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

   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
{

static uint32 lastUniquePeerID = 1;

//==============================================================================
ComponentPeer::ComponentPeer (Component& comp, int flags)
    : component (comp),
      styleFlags (flags),
      uniqueID (lastUniquePeerID += 2) // increment by 2 so that this can never hit 0
{
    auto& desktop = Desktop::getInstance();
    desktop.peers.add (this);
    desktop.addFocusChangeListener (this);
}

ComponentPeer::~ComponentPeer()
{
    auto& desktop = Desktop::getInstance();
    desktop.removeFocusChangeListener (this);
    desktop.peers.removeFirstMatchingValue (this);
    desktop.triggerFocusCallback();
}

//==============================================================================
int ComponentPeer::getNumPeers() noexcept
{
    return Desktop::getInstance().peers.size();
}

ComponentPeer* ComponentPeer::getPeer (const int index) noexcept
{
    return Desktop::getInstance().peers [index];
}

ComponentPeer* ComponentPeer::getPeerFor (const Component* const component) noexcept
{
    for (auto* peer : Desktop::getInstance().peers)
        if (&(peer->getComponent()) == component)
            return peer;

    return nullptr;
}

bool ComponentPeer::isValidPeer (const ComponentPeer* const peer) noexcept
{
    return Desktop::getInstance().peers.contains (const_cast<ComponentPeer*> (peer));
}

void ComponentPeer::updateBounds()
{
    setBounds (detail::ScalingHelpers::scaledScreenPosToUnscaled (component, component.getBoundsInParent()), false);
}

bool ComponentPeer::isKioskMode() const
{
    return Desktop::getInstance().getKioskModeComponent() == &component;
}

//==============================================================================
void ComponentPeer::handleMouseEvent (MouseInputSource::InputSourceType type, Point<float> pos, ModifierKeys newMods,
                                      float newPressure, float newOrientation, int64 time, PenDetails pen, int touchIndex)
{
    if (auto* mouse = Desktop::getInstance().mouseSources->getOrCreateMouseInputSource (type, touchIndex))
        MouseInputSource (*mouse).handleEvent (*this, pos, time, newMods, newPressure, newOrientation, pen);
}

void ComponentPeer::handleMouseWheel (MouseInputSource::InputSourceType type, Point<float> pos, int64 time, const MouseWheelDetails& wheel, int touchIndex)
{
    if (auto* mouse = Desktop::getInstance().mouseSources->getOrCreateMouseInputSource (type, touchIndex))
        MouseInputSource (*mouse).handleWheel (*this, pos, time, wheel);
}

void ComponentPeer::handleMagnifyGesture (MouseInputSource::InputSourceType type, Point<float> pos, int64 time, float scaleFactor, int touchIndex)
{
    if (auto* mouse = Desktop::getInstance().mouseSources->getOrCreateMouseInputSource (type, touchIndex))
        MouseInputSource (*mouse).handleMagnifyGesture (*this, pos, time, scaleFactor);
}

//==============================================================================
void ComponentPeer::handlePaint (LowLevelGraphicsContext& contextToPaintTo)
{
    Graphics g (contextToPaintTo);

    if (component.isTransformed())
        g.addTransform (component.getTransform());

    auto peerBounds = getBounds();
    auto componentBounds = component.getLocalBounds();

    if (component.isTransformed())
        componentBounds = componentBounds.transformedBy (component.getTransform());

    if (peerBounds.getWidth() != componentBounds.getWidth() || peerBounds.getHeight() != componentBounds.getHeight())
        // Tweak the scaling so that the component's integer size exactly aligns with the peer's scaled size
        g.addTransform (AffineTransform::scale ((float) peerBounds.getWidth()  / (float) componentBounds.getWidth(),
                                                (float) peerBounds.getHeight() / (float) componentBounds.getHeight()));

  #if JUCE_ENABLE_REPAINT_DEBUGGING
   #ifdef JUCE_IS_REPAINT_DEBUGGING_ACTIVE
    if (JUCE_IS_REPAINT_DEBUGGING_ACTIVE)
   #endif
    {
        g.saveState();
    }
  #endif

