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

   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
{

#define JUCE_NATIVE_ACCESSIBILITY_INCLUDED 1

#define JNI_CLASS_MEMBERS(METHOD, STATICMETHOD, FIELD, STATICFIELD, CALLBACK) \
 METHOD (setSource,                "setSource",                "(Landroid/view/View;I)V") \
 METHOD (addChild,                 "addChild",                 "(Landroid/view/View;I)V") \
 METHOD (setParent,                "setParent",                "(Landroid/view/View;)V") \
 METHOD (setVirtualParent,         "setParent",                "(Landroid/view/View;I)V") \
 METHOD (setBoundsInScreen,        "setBoundsInScreen",        "(Landroid/graphics/Rect;)V") \
 METHOD (setBoundsInParent,        "setBoundsInParent",        "(Landroid/graphics/Rect;)V") \
 METHOD (setPackageName,           "setPackageName",           "(Ljava/lang/CharSequence;)V") \
 METHOD (setClassName,             "setClassName",             "(Ljava/lang/CharSequence;)V") \
 METHOD (setContentDescription,    "setContentDescription",    "(Ljava/lang/CharSequence;)V") \
 METHOD (setCheckable,             "setCheckable",             "(Z)V") \
 METHOD (setChecked,               "setChecked",               "(Z)V") \
 METHOD (setClickable,             "setClickable",             "(Z)V") \
 METHOD (setEnabled,               "setEnabled",               "(Z)V") \
 METHOD (setFocusable,             "setFocusable",             "(Z)V") \
 METHOD (setFocused,               "setFocused",               "(Z)V") \
 METHOD (setPassword,              "setPassword",              "(Z)V") \
 METHOD (setSelected,              "setSelected",              "(Z)V") \
 METHOD (setVisibleToUser,         "setVisibleToUser",         "(Z)V") \
 METHOD (setAccessibilityFocused,  "setAccessibilityFocused",  "(Z)V") \
 METHOD (setText,                  "setText",                  "(Ljava/lang/CharSequence;)V") \
 METHOD (setMovementGranularities, "setMovementGranularities", "(I)V") \
 METHOD (addAction,                "addAction",                "(I)V") \
 METHOD (setCollectionInfo, "setCollectionInfo", "(Landroid/view/accessibility/AccessibilityNodeInfo$CollectionInfo;)V") \
 METHOD (setCollectionItemInfo, "setCollectionItemInfo", "(Landroid/view/accessibility/AccessibilityNodeInfo$CollectionItemInfo;)V")

 DECLARE_JNI_CLASS (AndroidAccessibilityNodeInfo, "android/view/accessibility/AccessibilityNodeInfo")
#undef JNI_CLASS_MEMBERS

#define JNI_CLASS_MEMBERS(METHOD, STATICMETHOD, FIELD, STATICFIELD, CALLBACK) \
 STATICMETHOD (obtain, "obtain", "(IIZ)Landroid/view/accessibility/AccessibilityNodeInfo$CollectionInfo;")

 DECLARE_JNI_CLASS (AndroidAccessibilityNodeInfoCollectionInfo, "android/view/accessibility/AccessibilityNodeInfo$CollectionInfo")
#undef JNI_CLASS_MEMBERS

#define JNI_CLASS_MEMBERS(METHOD, STATICMETHOD, FIELD, STATICFIELD, CALLBACK) \
 STATICMETHOD (obtain, "obtain", "(IIIIZ)Landroid/view/accessibility/AccessibilityNodeInfo$CollectionItemInfo;")

 DECLARE_JNI_CLASS (AndroidAccessibilityNodeInfoCollectionItemInfo, "android/view/accessibility/AccessibilityNodeInfo$CollectionItemInfo")
#undef JNI_CLASS_MEMBERS

#define JNI_CLASS_MEMBERS(METHOD, STATICMETHOD, FIELD, STATICFIELD, CALLBACK) \
 STATICMETHOD (obtain, "obtain", "(I)Landroid/view/accessibility/AccessibilityEvent;") \
 METHOD (setPackageName, "setPackageName", "(Ljava/lang/CharSequence;)V") \
 METHOD (setSource, "setSource","(Landroid/view/View;I)V") \
 METHOD (setAction, "setAction", "(I)V") \
 METHOD (setFromIndex, "setFromIndex", "(I)V") \
 METHOD (setToIndex, "setToIndex", "(I)V") \

 DECLARE_JNI_CLASS (AndroidAccessibilityEvent, "android/view/accessibility/AccessibilityEvent")
#undef JNI_CLASS_MEMBERS

#define JNI_CLASS_MEMBERS(METHOD, STATICMETHOD, FIELD, STATICFIELD, CALLBACK) \
 METHOD (isEnabled, "isEnabled", "()Z") \

