv;
    }

    mPresContext->Init(aDeviceContext, aPrefs); 
    rv = Init(aNativeParent, aBounds, mDocument, mPresContext, aScrolling);

    // Init(...) will addref the Presentation Context...
    if (NS_OK == rv) {
        // XXX FIX ME...
        mPresContext->Release();
    }
    return rv;
}


NS_IMETHODIMP
DocumentViewerImpl::Init(nsNativeWidget aNativeParent,
                         const nsRect& aBounds,
                         nsIDocument* aDocument,
                         nsIPresContext* aPresContext,
                         nsScrollPreference aScrolling)
{
    nsresult rv;
    nsRect bounds;
    nscoord width, height;

    NS_PRECONDITION(nsnull != aPresContext, "null ptr");
    NS_PRECONDITION(nsnull != aDocument,    "null ptr");
    if ((nsnull == aPresContext) || (nsnull == aDocument)) {
        rv = NS_ERROR_NULL_POINTER;
        goto done;
    }

    mPresContext = aPresContext;
    NS_ADDREF(mPresContext);

    if (nsnull != mContainer) {
        nsILinkHandler* linkHandler = nsnull;
        mContainer->QueryCapability(kILinkHandlerIID, (void**)&linkHandler);
        mPresContext->SetContainer(mContainer);
        mPresContext->SetLinkHandler(linkHandler);
        NS_IF_RELEASE(linkHandler);

        // Set script-context-owner in the document
        nsIScriptContextOwner* owner = nsnull;
        mContainer->QueryCapability(kIScriptContextOwnerIID, (void**)&owner);
        if (nsnull != owner) {
            aDocument->SetScriptContextOwner(owner);
            nsIScriptGlobalObject* global;
            owner->GetScriptGlobalObject(&global);
            if (nsnull != global) {
                nsIDOMDocument *domdoc = nsnull;
                aDocument->QueryInterface(kIDOMDocumentIID,
                                          (void**) &domdoc);
                if (nsnull != domdoc) {
                    global->SetNewDocument(domdoc);
                    NS_RELEASE(domdoc);
                }
                NS_RELEASE(global);
            }
            NS_RELEASE(owner);
        }
    }

    // Create the ViewManager and Root View...
    MakeWindow(aNativeParent, aBounds, aScrolling);

    // Create the style set...
    nsIStyleSet* styleSet;
    rv = CreateStyleSet(aDocument, &styleSet);
    if (NS_OK != rv) {
        goto done;
    }

    // Now make the shell for the document
    rv = aDocument->CreateShell(mPresContext, mViewManager, styleSet,
                                &mPresShell);
    NS_RELEASE(styleSet);
    if (NS_OK != rv) {
        goto done;
    }

    // Initialize our view manager
    mWindow->GetBounds(bounds);
    width = bounds.width;
    height = bounds.height;
    width = NSIntPixelsToTwips(width, mPresContext->GetPixelsToTwips());
    height = NSIntPixelsToTwips(height, mPresContext->GetPixelsToTwips());
    mViewManager->DisableRefresh();
    mViewManager->SetWindowDimensions(width, height);

done:
    return rv;
}

NS_IMETHODIMP
DocumentViewerImpl::SetUAStyleSheet(nsIStyleSheet* aUAStyleSheet)
{
    NS_IF_RELEASE(mUAStyleSheet);
    mUAStyleSheet = aUAStyleSheet;
    NS_IF_ADDREF(mUAStyleSheet);

    return NS_OK;
}
  
NS_IMETHODIMP
DocumentViewerImpl::GetDocument(nsIDocument*& aResult)
{
    aResult = mDocument;
    NS_IF_ADDREF(mDocument);
    return NS_OK;
}
  
NS_IMETHODIMP
DocumentViewerImpl::GetPresShell(nsIPresShell*& aResult)
{
    aResult = mPresShell;
    NS_IF_ADDREF(mPresShell);
    return NS_OK;
}
  