    JUCE_TRY
    {
        component.paintEntireComponent (g, true);
    }
    JUCE_CATCH_EXCEPTION

  #if JUCE_ENABLE_REPAINT_DEBUGGING
   #ifdef JUCE_IS_REPAINT_DEBUGGING_ACTIVE
    if (JUCE_IS_REPAINT_DEBUGGING_ACTIVE)
   #endif
    {
        // enabling this code will fill all areas that get repainted with a colour overlay, to show
        // clearly when things are being repainted.
        g.restoreState();

        static Random rng;

        g.fillAll (Colour ((uint8) rng.nextInt (255),
                           (uint8) rng.nextInt (255),
                           (uint8) rng.nextInt (255),
                           (uint8) 0x50));
    }
  #endif

    /** If this fails, it's probably be because your CPU floating-point precision mode has
        been set to low. This setting is sometimes changed by things like Direct3D, and can
        mess up a lot of the calculations that the library needs to do.
    */
    jassert (roundToInt (10.1f) == 10);

    ++peerFrameNumber;
}

Component* ComponentPeer::getTargetForKeyPress()
{
    auto* c = Component::getCurrentlyFocusedComponent();

    if (c == nullptr)
        c = &component;

    if (c->isCurrentlyBlockedByAnotherModalComponent())
        if (auto* currentModalComp = Component::getCurrentlyModalComponent())
            c = currentModalComp;

    return c;
}

bool ComponentPeer::handleKeyPress (const int keyCode, const juce_wchar textCharacter)
{
    return handleKeyPress (KeyPress (keyCode,
                                     ModifierKeys::getCurrentModifiers().withoutMouseButtons(),
                                     textCharacter));
}

bool ComponentPeer::handleKeyPress (const KeyPress& keyInfo)
{
    bool keyWasUsed = false;

    for (auto* target = getTargetForKeyPress(); target != nullptr; target = target->getParentComponent())
    {
        const WeakReference deletionChecker (target);

        if (auto* keyListeners = target->getKeyListeners())
        {
            for (int i = keyListeners->size(); --i >= 0;)
            {
                keyWasUsed = keyListeners->getUnchecked (i)->keyPressed (keyInfo, target);

                if (keyWasUsed || deletionChecker == nullptr)
                    return keyWasUsed;

                i = jmin (i, keyListeners->size());
            }
        }

        keyWasUsed = target->keyPressed (keyInfo);

        if (keyWasUsed || deletionChecker == nullptr)
            break;
    }

    if (! keyWasUsed && keyInfo.isKeyCode (KeyPress::tabKey))
    {
        if (auto* currentlyFocused = Component::getCurrentlyFocusedComponent())
        {
            currentlyFocused->moveKeyboardFocusToSibling (! keyInfo.getModifiers().isShiftDown());
            return true;
        }
    }

    return keyWasUsed;
}

bool ComponentPeer::handleKeyUpOrDown (const bool isKeyDown)
{
    bool keyWasUsed = false;

    for (auto* target = getTargetForKeyPress(); target != nullptr; target = target->getParentComponent())
    {
        const WeakReference deletionChecker (target);

        keyWasUsed = target->keyStateChanged (isKeyDown);

        if (keyWasUsed || deletionChecker == nullptr)
            break;

        if (auto* keyListeners = target->getKeyListeners())
        {
            for (int i = keyListeners->size(); --i >= 0;)
            {
                keyWasUsed = keyListeners->getUnchecked (i)->keyStateChanged (isKeyDown, target);

                if (keyWasUsed || deletionChecker == nullptr)
                    return keyWasUsed;

                i = jmin (i, keyListeners->size());
            }
        }
    }

    return keyWasUsed;
}

void ComponentPeer::handleModifierKeysChange()
{
    auto* target = Desktop::getInstance().getMainMouseSource().getComponentUnderMouse();

    if (target == nullptr)
        target = Component::getCurrentlyFocusedComponent();

    if (target == nullptr)
        target = &component;

    target->internalModifierKeysChanged();
}

void ComponentPeer::refreshTextInputTarget()
{
    const auto* lastTarget = std::exchange (textInputTarget, findCurrentTextInputTarget());

    if (lastTarget == textInputTarget)
        return;

    if (textInputTarget == nullptr)
        dismissPendingTextInput();
    else if (auto* c = Component::getCurrentlyFocusedComponent())
        textInputRequired (globalToLocal (c->getScreenPosition()), *textInputTarget);
}