 DECLARE_JNI_CLASS (AndroidAccessibilityManager, "android/view/accessibility/AccessibilityManager")
#undef JNI_CLASS_MEMBERS

namespace
{
    constexpr int HOST_VIEW_ID = -1;

    constexpr int TYPE_VIEW_CLICKED                                = 0x00000001,
                  TYPE_VIEW_SELECTED                               = 0x00000004,
                  TYPE_VIEW_ACCESSIBILITY_FOCUSED                  = 0x00008000,
                  TYPE_VIEW_ACCESSIBILITY_FOCUS_CLEARED            = 0x00010000,
                  TYPE_WINDOW_CONTENT_CHANGED                      = 0x00000800,
                  TYPE_VIEW_TEXT_SELECTION_CHANGED                 = 0x00002000,
                  TYPE_VIEW_TEXT_CHANGED                           = 0x00000010,
                  TYPE_VIEW_TEXT_TRAVERSED_AT_MOVEMENT_GRANULARITY = 0x00020000;

    constexpr int CONTENT_CHANGE_TYPE_SUBTREE             = 0x00000001,
                  CONTENT_CHANGE_TYPE_CONTENT_DESCRIPTION = 0x00000004;

    constexpr int ACTION_ACCESSIBILITY_FOCUS              = 0x00000040,
                  ACTION_CLEAR_ACCESSIBILITY_FOCUS        = 0x00000080,
                  ACTION_CLEAR_FOCUS                      = 0x00000002,
                  ACTION_CLEAR_SELECTION                  = 0x00000008,
                  ACTION_CLICK                            = 0x00000010,
                  ACTION_COLLAPSE                         = 0x00080000,
                  ACTION_EXPAND                           = 0x00040000,
                  ACTION_FOCUS                            = 0x00000001,
                  ACTION_NEXT_AT_MOVEMENT_GRANULARITY     = 0x00000100,
                  ACTION_PREVIOUS_AT_MOVEMENT_GRANULARITY = 0x00000200,
                  ACTION_SCROLL_BACKWARD                  = 0x00002000,
                  ACTION_SCROLL_FORWARD                   = 0x00001000,
                  ACTION_SELECT                           = 0x00000004,
                  ACTION_SET_SELECTION                    = 0x00020000,
                  ACTION_SET_TEXT                         = 0x00200000;

    constexpr int MOVEMENT_GRANULARITY_CHARACTER = 0x00000001,
                  MOVEMENT_GRANULARITY_LINE      = 0x00000004,
                  MOVEMENT_GRANULARITY_PAGE      = 0x00000010,
                  MOVEMENT_GRANULARITY_PARAGRAPH = 0x00000008,
                  MOVEMENT_GRANULARITY_WORD      = 0x00000002,
                  ALL_GRANULARITIES = MOVEMENT_GRANULARITY_CHARACTER
                                    | MOVEMENT_GRANULARITY_LINE
                                    | MOVEMENT_GRANULARITY_PAGE
                                    | MOVEMENT_GRANULARITY_PARAGRAPH
                                    | MOVEMENT_GRANULARITY_WORD;

    constexpr int ACCESSIBILITY_LIVE_REGION_POLITE = 0x00000001;
}

static jmethodID nodeInfoSetEditable                     = nullptr;
static jmethodID nodeInfoSetTextSelection                = nullptr;
static jmethodID nodeInfoSetLiveRegion                   = nullptr;
static jmethodID accessibilityEventSetContentChangeTypes = nullptr;

static void loadSDKDependentMethods()
{
    static bool hasChecked = false;

    if (! hasChecked)
    {
        hasChecked = true;

        auto* env = getEnv();

        nodeInfoSetEditable      = env->GetMethodID (AndroidAccessibilityNodeInfo, "setEditable",      "(Z)V");
        nodeInfoSetTextSelection = env->GetMethodID (AndroidAccessibilityNodeInfo, "setTextSelection", "(II)V");

        nodeInfoSetLiveRegion                   = env->GetMethodID (AndroidAccessibilityNodeInfo, "setLiveRegion",         "(I)V");
        accessibilityEventSetContentChangeTypes = env->GetMethodID (AndroidAccessibilityEvent,    "setContentChangeTypes", "(I)V");
    }
}

static constexpr auto getClassName (AccessibilityRole role)
{
    switch (role)
    {
        case AccessibilityRole::editableText:  return "android.widget.EditText";
        case AccessibilityRole::toggleButton:  return "android.widget.CheckBox";
        case AccessibilityRole::radioButton:   return "android.widget.RadioButton";
        case AccessibilityRole::image:         return "android.widget.ImageView";
        case AccessibilityRole::popupMenu:     return "android.widget.PopupMenu";
        case AccessibilityRole::comboBox:      return "android.widget.Spinner";
        case AccessibilityRole::tree:          return "android.widget.ExpandableListView";
        case AccessibilityRole::progressBar:   return "android.widget.ProgressBar";

        case AccessibilityRole::scrollBar:
        case AccessibilityRole::slider:        return "android.widget.SeekBar";

        case AccessibilityRole::hyperlink:
        case AccessibilityRole::button:        return "android.widget.Button";

        case AccessibilityRole::label:
        case AccessibilityRole::staticText:    return "android.widget.TextView";

        case AccessibilityRole::tooltip:
        case AccessibilityRole::splashScreen:
        case AccessibilityRole::dialogWindow:  return "android.widget.PopupWindow";

