package jcgp.gui.settings;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;

import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.geometry.Insets;
import javafx.scene.Cursor;
import javafx.scene.control.Button;
import javafx.scene.control.CheckBox;
import javafx.scene.control.ComboBox;
import javafx.scene.control.ScrollPane;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.AnchorPane;
import javafx.scene.layout.HBox;
import javafx.scene.layout.Priority;
import javafx.scene.layout.VBox;
import javafx.scene.text.Font;
import javafx.scene.text.FontSmoothingType;
import javafx.scene.text.Text;
import jcgp.JCGP;
import jcgp.backend.function.FunctionSet;
import jcgp.backend.modules.ea.EvolutionaryAlgorithm;
import jcgp.backend.modules.fitness.FitnessFunction;
import jcgp.backend.modules.mutator.Mutator;
import jcgp.backend.parameters.IntegerParameter;
import jcgp.backend.parameters.Parameter;
import jcgp.gui.GUI;
import jcgp.gui.settings.parameters.*;

public class SettingsPane extends AnchorPane {
	
	private VBox mainContainer;
	private VBox bpPane, eaPane, mutatorPane, ffPane, nfPane;
	private ArrayList<GUIParameter> parameters = new ArrayList<GUIParameter>();
	
	private boolean dragging = false;
	
	public SettingsPane(JCGP cgp, GUI gui) {
		super();
		
		setResizeListeners();
		
		mainContainer = new VBox(8);
		mainContainer.setPadding(new Insets(5, GUI.RESIZE_MARGIN, 0, 2));
		
		setMinWidth(GUI.SETTINGS_WIDTH);
		setPrefWidth(GUI.SETTINGS_WIDTH);
		
		initialiseBaseParameters(cgp, gui);
		
		initialiseEAParameters(cgp);
		
		initialiseMutatorParameters(cgp);
		
		initialiseFitnessFunctionParameters(cgp);
		
		initialiseNodeFunctionParameters(cgp);
		
		createControls(cgp, gui);
		
		ScrollPane scroll = new ScrollPane();
		scroll.setFitToWidth(true);
		scroll.setContent(mainContainer);
		scroll.setStyle("-fx-background-color: #FFFFFF");
		
		AnchorPane.setTopAnchor(scroll, 0.0);
		AnchorPane.setBottomAnchor(scroll, 0.0);
		AnchorPane.setRightAnchor(scroll, 0.0);
		AnchorPane.setLeftAnchor(scroll, GUI.RESIZE_MARGIN);
		
		getChildren().add(scroll);
	}

	private void initialiseBaseParameters(JCGP cgp, GUI gui) {
		bpPane = new VBox(2);
		
		Text header = new Text("Base Parameters");
		header.setFont(Font.font("Arial", 14));
		header.setUnderline(true);
		
		bpPane.getChildren().add(header);
		
		GUIParameter rows = GUIParameter.create((IntegerParameter) cgp.getResources().getParameter("rows"));
		parameters.add(rows);
		parameters.add(GUIParameter.create((IntegerParameter) cgp.getResources().getParameter("columns")));
		parameters.add(GUIParameter.create((IntegerParameter) cgp.getResources().getParameter("inputs")));
		parameters.add(GUIParameter.create((IntegerParameter) cgp.getResources().getParameter("outputs")));
		parameters.add(GUIParameter.create((IntegerParameter) cgp.getResources().getParameter("levelsBack")));
		
		parameters.add(GUIParameter.create((IntegerParameter) cgp.getResources().getParameter("popSize")));
		parameters.add(GUIParameter.create((IntegerParameter) cgp.getResources().getParameter("generations")));
		parameters.add(GUIParameter.create((IntegerParameter) cgp.getResources().getParameter("runs")));
		
		parameters.add(GUIParameter.create((IntegerParameter) cgp.getResources().getParameter("currentGen")));
		parameters.add(GUIParameter.create((IntegerParameter) cgp.getResources().getParameter("currentRun")));				
		
		parameters.add(GUIParameter.create((IntegerParameter) cgp.getResources().getParameter("seed")));
		parameters.add(GUIParameter.create((IntegerParameter) cgp.getResources().getParameter("report")));
		
		bpPane.getChildren().addAll(parameters);
		
		mainContainer.getChildren().add(bpPane);
		
		
	}

	private void initialiseEAParameters(final JCGP cgp) {
		eaPane = new VBox(2);
		
