package holeg.ui.view.canvas;

import holeg.model.*;
import holeg.ui.controller.Control;
import holeg.ui.model.GuiSettings;
import holeg.ui.view.dialog.CreateTemplatePopUp;
import holeg.utility.math.vector.Geometry;
import holeg.utility.math.vector.Vec2f;
import holeg.utility.math.vector.Vec2i;

import javax.swing.*;
import java.awt.*;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.util.HashSet;
import java.util.Optional;
import java.util.Set;
import java.util.logging.Logger;

public class Canvas extends JPanel {
    private static final Logger log = Logger.getLogger(Canvas.class.getName());
    private final Control control;
    private final CanvasMouseListener canvasMouseListener = new CanvasMouseListener();
    private GroupNode groupNode;
    private boolean enabled = true;
    private final JPopupMenu componentPopupMenu = new JPopupMenu();
    private final JMenuItem groupMenu = new JMenuItem("Group");
    private final JMenuItem ungroupMenu = new JMenuItem("Ungroup");
    private final JMenuItem deleteMenu = new JMenuItem("Delete");
    private final JMenuItem templateMenu = new JMenuItem("Template");



    public Canvas(Control control, GroupNode groupNode) {
        this.control = control;
        this.groupNode = groupNode;
        control.OnGuiSetEnabled.addListener(this::setCanvasEnabled);
        control.OnSelectionChanged.addListener(this::repaint);
        control.OnCanvasUpdate.addListener(this::repaint);
        this.setBackground(Color.WHITE);
        this.setPreferredSize(new Dimension(GuiSettings.canvasSize.getX(), GuiSettings.canvasSize.getY()));
        this.addMouseListener(canvasMouseListener);
        this.addMouseMotionListener(canvasMouseListener);
        initPopupMenu();
    }


    private void initPopupMenu() {
        componentPopupMenu.add(deleteMenu);
        componentPopupMenu.addSeparator();
        componentPopupMenu.add(groupMenu);
        componentPopupMenu.add(ungroupMenu);
        componentPopupMenu.addSeparator();
        componentPopupMenu.add(templateMenu);
        deleteMenu.addActionListener(clicked -> {
            control.deleteCanvasObjects(GuiSettings.getSelectedObjects());
            control.clearSelection();
        });
        groupMenu.addActionListener(clicked -> control.group());
        ungroupMenu.addActionListener(clicked -> control.ungroup());
        templateMenu.addActionListener(clicked -> GuiSettings.getSelectedObjects().stream().findAny().ifPresent(obj -> {
           HolonObject hObject = (HolonObject)obj;
            new CreateTemplatePopUp(hObject, (JFrame) SwingUtilities.getWindowAncestor(this), control);
        }));

    }

    public static Rectangle getBoundsOfObject(AbstractCanvasObject obj) {
        int pictureScale = GuiSettings.getPictureScale();
        int pictureScaleDiv2 = GuiSettings.getPictureScaleDiv2();
        Vec2i pos = obj.getPosition();
        return new Rectangle(pos.getX() - pictureScaleDiv2, pos.getY() - pictureScaleDiv2, pictureScale, pictureScale);
    }

    private void setCanvasEnabled(boolean state) {
        enabled = state;
    }

    public GroupNode getGroupNode() {
        return this.groupNode;
    }

    public void setGroupNode(GroupNode groupNode) {
        this.groupNode = groupNode;
    }

