KinderElektro/src/main/java/de/ph87/electro/circuit/CircuitPanelMouseAdapter.java

package de.ph87.electro.circuit;

import de.ph87.electro.circuit.part.Part;
import de.ph87.electro.circuit.part.Position;
import de.ph87.electro.circuit.part.junction.Junction;
import de.ph87.electro.circuit.wire.Wire;

import java.awt.*;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.Optional;

import static de.ph87.electro.CONFIG.*;
import static java.awt.event.MouseEvent.BUTTON1;
import static java.awt.event.MouseEvent.BUTTON3;

class CircuitPanelMouseAdapter extends MouseAdapter {

  private final CircuitPanel circuitPanel;

  private final Circuit circuit;

  private Part partHover = null;

  private Junction junctionHover = null;

  private Wire wireHover = null;

  private Part partDrag = null;

  private Junction junctionDrag = null;

  private Position dragPosition = null;

  CircuitPanelMouseAdapter(final CircuitPanel circuitPanel, final Circuit circuit) {
    this.circuitPanel = circuitPanel;
    this.circuit = circuit;
    circuitPanel.addMouseListener(this);
    circuitPanel.addMouseMotionListener(this);
  }

  @Override
  public void mouseClicked(final MouseEvent event) {
    final Position position = new Position(event);

    if (event.getButton() == BUTTON3) {
      final Optional<Wire> wireOptional = circuit.findWireByPosition(position);
      if (wireOptional.isPresent()) {
        circuit.removeWire(wireOptional.get());
        circuitPanel.evaluate();
        return;
      }
    }

    final Optional<Part> partOptional = circuit.findPartByPosition(position);
    switch (event.getButton()) {
      case BUTTON1:
        partOptional.ifPresent(Part::action);
        circuitPanel.evaluate();
        break;
      case BUTTON3:
        partOptional.ifPresent(Part::clockwise);
        circuitPanel.save();
        break;
    }
  }

  @Override
  public void mouseMoved(final MouseEvent event) {
    findHover(new Position(event));
    circuitPanel.repaint();
  }

  @Override
  public void mousePressed(final MouseEvent event) {
    final Position position = new Position(event);
    circuit.findPartByPosition(position).ifPresent(part -> startPartOrJunction(part, position));
  }

  private void startPartOrJunction(final Part part, final Position position) {
    part.findJunctionByPosition(position).ifPresentOrElse(junction -> {
      partDrag = null;
      junctionDrag = junction;
    }, () -> {
      partDrag = part;
      junctionDrag = null;
    });
  }

  @Override
  public void mouseDragged(final MouseEvent event) {
    final Position position = new Position(event);
    findHover(position);
    if (partDrag != null || junctionDrag != null) {
      dragPosition = position;
    }
    circuitPanel.repaint();
  }

  private void findHover(final Position position) {
    partHover = circuit.findPartByPosition(position).orElse(null);
    junctionHover = partHover != null ? partHover.findJunctionByPosition(position).orElse(null) : null;
    if (junctionHover != null) {
      partHover = null;
      wireHover = null;
      return;
    }
    wireHover = circuit.findWireByPosition(position).orElse(null);
    if (wireHover != null) {
      partHover = null;
    }
  }

  @Override
  public void mouseReleased(final MouseEvent event) {
    final Position position = new Position(event);
    if (partDrag != null) {
      circuit.movePart(partDrag, position);
      circuitPanel.save();
    }

    if (junctionDrag != null) {
      circuit.findJunctionByAbsolute(position).filter(destination -> destination != junctionDrag).ifPresent(destination -> {
        circuit.connect(junctionDrag, destination);
        circuitPanel.evaluate();
      });
    }

    partDrag = null;
    junctionDrag = null;
    dragPosition = null;
    circuitPanel.repaint();
  }

  public void drawHover(final Graphics2D g) {
    if (partHover != null) {
      g.setColor(PART_HOVER_COLOR);
      g.setStroke(HOVER_STROKE);
      g.drawRect(partHover.getPosition().absolute.x, partHover.getPosition().absolute.y, RASTER, RASTER);
    }
    if (junctionHover != null) {
      g.setColor(junctionHover.getColor());
      g.fillArc(junctionHover.getPosition().absolute.x - JUNCTION_RADIUS_HOVER, junctionHover.getPosition().absolute.y - JUNCTION_RADIUS_HOVER, 2 * JUNCTION_RADIUS_HOVER, 2 * JUNCTION_RADIUS_HOVER, 0, 360);

      g.setColor(JUNCTION_HOVER_BORDER_COLOR);
      g.setStroke(HOVER_STROKE);
      g.drawArc(junctionHover.getPosition().absolute.x - JUNCTION_RADIUS_HOVER, junctionHover.getPosition().absolute.y - JUNCTION_RADIUS_HOVER, 2 * JUNCTION_RADIUS_HOVER, 2 * JUNCTION_RADIUS_HOVER, 0, 360);
    }
    if (wireHover != null) {
      g.setColor(WIRE_HOVER_COLOR_BACK);
      g.setStroke(WIRE_HOVER_STROKE_BACK);
      g.drawLine(
        wireHover.getA().getPosition().absolute.x,
        wireHover.getA().getPosition().absolute.y,
        wireHover.getB().getPosition().absolute.x,
        wireHover.getB().getPosition().absolute.y
      );

      g.setColor(wireHover.getA().getColor());
      g.setStroke(WIRE_HOVER_STROKE);
      g.drawLine(
        wireHover.getA().getPosition().absolute.x,
        wireHover.getA().getPosition().absolute.y,
        wireHover.getB().getPosition().absolute.x,
        wireHover.getB().getPosition().absolute.y
      );
    }
  }

  public void drawDrag(final Graphics2D g) {
    if (dragPosition != null) {
      if (partDrag != null) {
        g.setColor(PART_HOVER_COLOR);
        g.fillRect(dragPosition.absolute.x - P50, dragPosition.absolute.y - P50, RASTER, RASTER);
      }
      if (junctionDrag != null) {
        g.setColor(junctionDrag.getColor());
        g.setStroke(WIRE_STROKE);
        g.drawLine(junctionDrag.getPosition().absolute.x, junctionDrag.getPosition().absolute.y, dragPosition.absolute.x, dragPosition.absolute.y);
      }
    }
  }

}