		Text header = new Text("Evolutionary Algorithm");
		header.setFont(Font.font("Arial", 14));
		header.setUnderline(true);
		
		final ComboBox<EvolutionaryAlgorithm> eaCBox = new ComboBox<EvolutionaryAlgorithm>();
		eaCBox.getItems().addAll(cgp.getEvolutionaryAlgorithms());
		eaCBox.getSelectionModel().select(cgp.getEvolutionaryAlgorithm());
		eaCBox.prefWidthProperty().bind(mainContainer.widthProperty());
		
		final VBox eaParameters = new VBox();
		eaParameters.setSpacing(2);
		if (cgp.getEvolutionaryAlgorithm().getLocalParameters() != null) {
			refreshParameters(cgp.getEvolutionaryAlgorithm().getLocalParameters().entrySet().iterator(), eaParameters);
		}
		
		eaCBox.setOnAction(new EventHandler<ActionEvent>() {
			@Override
			public void handle(ActionEvent event) {
				cgp.setEvolutionaryAlgorithm(eaCBox.getSelectionModel().getSelectedIndex());
				if (eaCBox.getSelectionModel().getSelectedItem().getLocalParameters() != null) {
					refreshParameters(eaCBox.getSelectionModel().getSelectedItem().getLocalParameters().entrySet().iterator(), eaParameters);
				}
			}
		});
		
		eaPane.getChildren().addAll(header, eaCBox, eaParameters);	
		mainContainer.getChildren().add(eaPane);
	}

	private void initialiseMutatorParameters(final JCGP cgp) {
		mutatorPane = new VBox(2);
		
		Text header = new Text("Mutator");
		header.setFontSmoothingType(FontSmoothingType.LCD);
		header.setFont(Font.font("Arial", 14));
		header.setUnderline(true);
		
		final ComboBox<Mutator> mutatorCBox = new ComboBox<Mutator>();
		mutatorCBox.getItems().addAll(cgp.getMutators());
		mutatorCBox.getSelectionModel().select(cgp.getMutator());
		mutatorCBox.prefWidthProperty().bind(mainContainer.widthProperty());
		
		final VBox mutatorParameters = new VBox();
		mutatorParameters.setSpacing(2);
		if (cgp.getEvolutionaryAlgorithm().getLocalParameters() != null) {
			refreshParameters(cgp.getMutator().getLocalParameters().entrySet().iterator(), mutatorParameters);
		}
		
		mutatorCBox.setOnAction(new EventHandler<ActionEvent>() {
			@Override
			public void handle(ActionEvent event) {
				cgp.setEvolutionaryAlgorithm(mutatorCBox.getSelectionModel().getSelectedIndex());
				if (mutatorCBox.getSelectionModel().getSelectedItem().getLocalParameters() != null) {
					refreshParameters(mutatorCBox.getSelectionModel().getSelectedItem().getLocalParameters().entrySet().iterator(), mutatorParameters);
				}			
			}
		});
		
		mutatorPane.getChildren().addAll(header, mutatorCBox, mutatorParameters);
		mainContainer.getChildren().add(mutatorPane); 
	}
	
	private void initialiseFitnessFunctionParameters(final JCGP cgp) {
		ffPane= new VBox(2);
		
		Text header = new Text("Fitness Function");
		header.setFont(Font.font("Arial", 14));
		header.setUnderline(true);
		
		final ComboBox<FitnessFunction> ffCBox = new ComboBox<FitnessFunction>();
		ffCBox.getItems().addAll(cgp.getFitnessFunctions());
		ffCBox.getSelectionModel().select(cgp.getFitnessFunction());
		ffCBox.prefWidthProperty().bind(mainContainer.widthProperty());
		
		final VBox ffParameters = new VBox();
		ffParameters.setSpacing(2);
		if (cgp.getFitnessFunction().getLocalParameters() != null) {
			refreshParameters(cgp.getFitnessFunction().getLocalParameters().entrySet().iterator(), ffParameters);
		}
		
		ffCBox.setOnAction(new EventHandler<ActionEvent>() {
			@Override
			public void handle(ActionEvent event) {
				cgp.setEvolutionaryAlgorithm(ffCBox.getSelectionModel().getSelectedIndex());
				if (ffCBox.getSelectionModel().getSelectedItem().getLocalParameters() != null) {
					refreshParameters(ffCBox.getSelectionModel().getSelectedItem().getLocalParameters().entrySet().iterator(), ffParameters);
				}		
			}
		});
		
		ffPane.getChildren().addAll(header, ffCBox, ffParameters); 
		mainContainer.getChildren().add(ffPane); 
		
