/*
  ==============================================================================

   This file is part of the JUCE 6 technical preview.
   Copyright (c) 2017 - ROLI Ltd.

   You may use this code under the terms of the GPL v3
   (see www.gnu.org/licenses).

   For this technical preview, this file is not subject to commercial licensing.

   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
   DISCLAIMED.

  ==============================================================================
*/

namespace juce
{

#if JUCE_MINGW
 JUCE_DECLARE_UUID_GETTER (IOleClientSite,           "00000118-0000-0000-c000-000000000046")
 JUCE_DECLARE_UUID_GETTER (IDispatch,                "00020400-0000-0000-c000-000000000046")

 #ifndef WebBrowser
  class WebBrowser;
 #endif
#endif

JUCE_DECLARE_UUID_GETTER (DWebBrowserEvents2,        "34A715A0-6587-11D0-924A-0020AFC7AC4D")
JUCE_DECLARE_UUID_GETTER (IConnectionPointContainer, "B196B284-BAB4-101A-B69C-00AA00341D07")
JUCE_DECLARE_UUID_GETTER (IWebBrowser2,              "D30C1661-CDAF-11D0-8A3E-00C04FC9E26E")
JUCE_DECLARE_UUID_GETTER (WebBrowser,                "8856F961-340A-11D0-A96B-00C04FD705A2")

class WebBrowserComponent::Pimpl   : public ActiveXControlComponent
{
public:
    Pimpl() {}

    ~Pimpl()
    {
        if (connectionPoint != nullptr)
            connectionPoint->Unadvise (adviseCookie);

        if (browser != nullptr)
            browser->Release();
    }

    void createBrowser()
    {
        auto webCLSID = __uuidof (WebBrowser);
        createControl (&webCLSID);

        auto iidWebBrowser2              = __uuidof (IWebBrowser2);
        auto iidConnectionPointContainer = __uuidof (IConnectionPointContainer);

        browser = (IWebBrowser2*) queryInterface (&iidWebBrowser2);

        if (auto connectionPointContainer = (IConnectionPointContainer*) queryInterface (&iidConnectionPointContainer))
        {
            connectionPointContainer->FindConnectionPoint (__uuidof (DWebBrowserEvents2), &connectionPoint);

            if (connectionPoint != nullptr)
            {
                auto* owner = dynamic_cast<WebBrowserComponent*> (getParentComponent());
                jassert (owner != nullptr);

                auto handler = new EventHandler (*owner);
                connectionPoint->Advise (handler, &adviseCookie);
                handler->Release();
            }
        }
    }

    void goToURL (const String& url,
                  const StringArray* headers,
                  const MemoryBlock* postData)
    {
        if (browser != nullptr)
        {
            VARIANT headerFlags, frame, postDataVar, headersVar;  // (_variant_t isn't available in all compilers)
            VariantInit (&headerFlags);
            VariantInit (&frame);
            VariantInit (&postDataVar);
            VariantInit (&headersVar);

            if (headers != nullptr)
            {
                V_VT (&headersVar) = VT_BSTR;
                V_BSTR (&headersVar) = SysAllocString ((const OLECHAR*) headers->joinIntoString ("\r\n").toWideCharPointer());
            }

            if (postData != nullptr && postData->getSize() > 0)
            {
                auto sa = SafeArrayCreateVector (VT_UI1, 0, (ULONG) postData->getSize());

                if (sa != nullptr)
                {
                    void* data = nullptr;
                    SafeArrayAccessData (sa, &data);
                    jassert (data != nullptr);

                    if (data != nullptr)
                    {
                        postData->copyTo (data, 0, postData->getSize());
                        SafeArrayUnaccessData (sa);

                        VARIANT postDataVar2;
                        VariantInit (&postDataVar2);
                        V_VT (&postDataVar2) = VT_ARRAY | VT_UI1;
                        V_ARRAY (&postDataVar2) = sa;

                        sa = nullptr;
                        postDataVar = postDataVar2;
                    }
                    else
                    {
                        SafeArrayDestroy (sa);
                    }
                }
            }

            auto urlBSTR = SysAllocString ((const OLECHAR*) url.toWideCharPointer());
            browser->Navigate (urlBSTR, &headerFlags, &frame, &postDataVar, &headersVar);
            SysFreeString (urlBSTR);

            VariantClear (&headerFlags);
            VariantClear (&frame);
            VariantClear (&postDataVar);
            VariantClear (&headersVar);
        }
    }

