/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsXMLPrettyPrinter.h"

#include "nsContentUtils.h"

#include "nsICSSDeclaration.h"

#include "nsIObserver.h"

#include "nsSyncLoadService.h"

#include "nsPIDOMWindow.h"

#include "nsIServiceManager.h"

#include "nsNetUtil.h"

#include "mozilla/dom/Element.h"

#include "nsBindingManager.h"

#include "nsXBLService.h"

#include "nsIScriptSecurityManager.h"

#include "mozilla/Preferences.h"

#include "nsIDocument.h"

#include "nsVariant.h"

#include "mozilla/dom/CustomEvent.h"

#include "mozilla/dom/DocumentFragment.h"

#include "mozilla/dom/ScriptSettings.h"

#include "mozilla/dom/ToJSValue.h"

#include "mozilla/dom/txMozillaXSLTProcessor.h"

using namespace mozilla;

using namespace mozilla::dom;

NS_IMPL_ISUPPORTS(nsXMLPrettyPrinter,

                  nsIDocumentObserver,

                  nsIMutationObserver)

nsXMLPrettyPrinter::nsXMLPrettyPrinter() : mDocument(nullptr),

                                           mUnhookPending(false)

{

}

nsXMLPrettyPrinter::~nsXMLPrettyPrinter()

{

    NS_ASSERTION(!mDocument, "we shouldn't be referencing the document still");

}

nsresult

nsXMLPrettyPrinter::PrettyPrint(nsIDocument* aDocument,

                                bool* aDidPrettyPrint)

{

    *aDidPrettyPrint = false;

    // Check for iframe with display:none. Such iframes don't have presshells

    nsCOMPtr<nsIPresShell> shell = aDocument->GetShell();

    if (!shell) {

        return NS_OK;

    }

    // check if we're in an invisible iframe

    nsPIDOMWindowOuter *internalWin = aDocument->GetWindow();

    nsCOMPtr<Element> frameElem;

    if (internalWin) {

        frameElem = internalWin->GetFrameElementInternal();

    }

    if (frameElem) {

        nsCOMPtr<nsICSSDeclaration> computedStyle;

        if (nsIDocument* frameOwnerDoc = frameElem->OwnerDoc()) {

            nsPIDOMWindowOuter* window = frameOwnerDoc->GetDefaultView();

            if (window) {

                nsCOMPtr<nsPIDOMWindowInner> innerWindow =

                    window->GetCurrentInnerWindow();

                ErrorResult dummy;

                computedStyle = innerWindow->GetComputedStyle(*frameElem,

                                                              EmptyString(),

                                                              dummy);

                dummy.SuppressException();

            }

        }

        if (computedStyle) {

            nsAutoString visibility;

            computedStyle->GetPropertyValue(NS_LITERAL_STRING("visibility"),

                                            visibility);

            if (!visibility.EqualsLiteral("visible")) {

                return NS_OK;

            }

        }

    }

    // check the pref

    if (!Preferences::GetBool("layout.xml.prettyprint", true)) {

        return NS_OK;

    }

    // Ok, we should prettyprint. Let's do it!

    *aDidPrettyPrint = true;

    nsresult rv = NS_OK;

    // Load the XSLT

    nsCOMPtr<nsIURI> xslUri;

    rv = NS_NewURI(getter_AddRefs(xslUri),

                   NS_LITERAL_CSTRING("chrome://global/content/xml/XMLPrettyPrint.xsl"));

    NS_ENSURE_SUCCESS(rv, rv);

    nsCOMPtr<nsIDocument> xslDocument;

    rv = nsSyncLoadService::LoadDocument(xslUri, nsIContentPolicy::TYPE_XSLT,

                                         nsContentUtils::GetSystemPrincipal(),

                                         nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_DATA_IS_NULL,

                                         nullptr, true, mozilla::net::RP_Unset,

                                         getter_AddRefs(xslDocument));

    NS_ENSURE_SUCCESS(rv, rv);

    // Transform the document

    RefPtr<txMozillaXSLTProcessor> transformer = new txMozillaXSLTProcessor();

    ErrorResult err;

    transformer->ImportStylesheet(*xslDocument, err);

    if (NS_WARN_IF(err.Failed())) {

        return err.StealNSResult();

    }

    RefPtr<DocumentFragment> resultFragment =

        transformer->TransformToFragment(*aDocument, *aDocument, err);

    if (NS_WARN_IF(err.Failed())) {

        return err.StealNSResult();

    }

    // Find the root element

    RefPtr<Element> rootElement = aDocument->GetRootElement();

    NS_ENSURE_TRUE(rootElement, NS_ERROR_UNEXPECTED);

    if (nsContentUtils::IsShadowDOMEnabled()) {

        // Attach a closed shadow root on it.

        RefPtr<ShadowRoot> shadowRoot =

            rootElement->AttachShadowWithoutNameChecks(ShadowRootMode::Closed);

        // Append the document fragment to the shadow dom.

        shadowRoot->AppendChild(*resultFragment, err);

        if (NS_WARN_IF(err.Failed())) {

            return err.StealNSResult();

        }

    } else {

        //

        // Apply the prettprint XBL binding.

