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

   This file is part of the JUCE framework.
   Copyright (c) Raw Material Software Limited

   JUCE is an open source framework subject to commercial or open source
   licensing.

   By downloading, installing, or using the JUCE framework, or combining the
   JUCE framework with any other source code, object code, content or any other
   copyrightable work, you agree to the terms of the JUCE End User Licence
   Agreement, and all incorporated terms including the JUCE Privacy Policy and
   the JUCE Website Terms of Service, as applicable, which will bind you. If you
   do not agree to the terms of these agreements, we will not license the JUCE
   framework to you, and you must discontinue the installation or download
   process and cease use of the JUCE framework.

   JUCE End User Licence Agreement: https://juce.com/legal/juce-8-licence/
   JUCE Privacy Policy: https://juce.com/juce-privacy-policy
   JUCE Website Terms of Service: https://juce.com/juce-website-terms-of-service/

   Or:

   You may also use this code under the terms of the AGPLv3:
   https://www.gnu.org/licenses/agpl-3.0.en.html

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

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

namespace juce
{

//==============================================================================
class UIATextProvider  : public UIAProviderBase,
                         public ComBaseClassHelper<ITextProvider2>
{
public:
    using UIAProviderBase::UIAProviderBase;

    //==============================================================================
    JUCE_COMRESULT QueryInterface (REFIID iid, void** result) override
    {
        JUCE_BEGIN_IGNORE_WARNINGS_GCC_LIKE ("-Wlanguage-extension-token")

        if (iid == __uuidof (IUnknown) || iid == __uuidof (ITextProvider))
            return castToType<ITextProvider> (result);

        if (iid == __uuidof (ITextProvider2))
            return castToType<ITextProvider2> (result);

        *result = nullptr;
        return E_NOINTERFACE;

        JUCE_END_IGNORE_WARNINGS_GCC_LIKE
    }

    //==============================================================================
    JUCE_COMRESULT get_DocumentRange (ITextRangeProvider** pRetVal) override
    {
        return withTextInterface (pRetVal, [&] (const AccessibilityTextInterface& textInterface)
        {
            *pRetVal = new UIATextRangeProvider (*this, { 0, textInterface.getTotalNumCharacters() });
            return S_OK;
        });
    }

    JUCE_COMRESULT get_SupportedTextSelection (SupportedTextSelection* pRetVal) override
    {
        return withCheckedComArgs (pRetVal, *this, [&]
        {
            *pRetVal = SupportedTextSelection_Single;
            return S_OK;
        });
    }

    JUCE_COMRESULT GetSelection (SAFEARRAY** pRetVal) override
    {
        return withTextInterface (pRetVal, [&] (const AccessibilityTextInterface& textInterface)
        {
            SafeArrayHandle result { SafeArrayCreateVector (VT_UNKNOWN, 0, 1) };

            if (result == nullptr)
                return E_FAIL;

            auto selection = textInterface.getSelection();
            auto hasSelection = ! selection.isEmpty();
            auto cursorPos = textInterface.getTextInsertionOffset();

            ComSmartPtr rangeProvider { new UIATextRangeProvider (*this,
                                                                  { hasSelection ? selection.getStart() : cursorPos,
                                                                  hasSelection ? selection.getEnd()   : cursorPos }),
                                        IncrementRef::no };

            if (LONG pos = 0; FAILED (SafeArrayPutElement (result.get(), &pos, static_cast<IUnknown*> (rangeProvider))))
                return E_FAIL;

            *pRetVal = result.release();
            return S_OK;
        });
    }

    JUCE_COMRESULT GetVisibleRanges (SAFEARRAY** pRetVal) override
    {
        return withTextInterface (pRetVal, [&] (const AccessibilityTextInterface& textInterface)
        {
            SafeArrayHandle result { SafeArrayCreateVector (VT_UNKNOWN, 0, 1) };

            if (result == nullptr)
                return E_FAIL;

            ComSmartPtr rangeProvider { new UIATextRangeProvider (*this, { 0, textInterface.getTotalNumCharacters() }),
                                        IncrementRef::no };

            if (LONG pos = 0; FAILED (SafeArrayPutElement (result.get(), &pos, static_cast<IUnknown*> (rangeProvider))))
                return E_FAIL;