TextInputTarget* ComponentPeer::findCurrentTextInputTarget()
{
    auto* c = Component::getCurrentlyFocusedComponent();

    if (c == &component || component.isParentOf (c))
        if (auto* ti = dynamic_cast<TextInputTarget*> (c))
            if (ti->isTextInputActive())
                return ti;

    return nullptr;
}

void ComponentPeer::closeInputMethodContext() {}

void ComponentPeer::dismissPendingTextInput()
{
    closeInputMethodContext();
}

//==============================================================================
void ComponentPeer::handleBroughtToFront()
{
    component.internalBroughtToFront();
}

void ComponentPeer::setConstrainer (ComponentBoundsConstrainer* const newConstrainer) noexcept
{
    constrainer = newConstrainer;
}

void ComponentPeer::handleMovedOrResized()
{
    const bool nowMinimised = isMinimised();

    if (component.flags.hasHeavyweightPeerFlag && ! nowMinimised)
    {
        const WeakReference<Component> deletionChecker (&component);

        auto newBounds = detail::ComponentHelpers::rawPeerPositionToLocal (component, getBounds());
        auto oldBounds = component.getBounds();

        const bool wasMoved   = (oldBounds.getPosition() != newBounds.getPosition());
        const bool wasResized = (oldBounds.getWidth() != newBounds.getWidth() || oldBounds.getHeight() != newBounds.getHeight());

        if (wasMoved || wasResized)
        {
            component.boundsRelativeToParent = newBounds;

            if (wasResized)
                component.repaint();

            component.sendMovedResizedMessages (wasMoved, wasResized);

            if (deletionChecker == nullptr)
                return;
        }
    }

    if (isWindowMinimised != nowMinimised)
    {
        isWindowMinimised = nowMinimised;
        component.minimisationStateChanged (nowMinimised);
        component.sendVisibilityChangeMessage();
    }

    const auto windowInSpecialState = isFullScreen() || isKioskMode() || nowMinimised;

    if (! windowInSpecialState)
        lastNonFullscreenBounds = component.getBounds();
}

void ComponentPeer::handleFocusGain()
{
    if (component.isParentOf (lastFocusedComponent)
          && lastFocusedComponent->isShowing()
          && lastFocusedComponent->getWantsKeyboardFocus())
    {
        Component::currentlyFocusedComponent = lastFocusedComponent;
        Desktop::getInstance().triggerFocusCallback();
        lastFocusedComponent->internalKeyboardFocusGain (Component::focusChangedDirectly);
    }
    else
    {
        if (! component.isCurrentlyBlockedByAnotherModalComponent())
            component.grabKeyboardFocus();
        else
            ModalComponentManager::getInstance()->bringModalComponentsToFront();
    }
}

void ComponentPeer::handleFocusLoss()
{
    if (component.hasKeyboardFocus (true))
    {
        lastFocusedComponent = Component::currentlyFocusedComponent;

        if (lastFocusedComponent != nullptr)
        {
            Component::currentlyFocusedComponent = nullptr;
            Desktop::getInstance().triggerFocusCallback();
            lastFocusedComponent->internalKeyboardFocusLoss (Component::focusChangedByMouseClick);
        }
    }
}

