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

   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
{

MultiDocumentPanelWindow::MultiDocumentPanelWindow (Colour backgroundColour)
    : DocumentWindow (String(), backgroundColour,
                      DocumentWindow::maximiseButton | DocumentWindow::closeButton, false)
{
}

MultiDocumentPanelWindow::~MultiDocumentPanelWindow()
{
}

//==============================================================================
void MultiDocumentPanelWindow::maximiseButtonPressed()
{
    if (auto* owner = getOwner())
        owner->setLayoutMode (MultiDocumentPanel::MaximisedWindowsWithTabs);
    else
        jassertfalse; // these windows are only designed to be used inside a MultiDocumentPanel!
}

void MultiDocumentPanelWindow::closeButtonPressed()
{
    if (auto* owner = getOwner())
        owner->closeDocumentAsync (getContentComponent(), true, nullptr);
    else
        jassertfalse; // these windows are only designed to be used inside a MultiDocumentPanel!
}

void MultiDocumentPanelWindow::activeWindowStatusChanged()
{
    DocumentWindow::activeWindowStatusChanged();
    updateActiveDocument();
}

void MultiDocumentPanelWindow::broughtToFront()
{
    DocumentWindow::broughtToFront();
    updateActiveDocument();
}

void MultiDocumentPanelWindow::updateActiveDocument()
{
    if (auto* owner = getOwner())
        owner->updateActiveDocumentFromUIState();
}

MultiDocumentPanel* MultiDocumentPanelWindow::getOwner() const noexcept
{
    return findParentComponentOfClass<MultiDocumentPanel>();
}

//==============================================================================
struct MultiDocumentPanel::TabbedComponentInternal   : public TabbedComponent
{
    TabbedComponentInternal() : TabbedComponent (TabbedButtonBar::TabsAtTop) {}

    void currentTabChanged (int, const String&) override
    {
        if (auto* owner = findParentComponentOfClass<MultiDocumentPanel>())
            owner->updateActiveDocumentFromUIState();
    }
};


//==============================================================================
MultiDocumentPanel::MultiDocumentPanel()
{
    setOpaque (true);
}

MultiDocumentPanel::~MultiDocumentPanel()
{
    for (int i = components.size(); --i >= 0;)
        if (auto* component = components[i])
            closeDocumentInternal (component);
}

//==============================================================================
namespace MultiDocHelpers
{
    static bool shouldDeleteComp (Component* const c)
    {
        return c->getProperties() ["mdiDocumentDelete_"];
    }
}

#if JUCE_MODAL_LOOPS_PERMITTED
bool MultiDocumentPanel::closeAllDocuments (const bool checkItsOkToCloseFirst)
{
    while (! components.isEmpty())
        if (! closeDocument (components.getLast(), checkItsOkToCloseFirst))
            return false;

    return true;
}
#endif

void MultiDocumentPanel::closeLastDocumentRecursive (SafePointer<MultiDocumentPanel> parent,
                                                     bool checkItsOkToCloseFirst,
                                                     std::function<void (bool)> callback)
{
    if (parent->components.isEmpty())
    {
        NullCheckedInvocation::invoke (callback, true);
        return;
    }

    parent->closeDocumentAsync (parent->components.getLast(),
                                checkItsOkToCloseFirst,
                                [parent, checkItsOkToCloseFirst, callback] (bool closeResult)
    {
        if (parent == nullptr)
            return;

        if (! closeResult)
        {
            NullCheckedInvocation::invoke (callback, false);
            return;
        }

        parent->closeLastDocumentRecursive (parent, checkItsOkToCloseFirst, std::move (callback));
    });
}

void MultiDocumentPanel::closeAllDocumentsAsync (bool checkItsOkToCloseFirst, std::function<void (bool)> callback)
{
    closeLastDocumentRecursive (this, checkItsOkToCloseFirst, std::move (callback));
}

#if JUCE_MODAL_LOOPS_PERMITTED
bool MultiDocumentPanel::tryToCloseDocument (Component*)
{
    // If you hit this assertion then you need to implement this method in a subclass.
    jassertfalse;
    return false;
}
#endif

