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

   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
{

class TableHeaderComponent::DragOverlayComp   : public Component
{
public:
    DragOverlayComp (const Image& i) : image (i)
    {
        image.duplicateIfShared();
        image.multiplyAllAlphas (0.8f);
        setAlwaysOnTop (true);
    }

    void paint (Graphics& g) override
    {
        g.drawImageAt (image, 0, 0);
    }

    Image image;

    JUCE_DECLARE_NON_COPYABLE (DragOverlayComp)
};


//==============================================================================
TableHeaderComponent::TableHeaderComponent()
{
}

TableHeaderComponent::~TableHeaderComponent()
{
    dragOverlayComp.reset();
}

//==============================================================================
void TableHeaderComponent::setPopupMenuActive (bool hasMenu)
{
    menuActive = hasMenu;
}

bool TableHeaderComponent::isPopupMenuActive() const    { return menuActive; }


//==============================================================================
int TableHeaderComponent::getNumColumns (const bool onlyCountVisibleColumns) const
{
    if (onlyCountVisibleColumns)
    {
        int num = 0;

        for (auto* c : columns)
            if (c->isVisible())
                ++num;

        return num;
    }

    return columns.size();
}

String TableHeaderComponent::getColumnName (const int columnId) const
{
    if (auto* ci = getInfoForId (columnId))
        return ci->name;

    return {};
}

void TableHeaderComponent::setColumnName (const int columnId, const String& newName)
{
    if (auto* ci = getInfoForId (columnId))
    {
        if (ci->name != newName)
        {
            ci->name = newName;
            sendColumnsChanged();
        }
    }
}

void TableHeaderComponent::addColumn (const String& columnName,
                                      int columnId,
                                      int width,
                                      int minimumWidth,
                                      int maximumWidth,
                                      int propertyFlags,
                                      int insertIndex)
{
    // can't have a duplicate or zero ID!
    jassert (columnId != 0 && getIndexOfColumnId (columnId, false) < 0);
    jassert (width > 0);

    auto ci = new ColumnInfo();
    ci->name = columnName;
    ci->id = columnId;
    ci->width = width;
    ci->lastDeliberateWidth = width;
    ci->minimumWidth = minimumWidth;
    ci->maximumWidth = maximumWidth >= 0 ? maximumWidth : std::numeric_limits<int>::max();
    jassert (ci->maximumWidth >= ci->minimumWidth);
    ci->propertyFlags = propertyFlags;

    columns.insert (insertIndex, ci);
    sendColumnsChanged();
}

void TableHeaderComponent::removeColumn (const int columnIdToRemove)
{
    auto index = getIndexOfColumnId (columnIdToRemove, false);

    if (index >= 0)
    {
        columns.remove (index);
        sortChanged = true;
        sendColumnsChanged();
    }
}

void TableHeaderComponent::removeAllColumns()
{
    if (columns.size() > 0)
    {
        columns.clear();
        sendColumnsChanged();
    }
}

void TableHeaderComponent::moveColumn (const int columnId, int newIndex)
{
    auto currentIndex = getIndexOfColumnId (columnId, false);
    newIndex = visibleIndexToTotalIndex (newIndex);

    if (columns[currentIndex] != nullptr && currentIndex != newIndex)
    {
        columns.move (currentIndex, newIndex);
        sendColumnsChanged();
    }
}

int TableHeaderComponent::getColumnWidth (const int columnId) const
{
    if (auto* ci = getInfoForId (columnId))
        return ci->width;

    return 0;
}

void TableHeaderComponent::setColumnWidth (const int columnId, const int newWidth)
{
    if (auto* ci = getInfoForId (columnId))
    {
        if (ci->width != newWidth)
        {
            auto numColumns = getNumColumns (true);

            ci->lastDeliberateWidth = ci->width
                = jlimit (ci->minimumWidth, ci->maximumWidth, newWidth);

            if (stretchToFit)
            {
                auto index = getIndexOfColumnId (columnId, true) + 1;

                if (isPositiveAndBelow (index, numColumns))
                {
                    auto x = getColumnPosition (index).getX();

                    if (lastDeliberateWidth == 0)
                        lastDeliberateWidth = getTotalWidth();

                    resizeColumnsToFit (visibleIndexToTotalIndex (index), lastDeliberateWidth - x);
                }
            }

            repaint();
            columnsResized = true;
            triggerAsyncUpdate();
        }
    }
}