        // If we don't supply a custom class type, then TalkBack will use the node's CollectionInfo
        // to make a sensible decision about how to describe the container
        case AccessibilityRole::list:
        case AccessibilityRole::table:

        case AccessibilityRole::column:
        case AccessibilityRole::row:
        case AccessibilityRole::cell:
        case AccessibilityRole::menuItem:
        case AccessibilityRole::menuBar:
        case AccessibilityRole::listItem:
        case AccessibilityRole::treeItem:
        case AccessibilityRole::window:
        case AccessibilityRole::tableHeader:
        case AccessibilityRole::unspecified:
        case AccessibilityRole::group:
        case AccessibilityRole::ignored:       break;
    }

    return "android.view.View";
}

static jobject getSourceView (const AccessibilityHandler& handler)
{
    if (auto* peer = handler.getComponent().getPeer())
        return (jobject) peer->getNativeHandle();

    return nullptr;
}

static jobject makeAndroidRect (Rectangle<int> r)
{
    return getEnv()->NewObject (AndroidRect,
                                AndroidRect.constructor,
                                r.getX(),
                                r.getY(),
                                r.getRight(),
                                r.getBottom());
}

static jobject makeAndroidPoint (Point<int> p)
{
    return getEnv()->NewObject (AndroidPoint,
                                AndroidPoint.create,
                                p.getX(),
                                p.getY());
}

//==============================================================================
class AccessibilityNativeHandle
{
public:
    static AccessibilityHandler* getAccessibilityHandlerForVirtualViewId (int virtualViewId)
    {
        auto iter = virtualViewIdMap.find (virtualViewId);

        if (iter != virtualViewIdMap.end())
            return iter->second;

        return nullptr;
    }

    explicit AccessibilityNativeHandle (AccessibilityHandler& h)
        : accessibilityHandler (h),
          virtualViewId (getVirtualViewIdForHandler (accessibilityHandler))
    {
        loadSDKDependentMethods();

        if (virtualViewId != HOST_VIEW_ID)
            virtualViewIdMap[virtualViewId] = &accessibilityHandler;
    }

    ~AccessibilityNativeHandle()
    {
        if (virtualViewId != HOST_VIEW_ID)
            virtualViewIdMap.erase (virtualViewId);

        if (nativeChildViewId.has_value())
            virtualViewIdMap.erase (*nativeChildViewId);
    }

    int getVirtualViewId() const noexcept  { return virtualViewId; }

    jobject getNativeView (int viewId) const
    {
        if (nativeChildViewId == viewId)
            return static_cast<jobject> (AccessibilityHandler::getNativeChildForComponent (accessibilityHandler.getComponent()));

        return nullptr;
    }

    void populateNodeInfo (jobject info, int infoVirtualViewId)
    {
        if (   AccessibilityHandler::getNativeChildForComponent (accessibilityHandler.getComponent()) != nullptr
            && ! nativeChildViewId.has_value())
        {
            nativeChildViewId.emplace (getNextVirtualViewId());
            virtualViewIdMap[*nativeChildViewId] = &accessibilityHandler;
        }

        const ScopedValueSetter<bool> svs (inPopulateNodeInfo, true);

        const auto sourceView = getSourceView (accessibilityHandler);

        if (sourceView == nullptr)
            return;

        auto* env = getEnv();
        auto appContext = getAppContext();

        if (appContext.get() == nullptr)
            return;

        {
            for (auto* child : accessibilityHandler.getChildren())
                env->CallVoidMethod (info, AndroidAccessibilityNodeInfo.addChild,
                                     sourceView, child->getNativeImplementation()->getVirtualViewId());

            if (nativeChildViewId.has_value() && nativeChildViewId != infoVirtualViewId)
                env->CallVoidMethod (info, AndroidAccessibilityNodeInfo.addChild,
                                     sourceView, *nativeChildViewId);

            if (auto* parent = accessibilityHandler.getParent())
                env->CallVoidMethod (info, AndroidAccessibilityNodeInfo.setVirtualParent,
                                     sourceView, parent->getNativeImplementation()->getVirtualViewId());
        }

        {
            const auto scale = Desktop::getInstance().getDisplays().getPrimaryDisplay()->scale;

            LocalRef<jobject> screenBounds (makeAndroidRect (accessibilityHandler.getComponent().getScreenBounds() * scale));

            env->CallVoidMethod (info, AndroidAccessibilityNodeInfo.setBoundsInScreen, screenBounds.get());