            *pRetVal = result.release();
            return S_OK;
        });
    }

    JUCE_COMRESULT RangeFromChild (IRawElementProviderSimple*, ITextRangeProvider** pRetVal) override
    {
        return withCheckedComArgs (pRetVal, *this, []
        {
            return S_OK;
        });
    }

    JUCE_COMRESULT RangeFromPoint (UiaPoint point, ITextRangeProvider** pRetVal) override
    {
        return withTextInterface (pRetVal, [&] (const AccessibilityTextInterface& textInterface)
        {
            auto offset = textInterface.getOffsetAtPoint ({ roundToInt (point.x), roundToInt (point.y) });

            if (offset > 0)
                *pRetVal = new UIATextRangeProvider (*this, { offset, offset });

            return S_OK;
        });
    }

    //==============================================================================
    JUCE_COMRESULT GetCaretRange (BOOL* isActive, ITextRangeProvider** pRetVal) override
    {
        return withTextInterface (pRetVal, [&] (const AccessibilityTextInterface& textInterface)
        {
            *isActive = getHandler().hasFocus (false);

            auto cursorPos = textInterface.getTextInsertionOffset();
            *pRetVal = new UIATextRangeProvider (*this, { cursorPos, cursorPos });

            return S_OK;
        });
    }

    JUCE_COMRESULT RangeFromAnnotation (IRawElementProviderSimple*, ITextRangeProvider** pRetVal) override
    {
        return withCheckedComArgs (pRetVal, *this, []
        {
            return S_OK;
        });
    }

private:
    //==============================================================================
    template <typename Value, typename Callback>
    JUCE_COMRESULT withTextInterface (Value* pRetVal, Callback&& callback) const
    {
        return withCheckedComArgs (pRetVal, *this, [&]() -> HRESULT
        {
            if (auto* textInterface = getHandler().getTextInterface())
                return callback (*textInterface);

            return (HRESULT) UIA_E_NOTSUPPORTED;
        });
    }

    //==============================================================================
    class UIATextRangeProvider  : public UIAProviderBase,
                                  public ComBaseClassHelper<ITextRangeProvider>
    {
    public:
        UIATextRangeProvider (UIATextProvider& textProvider, Range<int> range)
            : UIAProviderBase (textProvider.getHandler().getNativeImplementation()),
              owner (&textProvider, IncrementRef::yes),
              selectionRange (range)
        {
        }

        //==============================================================================
        Range<int> getSelectionRange() const noexcept  { return selectionRange; }

        //==============================================================================
        JUCE_COMRESULT AddToSelection() override
        {
            return Select();
        }

        JUCE_COMRESULT Clone (ITextRangeProvider** pRetVal) override
        {
            return withCheckedComArgs (pRetVal, *this, [&]
            {
                *pRetVal = new UIATextRangeProvider (*owner, selectionRange);
                return S_OK;
            });
        }

        JUCE_COMRESULT Compare (ITextRangeProvider* range, BOOL* pRetVal) override
        {
            return withCheckedComArgs (pRetVal, *this, [&]
            {
                *pRetVal = (selectionRange == static_cast<UIATextRangeProvider*> (range)->getSelectionRange());
                return S_OK;
            });
        }

        JUCE_COMRESULT CompareEndpoints (TextPatternRangeEndpoint endpoint,
                                         ITextRangeProvider* targetRange,
                                         TextPatternRangeEndpoint targetEndpoint,
                                         int* pRetVal) override
        {
            if (targetRange == nullptr)
                return E_INVALIDARG;

            return withCheckedComArgs (pRetVal, *this, [&]
            {
                auto offset = (endpoint == TextPatternRangeEndpoint_Start ? selectionRange.getStart()
                                                                          : selectionRange.getEnd());

                auto otherRange = static_cast<UIATextRangeProvider*> (targetRange)->getSelectionRange();
                auto otherOffset = (targetEndpoint == TextPatternRangeEndpoint_Start ? otherRange.getStart()
                                                                                     : otherRange.getEnd());

                *pRetVal = offset - otherOffset;
                return S_OK;
            });
        }