//==============================================================================
int TableHeaderComponent::getIndexOfColumnId (const int columnId, const bool onlyCountVisibleColumns) const
{
    int n = 0;

    for (auto* c : columns)
    {
        if ((! onlyCountVisibleColumns) || c->isVisible())
        {
            if (c->id == columnId)
                return n;

            ++n;
        }
    }

    return -1;
}

int TableHeaderComponent::getColumnIdOfIndex (int index, const bool onlyCountVisibleColumns) const
{
    if (onlyCountVisibleColumns)
        index = visibleIndexToTotalIndex (index);

    if (auto* ci = columns [index])
        return ci->id;

    return 0;
}

Rectangle<int> TableHeaderComponent::getColumnPosition (const int index) const
{
    int x = 0, width = 0, n = 0;

    for (auto* c : columns)
    {
        x += width;

        if (c->isVisible())
        {
            width = c->width;

            if (n++ == index)
                break;
        }
        else
        {
            width = 0;
        }
    }

    return { x, 0, width, getHeight() };
}

int TableHeaderComponent::getColumnIdAtX (const int xToFind) const
{
    if (xToFind >= 0)
    {
        int x = 0;

        for (auto* ci : columns)
        {
            if (ci->isVisible())
            {
                x += ci->width;

                if (xToFind < x)
                    return ci->id;
            }
        }
    }

    return 0;
}

int TableHeaderComponent::getTotalWidth() const
{
    int w = 0;

    for (auto* c : columns)
        if (c->isVisible())
            w += c->width;

    return w;
}

void TableHeaderComponent::setStretchToFitActive (const bool shouldStretchToFit)
{
    stretchToFit = shouldStretchToFit;
    lastDeliberateWidth = getTotalWidth();
    resized();
}

bool TableHeaderComponent::isStretchToFitActive() const
{
    return stretchToFit;
}

void TableHeaderComponent::resizeAllColumnsToFit (int targetTotalWidth)
{
    if (stretchToFit && getWidth() > 0
         && columnIdBeingResized == 0 && columnIdBeingDragged == 0)
    {
        lastDeliberateWidth = targetTotalWidth;
        resizeColumnsToFit (0, targetTotalWidth);
    }
}

void TableHeaderComponent::resizeColumnsToFit (int firstColumnIndex, int targetTotalWidth)
{
    targetTotalWidth = jmax (targetTotalWidth, 0);
    StretchableObjectResizer sor;

    for (int i = firstColumnIndex; i < columns.size(); ++i)
    {
        auto* ci = columns.getUnchecked(i);

        if (ci->isVisible())
            sor.addItem (ci->lastDeliberateWidth, ci->minimumWidth, ci->maximumWidth);
    }

    sor.resizeToFit (targetTotalWidth);
    int visIndex = 0;

    for (int i = firstColumnIndex; i < columns.size(); ++i)
    {
        auto* ci = columns.getUnchecked(i);

        if (ci->isVisible())
        {
            auto newWidth = jlimit (ci->minimumWidth, ci->maximumWidth,
                                    (int) std::floor (sor.getItemSize (visIndex++)));

            if (newWidth != ci->width)
            {
                ci->width = newWidth;
                repaint();
                columnsResized = true;
                triggerAsyncUpdate();
            }
        }
    }
}

void TableHeaderComponent::setColumnVisible (const int columnId, const bool shouldBeVisible)
{
    if (auto* ci = getInfoForId (columnId))
    {
        if (shouldBeVisible != ci->isVisible())
        {
            if (shouldBeVisible)
                ci->propertyFlags |= visible;
            else
                ci->propertyFlags &= ~visible;