MultiDocumentPanelWindow* MultiDocumentPanel::createNewDocumentWindow()
{
    return new MultiDocumentPanelWindow (backgroundColour);
}

void MultiDocumentPanel::addWindow (Component* component)
{
    auto* dw = createNewDocumentWindow();

    dw->setResizable (true, false);
    dw->setContentNonOwned (component, true);
    dw->setName (component->getName());

    auto bkg = component->getProperties() ["mdiDocumentBkg_"];
    dw->setBackgroundColour (bkg.isVoid() ? backgroundColour : Colour ((uint32) static_cast<int> (bkg)));

    int x = 4;

    if (auto* topComp = getChildren().getLast())
        if (topComp->getX() == x && topComp->getY() == x)
            x += 16;

    dw->setTopLeftPosition (x, x);

    auto pos = component->getProperties() ["mdiDocumentPos_"];
    if (pos.toString().isNotEmpty())
        dw->restoreWindowStateFromString (pos.toString());

    addAndMakeVisible (dw);
    dw->toFront (true);
}

bool MultiDocumentPanel::addDocument (Component* const component,
                                      Colour docColour,
                                      const bool deleteWhenRemoved)
{
    // If you try passing a full DocumentWindow or ResizableWindow in here, you'll end up
    // with a frame-within-a-frame! Just pass in the bare content component.
    jassert (dynamic_cast<ResizableWindow*> (component) == nullptr);

    if (component == nullptr || (maximumNumDocuments > 0 && components.size() >= maximumNumDocuments))
        return false;

    components.add (component);
    component->getProperties().set ("mdiDocumentDelete_", deleteWhenRemoved);
    component->getProperties().set ("mdiDocumentBkg_", (int) docColour.getARGB());
    component->addComponentListener (this);

    if (mode == FloatingWindows)
    {
        if (isFullscreenWhenOneDocument())
        {
            if (components.size() == 1)
            {
                addAndMakeVisible (component);
            }
            else
            {
                if (components.size() == 2)
                    addWindow (components.getFirst());

                addWindow (component);
            }
        }
        else
        {
           addWindow (component);
        }
    }
    else
    {
        if (tabComponent == nullptr && components.size() > numDocsBeforeTabsUsed)
        {
            tabComponent.reset (new TabbedComponentInternal());
            addAndMakeVisible (tabComponent.get());

            auto temp = components;

            for (auto& c : temp)
                tabComponent->addTab (c->getName(), docColour, c, false);

            resized();
        }
        else
        {
            if (tabComponent != nullptr)
                tabComponent->addTab (component->getName(), docColour, component, false);
            else
                addAndMakeVisible (component);
        }

        setActiveDocument (component);
    }

    resized();
    updateActiveDocument (component);
    return true;
}

void MultiDocumentPanel::recreateLayout()
{
    tabComponent.reset();

    for (int i = getNumChildComponents(); --i >= 0;)
    {
        std::unique_ptr<MultiDocumentPanelWindow> dw (dynamic_cast<MultiDocumentPanelWindow*> (getChildComponent (i)));

        if (dw != nullptr)
        {
            dw->getContentComponent()->getProperties().set ("mdiDocumentPos_", dw->getWindowStateAsString());
            dw->clearContentComponent();
        }
    }

    resized();

    auto tempComps = components;
    components.clear();

    {
        // We want to preserve the activeComponent, so we are blocking the changes originating
        // from addDocument()
        const ScopedValueSetter<bool> scope { isLayoutBeingChanged, true };

        for (auto* c : tempComps)
            addDocument (c,
                         Colour ((uint32) static_cast<int> (c->getProperties().getWithDefault ("mdiDocumentBkg_",
                                                                                               (int) Colours::white.getARGB()))),
                         MultiDocHelpers::shouldDeleteComp (c));
    }

    if (activeComponent != nullptr)
        setActiveDocument (activeComponent);

    updateActiveDocumentFromUIState();
}

void MultiDocumentPanel::closeDocumentInternal (Component* componentToClose)
{
    // Intellisense warns about component being uninitialised.
    // I'm not sure how a function argument could be uninitialised.
    JUCE_BEGIN_IGNORE_WARNINGS_MSVC (6001)

    const OptionalScopedPointer<Component> component { componentToClose,
                                                       MultiDocHelpers::shouldDeleteComp (componentToClose) };

    component->removeComponentListener (this);

    component->getProperties().remove ("mdiDocumentDelete_");
    component->getProperties().remove ("mdiDocumentBkg_");

    const auto removedIndex = components.indexOf (component);

    if (removedIndex < 0)
    {
        jassertfalse;
        return;
    }

    components.remove (removedIndex);