    //==============================================================================
    IWebBrowser2* browser = nullptr;

private:
    IConnectionPoint* connectionPoint = nullptr;
    DWORD adviseCookie = 0;

    //==============================================================================
    struct EventHandler  : public ComBaseClassHelper<IDispatch>,
                           public ComponentMovementWatcher
    {
        EventHandler (WebBrowserComponent& w)  : ComponentMovementWatcher (&w), owner (w) {}

        JUCE_COMRESULT GetTypeInfoCount (UINT*) override                                 { return E_NOTIMPL; }
        JUCE_COMRESULT GetTypeInfo (UINT, LCID, ITypeInfo**) override                    { return E_NOTIMPL; }
        JUCE_COMRESULT GetIDsOfNames (REFIID, LPOLESTR*, UINT, LCID, DISPID*) override   { return E_NOTIMPL; }

        JUCE_COMRESULT Invoke (DISPID dispIdMember, REFIID /*riid*/, LCID /*lcid*/, WORD /*wFlags*/, DISPPARAMS* pDispParams,
                               VARIANT* /*pVarResult*/, EXCEPINFO* /*pExcepInfo*/, UINT* /*puArgErr*/) override
        {
            if (dispIdMember == DISPID_BEFORENAVIGATE2)
            {
                *pDispParams->rgvarg->pboolVal
                    = owner.pageAboutToLoad (getStringFromVariant (pDispParams->rgvarg[5].pvarVal)) ? VARIANT_FALSE
                                                                                                    : VARIANT_TRUE;
                return S_OK;
            }

            if (dispIdMember == 273 /*DISPID_NEWWINDOW3*/)
            {
                owner.newWindowAttemptingToLoad (pDispParams->rgvarg[0].bstrVal);
                *pDispParams->rgvarg[3].pboolVal = VARIANT_TRUE;
                return S_OK;
            }

            if (dispIdMember == DISPID_DOCUMENTCOMPLETE)
            {
                owner.pageFinishedLoading (getStringFromVariant (pDispParams->rgvarg[0].pvarVal));
                return S_OK;
            }

            if (dispIdMember == 271 /*DISPID_NAVIGATEERROR*/)
            {
                int statusCode = pDispParams->rgvarg[1].pvarVal->intVal;
                *pDispParams->rgvarg[0].pboolVal = VARIANT_FALSE;

                // IWebBrowser2 also reports http status codes here, we need
                // report only network errors
                if (statusCode < 0)
                {
                    LPTSTR messageBuffer = nullptr;
                    auto size = FormatMessage (FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
                                               nullptr, statusCode, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
                                               (LPTSTR) &messageBuffer, 0, nullptr);

                    String message (messageBuffer, size);
                    LocalFree (messageBuffer);

                    if (! owner.pageLoadHadNetworkError (message))
                        *pDispParams->rgvarg[0].pboolVal = VARIANT_TRUE;
                }

                return S_OK;
            }

            if (dispIdMember == 263 /*DISPID_WINDOWCLOSING*/)
            {
                owner.windowCloseRequest();

                // setting this bool tells the browser to ignore the event - we'll handle it.
                if (pDispParams->cArgs > 0 && pDispParams->rgvarg[0].vt == (VT_BYREF | VT_BOOL))
                    *pDispParams->rgvarg[0].pboolVal = VARIANT_TRUE;

                return S_OK;
            }

            return E_NOTIMPL;
        }

        void componentMovedOrResized (bool, bool) override   {}
        void componentPeerChanged() override                 {}
        void componentVisibilityChanged() override           { owner.visibilityChanged(); }

    private:
        WebBrowserComponent& owner;

        static String getStringFromVariant (VARIANT* v)
        {
            return (v->vt & VT_BYREF) != 0 ? *v->pbstrVal
                                           : v->bstrVal;
        }

        JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (EventHandler)
    };

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (Pimpl)
};


//==============================================================================
WebBrowserComponent::WebBrowserComponent (const bool unloadPageWhenBrowserIsHidden_)
    : browser (new Pimpl()),
      blankPageShown (false),
      unloadPageWhenBrowserIsHidden (unloadPageWhenBrowserIsHidden_)
{
    setOpaque (true);
    addAndMakeVisible (browser.get());
}