            sendColumnsChanged();
            resized();
        }
    }
}

bool TableHeaderComponent::isColumnVisible (const int columnId) const
{
    if (auto* ci = getInfoForId (columnId))
        return ci->isVisible();

    return false;
}

//==============================================================================
void TableHeaderComponent::setSortColumnId (const int columnId, const bool sortForwards)
{
    if (getSortColumnId() != columnId || isSortedForwards() != sortForwards)
    {
        for (auto* c : columns)
            c->propertyFlags &= ~(sortedForwards | sortedBackwards);

        if (auto* ci = getInfoForId (columnId))
            ci->propertyFlags |= (sortForwards ? sortedForwards : sortedBackwards);

        reSortTable();
    }
}

int TableHeaderComponent::getSortColumnId() const
{
    for (auto* c : columns)
        if ((c->propertyFlags & (sortedForwards | sortedBackwards)) != 0)
            return c->id;

    return 0;
}

bool TableHeaderComponent::isSortedForwards() const
{
    for (auto* c : columns)
        if ((c->propertyFlags & (sortedForwards | sortedBackwards)) != 0)
            return (c->propertyFlags & sortedForwards) != 0;

    return true;
}

void TableHeaderComponent::reSortTable()
{
    sortChanged = true;
    repaint();
    triggerAsyncUpdate();
}

//==============================================================================
String TableHeaderComponent::toString() const
{
    String s;

    XmlElement doc ("TABLELAYOUT");

    doc.setAttribute ("sortedCol", getSortColumnId());
    doc.setAttribute ("sortForwards", isSortedForwards());

    for (auto* ci : columns)
    {
        auto* e = doc.createNewChildElement ("COLUMN");
        e->setAttribute ("id", ci->id);
        e->setAttribute ("visible", ci->isVisible());
        e->setAttribute ("width", ci->width);
    }

    return doc.toString (XmlElement::TextFormat().singleLine().withoutHeader());
}

void TableHeaderComponent::restoreFromString (const String& storedVersion)
{
    if (auto storedXML = parseXMLIfTagMatches (storedVersion, "TABLELAYOUT"))
    {
        int index = 0;

        forEachXmlChildElement (*storedXML, col)
        {
            auto tabId = col->getIntAttribute ("id");

            if (auto* ci = getInfoForId (tabId))
            {
                columns.move (columns.indexOf (ci), index);
                ci->width = col->getIntAttribute ("width");
                setColumnVisible (tabId, col->getBoolAttribute ("visible"));
            }

            ++index;
        }

        columnsResized = true;
        sendColumnsChanged();

        setSortColumnId (storedXML->getIntAttribute ("sortedCol"),
                         storedXML->getBoolAttribute ("sortForwards", true));
    }
}

//==============================================================================
void TableHeaderComponent::addListener (Listener* newListener)
{
    listeners.addIfNotAlreadyThere (newListener);
}

void TableHeaderComponent::removeListener (Listener* listenerToRemove)
{
    listeners.removeFirstMatchingValue (listenerToRemove);
}

//==============================================================================
void TableHeaderComponent::columnClicked (int columnId, const ModifierKeys& mods)
{
    if (auto* ci = getInfoForId (columnId))
        if ((ci->propertyFlags & sortable) != 0 && ! mods.isPopupMenu())
            setSortColumnId (columnId, (ci->propertyFlags & sortedForwards) == 0);
}

void TableHeaderComponent::addMenuItems (PopupMenu& menu, const int /*columnIdClicked*/)
{
    for (auto* ci : columns)
        if ((ci->propertyFlags & appearsOnColumnMenu) != 0)
            menu.addItem (ci->id, ci->name,
                          (ci->propertyFlags & (sortedForwards | sortedBackwards)) == 0,
                          isColumnVisible (ci->id));
}

void TableHeaderComponent::reactToMenuItem (const int menuReturnId, const int /*columnIdClicked*/)
{
    if (getIndexOfColumnId (menuReturnId, false) >= 0)
        setColumnVisible (menuReturnId, ! isColumnVisible (menuReturnId));
}

void TableHeaderComponent::paint (Graphics& g)
{
    auto& lf = getLookAndFeel();

