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

   This file is part of the JUCE 6 technical preview.
   Copyright (c) 2017 - ROLI Ltd.

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

   For this technical preview, this file is not subject to commercial licensing.

   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
{

TabBarButton::TabBarButton (const String& name, TabbedButtonBar& bar)
    : Button (name), owner (bar)
{
    setWantsKeyboardFocus (false);
}

TabBarButton::~TabBarButton() {}

int TabBarButton::getIndex() const                      { return owner.indexOfTabButton (this); }
Colour TabBarButton::getTabBackgroundColour() const     { return owner.getTabBackgroundColour (getIndex()); }
bool TabBarButton::isFrontTab() const                   { return getToggleState(); }

void TabBarButton::paintButton (Graphics& g, const bool shouldDrawButtonAsHighlighted, const bool shouldDrawButtonAsDown)
{
    getLookAndFeel().drawTabButton (*this, g, shouldDrawButtonAsHighlighted, shouldDrawButtonAsDown);
}

void TabBarButton::clicked (const ModifierKeys& mods)
{
    if (mods.isPopupMenu())
        owner.popupMenuClickOnTab (getIndex(), getButtonText());
    else
        owner.setCurrentTabIndex (getIndex());
}

bool TabBarButton::hitTest (int mx, int my)
{
    auto area = getActiveArea();

    if (owner.isVertical())
    {
        if (isPositiveAndBelow (mx, getWidth())
             && my >= area.getY() + overlapPixels && my < area.getBottom() - overlapPixels)
            return true;
    }
    else
    {
        if (isPositiveAndBelow (my, getHeight())
             && mx >= area.getX() + overlapPixels && mx < area.getRight() - overlapPixels)
            return true;
    }

    Path p;
    getLookAndFeel().createTabButtonShape (*this, p, false, false);

    return p.contains ((float) (mx - area.getX()),
                       (float) (my - area.getY()));
}

int TabBarButton::getBestTabLength (const int depth)
{
    return getLookAndFeel().getTabButtonBestWidth (*this, depth);
}

void TabBarButton::calcAreas (Rectangle<int>& extraComp, Rectangle<int>& textArea) const
{
    auto& lf = getLookAndFeel();
    textArea = getActiveArea();

    auto depth = owner.isVertical() ? textArea.getWidth() : textArea.getHeight();
    auto overlap = lf.getTabButtonOverlap (depth);

    if (overlap > 0)
    {
        if (owner.isVertical())
            textArea.reduce (0, overlap);
        else
            textArea.reduce (overlap, 0);
    }

    if (extraComponent != nullptr)
    {
        extraComp = lf.getTabButtonExtraComponentBounds (*this, textArea, *extraComponent);

        auto orientation = owner.getOrientation();

        if (orientation == TabbedButtonBar::TabsAtLeft || orientation == TabbedButtonBar::TabsAtRight)
        {
            if (extraComp.getCentreY() > textArea.getCentreY())
                textArea.setBottom (jmin (textArea.getBottom(), extraComp.getY()));
            else
                textArea.setTop (jmax (textArea.getY(), extraComp.getBottom()));
        }
        else
        {
            if (extraComp.getCentreX() > textArea.getCentreX())
                textArea.setRight (jmin (textArea.getRight(), extraComp.getX()));
            else
                textArea.setLeft (jmax (textArea.getX(), extraComp.getRight()));
        }
    }
}

Rectangle<int> TabBarButton::getTextArea() const
{
    Rectangle<int> extraComp, textArea;
    calcAreas (extraComp, textArea);
    return textArea;
}