        JUCE_COMRESULT ExpandToEnclosingUnit (TextUnit unit) override
        {
            if (! isElementValid())
                return (HRESULT) UIA_E_ELEMENTNOTAVAILABLE;

            if (auto* textInterface = owner->getHandler().getTextInterface())
            {
                using ATH = AccessibilityTextHelpers;

                const auto boundaryType = getBoundaryType (unit);
                const auto start = ATH::findTextBoundary (*textInterface,
                                                          selectionRange.getStart(),
                                                          boundaryType,
                                                          ATH::Direction::backwards,
                                                          ATH::IncludeThisBoundary::yes,
                                                          ATH::IncludeWhitespaceAfterWords::no);

                const auto end = ATH::findTextBoundary (*textInterface,
                                                        start,
                                                        boundaryType,
                                                        ATH::Direction::forwards,
                                                        ATH::IncludeThisBoundary::no,
                                                        ATH::IncludeWhitespaceAfterWords::yes);

                selectionRange = Range<int> (start, end);

                return S_OK;
            }

            return (HRESULT) UIA_E_NOTSUPPORTED;
        }

        JUCE_COMRESULT FindAttribute (TEXTATTRIBUTEID, VARIANT, BOOL, ITextRangeProvider** pRetVal) override
        {
            return withCheckedComArgs (pRetVal, *this, []
            {
                return S_OK;
            });
        }

        JUCE_COMRESULT FindText (BSTR text, BOOL backward, BOOL ignoreCase,
                                 ITextRangeProvider** pRetVal) override
        {
            return owner->withTextInterface (pRetVal, [&] (const AccessibilityTextInterface& textInterface)
            {
                auto selectionText = textInterface.getText (selectionRange);
                String textToSearchFor (text);

                auto offset = (backward ? (ignoreCase ? selectionText.lastIndexOfIgnoreCase (textToSearchFor) : selectionText.lastIndexOf (textToSearchFor))
                                        : (ignoreCase ? selectionText.indexOfIgnoreCase (textToSearchFor)     : selectionText.indexOf (textToSearchFor)));

                if (offset != -1)
                    *pRetVal = new UIATextRangeProvider (*owner, { offset, offset + textToSearchFor.length() });

                return S_OK;
            });
        }

        JUCE_COMRESULT GetAttributeValue (TEXTATTRIBUTEID attributeId, VARIANT* pRetVal) override
        {
            return owner->withTextInterface (pRetVal, [&] (const AccessibilityTextInterface& textInterface)
            {
                VariantHelpers::clear (pRetVal);

                switch (attributeId)
                {
                    case UIA_IsReadOnlyAttributeId:
                    {
                        VariantHelpers::setBool (textInterface.isReadOnly(), pRetVal);
                        break;
                    }

                    case UIA_CaretPositionAttributeId:
                    {
                        auto cursorPos = textInterface.getTextInsertionOffset();

                        auto caretPos = [&]
                        {
                            if (cursorPos == 0)
                                return CaretPosition_BeginningOfLine;

                            if (cursorPos == textInterface.getTotalNumCharacters())
                                return CaretPosition_EndOfLine;

                            return CaretPosition_Unknown;
                        }();

                        VariantHelpers::setInt (caretPos, pRetVal);
                        break;
                    }
                }

                return S_OK;
            });
        }

        JUCE_COMRESULT GetBoundingRectangles (SAFEARRAY** pRetVal) override
        {
            return owner->withTextInterface (pRetVal, [&] (const AccessibilityTextInterface& textInterface)
            {
                auto rectangleList = textInterface.getTextBounds (selectionRange);
                auto numRectangles = rectangleList.getNumRectangles();

                SafeArrayHandle result { SafeArrayCreateVector (VT_R8, 0, 4 * (ULONG) numRectangles) };

                if (result == nullptr)
                    return E_FAIL;

                if (numRectangles > 0)
                {
                    double* doubleArr = nullptr;

                    if (FAILED (SafeArrayAccessData (result.get(), reinterpret_cast<void**> (&doubleArr))))
                        return E_FAIL;

                    for (int i = 0; i < numRectangles; ++i)
                    {
                        auto r = Desktop::getInstance().getDisplays().logicalToPhysical (rectangleList.getRectangle (i));