            LocalRef<jobject> boundsInParent (makeAndroidRect (accessibilityHandler.getComponent().getBoundsInParent() * scale));

            env->CallVoidMethod (info, AndroidAccessibilityNodeInfo.setBoundsInParent, boundsInParent.get());
        }

        const auto state = accessibilityHandler.getCurrentState();

        env->CallVoidMethod (info,
                             AndroidAccessibilityNodeInfo.setEnabled,
                             ! state.isIgnored());
        env->CallVoidMethod (info,
                             AndroidAccessibilityNodeInfo.setVisibleToUser,
                             true);
        env->CallVoidMethod (info,
                             AndroidAccessibilityNodeInfo.setPackageName,
                             env->CallObjectMethod (appContext.get(),
                                                    AndroidContext.getPackageName));
        env->CallVoidMethod (info,
                             AndroidAccessibilityNodeInfo.setSource,
                             sourceView,
                             virtualViewId);
        env->CallVoidMethod (info,
                             AndroidAccessibilityNodeInfo.setClassName,
                             javaString (getClassName (accessibilityHandler.getRole())).get());
        env->CallVoidMethod (info,
                             AndroidAccessibilityNodeInfo.setContentDescription,
                             getDescriptionString().get());

        if (state.isFocusable())
        {
            env->CallVoidMethod (info, AndroidAccessibilityNodeInfo.setFocusable, true);

            const auto& component = accessibilityHandler.getComponent();

            if (component.getWantsKeyboardFocus())
            {
                const auto hasKeyboardFocus = component.hasKeyboardFocus (false);

                env->CallVoidMethod (info,
                                     AndroidAccessibilityNodeInfo.setFocused,
                                     hasKeyboardFocus);
                env->CallVoidMethod (info,
                                     AndroidAccessibilityNodeInfo.addAction,
                                     hasKeyboardFocus ? ACTION_CLEAR_FOCUS : ACTION_FOCUS);
            }

            const auto isAccessibleFocused = accessibilityHandler.hasFocus (false);

            env->CallVoidMethod (info,
                                 AndroidAccessibilityNodeInfo.setAccessibilityFocused,
                                 isAccessibleFocused);

            env->CallVoidMethod (info,
                                 AndroidAccessibilityNodeInfo.addAction,
                                 isAccessibleFocused ? ACTION_CLEAR_ACCESSIBILITY_FOCUS
                                                     : ACTION_ACCESSIBILITY_FOCUS);
        }

        if (state.isCheckable())
        {
            env->CallVoidMethod (info,
                                 AndroidAccessibilityNodeInfo.setCheckable,
                                 true);
            env->CallVoidMethod (info,
                                 AndroidAccessibilityNodeInfo.setChecked,
                                 state.isChecked());
        }

        if (state.isSelectable() || state.isMultiSelectable())
        {
            const auto isSelected = state.isSelected();

            env->CallVoidMethod (info,
                                 AndroidAccessibilityNodeInfo.setSelected,
                                 isSelected);
            env->CallVoidMethod (info,
                                 AndroidAccessibilityNodeInfo.addAction,
                                 isSelected ? ACTION_CLEAR_SELECTION : ACTION_SELECT);
        }

        if ((accessibilityHandler.getCurrentState().isCheckable() && accessibilityHandler.getActions().contains (AccessibilityActionType::toggle))
            || accessibilityHandler.getActions().contains (AccessibilityActionType::press))
        {
            env->CallVoidMethod (info,
                                 AndroidAccessibilityNodeInfo.setClickable,
                                 true);
            env->CallVoidMethod (info,
                                 AndroidAccessibilityNodeInfo.addAction,
                                 ACTION_CLICK);
        }

        if (accessibilityHandler.getActions().contains (AccessibilityActionType::showMenu)
            && state.isExpandable())
        {
            env->CallVoidMethod (info,
                                 AndroidAccessibilityNodeInfo.addAction,
                                 state.isExpanded() ? ACTION_COLLAPSE : ACTION_EXPAND);
        }

        if (auto* textInterface = accessibilityHandler.getTextInterface())
        {
            env->CallVoidMethod (info,
                                 AndroidAccessibilityNodeInfo.setText,
                                 javaString (textInterface->getAllText()).get());

            const auto isReadOnly = textInterface->isReadOnly();

            env->CallVoidMethod (info,
                                 AndroidAccessibilityNodeInfo.setPassword,
                                 textInterface->isDisplayingProtectedText());

            if (nodeInfoSetEditable != nullptr)
                env->CallVoidMethod (info, nodeInfoSetEditable, ! isReadOnly);

            const auto selection = textInterface->getSelection();

            if (nodeInfoSetTextSelection != nullptr && ! selection.isEmpty())
                env->CallVoidMethod (info,
                                     nodeInfoSetTextSelection,
                                     selection.getStart(), selection.getEnd());

            if (nodeInfoSetLiveRegion != nullptr && accessibilityHandler.hasFocus (false))
                env->CallVoidMethod (info,
                                     nodeInfoSetLiveRegion,
                                     ACCESSIBILITY_LIVE_REGION_POLITE);

            env->CallVoidMethod (info,
                                 AndroidAccessibilityNodeInfo.setMovementGranularities,
                                 ALL_GRANULARITIES);

            env->CallVoidMethod (info,
                                 AndroidAccessibilityNodeInfo.addAction,
                                 ACTION_NEXT_AT_MOVEMENT_GRANULARITY);
            env->CallVoidMethod (info,
                                 AndroidAccessibilityNodeInfo.addAction,
                                 ACTION_PREVIOUS_AT_MOVEMENT_GRANULARITY);
            env->CallVoidMethod (info,
                                 AndroidAccessibilityNodeInfo.addAction,
                                 ACTION_SET_SELECTION);

