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

   This file is part of the JUCE 7 technical preview.
   Copyright (c) 2022 - Raw Material Software Limited

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

   For the technical preview this file cannot be licensed commercially.

   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
{

class MenuBarComponent::AccessibleItemComponent  : public Component
{
public:
    AccessibleItemComponent (MenuBarComponent& comp, const String& menuItemName)
        : owner (comp),
          name (menuItemName)
    {
        setInterceptsMouseClicks (false, false);
    }

    const String& getName() const noexcept    { return name; }

private:
    std::unique_ptr<AccessibilityHandler> createAccessibilityHandler() override
    {
        class ComponentHandler  : public AccessibilityHandler
        {
        public:
            explicit ComponentHandler (AccessibleItemComponent& item)
                : AccessibilityHandler (item,
                                        AccessibilityRole::menuItem,
                                        getAccessibilityActions (item)),
                  itemComponent (item)
            {
            }

            String getTitle() const override  { return itemComponent.name; }

        private:
            static AccessibilityActions getAccessibilityActions (AccessibleItemComponent& item)
            {
                auto showMenu = [&item] { item.owner.showMenu (item.owner.indexOfItemComponent (&item)); };

                return AccessibilityActions().addAction (AccessibilityActionType::focus,
                                                         [&item] { item.owner.setItemUnderMouse (item.owner.indexOfItemComponent (&item)); })
                                             .addAction (AccessibilityActionType::press,    showMenu)
                                             .addAction (AccessibilityActionType::showMenu, showMenu);
            }

            AccessibleItemComponent& itemComponent;
        };

        return std::make_unique<ComponentHandler> (*this);
    }

    MenuBarComponent& owner;
    const String name;
};

MenuBarComponent::MenuBarComponent (MenuBarModel* m)
{
    setRepaintsOnMouseActivity (true);
    setWantsKeyboardFocus (false);
    setMouseClickGrabsKeyboardFocus (false);

    setModel (m);
}

MenuBarComponent::~MenuBarComponent()
{
    setModel (nullptr);
    Desktop::getInstance().removeGlobalMouseListener (this);
}

MenuBarModel* MenuBarComponent::getModel() const noexcept
{
    return model;
}

void MenuBarComponent::setModel (MenuBarModel* const newModel)
{
    if (model != newModel)
    {
        if (model != nullptr)
            model->removeListener (this);

        model = newModel;

        if (model != nullptr)
            model->addListener (this);

        repaint();
        menuBarItemsChanged (nullptr);
    }
}

//==============================================================================
void MenuBarComponent::paint (Graphics& g)
{
    const auto isMouseOverBar = (currentPopupIndex >= 0 || itemUnderMouse >= 0 || isMouseOver());

    getLookAndFeel().drawMenuBarBackground (g, getWidth(), getHeight(), isMouseOverBar, *this);

    if (model == nullptr)
        return;

    for (size_t i = 0; i < itemComponents.size(); ++i)
    {
        const auto& itemComponent = itemComponents[i];
        const auto itemBounds = itemComponent->getBounds();

        Graphics::ScopedSaveState ss (g);

        g.setOrigin (itemBounds.getX(), 0);
        g.reduceClipRegion (0, 0, itemBounds.getWidth(), itemBounds.getHeight());

        getLookAndFeel().drawMenuBarItem (g,
                                          itemBounds.getWidth(),
                                          itemBounds.getHeight(),
                                          (int) i,
                                          itemComponent->getName(),
                                          (int) i == itemUnderMouse,
                                          (int) i == currentPopupIndex,
                                          isMouseOverBar,
                                          *this);
    }
}

void MenuBarComponent::resized()
{
    int x = 0;

    for (size_t i = 0; i < itemComponents.size(); ++i)
    {
        auto& itemComponent = itemComponents[i];

        auto w = getLookAndFeel().getMenuBarItemWidth (*this, (int) i, itemComponent->getName());
        itemComponent->setBounds (x, 0, w, getHeight());
        x += w;
    }
}

int MenuBarComponent::getItemAt (Point<int> p)
{
    for (size_t i = 0; i < itemComponents.size(); ++i)
        if (itemComponents[i]->getBounds().contains (p) && reallyContains (p, true))
            return (int) i;