    @Override
    public void paintComponent(java.awt.Graphics g) {
        super.paintComponent(g);
        Graphics2D g2d = Rendering.initGraphics2D(g);
        g2d.setColor(Color.gray);
        g2d.fillRect(0,0,getWidth(), getHeight());
        g2d.setColor(Color.white);
        g2d.fillRect(0,0,GuiSettings.canvasSize.getX(), GuiSettings.canvasSize.getY());
        Rendering.drawSelection(g2d);
        paintEdges(g2d);
        groupNode.getHolonObjects().forEach(hO -> Rendering.drawHolonObject(g2d, hO));
        groupNode.getSwitches().forEach(hS -> Rendering.drawSwitchObject(g2d, hS));
        groupNode.getGroupNodes().forEach(groupNode -> Rendering.drawGroupNode(g2d, groupNode));
        groupNode.getNodes().forEach(node -> Rendering.drawNode(g2d, node));
        switch (canvasMouseListener.state) {
            case BoxSelection -> Rendering.drawSelectionBox(g2d, canvasMouseListener.getRectangleOfSelectionBox());
            case EdgeCreation -> Rendering.drawNewEdgeLine(g2d, canvasMouseListener.selectedOnPressed.getPosition(), canvasMouseListener.lastPosition);
        }
        if(canvasMouseListener.canBeReplaced){
            Rendering.drawReplacementSymbol(g2d, canvasMouseListener.selectedOnPressed);
        }
    }


    private void paintEdges(Graphics2D g2d) {
        control.getModel().getEdgesOnCanvas().forEach(edge -> {
            if (edge.getA().getGroupNode().isEmpty() || edge.getB().getGroupNode().isEmpty()) {
                return;
            }
            boolean aInside = edge.getA().getGroupNode().get() == groupNode;
            boolean bInside = edge.getB().getGroupNode().get() == groupNode;
            //both
            if (aInside && bInside) {
                Rendering.drawEdge(g2d, edge, edge.getA(), edge.getB());
            } else if (aInside) {
                SearchObjectIfParentOfGroupNode(edge.getB()).ifPresentOrElse(
                        alternative -> Rendering.drawEdge(g2d, edge, edge.getA(), alternative),
                        () -> Rendering.drawExternConnection(g2d, edge.getA()));
            } else if (bInside) {
                SearchObjectIfParentOfGroupNode(edge.getA()).ifPresentOrElse(
                        alternative -> Rendering.drawEdge(g2d, edge, alternative, edge.getB()),
                        () -> Rendering.drawExternConnection(g2d, edge.getB()));
            } else {
                Optional<AbstractCanvasObject> alternativeA = SearchObjectIfParentOfGroupNode(edge.getA());
                Optional<AbstractCanvasObject> alternativeB = SearchObjectIfParentOfGroupNode(edge.getB());
                if (alternativeA.isPresent() && alternativeB.isPresent() && !alternativeA.equals(alternativeB)) {
                    Rendering.drawEdge(g2d, edge, alternativeA.get(), alternativeB.get());
                }
            }
            //none
        });
    }

    private Optional<AbstractCanvasObject> SearchObjectIfParentOfGroupNode(AbstractCanvasObject current) {
        while (current.getGroupNode().isPresent()) {
            if (current.getGroupNode().get() == this.groupNode) {
                return Optional.of(current);
            }
            current = current.getGroupNode().get();
        }
        return Optional.empty();
    }

    private Optional<AbstractCanvasObject> getObjectAtPosition(Vec2i pos) {
        return groupNode.getObjectsInThisLayer().filter(obj ->
                getBoundsOfObject(obj).contains(pos.getX(), pos.getY())
        ).findAny();
    }

    public static Vec2i boundsToCanvas(Vec2i pos){
        Vec2i position = new Vec2i(pos);
        position.clampX(GuiSettings.getPictureScaleDiv2(), GuiSettings.canvasSize.getX() - GuiSettings.getPictureScaleDiv2());
        position.clampY(GuiSettings.getPictureScaleDiv2(), GuiSettings.canvasSize.getY() - GuiSettings.getPictureScaleDiv2());
        return position;
    }


    /**
     * Microsoft Windows10 selection & dragging behavior
     */
    private class CanvasMouseListener implements MouseListener, MouseMotionListener {
        private Vec2i lastPosition = new Vec2i();
        private Vec2i pressedPosition = new Vec2i();
        private Set<AbstractCanvasObject> selectionBeforeBoxSelection = new HashSet<>();
        private State state = State.None;
        private AbstractCanvasObject selectedOnPressed = null;
        private boolean canBeReplaced = false;




        @Override
        public void mousePressed(MouseEvent e) {
            if (!enabled) {
                return;
            }
            log.finest(state.toString());