            if (! isReadOnly)
                env->CallVoidMethod (info, AndroidAccessibilityNodeInfo.addAction, ACTION_SET_TEXT);
        }

        if (auto* valueInterface = accessibilityHandler.getValueInterface())
        {
            if (! valueInterface->isReadOnly())
            {
                const auto range = valueInterface->getRange();

                if (range.isValid())
                {
                    env->CallVoidMethod (info,
                                         AndroidAccessibilityNodeInfo.addAction,
                                         ACTION_SCROLL_FORWARD);
                    env->CallVoidMethod (info,
                                         AndroidAccessibilityNodeInfo.addAction,
                                         ACTION_SCROLL_BACKWARD);
                }
            }
        }

        if (auto* tableInterface = accessibilityHandler.getTableInterface())
        {
            const auto rows    = tableInterface->getNumRows();
            const auto columns = tableInterface->getNumColumns();
            const LocalRef<jobject> collectionInfo { env->CallStaticObjectMethod (AndroidAccessibilityNodeInfoCollectionInfo,
                                                                                  AndroidAccessibilityNodeInfoCollectionInfo.obtain,
                                                                                  (jint) rows,
                                                                                  (jint) columns,
                                                                                  (jboolean) false) };
            env->CallVoidMethod (info, AndroidAccessibilityNodeInfo.setCollectionInfo, collectionInfo.get());
        }

        if (auto* enclosingTableHandler = detail::AccessibilityHelpers::getEnclosingHandlerWithInterface (&accessibilityHandler, &AccessibilityHandler::getTableInterface))
        {
            auto* interface = enclosingTableHandler->getTableInterface();
            jassert (interface != nullptr);
            const auto rowSpan    = interface->getRowSpan    (accessibilityHandler);
            const auto columnSpan = interface->getColumnSpan (accessibilityHandler);

            enum class IsHeader { no, yes };

            const auto addCellInfo = [env, &info] (AccessibilityTableInterface::Span rows, AccessibilityTableInterface::Span columns, IsHeader header)
            {
                const LocalRef<jobject> collectionItemInfo { env->CallStaticObjectMethod (AndroidAccessibilityNodeInfoCollectionItemInfo,
                                                                                          AndroidAccessibilityNodeInfoCollectionItemInfo.obtain,
                                                                                          (jint) rows.begin,
                                                                                          (jint) rows.num,
                                                                                          (jint) columns.begin,
                                                                                          (jint) columns.num,
                                                                                          (jboolean) (header == IsHeader::yes)) };
                env->CallVoidMethod (info, AndroidAccessibilityNodeInfo.setCollectionItemInfo, collectionItemInfo.get());
            };

            if (rowSpan.hasValue() && columnSpan.hasValue())
            {
                addCellInfo (*rowSpan, *columnSpan, IsHeader::no);
            }
            else
            {
                if (auto* tableHeader = interface->getHeaderHandler())
                {
                    if (accessibilityHandler.getParent() == tableHeader)
                    {
                        const auto children = tableHeader->getChildren();
                        const auto column = std::distance (children.cbegin(), std::find (children.cbegin(), children.cend(), &accessibilityHandler));

                        // Talkback will only treat a row as a column header if its row index is zero
                        // https://github.com/google/talkback/blob/acd0bc7631a3dfbcf183789c7557596a45319e1f/utils/src/main/java/CollectionState.java#L853
                        addCellInfo ({ 0, 1 }, { (int) column, 1 }, IsHeader::yes);
                    }
                }
            }
        }
    }

    bool performAction (int action, jobject arguments)
    {
        switch (action)
        {
            case ACTION_ACCESSIBILITY_FOCUS:
            {
                const WeakReference<Component> safeComponent (&accessibilityHandler.getComponent());

                accessibilityHandler.getActions().invoke (AccessibilityActionType::focus);

                if (safeComponent != nullptr)
                    accessibilityHandler.grabFocus();

                return true;
            }

            case ACTION_CLEAR_ACCESSIBILITY_FOCUS:
            {
                accessibilityHandler.giveAwayFocus();
                return true;
            }

            case ACTION_FOCUS:
            case ACTION_CLEAR_FOCUS:
            {
                auto& component = accessibilityHandler.getComponent();

                if (component.getWantsKeyboardFocus())
                {
                    const auto hasFocus = component.hasKeyboardFocus (false);

                    if (hasFocus && action == ACTION_CLEAR_FOCUS)
                        component.giveAwayKeyboardFocus();
                    else if (! hasFocus && action == ACTION_FOCUS)
                        component.grabKeyboardFocus();

                    return true;
                }

                break;
            }

            case ACTION_CLICK:
            {
                // Invoking the action may delete this handler
                const WeakReference<AccessibilityNativeHandle> savedHandle { this };