    // See if the active document needs to change because of closing a document. It should only
    // change if we closed the active document. If so, the next active document should be the
    // subsequent one.
    if (component == activeComponent)
    {
        auto* newActiveComponent = components[jmin (removedIndex, components.size() - 1)];
        updateActiveDocument (newActiveComponent);
    }

    // We update the UI to reflect the new state, but we want to prevent the UI state callback
    // to change the active document.
    const ScopedValueSetter<bool> scope { isLayoutBeingChanged, true };

    if (mode == FloatingWindows)
    {
        for (auto* child : getChildren())
        {
            if (auto* dw = dynamic_cast<MultiDocumentPanelWindow*> (child))
            {
                if (dw->getContentComponent() == component)
                {
                    std::unique_ptr<MultiDocumentPanelWindow> (dw)->clearContentComponent();
                    break;
                }
            }
        }

        if (isFullscreenWhenOneDocument() && components.size() == 1)
        {
            for (int i = getNumChildComponents(); --i >= 0;)
            {
                std::unique_ptr<MultiDocumentPanelWindow> dw (dynamic_cast<MultiDocumentPanelWindow*> (getChildComponent (i)));

                if (dw != nullptr)
                    dw->clearContentComponent();
            }

            addAndMakeVisible (getActiveDocument());
        }
    }
    else
    {
        if (tabComponent != nullptr)
        {
            for (int i = tabComponent->getNumTabs(); --i >= 0;)
                if (tabComponent->getTabContentComponent (i) == component)
                    tabComponent->removeTab (i);
        }
        else
        {
            removeChildComponent (component);
        }

        if (components.size() <= numDocsBeforeTabsUsed && getActiveDocument() != nullptr)
        {
            tabComponent.reset();
            addAndMakeVisible (getActiveDocument());
        }
    }

    resized();

    // This ensures that the active tab is painted properly when a tab is closed!
    if (auto* activeDocument = getActiveDocument())
        setActiveDocument (activeDocument);

    JUCE_END_IGNORE_WARNINGS_MSVC
}

#if JUCE_MODAL_LOOPS_PERMITTED
bool MultiDocumentPanel::closeDocument (Component* component,
                                        const bool checkItsOkToCloseFirst)
{
    // Intellisense warns about component being uninitialised.
    // I'm not sure how a function argument could be uninitialised.
    JUCE_BEGIN_IGNORE_WARNINGS_MSVC (6001)

    if (component == nullptr)
        return true;

    if (components.contains (component))
    {
        if (checkItsOkToCloseFirst && ! tryToCloseDocument (component))
            return false;

        closeDocumentInternal (component);
    }
    else
    {
        jassertfalse;
    }

    return true;

    JUCE_END_IGNORE_WARNINGS_MSVC
}
#endif

void MultiDocumentPanel::closeDocumentAsync (Component* component,
                                             const bool checkItsOkToCloseFirst,
                                             std::function<void (bool)> callback)
{
    // Intellisense warns about component being uninitialised.
    // I'm not sure how a function argument could be uninitialised.
    JUCE_BEGIN_IGNORE_WARNINGS_MSVC (6001)

    if (component == nullptr)
    {
        NullCheckedInvocation::invoke (callback, true);
        return;
    }

    if (components.contains (component))
    {
        if (checkItsOkToCloseFirst)
        {
            tryToCloseDocumentAsync (component,
                                     [parent = SafePointer<MultiDocumentPanel> { this }, component, callback] (bool closedSuccessfully)
            {
                if (parent == nullptr)
                    return;

                if (closedSuccessfully)
                    parent->closeDocumentInternal (component);

                NullCheckedInvocation::invoke (callback, closedSuccessfully);
            });

            return;
        }

        closeDocumentInternal (component);
    }
    else
    {
        jassertfalse;
    }

    NullCheckedInvocation::invoke (callback, true);

    JUCE_END_IGNORE_WARNINGS_MSVC
}

int MultiDocumentPanel::getNumDocuments() const noexcept
{
    return components.size();
}