            Vec2i pos = new Vec2i(e.getPoint());
            getObjectAtPosition(pos).ifPresentOrElse(obj -> {
                if (!e.isControlDown() && !GuiSettings.getSelectedObjects().contains(obj)) {
                    GuiSettings.getSelectedObjects().clear();
                }
                state = State.Selection;
                GuiSettings.getSelectedObjects().add(obj);
                selectedOnPressed = obj;
            }, () -> {
                if (!e.isControlDown()) {
                    GuiSettings.getSelectedObjects().clear();
                }
                state = State.BoxSelection;
                selectionBeforeBoxSelection = Set.copyOf(GuiSettings.getSelectedObjects());
            });
            control.OnSelectionChanged.broadcast();
            lastPosition = pressedPosition = pos;
        }

        @Override
        public void mouseDragged(MouseEvent e) {
            if (!enabled) {
                return;
            }
            log.finest(state.toString());
            Vec2i actualPos = new Vec2i(e.getPoint());
            switch (state) {
                case Selection -> {
                    // Not handle to small mouse dragging
                    if (!(pressedPosition.getSquaredDistance(actualPos) > GuiSettings.dragThresholdDistance)) {
                        return;
                    }
                    if (SwingUtilities.isLeftMouseButton(e)) {
                        state = State.ObjectDragging;
                    } else if (SwingUtilities.isRightMouseButton(e) && !(selectedOnPressed instanceof GroupNode)) {
                        state = State.EdgeCreation;
                    }
                }
                case BoxSelection -> {
                    Rectangle selectionBox = getRectangleOfSelectionBox();
                    groupNode.getObjectsInThisLayer().forEach(obj -> {
                        Rectangle bounds = getBoundsOfObject(obj);
                        if (selectionBox.intersects(bounds) ^ selectionBeforeBoxSelection.contains(obj)) {
                            GuiSettings.getSelectedObjects().add(obj);
                        } else {
                            GuiSettings.getSelectedObjects().remove(obj);
                        }
                    });
                    repaint();
                }
                case ObjectDragging -> {
                    Vec2i delta = actualPos.subtract(lastPosition);
                    GuiSettings.getSelectedObjects().forEach(obj -> obj.setPosition(boundsToCanvas(obj.getPosition().add(delta))));
                    canBeReplaced = checkForReplacement(actualPos).isPresent();
                    repaint();
                }
                case EdgeCreation -> repaint();
            }
            lastPosition = actualPos;
        }

        private Optional<AbstractCanvasObject> checkForReplacement(Vec2i pos){
            return groupNode.getObjectsInThisLayer().filter(obj -> obj != selectedOnPressed &&
                    getBoundsOfObject(obj).contains(pos.getX(), pos.getY())
            ).findAny();
        }

        @Override
        public void mouseReleased(MouseEvent e) {
            if (!enabled) {
                return;
            }
            log.info(state.toString());
            switch (state) {
                case None -> {
                    if(SwingUtilities.isRightMouseButton(e)){
                        preparePopupMenu();
                        componentPopupMenu.show(Canvas.this, e.getX(), e.getY());
                    }else {
                        if (GuiSettings.getSelectedObjects().contains(selectedOnPressed)) {
                            control.removeObjectFromSelection(selectedOnPressed);
                        } else {
                            control.addObjectToSelection(selectedOnPressed);
                        }
                    }
                }
                case Selection, BoxSelection -> {
                    control.OnSelectionChanged.broadcast();
                    if(SwingUtilities.isRightMouseButton(e)){
                        preparePopupMenu();
                        componentPopupMenu.show(Canvas.this, e.getX(), e.getY());
                    }
                }
                case EdgeCreation -> getObjectAtPosition(lastPosition).ifPresentOrElse(obj -> {
                    boolean isGroupNode = obj instanceof GroupNode;
                    if (!isGroupNode) {
                        control.addEdgeOnCanvasOrRemoveExisting(new Edge(selectedOnPressed, obj, GuiSettings.maxCapacityForNewCreatedEdges));
                    }
                }, () -> {