                if ((accessibilityHandler.getCurrentState().isCheckable() && accessibilityHandler.getActions().invoke (AccessibilityActionType::toggle))
                    || accessibilityHandler.getActions().invoke (AccessibilityActionType::press))
                {
                    if (savedHandle != nullptr)
                        sendAccessibilityEventImpl (accessibilityHandler, TYPE_VIEW_CLICKED, 0);

                    return true;
                }

                break;
            }

            case ACTION_SELECT:
            case ACTION_CLEAR_SELECTION:
            {
                const auto state = accessibilityHandler.getCurrentState();

                if (state.isSelectable() || state.isMultiSelectable())
                {
                    const auto isSelected = state.isSelected();

                    if ((isSelected && action == ACTION_CLEAR_SELECTION)
                        || (! isSelected && action == ACTION_SELECT))
                    {
                        return accessibilityHandler.getActions().invoke (AccessibilityActionType::toggle);
                    }

                }

                break;
            }

            case ACTION_EXPAND:
            case ACTION_COLLAPSE:
            {
                const auto state = accessibilityHandler.getCurrentState();

                if (state.isExpandable())
                {
                    const auto isExpanded = state.isExpanded();

                    if ((isExpanded && action == ACTION_COLLAPSE)
                        || (! isExpanded && action == ACTION_EXPAND))
                    {
                        return accessibilityHandler.getActions().invoke (AccessibilityActionType::showMenu);
                    }
                }

                break;
            }

            case ACTION_NEXT_AT_MOVEMENT_GRANULARITY:      return moveCursor (arguments, true);
            case ACTION_PREVIOUS_AT_MOVEMENT_GRANULARITY:  return moveCursor (arguments, false);

            case ACTION_SET_SELECTION:
            {
                if (auto* textInterface = accessibilityHandler.getTextInterface())
                {
                    auto* env = getEnv();

                    const auto selection = [&]() -> Range<int>
                    {
                        const auto selectionStartKey = javaString ("ACTION_ARGUMENT_SELECTION_START_INT");
                        const auto selectionEndKey   = javaString ("ACTION_ARGUMENT_SELECTION_END_INT");

                        const auto hasKey = [&env, &arguments] (const auto& key)
                        {
                            return env->CallBooleanMethod (arguments, AndroidBundle.containsKey, key.get());
                        };

                        if (hasKey (selectionStartKey) && hasKey (selectionEndKey))
                        {
                            const auto getKey = [&env, &arguments] (const auto& key)
                            {
                                return env->CallIntMethod (arguments, AndroidBundle.getInt, key.get());
                            };

                            const auto start = getKey (selectionStartKey);
                            const auto end   = getKey (selectionEndKey);

                            return Range<int>::between (start, end);
                        }

                        return {};
                    }();

                    textInterface->setSelection (selection);

                    return true;
                }

                break;
            }

            case ACTION_SET_TEXT:
            {
                if (auto* textInterface = accessibilityHandler.getTextInterface())
                {
                    if (! textInterface->isReadOnly())
                    {
                        const auto charSequenceKey = javaString ("ACTION_ARGUMENT_SET_TEXT_CHARSEQUENCE");

                        auto* env = getEnv();

                        const auto text = [&]() -> String
                        {
                            if (env->CallBooleanMethod (arguments, AndroidBundle.containsKey, charSequenceKey.get()))
                            {
                                LocalRef<jobject> charSequence (env->CallObjectMethod (arguments,
                                                                                       AndroidBundle.getCharSequence,
                                                                                       charSequenceKey.get()));
                                LocalRef<jstring> textStringRef ((jstring) env->CallObjectMethod (charSequence,
                                                                                                  JavaCharSequence.toString));

                                return juceString (textStringRef.get());
                            }

                            return {};
                        }();

                        textInterface->setText (text);
                    }
                }

                break;
            }

            case ACTION_SCROLL_BACKWARD:
            case ACTION_SCROLL_FORWARD:
            {
                if (auto* valueInterface = accessibilityHandler.getValueInterface())
                {
                    if (! valueInterface->isReadOnly())
                    {
                        const auto range = valueInterface->getRange();

                        if (range.isValid())
                        {
                            const auto interval = action == ACTION_SCROLL_BACKWARD ? -range.getInterval()
                                                                                   : range.getInterval();
                            valueInterface->setValue (jlimit (range.getMinimumValue(),
                                                              range.getMaximumValue(),
                                                              valueInterface->getCurrentValue() + interval));