    lf.drawTableHeaderBackground (g, *this);

    auto clip = g.getClipBounds();

    int x = 0;

    for (auto* ci : columns)
    {
        if (ci->isVisible())
        {
            if (x + ci->width > clip.getX()
                 && (ci->id != columnIdBeingDragged
                      || dragOverlayComp == nullptr
                      || ! dragOverlayComp->isVisible()))
            {
                Graphics::ScopedSaveState ss (g);

                g.setOrigin (x, 0);
                g.reduceClipRegion (0, 0, ci->width, getHeight());

                lf.drawTableHeaderColumn (g, *this, ci->name, ci->id, ci->width, getHeight(),
                                          ci->id == columnIdUnderMouse,
                                          ci->id == columnIdUnderMouse && isMouseButtonDown(),
                                          ci->propertyFlags);
            }

            x += ci->width;

            if (x >= clip.getRight())
                break;
        }
    }
}

void TableHeaderComponent::mouseMove  (const MouseEvent& e)  { updateColumnUnderMouse (e); }
void TableHeaderComponent::mouseEnter (const MouseEvent& e)  { updateColumnUnderMouse (e); }
void TableHeaderComponent::mouseExit  (const MouseEvent&)    { setColumnUnderMouse (0); }

void TableHeaderComponent::mouseDown (const MouseEvent& e)
{
    repaint();
    columnIdBeingResized = 0;
    columnIdBeingDragged = 0;

    if (columnIdUnderMouse != 0)
    {
        draggingColumnOffset = e.x - getColumnPosition (getIndexOfColumnId (columnIdUnderMouse, true)).getX();

        if (e.mods.isPopupMenu())
            columnClicked (columnIdUnderMouse, e.mods);
    }

    if (menuActive && e.mods.isPopupMenu())
        showColumnChooserMenu (columnIdUnderMouse);
}

void TableHeaderComponent::mouseDrag (const MouseEvent& e)
{
    if (columnIdBeingResized == 0
         && columnIdBeingDragged == 0
         && e.mouseWasDraggedSinceMouseDown()
         && ! e.mods.isPopupMenu())
    {
        dragOverlayComp.reset();

        columnIdBeingResized = getResizeDraggerAt (e.getMouseDownX());

        if (columnIdBeingResized != 0)
        {
            if (auto* ci = getInfoForId (columnIdBeingResized))
                initialColumnWidth = ci->width;
            else
                jassertfalse;
        }
        else
        {
            beginDrag (e);
        }
    }

    if (columnIdBeingResized != 0)
    {
        if (auto* ci = getInfoForId (columnIdBeingResized))
        {
            auto w = jlimit (ci->minimumWidth, ci->maximumWidth,
                             initialColumnWidth + e.getDistanceFromDragStartX());

            if (stretchToFit)
            {
                // prevent us dragging a column too far right if we're in stretch-to-fit mode
                int minWidthOnRight = 0;

                for (int i = getIndexOfColumnId (columnIdBeingResized, false) + 1; i < columns.size(); ++i)
                    if (columns.getUnchecked (i)->isVisible())
                        minWidthOnRight += columns.getUnchecked (i)->minimumWidth;

                auto currentPos = getColumnPosition (getIndexOfColumnId (columnIdBeingResized, true));
                w = jmax (ci->minimumWidth, jmin (w, lastDeliberateWidth - minWidthOnRight - currentPos.getX()));
            }

            setColumnWidth (columnIdBeingResized, w);
        }
    }
    else if (columnIdBeingDragged != 0)
    {
        if (e.y >= -50 && e.y < getHeight() + 50)
        {
            if (dragOverlayComp != nullptr)
            {
                dragOverlayComp->setVisible (true);
                dragOverlayComp->setBounds (jlimit (0,
                                                    jmax (0, getTotalWidth() - dragOverlayComp->getWidth()),
                                                    e.x - draggingColumnOffset),
                                            0,
                                            dragOverlayComp->getWidth(),
                                            getHeight());

                for (int i = columns.size(); --i >= 0;)
                {
                    const int currentIndex = getIndexOfColumnId (columnIdBeingDragged, true);
                    int newIndex = currentIndex;

                    if (newIndex > 0)
                    {
                        // if the previous column isn't draggable, we can't move our column
                        // past it, because that'd change the undraggable column's position..
                        auto* previous = columns.getUnchecked (newIndex - 1);

