/*      _______   __   __   __   ______   __   __   _______   __   __
 *     / _____/\ / /\ / /\ / /\ / ____/\ / /\ / /\ / ___  /\ /  |\/ /\
 *    / /\____\// / // / // / // /\___\// /_// / // /\_/ / // , |/ / /
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 * \______\/ \______\/ \_\/ \_____\/ \_\/ \_\/ \_\/ \_\/ \_\/ \_\/
 *
 * Copyright (c) 2004, 2005, 2006, 2007 Olof Naessén and Per Larsson
 *
 *                                                         Js_./
 * Per Larsson a.k.a finalman                          _RqZ{a<^_aa
 * Olof Naessén a.k.a jansem/yakslem                _asww7!uY`>  )\a//
 *                                                 _Qhm`] _f "'c  1!5m
 * Visit: http://guichan.darkbits.org             )Qk<P ` _: :+' .'  "{[
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#include "guisan/widgets/dropdown.hpp"

#include "guisan/exception.hpp"
#include "guisan/font.hpp"
#include "guisan/graphics.hpp"
#include "guisan/key.hpp"
#include "guisan/listmodel.hpp"
#include "guisan/mouseinput.hpp"
#include "guisan/widgets/listbox.hpp"
#include "guisan/widgets/scrollarea.hpp"

namespace gcn
{
    DropDown::DropDown(ListModel* listModel, ScrollArea* scrollArea, ListBox* listBox) :
        DropDown(listModel,
                 std::shared_ptr<ScrollArea>(scrollArea, [](ScrollArea*) {}),
                 std::shared_ptr<ListBox>(listBox, [](ListBox*) {}))
    {}

    DropDown::DropDown(ListModel* listModel,
                       std::shared_ptr<ScrollArea> scrollArea,
                       std::shared_ptr<ListBox> listBox) :
        mScrollArea(scrollArea ? scrollArea : std::make_shared<ScrollArea>()),
        mListBox(listBox ? listBox : std::make_shared<ListBox>()),
        mInternalScrollArea(scrollArea == nullptr),
        mInternalListBox(listBox == nullptr)
    {
        setWidth(100);
        setFocusable(true);

        setInternalFocusHandler(&mInternalFocusHandler);

        mScrollArea->setContent(mListBox.get());
        add(mScrollArea.get());

        mListBox->addActionListener(this);
        mListBox->addSelectionListener(this);

        setListModel(listModel);

        if (mListBox->getSelected() < 0)
        {
            mListBox->setSelected(0);
        }

        addMouseListener(this);
        addKeyListener(this);
        addFocusListener(this);

        adjustHeight();
    }

    DropDown::~DropDown()
    {
        if (widgetExists(mListBox.get()))
            mListBox->removeSelectionListener(this);

        setInternalFocusHandler(nullptr);
    }

    void DropDown::draw(Graphics* graphics)
    {
        int h;

        if (mDroppedDown)
        {
            h = mFoldedUpHeight;
        }
        else
        {
            h = getHeight();
        }

        int alpha = getBaseColor().a;
        Color faceColor = getBaseColor();
        faceColor.a = alpha;
        Color highlightColor = faceColor + 0x303030;
        highlightColor.a = alpha;
        Color shadowColor = faceColor - 0x303030;
        shadowColor.a = alpha;

        // Draw a border.
        graphics->setColor(shadowColor);
        graphics->drawLine(0, 0, getWidth() - 1, 0);
        graphics->drawLine(0, 1, 0, h - 2);
        graphics->setColor(highlightColor);
        graphics->drawLine(getWidth() - 1, 1, getWidth() - 1, h - 1);
        graphics->drawLine(0, h - 1, getWidth() - 1, h - 1);

        // Push a clip area so the other drawings don't need to worry
        // about the border.
        graphics->pushClipArea(Rectangle(1, 1, getWidth() - 2, h - 2));
        const Rectangle currentClipArea = graphics->getCurrentClipArea();