NS_IMETHODIMP
DocumentViewerImpl::GetPresContext(nsIPresContext*& aResult)
{
    aResult = mPresContext;
    NS_IF_ADDREF(mPresContext);
    return NS_OK;
}


nsRect DocumentViewerImpl::GetBounds()
{
    NS_PRECONDITION(nsnull != mWindow, "null window");
    nsRect zr(0, 0, 0, 0);
    if (nsnull != mWindow) {
        mWindow->GetBounds(zr);
    }
    return zr;
}


void DocumentViewerImpl::SetBounds(const nsRect& aBounds)
{
    NS_PRECONDITION(nsnull != mWindow, "null window");
    if (nsnull != mWindow) {
        // Don't have the widget repaint. Layout will generate repaint requests
        // during reflow
        mWindow->Resize(aBounds.x, aBounds.y, aBounds.width, aBounds.height, PR_FALSE);
    }
}


void DocumentViewerImpl::Move(PRInt32 aX, PRInt32 aY)
{
    NS_PRECONDITION(nsnull != mWindow, "null window");
    if (nsnull != mWindow) {
        mWindow->Move(aX, aY);
    }
}

void DocumentViewerImpl::Show()
{
    NS_PRECONDITION(nsnull != mWindow, "null window");
    if (nsnull != mWindow) {
        mWindow->Show(PR_TRUE);
    }
}

void DocumentViewerImpl::Hide()
{
    NS_PRECONDITION(nsnull != mWindow, "null window");
    if (nsnull != mWindow) {
        mWindow->Show(PR_FALSE);
    }
}



void DocumentViewerImpl::ForceRefresh()
{
    mWindow->Invalidate(PR_TRUE);
}

nsresult DocumentViewerImpl::CreateStyleSet(nsIDocument* aDocument, nsIStyleSet** aStyleSet)
{ // this should eventually get expanded to allow for creating different sets for different media
    nsresult rv;

    if (nsnull == mUAStyleSheet) {
        NS_WARNING("unable to load UA style sheet");
    }

    rv = NS_NewStyleSet(aStyleSet);
    if (NS_OK == rv) {
        PRInt32 index = aDocument->GetNumberOfStyleSheets();

        while (0 < index--) {
            nsIStyleSheet* sheet = aDocument->GetStyleSheetAt(index);
            (*aStyleSet)->AppendDocStyleSheet(sheet);
            NS_RELEASE(sheet);
        }
        if (nsnull != mUAStyleSheet) {
            (*aStyleSet)->AppendBackstopStyleSheet(mUAStyleSheet);
        }
    }
    return rv;
}


nsresult DocumentViewerImpl::MakeWindow(nsNativeWidget aNativeParent,
                                       const nsRect& aBounds,
                                       nsScrollPreference aScrolling)
{
    nsresult rv;

    rv = nsRepository::CreateInstance(kViewManagerCID, 
                                      nsnull, 
                                      kIViewManagerIID, 
                                      (void **)&mViewManager);

    nsIDeviceContext  *dx = mPresContext->GetDeviceContext();

    if ((NS_OK != rv) || (NS_OK != mViewManager->Init(dx))) {
      return rv;
    }

    NS_IF_RELEASE(dx);

    nsRect tbounds = aBounds;
    tbounds *= mPresContext->GetPixelsToTwips();

    // Create a child window of the parent that is our "root view/window"
    // Create a view
    rv = nsRepository::CreateInstance(kScrollingViewCID, 
                                      nsnull, 
                                      kIViewIID, 
                                      (void **)&mView);
    static NS_DEFINE_IID(kWidgetCID, NS_CHILD_CID);
    if ((NS_OK != rv) || (NS_OK != mView->Init(mViewManager, 
                                               tbounds, 
                                               nsnull,
                                               &kWidgetCID,
                                               nsnull,
                                               aNativeParent))) {
        return rv;
    }

    nsIScrollableView* scrollView;
    rv = mView->QueryInterface(kScrollViewIID, (void**)&scrollView);
    if (NS_OK == rv) {
        scrollView->SetScrollPreference(aScrolling);
    }
    else {
        NS_ASSERTION(0, "invalid scrolling view");
        return rv;
    }

    // Setup hierarchical relationship in view manager
    mViewManager->SetRootView(mView);
    mView->GetWidget(mWindow);

    //set frame rate to 25 fps
    mViewManager->SetFrameRate(25);

    // This SetFocus is necessary so the Arrow Key and Page Key events
    // go to the scrolled view as soon as the Window is created instead of going to
    // the browser window (this enables keyboard scrolling of the document)
    mWindow->SetFocus();

    return rv;
}

NS_WEB nsresult NS_NewDocumentViewer(nsIDocumentViewer*& aViewer)
{
    aViewer = new DocumentViewerImpl();
    if (nsnull == aViewer) {
        return NS_ERROR_OUT_OF_MEMORY;
    }
    NS_ADDREF(aViewer);
    return NS_OK;
}