Rectangle<int> TabBarButton::getActiveArea() const
{
    auto r = getLocalBounds();
    auto spaceAroundImage = getLookAndFeel().getTabButtonSpaceAroundImage();
    auto orientation = owner.getOrientation();

    if (orientation != TabbedButtonBar::TabsAtLeft)      r.removeFromRight  (spaceAroundImage);
    if (orientation != TabbedButtonBar::TabsAtRight)     r.removeFromLeft   (spaceAroundImage);
    if (orientation != TabbedButtonBar::TabsAtBottom)    r.removeFromTop    (spaceAroundImage);
    if (orientation != TabbedButtonBar::TabsAtTop)       r.removeFromBottom (spaceAroundImage);

    return r;
}

void TabBarButton::setExtraComponent (Component* comp, ExtraComponentPlacement placement)
{
    jassert (extraCompPlacement == beforeText || extraCompPlacement == afterText);
    extraCompPlacement = placement;
    extraComponent.reset (comp);
    addAndMakeVisible (extraComponent.get());
    resized();
}

void TabBarButton::childBoundsChanged (Component* c)
{
    if (c == extraComponent.get())
    {
        owner.resized();
        resized();
    }
}

void TabBarButton::resized()
{
    if (extraComponent != nullptr)
    {
        Rectangle<int> extraComp, textArea;
        calcAreas (extraComp, textArea);

        if (! extraComp.isEmpty())
            extraComponent->setBounds (extraComp);
    }
}

//==============================================================================
class TabbedButtonBar::BehindFrontTabComp  : public Component
{
public:
    BehindFrontTabComp (TabbedButtonBar& tb)  : owner (tb)
    {
        setInterceptsMouseClicks (false, false);
    }

    void paint (Graphics& g) override
    {
        getLookAndFeel().drawTabAreaBehindFrontButton (owner, g, getWidth(), getHeight());
    }

    void enablementChanged() override
    {
        repaint();
    }

    TabbedButtonBar& owner;

    JUCE_DECLARE_NON_COPYABLE (BehindFrontTabComp)
};


//==============================================================================
TabbedButtonBar::TabbedButtonBar (Orientation orientationToUse)
    : orientation (orientationToUse)
{
    setInterceptsMouseClicks (false, true);
    behindFrontTab.reset (new BehindFrontTabComp (*this));
    addAndMakeVisible (behindFrontTab.get());
    setFocusContainer (true);
}

TabbedButtonBar::~TabbedButtonBar()
{
    tabs.clear();
    extraTabsButton.reset();
}

//==============================================================================
void TabbedButtonBar::setOrientation (const Orientation newOrientation)
{
    orientation = newOrientation;

    for (auto* child : getChildren())
        child->resized();

    resized();
}

TabBarButton* TabbedButtonBar::createTabButton (const String& name, const int /*index*/)
{
    return new TabBarButton (name, *this);
}

void TabbedButtonBar::setMinimumTabScaleFactor (double newMinimumScale)
{
    minimumScale = newMinimumScale;
    resized();
}

//==============================================================================
void TabbedButtonBar::clearTabs()
{
    tabs.clear();
    extraTabsButton.reset();
    setCurrentTabIndex (-1);
}

void TabbedButtonBar::addTab (const String& tabName,
                              Colour tabBackgroundColour,
                              int insertIndex)
{
    jassert (tabName.isNotEmpty()); // you have to give them all a name..

    if (tabName.isNotEmpty())
    {
        if (! isPositiveAndBelow (insertIndex, tabs.size()))
            insertIndex = tabs.size();

        auto* currentTab = tabs[currentTabIndex];

        auto* newTab = new TabInfo();
        newTab->name = tabName;
        newTab->colour = tabBackgroundColour;
        newTab->button.reset (createTabButton (tabName, insertIndex));
        jassert (newTab->button != nullptr);

        tabs.insert (insertIndex, newTab);
        currentTabIndex = tabs.indexOf (currentTab);
        addAndMakeVisible (newTab->button.get(), insertIndex);

        resized();

        if (currentTabIndex < 0)
            setCurrentTabIndex (0);
    }
}

void TabbedButtonBar::setTabName (int tabIndex, const String& newName)
{
    if (auto* tab = tabs[tabIndex])
    {
        if (tab->name != newName)
        {
            tab->name = newName;
            tab->button->setButtonText (newName);
            resized();
        }
    }
}