Component* ComponentPeer::getLastFocusedSubcomponent() const noexcept
{
    return (component.isParentOf (lastFocusedComponent) && lastFocusedComponent->isShowing())
                ? static_cast<Component*> (lastFocusedComponent)
                : &component;
}

void ComponentPeer::handleScreenSizeChange()
{
    component.parentSizeChanged();
    handleMovedOrResized();
}

void ComponentPeer::setNonFullScreenBounds (const Rectangle<int>& newBounds) noexcept
{
    lastNonFullscreenBounds = newBounds;
}

const Rectangle<int>& ComponentPeer::getNonFullScreenBounds() const noexcept
{
    return lastNonFullscreenBounds;
}

Point<int> ComponentPeer::localToGlobal (Point<int> p)   { return localToGlobal (p.toFloat()).roundToInt(); }
Point<int> ComponentPeer::globalToLocal (Point<int> p)   { return globalToLocal (p.toFloat()).roundToInt(); }

Rectangle<int> ComponentPeer::localToGlobal (const Rectangle<int>& relativePosition)
{
    return relativePosition.withPosition (localToGlobal (relativePosition.getPosition()));
}

Rectangle<int> ComponentPeer::globalToLocal (const Rectangle<int>& screenPosition)
{
    return screenPosition.withPosition (globalToLocal (screenPosition.getPosition()));
}

Rectangle<float> ComponentPeer::localToGlobal (const Rectangle<float>& relativePosition)
{
    return relativePosition.withPosition (localToGlobal (relativePosition.getPosition()));
}

Rectangle<float> ComponentPeer::globalToLocal (const Rectangle<float>& screenPosition)
{
    return screenPosition.withPosition (globalToLocal (screenPosition.getPosition()));
}

Rectangle<int> ComponentPeer::getAreaCoveredBy (const Component& subComponent) const
{
    return detail::ScalingHelpers::scaledScreenPosToUnscaled
            (component, component.getLocalArea (&subComponent, subComponent.getLocalBounds()));
}

//==============================================================================
namespace DragHelpers
{
    static bool isFileDrag (const ComponentPeer::DragInfo& info)
    {
        return ! info.files.isEmpty();
    }

    static bool isSuitableTarget (const ComponentPeer::DragInfo& info, Component* target)
    {
        return isFileDrag (info) ? dynamic_cast<FileDragAndDropTarget*> (target) != nullptr
                                 : dynamic_cast<TextDragAndDropTarget*> (target) != nullptr;
    }

    static bool isInterested (const ComponentPeer::DragInfo& info, Component* target)
    {
        return isFileDrag (info) ? dynamic_cast<FileDragAndDropTarget*> (target)->isInterestedInFileDrag (info.files)
                                 : dynamic_cast<TextDragAndDropTarget*> (target)->isInterestedInTextDrag (info.text);
    }

    static Component* findDragAndDropTarget (Component* c, const ComponentPeer::DragInfo& info, Component* lastOne)
    {
        for (; c != nullptr; c = c->getParentComponent())
            if (isSuitableTarget (info, c) && (c == lastOne || isInterested (info, c)))
                return c;

        return nullptr;
    }
}

bool ComponentPeer::handleDragMove (const ComponentPeer::DragInfo& info)
{
    auto* compUnderMouse = component.getComponentAt (info.position);
    auto* lastTarget = dragAndDropTargetComponent.get();
    Component* newTarget = nullptr;

    if (compUnderMouse != lastDragAndDropCompUnderMouse)
    {
        lastDragAndDropCompUnderMouse = compUnderMouse;
        newTarget = DragHelpers::findDragAndDropTarget (compUnderMouse, info, lastTarget);

        if (newTarget != lastTarget)
        {
            if (lastTarget != nullptr)
            {
                if (DragHelpers::isFileDrag (info))
                    dynamic_cast<FileDragAndDropTarget*> (lastTarget)->fileDragExit (info.files);
                else
                    dynamic_cast<TextDragAndDropTarget*> (lastTarget)->textDragExit (info.text);
            }

            dragAndDropTargetComponent = nullptr;

            if (DragHelpers::isSuitableTarget (info, newTarget))
            {
                dragAndDropTargetComponent = newTarget;
                auto pos = newTarget->getLocalPoint (&component, info.position);