                    Node node = new Node("Node");
                    groupNode.add(node);
                    final float splitDetectionDistance = 15f;
                    Geometry.Circle detectionCircle = new Geometry.Circle(new Vec2f(lastPosition), splitDetectionDistance);
                    node.setPosition(new Vec2i(boundsToCanvas(lastPosition)));
                    for(Edge edge : control.getModel().getEdgesOnCanvas()) {
                        if(edge.getA().getGroupNode().isEmpty() || edge.getB().getGroupNode().isEmpty() ||
                                edge.getA().getGroupNode().get() != groupNode || edge.getB().getGroupNode().get() != groupNode){
                            continue;
                        }
                        Optional<Vec2f> pos = Geometry.getProjectionOnSegmentIfInRange(new Geometry.Line(new Vec2f(edge.getA().getPosition())
                                , new Vec2f(edge.getB().getPosition())), detectionCircle);
                        if(pos.isPresent()){
                            Vec2f position = pos.get();
                            node.setPosition(new Vec2i((int)position.getX(), (int)position.getY()));
                            splitEdge(edge, node);
                            break;
                        }
                    }
                    control.addEdgeOnCanvas(new Edge(selectedOnPressed, node, GuiSettings.maxCapacityForNewCreatedEdges));
                    control.calculateStateForCurrentIteration();
                });
                case ObjectDragging -> checkForReplacement(new Vec2i(e.getPoint())).ifPresent(obj -> control.replaceCanvasObject(obj, selectedOnPressed));
            }
            canBeReplaced = false;
            state = State.None;
            repaint();
        }

        private void preparePopupMenu(){
            int count = GuiSettings.getSelectedObjects().size();
            boolean isAGroupNodeSelected = GuiSettings.getSelectedObjects().stream().anyMatch(obj -> obj instanceof GroupNode);
            switch (count){
                case 0 -> {
                    groupMenu.setEnabled(false);
                    ungroupMenu.setEnabled(false);
                    deleteMenu.setEnabled(false);
                    templateMenu.setEnabled(false);
                }
                case 1 -> {
                    deleteMenu.setEnabled(true);
                    boolean isSelectedObjectAHolonObject = GuiSettings.getSelectedObjects().stream().anyMatch(obj -> obj instanceof HolonObject);
                    templateMenu.setEnabled(isSelectedObjectAHolonObject);
                    groupMenu.setEnabled(true);
                    ungroupMenu.setEnabled(isAGroupNodeSelected);
                }
                default -> {
                    deleteMenu.setEnabled(true);
                    templateMenu.setEnabled(false);
                    groupMenu.setEnabled(true);
                    ungroupMenu.setEnabled(isAGroupNodeSelected);
                }
            }
        }


        @Override
        public void mouseClicked(MouseEvent e) {
            boolean doubleLeftClick = e.getClickCount() % 2 == 0 && SwingUtilities.isLeftMouseButton(e);
            if (doubleLeftClick) {
                log.finest(state.toString());
                getObjectAtPosition(new Vec2i(e.getPoint())).ifPresent(obj -> {
                    if (obj instanceof HolonSwitch sw) {
                        sw.setMode(HolonSwitch.SwitchMode.Manual);
                        sw.flipManualState();
                        control.calculateStateForCurrentIteration();
                    } else if (obj instanceof GroupNode gNode) {
                        control.showGroupNode(gNode);
                    }
                });
            }
        }


        Rectangle getRectangleOfSelectionBox() {
            return Geometry.createRectangleFromCorners(lastPosition, pressedPosition);
        }


        public void splitEdge(Edge edge, Node node){
            AbstractCanvasObject end = edge.getB();
            edge.setB(node);
            Edge additional = new Edge(node, end, edge.maxCapacity);
            control.getModel().addEdgeOnCanvas(additional);
        }

        @Override
        public void mouseEntered(MouseEvent e) {
        }

        @Override
        public void mouseExited(MouseEvent e) {
        }

        @Override
        public void mouseMoved(MouseEvent e) {
        }

        private enum State {
            None, BoxSelection, EdgeCreation, ObjectDragging, Selection
        }

    }
}