                        doubleArr[i * 4]     = r.getX();
                        doubleArr[i * 4 + 1] = r.getY();
                        doubleArr[i * 4 + 2] = r.getWidth();
                        doubleArr[i * 4 + 3] = r.getHeight();
                    }

                    if (FAILED (SafeArrayUnaccessData (result.get())))
                        return E_FAIL;
                }

                *pRetVal = result.release();
                return S_OK;
            });
        }

        JUCE_COMRESULT GetChildren (SAFEARRAY** pRetVal) override
        {
            return withCheckedComArgs (pRetVal, *this, [&]
            {
                SafeArrayHandle result { SafeArrayCreateVector (VT_UNKNOWN, 0, 0) };

                if (result == nullptr)
                    return E_FAIL;

                *pRetVal = result.release();
                return S_OK;
            });
        }

        JUCE_COMRESULT GetEnclosingElement (IRawElementProviderSimple** pRetVal) override
        {
            JUCE_BEGIN_IGNORE_WARNINGS_GCC_LIKE ("-Wlanguage-extension-token")

            return withCheckedComArgs (pRetVal, *this, [&]
            {
                getHandler().getNativeImplementation()->QueryInterface (IID_PPV_ARGS (pRetVal));
                return S_OK;
            });

            JUCE_END_IGNORE_WARNINGS_GCC_LIKE
        }

        JUCE_COMRESULT GetText (int maxLength, BSTR* pRetVal) override
        {
            return owner->withTextInterface (pRetVal, [&] (const AccessibilityTextInterface& textInterface)
            {
                auto text = textInterface.getText (selectionRange);

                if (maxLength >= 0 && text.length() > maxLength)
                    text = text.substring (0, maxLength);

                *pRetVal = SysAllocString ((const OLECHAR*) text.toWideCharPointer());
                return S_OK;
            });
        }

        JUCE_COMRESULT Move (TextUnit unit, int count, int* pRetVal) override
        {
            return owner->withTextInterface (pRetVal, [&] (const AccessibilityTextInterface& textInterface)
            {
                using ATH = AccessibilityTextHelpers;

                const auto boundaryType = getBoundaryType (unit);
                const auto previousUnitBoundary = ATH::findTextBoundary (textInterface,
                                                                         selectionRange.getStart(),
                                                                         boundaryType,
                                                                         ATH::Direction::backwards,
                                                                         ATH::IncludeThisBoundary::yes,
                                                                         ATH::IncludeWhitespaceAfterWords::no);

                auto numMoved = 0;
                auto movedEndpoint = previousUnitBoundary;

                for (; numMoved < std::abs (count); ++numMoved)
                {
                    const auto nextEndpoint = ATH::findTextBoundary (textInterface,
                                                                     movedEndpoint,
                                                                     boundaryType,
                                                                     count > 0 ? ATH::Direction::forwards : ATH::Direction::backwards,
                                                                     ATH::IncludeThisBoundary::no,
                                                                     count > 0 ? ATH::IncludeWhitespaceAfterWords::yes : ATH::IncludeWhitespaceAfterWords::no);

                    if (nextEndpoint == movedEndpoint)
                        break;

                    movedEndpoint = nextEndpoint;
                }

                *pRetVal = numMoved;

                ExpandToEnclosingUnit (unit);
                return S_OK;
            });
        }

        JUCE_COMRESULT MoveEndpointByRange (TextPatternRangeEndpoint endpoint,
                                            ITextRangeProvider* targetRange,
                                            TextPatternRangeEndpoint targetEndpoint) override
        {
            if (targetRange == nullptr)
                return E_INVALIDARG;

            if (! isElementValid())
                return (HRESULT) UIA_E_ELEMENTNOTAVAILABLE;

            if (owner->getHandler().getTextInterface() != nullptr)
            {
                auto otherRange = static_cast<UIATextRangeProvider*> (targetRange)->getSelectionRange();
                auto targetPoint = (targetEndpoint == TextPatternRangeEndpoint_Start ? otherRange.getStart()
                                                                                     : otherRange.getEnd());

                setEndpointChecked (endpoint, targetPoint);
                return S_OK;
            }