                        if ((previous->propertyFlags & draggable) != 0)
                        {
                            auto leftOfPrevious = getColumnPosition (newIndex - 1).getX();
                            auto rightOfCurrent = getColumnPosition (newIndex).getRight();

                            if (std::abs (dragOverlayComp->getX() - leftOfPrevious)
                                 < std::abs (dragOverlayComp->getRight() - rightOfCurrent))
                            {
                                --newIndex;
                            }
                        }
                    }

                    if (newIndex < columns.size() - 1)
                    {
                        // if the next column isn't draggable, we can't move our column
                        // past it, because that'd change the undraggable column's position..
                        auto* nextCol = columns.getUnchecked (newIndex + 1);

                        if ((nextCol->propertyFlags & draggable) != 0)
                        {
                            auto leftOfCurrent = getColumnPosition (newIndex).getX();
                            auto rightOfNext = getColumnPosition (newIndex + 1).getRight();

                            if (std::abs (dragOverlayComp->getX() - leftOfCurrent)
                                 > std::abs (dragOverlayComp->getRight() - rightOfNext))
                            {
                                ++newIndex;
                            }
                        }
                    }

                    if (newIndex != currentIndex)
                        moveColumn (columnIdBeingDragged, newIndex);
                    else
                        break;
                }
            }
        }
        else
        {
            endDrag (draggingColumnOriginalIndex);
        }
    }
}

void TableHeaderComponent::beginDrag (const MouseEvent& e)
{
    if (columnIdBeingDragged == 0)
    {
        columnIdBeingDragged = getColumnIdAtX (e.getMouseDownX());

        auto* ci = getInfoForId (columnIdBeingDragged);

        if (ci == nullptr || (ci->propertyFlags & draggable) == 0)
        {
            columnIdBeingDragged = 0;
        }
        else
        {
            draggingColumnOriginalIndex = getIndexOfColumnId (columnIdBeingDragged, true);

            auto columnRect = getColumnPosition (draggingColumnOriginalIndex);
            auto temp = columnIdBeingDragged;
            columnIdBeingDragged = 0;

            dragOverlayComp.reset (new DragOverlayComp (createComponentSnapshot (columnRect, false)));
            addAndMakeVisible (dragOverlayComp.get());
            columnIdBeingDragged = temp;

            dragOverlayComp->setBounds (columnRect);

            for (int i = listeners.size(); --i >= 0;)
            {
                listeners.getUnchecked(i)->tableColumnDraggingChanged (this, columnIdBeingDragged);
                i = jmin (i, listeners.size() - 1);
            }
        }
    }
}

void TableHeaderComponent::endDrag (const int finalIndex)
{
    if (columnIdBeingDragged != 0)
    {
        moveColumn (columnIdBeingDragged, finalIndex);

        columnIdBeingDragged = 0;
        repaint();

        for (int i = listeners.size(); --i >= 0;)
        {
            listeners.getUnchecked(i)->tableColumnDraggingChanged (this, 0);
            i = jmin (i, listeners.size() - 1);
        }
    }
}

void TableHeaderComponent::mouseUp (const MouseEvent& e)
{
    mouseDrag (e);

    for (auto* c : columns)
        if (c->isVisible())
            c->lastDeliberateWidth = c->width;

    columnIdBeingResized = 0;
    repaint();

    endDrag (getIndexOfColumnId (columnIdBeingDragged, true));

    updateColumnUnderMouse (e);

    if (columnIdUnderMouse != 0 && ! (e.mouseWasDraggedSinceMouseDown() || e.mods.isPopupMenu()))
        columnClicked (columnIdUnderMouse, e.mods);

    dragOverlayComp.reset();
}

MouseCursor TableHeaderComponent::getMouseCursor()
{
    if (columnIdBeingResized != 0 || (getResizeDraggerAt (getMouseXYRelative().getX()) != 0 && ! isMouseButtonDown()))
        return MouseCursor (MouseCursor::LeftRightResizeCursor);

    return Component::getMouseCursor();
}

//==============================================================================
bool TableHeaderComponent::ColumnInfo::isVisible() const
{
    return (propertyFlags & TableHeaderComponent::visible) != 0;
}