void TabbedButtonBar::removeTab (const int indexToRemove, const bool animate)
{
    if (isPositiveAndBelow (indexToRemove, tabs.size()))
    {
        auto oldSelectedIndex = currentTabIndex;

        if (indexToRemove == currentTabIndex)
            oldSelectedIndex = -1;
        else if (indexToRemove < oldSelectedIndex)
            --oldSelectedIndex;

        tabs.remove (indexToRemove);

        setCurrentTabIndex (oldSelectedIndex);
        updateTabPositions (animate);
    }
}

void TabbedButtonBar::moveTab (const int currentIndex, const int newIndex, const bool animate)
{
    auto* currentTab = tabs[currentTabIndex];
    tabs.move (currentIndex, newIndex);
    currentTabIndex = tabs.indexOf (currentTab);
    updateTabPositions (animate);
}

int TabbedButtonBar::getNumTabs() const
{
    return tabs.size();
}

String TabbedButtonBar::getCurrentTabName() const
{
    if (auto* tab = tabs [currentTabIndex])
        return tab->name;

    return {};
}

StringArray TabbedButtonBar::getTabNames() const
{
    StringArray names;

    for (auto* t : tabs)
        names.add (t->name);

    return names;
}

void TabbedButtonBar::setCurrentTabIndex (int newIndex, bool shouldSendChangeMessage)
{
    if (currentTabIndex != newIndex)
    {
        if (! isPositiveAndBelow (newIndex, tabs.size()))
            newIndex = -1;

        currentTabIndex = newIndex;

        for (int i = 0; i < tabs.size(); ++i)
            tabs.getUnchecked(i)->button->setToggleState (i == newIndex, dontSendNotification);

        resized();

        if (shouldSendChangeMessage)
            sendChangeMessage();

        currentTabChanged (newIndex, getCurrentTabName());
    }
}

TabBarButton* TabbedButtonBar::getTabButton (const int index) const
{
    if (auto* tab = tabs[index])
        return static_cast<TabBarButton*> (tab->button.get());

    return nullptr;
}

int TabbedButtonBar::indexOfTabButton (const TabBarButton* button) const
{
    for (int i = tabs.size(); --i >= 0;)
        if (tabs.getUnchecked(i)->button.get() == button)
            return i;

    return -1;
}

Rectangle<int> TabbedButtonBar::getTargetBounds (TabBarButton* button) const
{
    if (button == nullptr || indexOfTabButton (button) == -1)
        return {};

    auto& animator = Desktop::getInstance().getAnimator();

    return animator.isAnimating (button) ? animator.getComponentDestination (button)
                                         : button->getBounds();
}

void TabbedButtonBar::lookAndFeelChanged()
{
    extraTabsButton.reset();
    resized();
}

void TabbedButtonBar::paint (Graphics& g)
{
    getLookAndFeel().drawTabbedButtonBarBackground (*this, g);
}

void TabbedButtonBar::resized()
{
    updateTabPositions (false);
}

//==============================================================================
void TabbedButtonBar::updateTabPositions (bool animate)
{
    auto& lf = getLookAndFeel();

    auto depth = getWidth();
    auto length = getHeight();

    if (! isVertical())
        std::swap (depth, length);

    auto overlap = lf.getTabButtonOverlap (depth) + lf.getTabButtonSpaceAroundImage() * 2;

    auto totalLength = jmax (0, overlap);
    auto numVisibleButtons = tabs.size();

    for (int i = 0; i < tabs.size(); ++i)
    {
        auto* tb = tabs.getUnchecked(i)->button.get();

        totalLength += tb->getBestTabLength (depth) - overlap;
        tb->overlapPixels = jmax (0, overlap / 2);
    }

    double scale = 1.0;

    if (totalLength > length)
        scale = jmax (minimumScale, length / (double) totalLength);

    const bool isTooBig = (int) (totalLength * scale) > length;
    int tabsButtonPos = 0;