    return -1;
}

void MenuBarComponent::repaintMenuItem (int index)
{
    if (isPositiveAndBelow (index, (int) itemComponents.size()))
    {
        auto itemBounds = itemComponents[(size_t) index]->getBounds();

        repaint (itemBounds.getX() - 2,
                 0,
                 itemBounds.getWidth() + 4,
                 itemBounds.getHeight());
    }
}

void MenuBarComponent::setItemUnderMouse (int index)
{
    if (itemUnderMouse == index)
        return;

    repaintMenuItem (itemUnderMouse);
    itemUnderMouse = index;
    repaintMenuItem (itemUnderMouse);

    if (isPositiveAndBelow (itemUnderMouse, (int) itemComponents.size()))
        if (auto* handler = itemComponents[(size_t) itemUnderMouse]->getAccessibilityHandler())
            handler->grabFocus();
}

void MenuBarComponent::setOpenItem (int index)
{
    if (currentPopupIndex != index)
    {
        if (currentPopupIndex < 0 && index >= 0)
            model->handleMenuBarActivate (true);
        else if (currentPopupIndex >= 0 && index < 0)
            model->handleMenuBarActivate (false);

        repaintMenuItem (currentPopupIndex);
        currentPopupIndex = index;
        repaintMenuItem (currentPopupIndex);

        auto& desktop = Desktop::getInstance();

        if (index >= 0)
            desktop.addGlobalMouseListener (this);
        else
            desktop.removeGlobalMouseListener (this);
    }
}

void MenuBarComponent::updateItemUnderMouse (Point<int> p)
{
    setItemUnderMouse (getItemAt (p));
}

void MenuBarComponent::showMenu (int index)
{
    if (index != currentPopupIndex)
    {
        PopupMenu::dismissAllActiveMenus();
        menuBarItemsChanged (nullptr);

        setOpenItem (index);
        setItemUnderMouse (index);

        if (isPositiveAndBelow (index, (int) itemComponents.size()))
        {
            const auto& itemComponent = itemComponents[(size_t) index];
            auto m = model->getMenuForIndex (itemUnderMouse, itemComponent->getName());

            if (m.lookAndFeel == nullptr)
                m.setLookAndFeel (&getLookAndFeel());

            auto itemBounds = itemComponent->getBounds();

            const auto callback = [ref = SafePointer<MenuBarComponent> (this), index] (int result)
            {
                if (ref != nullptr)
                    ref->menuDismissed (index, result);
            };

            m.showMenuAsync (PopupMenu::Options().withTargetComponent (this)
                                                 .withTargetScreenArea (localAreaToGlobal (itemBounds))
                                                 .withMinimumWidth (itemBounds.getWidth()),
                             callback);
        }
    }
}

void MenuBarComponent::menuDismissed (int topLevelIndex, int itemId)
{
    topLevelIndexClicked = topLevelIndex;
    postCommandMessage (itemId);
}

void MenuBarComponent::handleCommandMessage (int commandId)
{
    updateItemUnderMouse (getMouseXYRelative());

    if (currentPopupIndex == topLevelIndexClicked)
        setOpenItem (-1);

    if (commandId != 0 && model != nullptr)
        model->menuItemSelected (commandId, topLevelIndexClicked);
}

//==============================================================================
void MenuBarComponent::mouseEnter (const MouseEvent& e)
{
    if (e.eventComponent == this)
        updateItemUnderMouse (e.getPosition());
}

void MenuBarComponent::mouseExit (const MouseEvent& e)
{
    if (e.eventComponent == this)
        updateItemUnderMouse (e.getPosition());
}

void MenuBarComponent::mouseDown (const MouseEvent& e)
{
    if (currentPopupIndex < 0)
    {
        updateItemUnderMouse (e.getEventRelativeTo (this).getPosition());

        currentPopupIndex = -2;
        showMenu (itemUnderMouse);
    }
}

void MenuBarComponent::mouseDrag (const MouseEvent& e)
{
    const auto item = getItemAt (e.getEventRelativeTo (this).getPosition());