            return (HRESULT) UIA_E_NOTSUPPORTED;
        }

        JUCE_COMRESULT MoveEndpointByUnit (TextPatternRangeEndpoint endpoint,
                                           TextUnit unit,
                                           int count,
                                           int* pRetVal) override
        {
            return owner->withTextInterface (pRetVal, [&] (const AccessibilityTextInterface& textInterface)
            {
                if (count == 0 || textInterface.getTotalNumCharacters() == 0)
                    return S_OK;

                const auto endpointToMove = (endpoint == TextPatternRangeEndpoint_Start ? selectionRange.getStart()
                                                                                        : selectionRange.getEnd());

                using ATH = AccessibilityTextHelpers;

                const auto direction = (count > 0 ? ATH::Direction::forwards
                                                  : ATH::Direction::backwards);

                const auto boundaryType = getBoundaryType (unit);
                auto movedEndpoint = endpointToMove;

                int numMoved = 0;
                for (; numMoved < std::abs (count); ++numMoved)
                {
                    auto nextEndpoint = ATH::findTextBoundary (textInterface,
                                                               movedEndpoint,
                                                               boundaryType,
                                                               direction,
                                                               ATH::IncludeThisBoundary::no,
                                                               direction == ATH::Direction::forwards ? ATH::IncludeWhitespaceAfterWords::yes
                                                                                                     : ATH::IncludeWhitespaceAfterWords::no);

                    if (nextEndpoint == movedEndpoint)
                        break;

                    movedEndpoint = nextEndpoint;
                }

                *pRetVal = numMoved;

                setEndpointChecked (endpoint, movedEndpoint);

                return S_OK;
            });
        }

        JUCE_COMRESULT RemoveFromSelection() override
        {
            if (! isElementValid())
                return (HRESULT) UIA_E_ELEMENTNOTAVAILABLE;

            if (auto* textInterface = owner->getHandler().getTextInterface())
            {
                textInterface->setSelection ({});
                return S_OK;
            }

            return (HRESULT) UIA_E_NOTSUPPORTED;
        }

        JUCE_COMRESULT ScrollIntoView (BOOL) override
        {
            if (! isElementValid())
                return (HRESULT) UIA_E_ELEMENTNOTAVAILABLE;

            return (HRESULT) UIA_E_NOTSUPPORTED;
        }

        JUCE_COMRESULT Select() override
        {
            if (! isElementValid())
                return (HRESULT) UIA_E_ELEMENTNOTAVAILABLE;

            if (auto* textInterface = owner->getHandler().getTextInterface())
            {
                textInterface->setSelection ({});
                textInterface->setSelection (selectionRange);

                return S_OK;
            }

            return (HRESULT) UIA_E_NOTSUPPORTED;
        }

    private:
        static AccessibilityTextHelpers::BoundaryType getBoundaryType (TextUnit unit)
        {
            switch (unit)
            {
                case TextUnit_Character:
                    return AccessibilityTextHelpers::BoundaryType::character;

                case TextUnit_Format:
                case TextUnit_Word:
                    return AccessibilityTextHelpers::BoundaryType::word;

                case TextUnit_Line:
                    return AccessibilityTextHelpers::BoundaryType::line;

                case TextUnit_Paragraph:
                case TextUnit_Page:
                case TextUnit_Document:
                    return AccessibilityTextHelpers::BoundaryType::document;
            };

            jassertfalse;
            return AccessibilityTextHelpers::BoundaryType::character;
        }

        void setEndpointChecked (TextPatternRangeEndpoint endpoint, int newEndpoint)
        {
            if (endpoint == TextPatternRangeEndpoint_Start)
            {
                if (selectionRange.getEnd() < newEndpoint)
                    selectionRange.setEnd (newEndpoint);

                selectionRange.setStart (newEndpoint);
            }
            else
            {
                if (selectionRange.getStart() > newEndpoint)
                    selectionRange.setStart (newEndpoint);

                selectionRange.setEnd (newEndpoint);
            }
        }

        ComSmartPtr<UIATextProvider> owner;
        Range<int> selectionRange;

        //==============================================================================
        JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (UIATextRangeProvider)
    };

    //==============================================================================
    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (UIATextProvider)
};

} // namespace juce