        Color backgroundColor = getBackgroundColor();
        if (!isEnabled())
        {
            backgroundColor = backgroundColor - 0x303030;
        }
        graphics->setColor(backgroundColor);
        graphics->fillRectangle(Rectangle(0, 0, currentClipArea.width, currentClipArea.height));

        if (isFocused())
        {
            graphics->setColor(getSelectionColor());
            graphics->fillRectangle(Rectangle(
                0, 0, currentClipArea.width - currentClipArea.height, currentClipArea.height));
            graphics->setColor(getForegroundColor());
        }

        if (isEnabled())
            graphics->setColor(getForegroundColor());
        else
            graphics->setColor(Color(128, 128, 128));

        graphics->setFont(getFont());

        if (mListBox->getListModel() && mListBox->getSelected() >= 0)
            graphics->drawText(mListBox->getListModel()->getElementAt(mListBox->getSelected()), 1, 0, Graphics::Left, isEnabled());

        // Push a clip area before drawing the button.
        graphics->pushClipArea(Rectangle(currentClipArea.width - currentClipArea.height,
                                         0,
                                         currentClipArea.height,
                                         currentClipArea.height));

        drawButton(graphics);
        graphics->popClipArea();
        graphics->popClipArea();

        if (mDroppedDown)
        {
            // Draw a border around the children.
            graphics->setColor(shadowColor);
            graphics->drawRectangle(
                Rectangle(0, mFoldedUpHeight, getWidth(), getHeight() - mFoldedUpHeight));

            //drawChildren(graphics);
        }
    }

    void DropDown::drawButton(Graphics *graphics)
    {
        Color faceColor, highlightColor, shadowColor;
        int offset;
        const int alpha = getBaseColor().a;

        if (mPushed)
        {
            faceColor = getBaseColor() - 0x303030;
            faceColor.a = alpha;
            highlightColor = faceColor - 0x303030;
            highlightColor.a = alpha;
            shadowColor = faceColor + 0x303030;
            shadowColor.a = alpha;
            offset = 1;
        }
        else
        {
            faceColor = getBaseColor();
            faceColor.a = alpha;
            highlightColor = faceColor + 0x303030;
            highlightColor.a = alpha;
            shadowColor = faceColor - 0x303030;
            shadowColor.a = alpha;
            offset = 0;
        }

        const Rectangle currentClipArea = graphics->getCurrentClipArea();
        graphics->setColor(highlightColor);
        graphics->drawLine(0, 0, currentClipArea.width - 1, 0);
        graphics->drawLine(0, 1, 0, currentClipArea.height - 1);
        graphics->setColor(shadowColor);
        graphics->drawLine(
            currentClipArea.width - 1, 1, currentClipArea.width - 1, currentClipArea.height - 1);
        graphics->drawLine(
            1, currentClipArea.height - 1, currentClipArea.width - 2, currentClipArea.height - 1);

        graphics->setColor(faceColor);
        graphics->fillRectangle(
            Rectangle(1, 1, currentClipArea.width - 2, currentClipArea.height - 2));

        if (isEnabled())
            graphics->setColor(getForegroundColor());
        else
            graphics->setColor(Color(128, 128, 128));

        int i;
        int n = currentClipArea.height / 3;
        int dx = currentClipArea.height / 2;
        int dy = (currentClipArea.height * 2) / 3;
        for (i = 0; i < n; i++)
        {
            graphics->drawLine(dx - i + offset, dy - i + offset, dx + i + offset, dy - i + offset);
        }
    }

    int DropDown::getSelected() const
    {
        return mListBox->getSelected();
    }

    void DropDown::setSelected(int selected) const
    {
        if (selected >= 0)
        {
            mListBox->setSelected(selected);
        }
    }

    void DropDown::clearSelected() const
    {
        mListBox->setSelected(-1);
    }

    void DropDown::keyPressed(KeyEvent& keyEvent)
    {
        if (keyEvent.isConsumed())
        {
            return;
        }
        Key key = keyEvent.getKey();