Component* MultiDocumentPanel::getDocument (const int index) const noexcept
{
    return components [index];
}

Component* MultiDocumentPanel::getActiveDocument() const noexcept
{
    return activeComponent;
}

void MultiDocumentPanel::setActiveDocument (Component* component)
{
    jassert (component != nullptr);

    if (mode == FloatingWindows)
    {
        component = getContainerComp (component);

        if (component != nullptr)
            component->toFront (true);
    }
    else if (tabComponent != nullptr)
    {
        jassert (components.indexOf (component) >= 0);

        for (int i = tabComponent->getNumTabs(); --i >= 0;)
        {
            if (tabComponent->getTabContentComponent (i) == component)
            {
                tabComponent->setCurrentTabIndex (i);
                break;
            }
        }
    }
    else
    {
        component->grabKeyboardFocus();
    }
}

void MultiDocumentPanel::activeDocumentChanged()
{
}

void MultiDocumentPanel::setMaximumNumDocuments (const int newNumber)
{
    maximumNumDocuments = newNumber;
}

void MultiDocumentPanel::useFullscreenWhenOneDocument (const bool shouldUseTabs)
{
    const auto newNumDocsBeforeTabsUsed = shouldUseTabs ? 1 : 0;

    if (std::exchange (numDocsBeforeTabsUsed, newNumDocsBeforeTabsUsed) != newNumDocsBeforeTabsUsed)
        recreateLayout();
}

bool MultiDocumentPanel::isFullscreenWhenOneDocument() const noexcept
{
    return numDocsBeforeTabsUsed != 0;
}

//==============================================================================
void MultiDocumentPanel::setLayoutMode (const LayoutMode newLayoutMode)
{
    if (std::exchange (mode, newLayoutMode) != newLayoutMode)
        recreateLayout();
}

void MultiDocumentPanel::setBackgroundColour (Colour newBackgroundColour)
{
    if (backgroundColour != newBackgroundColour)
    {
        backgroundColour = newBackgroundColour;
        setOpaque (newBackgroundColour.isOpaque());
        repaint();
    }
}

//==============================================================================
void MultiDocumentPanel::paint (Graphics& g)
{
    g.fillAll (backgroundColour);
}

void MultiDocumentPanel::resized()
{
    if (mode == MaximisedWindowsWithTabs || components.size() == numDocsBeforeTabsUsed)
    {
        for (auto* child : getChildren())
            child->setBounds (getLocalBounds());
    }

    setWantsKeyboardFocus (components.size() == 0);
}

Component* MultiDocumentPanel::getContainerComp (Component* c) const
{
    if (mode == FloatingWindows)
    {
        for (auto* child : getChildren())
            if (auto* dw = dynamic_cast<MultiDocumentPanelWindow*> (child))
                if (dw->getContentComponent() == c)
                    return dw;
    }

    return c;
}

void MultiDocumentPanel::componentNameChanged (Component&)
{
    if (mode == FloatingWindows)
    {
        for (auto* child : getChildren())
            if (auto* dw = dynamic_cast<MultiDocumentPanelWindow*> (child))
                dw->setName (dw->getContentComponent()->getName());
    }
    else if (tabComponent != nullptr)
    {
        for (int i = tabComponent->getNumTabs(); --i >= 0;)
            tabComponent->setTabName (i, tabComponent->getTabContentComponent (i)->getName());
    }
}

void MultiDocumentPanel::updateActiveDocumentFromUIState()
{
    auto* newActiveComponent = [&]() -> Component*
    {
        if (mode == FloatingWindows)
        {
            for (auto* c : components)
            {
                if (auto* window = static_cast<MultiDocumentPanelWindow*> (c->getParentComponent()))
                    if (window->isActiveWindow())
                        return c;
            }
        }

        if (tabComponent != nullptr)
            if (auto* current = tabComponent->getCurrentContentComponent())
                return current;

        return activeComponent;
    }();

    updateActiveDocument (newActiveComponent);
}

void MultiDocumentPanel::updateActiveDocument (Component* component)
{
    if (isLayoutBeingChanged)
        return;

    if (std::exchange (activeComponent, component) != component)
        activeDocumentChanged();
}

} // namespace juce