                            // required for Android to announce the new value
                            sendAccessibilityEventImpl (accessibilityHandler, TYPE_VIEW_SELECTED, 0);
                            return true;
                        }
                    }
                }

                break;
            }
        }

        return false;
    }

    bool isInPopulateNodeInfo() const noexcept  { return inPopulateNodeInfo; }

    static bool areAnyAccessibilityClientsActive()
    {
        auto* env = getEnv();
        auto appContext = getAppContext();

        if (appContext.get() != nullptr)
        {
            LocalRef<jobject> accessibilityManager (env->CallObjectMethod (appContext.get(), AndroidContext.getSystemService,
                                                                           javaString ("accessibility").get()));

            if (accessibilityManager != nullptr)
                return env->CallBooleanMethod (accessibilityManager.get(), AndroidAccessibilityManager.isEnabled);
        }

        return false;
    }

    template <typename ModificationCallback>
    static void sendAccessibilityEventExtendedImpl (const AccessibilityHandler& handler,
                                                    int eventType,
                                                    ModificationCallback&& modificationCallback)
    {
        if (! areAnyAccessibilityClientsActive())
            return;

        if (const auto sourceView = getSourceView (handler))
        {
            const auto* nativeImpl = handler.getNativeImplementation();

            if (nativeImpl == nullptr || nativeImpl->isInPopulateNodeInfo())
                return;

            auto* env = getEnv();
            auto appContext = getAppContext();

            if (appContext.get() == nullptr)
                return;

            LocalRef<jobject> event (env->CallStaticObjectMethod (AndroidAccessibilityEvent,
                                                                  AndroidAccessibilityEvent.obtain,
                                                                  eventType));

            env->CallVoidMethod (event,
                                 AndroidAccessibilityEvent.setPackageName,
                                 env->CallObjectMethod (appContext.get(),
                                                        AndroidContext.getPackageName));

            env->CallVoidMethod (event,
                                 AndroidAccessibilityEvent.setSource,
                                 sourceView,
                                 nativeImpl->getVirtualViewId());

            modificationCallback (event);

            env->CallBooleanMethod (sourceView,
                                    AndroidViewGroup.requestSendAccessibilityEvent,
                                    sourceView,
                                    event.get());
        }
    }

    static void sendAccessibilityEventImpl (const AccessibilityHandler& handler, int eventType, int contentChangeTypes)
    {
        sendAccessibilityEventExtendedImpl (handler, eventType, [contentChangeTypes] (auto event)
        {
            if (contentChangeTypes != 0 && accessibilityEventSetContentChangeTypes != nullptr)
                getEnv()->CallVoidMethod (event,
                                          accessibilityEventSetContentChangeTypes,
                                          contentChangeTypes);
        });
    }

private:
    static std::unordered_map<int, AccessibilityHandler*> virtualViewIdMap;

    static int getNextVirtualViewId()
    {
        static int counter = 0;

        return counter++;
    }

    static int getVirtualViewIdForHandler (const AccessibilityHandler& handler)
    {
        if (handler.getComponent().isOnDesktop())
            return HOST_VIEW_ID;

        return getNextVirtualViewId();
    }

    LocalRef<jstring> getDescriptionString() const
    {
        const auto valueString = [this]() -> String
        {
            if (auto* textInterface = accessibilityHandler.getTextInterface())
                return textInterface->getAllText();

            if (auto* valueInterface = accessibilityHandler.getValueInterface())
                return valueInterface->getCurrentValueAsString();

            return {};
        }();

        StringArray strings (accessibilityHandler.getTitle(),
                             valueString,
                             accessibilityHandler.getDescription(),
                             accessibilityHandler.getHelp());

        strings.removeEmptyStrings();

        return javaString (strings.joinIntoString (","));
    }

    bool moveCursor (jobject arguments, bool forwards)
    {
        using ATH = AccessibilityTextHelpers;

        auto* textInterface = accessibilityHandler.getTextInterface();

        if (textInterface == nullptr)
            return false;

        const auto granularityKey = javaString ("ACTION_ARGUMENT_MOVEMENT_GRANULARITY_INT");
        const auto extendSelectionKey = javaString ("ACTION_ARGUMENT_EXTEND_SELECTION_BOOLEAN");

        auto* env = getEnv();

        const auto boundaryType = [&]
        {
            const auto granularity = env->CallIntMethod (arguments, AndroidBundle.getInt, granularityKey.get());

            using BoundaryType = ATH::BoundaryType;

            switch (granularity)
            {
                case MOVEMENT_GRANULARITY_CHARACTER:  return BoundaryType::character;
                case MOVEMENT_GRANULARITY_WORD:       return BoundaryType::word;
                case MOVEMENT_GRANULARITY_LINE:       return BoundaryType::line;
                case MOVEMENT_GRANULARITY_PARAGRAPH:
                case MOVEMENT_GRANULARITY_PAGE:       return BoundaryType::document;
            }

            jassertfalse;
            return BoundaryType::character;
        }();

        const auto direction = forwards
                             ? ATH::Direction::forwards
                             : ATH::Direction::backwards;

        const auto extend = env->CallBooleanMethod (arguments, AndroidBundle.getBoolean, extendSelectionKey.get())
                          ? ATH::ExtendSelection::yes
                          : ATH::ExtendSelection::no;

        const auto oldSelection = textInterface->getSelection();
        const auto newSelection = ATH::findNewSelectionRangeAndroid (*textInterface, boundaryType, extend, direction);
        textInterface->setSelection (newSelection);