        if ((key.getValue() == Key::Enter || key.getValue() == Key::Space)
            && !mDroppedDown)
        {
            dropDown();
            keyEvent.consume();
        }
        else if (key.getValue() == Key::Up)
        {
            setSelected(getSelected() - 1);
            keyEvent.consume();
        }
        else if (key.getValue() == Key::Down)
        {
            setSelected(getSelected() + 1);
            keyEvent.consume();
        }
    }

    void DropDown::mousePressed(MouseEvent& mouseEvent)
    {
        // If we have a mouse press on the widget.
        if (0 <= mouseEvent.getY()
            && mouseEvent.getY() < getHeight()
            && mouseEvent.getX() >= 0
            && mouseEvent.getX() < getWidth()
            && mouseEvent.getButton() == MouseEvent::Left
            && !mDroppedDown
            && mouseEvent.getSource() == this)
        {
            mPushed = true;
            dropDown();
            requestModalMouseInputFocus();
        }
        // Fold up the listbox if the upper part is clicked after fold down
        else if (0 <= mouseEvent.getY()
            && mouseEvent.getY() < mFoldedUpHeight
            && mouseEvent.getX() >= 0
            && mouseEvent.getX() < getWidth()
            && mouseEvent.getButton() == MouseEvent::Left
            && mDroppedDown
            && mouseEvent.getSource() == this)
        {
            mPushed = false;
            foldUp();
            releaseModalMouseInputFocus();
        }
        // If we have a mouse press outside the widget
        else if (0 > mouseEvent.getY()
            || mouseEvent.getY() >= getHeight()
            || mouseEvent.getX() < 0
            || mouseEvent.getX() >= getWidth())
        {
            mPushed = false;
            foldUp();
        }
    }

    void DropDown::mouseReleased(MouseEvent& mouseEvent)
    {
        if (mIsDragged)
        {
            mPushed = false;
        }

        // Released outside of widget. Can happen when we have modal input focus.
        if ((0 > mouseEvent.getY() || mouseEvent.getY() >= getHeight() || mouseEvent.getX() < 0
             || mouseEvent.getX() >= getWidth())
            && mouseEvent.getButton() == MouseEvent::Left && isModalMouseInputFocused())
        {
            releaseModalMouseInputFocus();

            if (mIsDragged)
            {
                foldUp();
            }
        }
        else if (mouseEvent.getButton() == MouseEvent::Left)
        {
            mPushed = false;
        }

        mIsDragged = false;
    }

    void DropDown::mouseDragged(MouseEvent& mouseEvent)
    {
        mIsDragged = true;

        mouseEvent.consume();
    }

    void DropDown::setListModel(ListModel *listModel)
    {
        mListBox->setListModel(listModel);

        if (mListBox->getSelected() < 0)
        {
            mListBox->setSelected(0);
        }

        adjustHeight();
    }

    ListModel *DropDown::getListModel()
    {
        return mListBox->getListModel();
    }

    void DropDown::adjustHeight()
    {
        if (mScrollArea == nullptr)
            throw GCN_EXCEPTION("Scroll Area has been deleted.");

    if (mListBox == nullptr)
        throw GCN_EXCEPTION("List box has been deleted.");

        int listBoxHeight = mListBox->getHeight();
        // We add 2 for the border
        int h2 = getFont()->getHeight() + 2;

        setHeight(h2);

        // The addition/subtraction of 2 compensates for the separation lines
        // separating the selected element view and the scroll area.

        if (mDroppedDown && getParent())
        {
            const int h = getParent()->getChildrenArea().height - getY();

            if (listBoxHeight > h - h2 - 2)
            {
                mScrollArea->setHeight(h - h2 - 2);
                setHeight(h);
            }
            else
            {
                setHeight(listBoxHeight + h2 + 2);
                mScrollArea->setHeight(listBoxHeight + mScrollArea->getScrollbarWidth());
            }
        }

        mScrollArea->setWidth(getWidth() + mScrollArea->getScrollbarWidth());
        // Resize the ListBox to exactly fit the ScrollArea.
        mListBox->setWidth(mScrollArea->getChildrenArea().width);
        mScrollArea->setPosition(0, 0);
    }