WebBrowserComponent::~WebBrowserComponent()
{
}

//==============================================================================
void WebBrowserComponent::goToURL (const String& url,
                                   const StringArray* headers,
                                   const MemoryBlock* postData)
{
    lastURL = url;

    if (headers != nullptr)
        lastHeaders = *headers;
    else
        lastHeaders.clear();

    if (postData != nullptr)
        lastPostData = *postData;
    else
        lastPostData.reset();

    blankPageShown = false;

    if (browser->browser == nullptr)
        checkWindowAssociation();

    browser->goToURL (url, headers, postData);
}

void WebBrowserComponent::stop()
{
    if (browser->browser != nullptr)
        browser->browser->Stop();
}

void WebBrowserComponent::goBack()
{
    lastURL.clear();
    blankPageShown = false;

    if (browser->browser != nullptr)
        browser->browser->GoBack();
}

void WebBrowserComponent::goForward()
{
    lastURL.clear();

    if (browser->browser != nullptr)
        browser->browser->GoForward();
}

void WebBrowserComponent::refresh()
{
    if (browser->browser != nullptr)
        browser->browser->Refresh();
}

//==============================================================================
void WebBrowserComponent::paint (Graphics& g)
{
    if (browser->browser == nullptr)
    {
        g.fillAll (Colours::white);
        checkWindowAssociation();
    }
}

void WebBrowserComponent::checkWindowAssociation()
{
    if (isShowing())
    {
        if (browser->browser == nullptr && getPeer() != nullptr)
        {
            browser->createBrowser();
            reloadLastURL();
        }
        else
        {
            if (blankPageShown)
                goBack();
        }
    }
    else
    {
        if (browser != nullptr && unloadPageWhenBrowserIsHidden && ! blankPageShown)
        {
            // when the component becomes invisible, some stuff like flash
            // carries on playing audio, so we need to force it onto a blank
            // page to avoid this..

            blankPageShown = true;
            browser->goToURL ("about:blank", 0, 0);
        }
    }
}

void WebBrowserComponent::reloadLastURL()
{
    if (lastURL.isNotEmpty())
    {
        goToURL (lastURL, &lastHeaders, &lastPostData);
        lastURL.clear();
    }
}

void WebBrowserComponent::parentHierarchyChanged()
{
    checkWindowAssociation();
}

void WebBrowserComponent::resized()
{
    browser->setSize (getWidth(), getHeight());
}

void WebBrowserComponent::visibilityChanged()
{
    checkWindowAssociation();
}

void WebBrowserComponent::focusGained (FocusChangeType)
{
    auto iidOleObject = __uuidof (IOleObject);
    auto iidOleWindow = __uuidof (IOleWindow);

    if (auto oleObject = (IOleObject*) browser->queryInterface (&iidOleObject))
    {
        if (auto oleWindow = (IOleWindow*) browser->queryInterface (&iidOleWindow))
        {
            IOleClientSite* oleClientSite = nullptr;

            if (SUCCEEDED (oleObject->GetClientSite (&oleClientSite)))
            {
                HWND hwnd;
                oleWindow->GetWindow (&hwnd);
                oleObject->DoVerb (OLEIVERB_UIACTIVATE, nullptr, oleClientSite, 0, hwnd, nullptr);
                oleClientSite->Release();
            }

            oleWindow->Release();
        }

        oleObject->Release();
    }
}

void WebBrowserComponent::clearCookies()
{
    HeapBlock<::INTERNET_CACHE_ENTRY_INFOA> entry;
    ::DWORD entrySize = sizeof (::INTERNET_CACHE_ENTRY_INFOA);
    ::HANDLE urlCacheHandle = ::FindFirstUrlCacheEntryA ("cookie:", entry.getData(), &entrySize);

    if (urlCacheHandle == nullptr && GetLastError() == ERROR_INSUFFICIENT_BUFFER)
    {
        entry.realloc (1, entrySize);
        urlCacheHandle = ::FindFirstUrlCacheEntryA ("cookie:", entry.getData(), &entrySize);
    }

    if (urlCacheHandle != nullptr)
    {
        for (;;)
        {
            ::DeleteUrlCacheEntryA (entry.getData()->lpszSourceUrlName);

            if (::FindNextUrlCacheEntryA (urlCacheHandle, entry.getData(), &entrySize) == 0)
            {
                if (GetLastError() == ERROR_INSUFFICIENT_BUFFER)
                {
                    entry.realloc (1, entrySize);

                    if (::FindNextUrlCacheEntryA (urlCacheHandle, entry.getData(), &entrySize) != 0)
                        continue;
                }

                break;
            }
        }

        FindCloseUrlCache (urlCacheHandle);
    }
}

} // namespace juce