TableHeaderComponent::ColumnInfo* TableHeaderComponent::getInfoForId (int id) const
{
    for (auto* c : columns)
        if (c->id == id)
            return c;

    return nullptr;
}

int TableHeaderComponent::visibleIndexToTotalIndex (const int visibleIndex) const
{
    int n = 0;

    for (int i = 0; i < columns.size(); ++i)
    {
        if (columns.getUnchecked(i)->isVisible())
        {
            if (n == visibleIndex)
                return i;

            ++n;
        }
    }

    return -1;
}

void TableHeaderComponent::sendColumnsChanged()
{
    if (stretchToFit && lastDeliberateWidth > 0)
        resizeAllColumnsToFit (lastDeliberateWidth);

    repaint();
    columnsChanged = true;
    triggerAsyncUpdate();
}

void TableHeaderComponent::handleAsyncUpdate()
{
    const bool changed = columnsChanged || sortChanged;
    const bool sized = columnsResized || changed;
    const bool sorted = sortChanged;
    columnsChanged = false;
    columnsResized = false;
    sortChanged = false;

    if (sorted)
    {
        for (int i = listeners.size(); --i >= 0;)
        {
            listeners.getUnchecked(i)->tableSortOrderChanged (this);
            i = jmin (i, listeners.size() - 1);
        }
    }

    if (changed)
    {
        for (int i = listeners.size(); --i >= 0;)
        {
            listeners.getUnchecked(i)->tableColumnsChanged (this);
            i = jmin (i, listeners.size() - 1);
        }
    }

    if (sized)
    {
        for (int i = listeners.size(); --i >= 0;)
        {
            listeners.getUnchecked(i)->tableColumnsResized (this);
            i = jmin (i, listeners.size() - 1);
        }
    }
}

int TableHeaderComponent::getResizeDraggerAt (const int mouseX) const
{
    if (isPositiveAndBelow (mouseX, getWidth()))
    {
        const int draggableDistance = 3;
        int x = 0;

        for (auto* ci : columns)
        {
            if (ci->isVisible())
            {
                if (std::abs (mouseX - (x + ci->width)) <= draggableDistance
                     && (ci->propertyFlags & resizable) != 0)
                    return ci->id;

                x += ci->width;
            }
        }
    }

    return 0;
}

void TableHeaderComponent::setColumnUnderMouse (const int newCol)
{
    if (newCol != columnIdUnderMouse)
    {
        columnIdUnderMouse = newCol;
        repaint();
    }
}

void TableHeaderComponent::updateColumnUnderMouse (const MouseEvent& e)
{
    setColumnUnderMouse (reallyContains (e.getPosition(), true) && getResizeDraggerAt (e.x) == 0
                            ? getColumnIdAtX (e.x) : 0);
}

static void tableHeaderMenuCallback (int result, TableHeaderComponent* tableHeader, int columnIdClicked)
{
    if (tableHeader != nullptr && result != 0)
        tableHeader->reactToMenuItem (result, columnIdClicked);
}

void TableHeaderComponent::showColumnChooserMenu (const int columnIdClicked)
{
    PopupMenu m;
    addMenuItems (m, columnIdClicked);

    if (m.getNumItems() > 0)
    {
        m.setLookAndFeel (&getLookAndFeel());

        m.showMenuAsync (PopupMenu::Options(),
                         ModalCallbackFunction::forComponent (tableHeaderMenuCallback, this, columnIdClicked));
    }
}

void TableHeaderComponent::Listener::tableColumnDraggingChanged (TableHeaderComponent*, int)
{
}

} // namespace juce