    void DropDown::dropDown()
    {
        if (!mDroppedDown)
        {
            mDroppedDown = true;
            mFoldedUpHeight = getHeight();
            adjustHeight();

            if (getParent())
            {
                getParent()->moveToTop(this);
            }
        }

        mListBox->requestFocus();
    }

    bool DropDown::isDroppedDown() const
    {
        return mDroppedDown;
    }

    void DropDown::foldUp()
    {
        if (mDroppedDown)
        {
            mDroppedDown = false;
            adjustHeight();
            mInternalFocusHandler.focusNone();
        }
    }

    void DropDown::focusLost(const Event& event)
    {
        foldUp();
        mInternalFocusHandler.focusNone();
    }


    void DropDown::death(const Event& event)
    {
        if (event.getSource() == mScrollArea.get())
        {
            mScrollArea = nullptr;
        }
    }

    void DropDown::action(const ActionEvent& actionEvent)
    {
        foldUp();
        releaseModalMouseInputFocus();
        distributeActionEvent();
    }

    Rectangle DropDown::getChildrenArea()
    {
        if (mDroppedDown)
        {
            // Calculate the children area (with the one pixel border in mind)
            return Rectangle(
                1, mFoldedUpHeight + 1, getWidth() - 2, getHeight() - mFoldedUpHeight - 2);
        }

        return Rectangle();
    }

    void DropDown::setBaseColor(const Color& color)
    {

        if (mInternalScrollArea)
        {
            mScrollArea->setBaseColor(color);
        }

        if (mInternalListBox)
        {
            mListBox->setBaseColor(color);
        }

        Widget::setBaseColor(color);
    }

    void DropDown::setBackgroundColor(const Color& color)
    {
        if (mInternalScrollArea)
        {
            mScrollArea->setBackgroundColor(color);
        }

        if (mInternalListBox)
        {
            mListBox->setBackgroundColor(color);
        }

        Widget::setBackgroundColor(color);
    }

    void DropDown::setForegroundColor(const Color& color)
    {
        if (mInternalScrollArea)
        {
            mScrollArea->setForegroundColor(color);
        }

        if (mInternalListBox)
        {
            mListBox->setForegroundColor(color);
        }

        Widget::setForegroundColor(color);
    }

    void DropDown::setFont(Font *font)
    {
        if (mInternalScrollArea)
        {
            mScrollArea->setFont(font);
        }

        if (mInternalListBox)
        {
            mListBox->setFont(font);
        }

        Widget::setFont(font);
    }

    void DropDown::mouseWheelMovedUp(MouseEvent& mouseEvent)
    {
        if (isFocused() && mouseEvent.getSource() == this)
        {                   
            mouseEvent.consume();

            if (mListBox->getSelected() > 0)
            {
                mListBox->setSelected(mListBox->getSelected() - 1);
            }
        }
    }

    void DropDown::mouseWheelMovedDown(MouseEvent& mouseEvent)
    {
        if (isFocused() && mouseEvent.getSource() == this)
        {            
            mouseEvent.consume();

            mListBox->setSelected(mListBox->getSelected() + 1);
        }
    }

    void DropDown::setSelectionColor(const Color& color)
    {
        Widget::setSelectionColor(color);
        
        if (mInternalListBox)
        {
            mListBox->setSelectionColor(color);
        }       
    }

    void DropDown::valueChanged(const SelectionEvent& event)
    {
        distributeValueChangedEvent();
    }

    void DropDown::addSelectionListener(SelectionListener* selectionListener)
    {
        mSelectionListeners.push_back(selectionListener);
    }
   
    void DropDown::removeSelectionListener(SelectionListener* selectionListener)
    {
        mSelectionListeners.remove(selectionListener);
    }

    void DropDown::distributeValueChangedEvent()
    {
        const SelectionEvent event(this);

        for (SelectionListener* selectionListener : mSelectionListeners)
        {
            selectionListener->valueChanged(event);
        }
    }
}