        // Required for Android to read back the text that the cursor moved over
        sendAccessibilityEventExtendedImpl (accessibilityHandler, TYPE_VIEW_TEXT_TRAVERSED_AT_MOVEMENT_GRANULARITY, [&] (auto event)
        {
            env->CallVoidMethod (event,
                                 AndroidAccessibilityEvent.setAction,
                                 forwards ? ACTION_NEXT_AT_MOVEMENT_GRANULARITY : ACTION_PREVIOUS_AT_MOVEMENT_GRANULARITY);

            env->CallVoidMethod (event,
                                 AndroidAccessibilityEvent.setFromIndex,
                                 oldSelection.getStart() != newSelection.getStart() ? oldSelection.getStart()
                                                                                    : oldSelection.getEnd());

            env->CallVoidMethod (event,
                                 AndroidAccessibilityEvent.setToIndex,
                                 oldSelection.getStart() != newSelection.getStart() ? newSelection.getStart()
                                                                                    : newSelection.getEnd());
        });

        return true;
    }

    AccessibilityHandler& accessibilityHandler;
    const int virtualViewId;
    std::optional<int> nativeChildViewId;
    bool inPopulateNodeInfo = false;

    //==============================================================================
    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (AccessibilityNativeHandle)

    JUCE_DECLARE_WEAK_REFERENCEABLE (AccessibilityNativeHandle)
};

std::unordered_map<int, AccessibilityHandler*> AccessibilityNativeHandle::virtualViewIdMap;

class AccessibilityHandler::AccessibilityNativeImpl : public AccessibilityNativeHandle
{
public:
    using AccessibilityNativeHandle::AccessibilityNativeHandle;
};

//==============================================================================
AccessibilityNativeHandle* AccessibilityHandler::getNativeImplementation() const
{
    return nativeImpl.get();
}

void detail::AccessibilityHelpers::notifyAccessibilityEvent (const AccessibilityHandler& handler,
                                                             Event eventType)
{
    if (eventType == Event::elementCreated
        || eventType == Event::elementDestroyed
        || eventType == Event::elementMovedOrResized)
    {
        if (auto* parent = handler.getParent())
            AccessibilityNativeHandle::sendAccessibilityEventImpl (*parent, TYPE_WINDOW_CONTENT_CHANGED, CONTENT_CHANGE_TYPE_SUBTREE);

        return;
    }

    auto notification = [&handler, eventType]
    {
        switch (eventType)
        {
            case Event::focusChanged:
                return handler.hasFocus (false) ? TYPE_VIEW_ACCESSIBILITY_FOCUSED
                                                : TYPE_VIEW_ACCESSIBILITY_FOCUS_CLEARED;

            case Event::elementCreated:
            case Event::elementDestroyed:
            case Event::elementMovedOrResized:
            case Event::windowOpened:
            case Event::windowClosed:
                break;
        }

        return 0;
    }();

    if (notification != 0)
        AccessibilityNativeHandle::sendAccessibilityEventImpl (handler, notification, 0);
}

void AccessibilityHandler::notifyAccessibilityEvent (AccessibilityEvent eventType) const
{
    auto notification = [eventType]
    {
        switch (eventType)
        {
            case AccessibilityEvent::textSelectionChanged:  return TYPE_VIEW_TEXT_SELECTION_CHANGED;
            case AccessibilityEvent::textChanged:           return TYPE_VIEW_TEXT_CHANGED;

            case AccessibilityEvent::titleChanged:
            case AccessibilityEvent::structureChanged:      return TYPE_WINDOW_CONTENT_CHANGED;

            case AccessibilityEvent::rowSelectionChanged:
            case AccessibilityEvent::valueChanged:          break;
        }

        return 0;
    }();

    if (notification == 0)
        return;

    const auto contentChangeTypes = [eventType]
    {
        if (eventType == AccessibilityEvent::titleChanged)      return CONTENT_CHANGE_TYPE_CONTENT_DESCRIPTION;
        if (eventType == AccessibilityEvent::structureChanged)  return CONTENT_CHANGE_TYPE_SUBTREE;

        return 0;
    }();

    AccessibilityNativeHandle::sendAccessibilityEventImpl (*this, notification, contentChangeTypes);
}

void AccessibilityHandler::postAnnouncement (const String& announcementString,
                                             AnnouncementPriority)
{
    if (! AccessibilityNativeHandle::areAnyAccessibilityClientsActive())
        return;

    const auto rootView = []
    {
        LocalRef<jobject> activity (getMainActivity());

        if (activity != nullptr)
        {
            auto* env = getEnv();

            LocalRef<jobject> mainWindow (env->CallObjectMethod (activity.get(), AndroidActivity.getWindow));
            LocalRef<jobject> decorView (env->CallObjectMethod (mainWindow.get(), AndroidWindow.getDecorView));

            return LocalRef<jobject> (env->CallObjectMethod (decorView.get(), AndroidView.getRootView));
        }

        return LocalRef<jobject>();
    }();

    if (rootView != nullptr)
        getEnv()->CallVoidMethod (rootView.get(),
                                  AndroidView.announceForAccessibility,
                                  javaString (announcementString).get());
}

bool AccessibilityHandler::areAnyAccessibilityClientsActive()
{
    return AccessibilityNativeHandle::areAnyAccessibilityClientsActive();
}

} // namespace juce