                if (DragHelpers::isFileDrag (info))
                    dynamic_cast<FileDragAndDropTarget*> (newTarget)->fileDragEnter (info.files, pos.x, pos.y);
                else
                    dynamic_cast<TextDragAndDropTarget*> (newTarget)->textDragEnter (info.text, pos.x, pos.y);
            }
        }
    }
    else
    {
        newTarget = lastTarget;
    }

    if (! DragHelpers::isSuitableTarget (info, newTarget))
        return false;

    auto pos = newTarget->getLocalPoint (&component, info.position);

    if (DragHelpers::isFileDrag (info))
        dynamic_cast<FileDragAndDropTarget*> (newTarget)->fileDragMove (info.files, pos.x, pos.y);
    else
        dynamic_cast<TextDragAndDropTarget*> (newTarget)->textDragMove (info.text, pos.x, pos.y);

    return true;
}

bool ComponentPeer::handleDragExit (const ComponentPeer::DragInfo& info)
{
    DragInfo info2 (info);
    info2.position.setXY (-1, -1);
    const bool used = handleDragMove (info2);

    jassert (dragAndDropTargetComponent == nullptr);
    lastDragAndDropCompUnderMouse = nullptr;
    return used;
}

bool ComponentPeer::handleDragDrop (const ComponentPeer::DragInfo& info)
{
    handleDragMove (info);

    if (WeakReference<Component> targetComp = dragAndDropTargetComponent)
    {
        dragAndDropTargetComponent = nullptr;
        lastDragAndDropCompUnderMouse = nullptr;

        if (DragHelpers::isSuitableTarget (info, targetComp))
        {
            if (targetComp->isCurrentlyBlockedByAnotherModalComponent())
            {
                targetComp->internalModalInputAttempt();

                if (targetComp->isCurrentlyBlockedByAnotherModalComponent())
                    return true;
            }

            ComponentPeer::DragInfo infoCopy (info);
            infoCopy.position = targetComp->getLocalPoint (&component, info.position);

            // We'll use an async message to deliver the drop, because if the target decides
            // to run a modal loop, it can gum-up the operating system.
            MessageManager::callAsync ([=]
            {
                if (auto* c = targetComp.get())
                {
                    if (DragHelpers::isFileDrag (info))
                        dynamic_cast<FileDragAndDropTarget*> (c)->filesDropped (infoCopy.files, infoCopy.position.x, infoCopy.position.y);
                    else
                        dynamic_cast<TextDragAndDropTarget*> (c)->textDropped (infoCopy.text, infoCopy.position.x, infoCopy.position.y);
                }
            });

            return true;
        }
    }

    return false;
}

//==============================================================================
void ComponentPeer::handleUserClosingWindow()
{
    component.userTriedToCloseWindow();
}

bool ComponentPeer::setDocumentEditedStatus (bool)
{
    return false;
}

void ComponentPeer::setRepresentedFile (const File&)
{
}

//==============================================================================
int ComponentPeer::getCurrentRenderingEngine() const                             { return 0; }
void ComponentPeer::setCurrentRenderingEngine ([[maybe_unused]] int index)       { jassert (index == 0); }

//==============================================================================
std::function<ModifierKeys()> ComponentPeer::getNativeRealtimeModifiers = nullptr;

ModifierKeys ComponentPeer::getCurrentModifiersRealtime() noexcept
{
    if (getNativeRealtimeModifiers != nullptr)
        return getNativeRealtimeModifiers();

    return ModifierKeys::currentModifiers;
}

//==============================================================================
void ComponentPeer::forceDisplayUpdate()
{
    Desktop::getInstance().displays->refresh();
}

void ComponentPeer::callVBlankListeners (double timestampSec)
{
    vBlankListeners.call ([timestampSec] (auto& l) { l.onVBlank (timestampSec); });
}

void ComponentPeer::globalFocusChanged ([[maybe_unused]] Component* comp)
{
    refreshTextInputTarget();
}

} // namespace juce