    if (isTooBig)
    {
        if (extraTabsButton == nullptr)
        {
            extraTabsButton.reset (lf.createTabBarExtrasButton());
            addAndMakeVisible (extraTabsButton.get());
            extraTabsButton->setAlwaysOnTop (true);
            extraTabsButton->setTriggeredOnMouseDown (true);
            extraTabsButton->onClick = [this] { showExtraItemsMenu(); };
        }

        auto buttonSize = jmin (proportionOfWidth (0.7f), proportionOfHeight (0.7f));
        extraTabsButton->setSize (buttonSize, buttonSize);

        if (isVertical())
        {
            tabsButtonPos = getHeight() - buttonSize / 2 - 1;
            extraTabsButton->setCentrePosition (getWidth() / 2, tabsButtonPos);
        }
        else
        {
            tabsButtonPos = getWidth() - buttonSize / 2 - 1;
            extraTabsButton->setCentrePosition (tabsButtonPos, getHeight() / 2);
        }

        totalLength = 0;

        for (int i = 0; i < tabs.size(); ++i)
        {
            auto* tb = tabs.getUnchecked(i)->button.get();
            auto newLength = totalLength + tb->getBestTabLength (depth);

            if (i > 0 && newLength * minimumScale > tabsButtonPos)
            {
                totalLength += overlap;
                break;
            }

            numVisibleButtons = i + 1;
            totalLength = newLength - overlap;
        }

        scale = jmax (minimumScale, tabsButtonPos / (double) totalLength);
    }
    else
    {
        extraTabsButton.reset();
    }

    int pos = 0;

    TabBarButton* frontTab = nullptr;
    auto& animator = Desktop::getInstance().getAnimator();

    for (int i = 0; i < tabs.size(); ++i)
    {
        if (auto* tb = getTabButton (i))
        {
            auto bestLength = roundToInt (scale * tb->getBestTabLength (depth));

            if (i < numVisibleButtons)
            {
                auto newBounds = isVertical() ? Rectangle<int> (0, pos, getWidth(), bestLength)
                                              : Rectangle<int> (pos, 0, bestLength, getHeight());

                if (animate)
                {
                    animator.animateComponent (tb, newBounds, 1.0f, 200, false, 3.0, 0.0);
                }
                else
                {
                    animator.cancelAnimation (tb, false);
                    tb->setBounds (newBounds);
                }

                tb->toBack();

                if (i == currentTabIndex)
                    frontTab = tb;

                tb->setVisible (true);
            }
            else
            {
                tb->setVisible (false);
            }

            pos += bestLength - overlap;
        }
    }

    behindFrontTab->setBounds (getLocalBounds());

    if (frontTab != nullptr)
    {
        frontTab->toFront (false);
        behindFrontTab->toBehind (frontTab);
    }
}

//==============================================================================
Colour TabbedButtonBar::getTabBackgroundColour (int tabIndex)
{
    if (auto* tab = tabs[tabIndex])
        return tab->colour;

    return Colours::transparentBlack;
}

void TabbedButtonBar::setTabBackgroundColour (int tabIndex, Colour newColour)
{
    if (auto* tab = tabs [tabIndex])
    {
        if (tab->colour != newColour)
        {
            tab->colour = newColour;
            repaint();
        }
    }
}

void TabbedButtonBar::showExtraItemsMenu()
{
    PopupMenu m;

    for (int i = 0; i < tabs.size(); ++i)
    {
        auto* tab = tabs.getUnchecked(i);

        if (! tab->button->isVisible())
            m.addItem (PopupMenu::Item (tab->name)
                         .setTicked (i == currentTabIndex)
                         .setAction ([this, i] { setCurrentTabIndex (i); }));
    }

    m.showMenuAsync (PopupMenu::Options()
                        .withDeletionCheck (*this)
                        .withTargetComponent (extraTabsButton.get()));
}

//==============================================================================
void TabbedButtonBar::currentTabChanged (int, const String&) {}
void TabbedButtonBar::popupMenuClickOnTab (int, const String&) {}

} // namespace juce