        //

        // We take some shortcuts here. In particular, we don't bother invoking the

        // contstructor (since the binding has no constructor), and we don't bother

        // calling LoadBindingDocument because it's a chrome:// URI and thus will get

        // sync loaded no matter what.

        //

        // Grab the XBL service.

        nsXBLService* xblService = nsXBLService::GetInstance();

        NS_ENSURE_TRUE(xblService, NS_ERROR_NOT_AVAILABLE);

        // Compute the binding URI.

        nsCOMPtr<nsIURI> bindingUri;

        rv = NS_NewURI(getter_AddRefs(bindingUri),

            NS_LITERAL_STRING("chrome://global/content/xml/XMLPrettyPrint.xml#prettyprint"));

        NS_ENSURE_SUCCESS(rv, rv);

        // Grab the system principal.

        nsCOMPtr<nsIPrincipal> sysPrincipal;

        nsContentUtils::GetSecurityManager()->

            GetSystemPrincipal(getter_AddRefs(sysPrincipal));

        // Destroy any existing frames before we unbind anonymous content.

        // Note that the shell might be Destroy'ed by now (see bug 1415541).

        if (!shell->IsDestroying()) {

            shell->DestroyFramesForAndRestyle(rootElement);

        }

        // Load the bindings.

        RefPtr<nsXBLBinding> unused;

        bool ignored;

        rv = xblService->LoadBindings(rootElement, bindingUri, sysPrincipal,

                                      getter_AddRefs(unused), &ignored);

        NS_ENSURE_SUCCESS(rv, rv);

        // Fire an event at the bound element to pass it |resultFragment|.

        RefPtr<CustomEvent> event =

          NS_NewDOMCustomEvent(rootElement, nullptr, nullptr);

        MOZ_ASSERT(event);

        AutoJSAPI jsapi;

        if (!jsapi.Init(event->GetParentObject())) {

            return NS_ERROR_UNEXPECTED;

        }

        JSContext* cx = jsapi.cx();

        JS::Rooted<JS::Value> detail(cx);

        if (!ToJSValue(cx, resultFragment, &detail)) {

            return NS_ERROR_UNEXPECTED;

        }

        event->InitCustomEvent(cx, NS_LITERAL_STRING("prettyprint-dom-created"),

                               /* bubbles = */ false, /* cancelable = */ false,

                               detail);

        event->SetTrusted(true);

        rootElement->DispatchEvent(*event, err);

        if (NS_WARN_IF(err.Failed())) {

            return err.StealNSResult();

        }

    }

    // Observe the document so we know when to switch to "normal" view

    aDocument->AddObserver(this);

    mDocument = aDocument;

    NS_ADDREF_THIS();

    return NS_OK;

}

void

nsXMLPrettyPrinter::MaybeUnhook(nsIContent* aContent)

{

    // If aContent is null, the document-node was modified.

    // If it is not null but in the shadow tree, the <scrollbar> NACs,

    // or the XBL binding, the change was in the generated content, and

    // it should be ignored.

    bool isGeneratedContent = !aContent ?

        false :

        aContent->GetBindingParent() || aContent->IsInShadowTree();

    if (!isGeneratedContent && !mUnhookPending) {

        // Can't blindly to mUnhookPending after AddScriptRunner,

        // since AddScriptRunner _could_ in theory run us

        // synchronously

        mUnhookPending = true;

        nsContentUtils::AddScriptRunner(NewRunnableMethod(

          "nsXMLPrettyPrinter::Unhook", this, &nsXMLPrettyPrinter::Unhook));

    }

}

void

nsXMLPrettyPrinter::Unhook()

{

    mDocument->RemoveObserver(this);

    nsCOMPtr<Element> element = mDocument->GetDocumentElement();

    if (element) {

        // Remove the shadow root

        element->UnattachShadow();

        // Remove the bound XBL binding

        mDocument->BindingManager()->ClearBinding(element);

    }

    mDocument = nullptr;

    NS_RELEASE_THIS();

}

void

nsXMLPrettyPrinter::AttributeChanged(Element* aElement,

                                     int32_t aNameSpaceID,

                                     nsAtom* aAttribute,

                                     int32_t aModType,

                                     const nsAttrValue* aOldValue)

{

    MaybeUnhook(aElement);

}

void

nsXMLPrettyPrinter::ContentAppended(nsIContent* aFirstNewContent)

{

    MaybeUnhook(aFirstNewContent->GetParent());

}

void

nsXMLPrettyPrinter::ContentInserted(nsIContent* aChild)

{

    MaybeUnhook(aChild->GetParent());

}

void

nsXMLPrettyPrinter::ContentRemoved(nsIContent* aChild,

                                   nsIContent* aPreviousSibling)

{

    MaybeUnhook(aChild->GetParent());

}

void

nsXMLPrettyPrinter::NodeWillBeDestroyed(const nsINode* aNode)

{

    mDocument = nullptr;

    NS_RELEASE_THIS();

}

nsresult NS_NewXMLPrettyPrinter(nsXMLPrettyPrinter** aPrinter)

{

    *aPrinter = new nsXMLPrettyPrinter;

    NS_ADDREF(*aPrinter);

    return NS_OK;

}