    if (item >= 0)
        showMenu (item);
}

void MenuBarComponent::mouseUp (const MouseEvent& e)
{
    const auto e2 = e.getEventRelativeTo (this);

    updateItemUnderMouse (e2.getPosition());

    if (itemUnderMouse < 0 && getLocalBounds().contains (e2.x, e2.y))
    {
        setOpenItem (-1);
        PopupMenu::dismissAllActiveMenus();
    }
}

void MenuBarComponent::mouseMove (const MouseEvent& e)
{
    const auto e2 = e.getEventRelativeTo (this);

    if (lastMousePos != e2.getPosition())
    {
        if (currentPopupIndex >= 0)
        {
            const auto item = getItemAt (e2.getPosition());

            if (item >= 0)
                showMenu (item);
        }
        else
        {
            updateItemUnderMouse (e2.getPosition());
        }

        lastMousePos = e2.getPosition();
    }
}

bool MenuBarComponent::keyPressed (const KeyPress& key)
{
    const auto numMenus = (int) itemComponents.size();

    if (numMenus > 0)
    {
        const auto currentIndex = jlimit (0, numMenus - 1, currentPopupIndex);

        if (key.isKeyCode (KeyPress::leftKey))
        {
            showMenu ((currentIndex + numMenus - 1) % numMenus);
            return true;
        }

        if (key.isKeyCode (KeyPress::rightKey))
        {
            showMenu ((currentIndex + 1) % numMenus);
            return true;
        }
    }

    return false;
}

void MenuBarComponent::menuBarItemsChanged (MenuBarModel*)
{
    StringArray newNames;

    if (model != nullptr)
        newNames = model->getMenuBarNames();

    auto itemsHaveChanged = [this, &newNames]
    {
        if ((int) itemComponents.size() != newNames.size())
            return true;

        for (size_t i = 0; i < itemComponents.size(); ++i)
            if (itemComponents[i]->getName() != newNames[(int) i])
                return true;

        return false;
    }();

    if (itemsHaveChanged)
    {
        updateItemComponents (newNames);

        repaint();
        resized();
    }
}

void MenuBarComponent::updateItemComponents (const StringArray& menuNames)
{
    itemComponents.clear();

    for (const auto& name : menuNames)
    {
        itemComponents.push_back (std::make_unique<AccessibleItemComponent> (*this, name));
        addAndMakeVisible (*itemComponents.back());
    }
}

int MenuBarComponent::indexOfItemComponent (AccessibleItemComponent* itemComponent) const
{
    const auto iter = std::find_if (itemComponents.cbegin(), itemComponents.cend(),
                                    [itemComponent] (const std::unique_ptr<AccessibleItemComponent>& c) { return c.get() == itemComponent; });

    if (iter != itemComponents.cend())
        return (int) std::distance (itemComponents.cbegin(), iter);

    jassertfalse;
    return -1;
}

void MenuBarComponent::menuCommandInvoked (MenuBarModel*, const ApplicationCommandTarget::InvocationInfo& info)
{
    if (model == nullptr || (info.commandFlags & ApplicationCommandInfo::dontTriggerVisualFeedback) != 0)
        return;

    for (size_t i = 0; i < itemComponents.size(); ++i)
    {
        const auto menu = model->getMenuForIndex ((int) i, itemComponents[i]->getName());

        if (menu.containsCommandItem (info.commandID))
        {
            setItemUnderMouse ((int) i);
            startTimer (200);
            break;
        }
    }
}

void MenuBarComponent::timerCallback()
{
    stopTimer();
    updateItemUnderMouse (getMouseXYRelative());
}

//==============================================================================
std::unique_ptr<AccessibilityHandler> MenuBarComponent::createAccessibilityHandler()
{
    struct MenuBarComponentAccessibilityHandler  : public AccessibilityHandler
    {
        explicit MenuBarComponentAccessibilityHandler (MenuBarComponent& menuBarComponent)
            : AccessibilityHandler (menuBarComponent, AccessibilityRole::menuBar)
        {
        }

        AccessibleState getCurrentState() const override  { return AccessibleState().withIgnored(); }
    };

    return std::make_unique<MenuBarComponentAccessibilityHandler> (*this);
}

} // namespace juce