	}
	
	private void initialiseNodeFunctionParameters(JCGP cgp) {
		nfPane = new VBox(2);
		
		Text header = new Text("Node Functions");
		header.setFont(Font.font("Arial", 14));
		header.setUnderline(true);

		final ComboBox<FunctionSet> nfCBox = new ComboBox<FunctionSet>();
		nfCBox.getItems().addAll(cgp.getResources().getFunctionSets());
		nfCBox.getSelectionModel().select(cgp.getResources().getFunctionSet());
		nfCBox.prefWidthProperty().bind(mainContainer.widthProperty());

		final VBox nfParameters = new VBox();
		nfParameters.setSpacing(2);
		refreshFunctions(cgp.getResources().getFunctionSet(), nfParameters);
		
		nfCBox.setOnAction(new EventHandler<ActionEvent>() {
			@Override
			public void handle(ActionEvent event) {
				refreshFunctions(nfCBox.getSelectionModel().getSelectedItem(), nfParameters);
			}
		});
		
		nfPane.getChildren().addAll(header, nfCBox, nfParameters);
		mainContainer.getChildren().add(nfPane); 
	}
	
	private void createControls(final JCGP cgp, final GUI gui) {
		final VBox controls = new VBox(2);
		controls.setFillWidth(true);
		
		final HBox flowButtons = new HBox(2);
		final Button play = new Button("Run");
		
		play.setOnAction(new EventHandler<ActionEvent>() {
			@Override
			public void handle(ActionEvent event) {				
				if (play.getText() == "Run") {
					if (applyChanges()) {
						gui.resetCGP();
					}
					play.setText("Pause");
				} else {
					play.setText("Run");
				}
				gui.playPause();
			}
		});
		
		Button step = new Button("Step");
		
		step.setOnAction(new EventHandler<ActionEvent>() {
			@Override
			public void handle(ActionEvent event) {
				if (applyChanges()) {
					gui.resetCGP();
				}
				gui.step();
			}
		});
		
		flowButtons.getChildren().addAll(play, step);
		
		HBox.setHgrow(play, Priority.ALWAYS);
		play.setMaxWidth(Double.MAX_VALUE);
		
		HBox.setHgrow(step, Priority.ALWAYS);
		step.setMaxWidth(Double.MAX_VALUE);
		
		controls.getChildren().add(flowButtons);
		
		mainContainer.getChildren().add(controls);	
	}
	
	/**
	 * @param cgp
	 * @param vb
	 */
	private void refreshParameters(Iterator<Entry<String, Parameter>> it, VBox vb) {
		parameters.removeAll(vb.getChildren());
		vb.getChildren().clear();
	    while (it.hasNext()) {
	        Parameter parameter = ((Map.Entry<String, Parameter>) it.next()).getValue();
	        GUIParameter gp = GUIParameter.create(parameter);
	        
	        parameters.add(gp);
        	vb.getChildren().add(gp);
	    }
	}
	
	private void refreshFunctions(final FunctionSet fs, VBox vb) {
		vb.getChildren().clear();
		CheckBox cb;
		for (int i = 0; i < fs.getTotalFunctionCount(); i++) {
			cb = new CheckBox(fs.getFunction(i).getName());
			cb.setId(String.valueOf(i));
			cb.setSelected(fs.isEnabled(fs.getFunction(i)));
			final int index = i;
			cb.setOnAction(new EventHandler<ActionEvent>() {
				@Override
				public void handle(ActionEvent event) {
					if (((CheckBox) event.getSource()).isSelected()) {
						fs.enableFunction(index);
					} else {
						fs.disableFunction(index);
					}
				}
			});
			vb.getChildren().add(cb);
		}
	}
	
	private void setResizeListeners() {
		setOnMousePressed(new EventHandler<MouseEvent>() {
			@Override
			public void handle(MouseEvent event) {
		        if(isInDraggableZone(event)) {
			        dragging = true;
		        }
			}
		});
		setOnMouseDragged(new EventHandler<MouseEvent>() {
			@Override
			public void handle(MouseEvent event) {
				if(dragging) {
					double newWidth = getWidth() - event.getX();
					if (newWidth >= getMinWidth()) {
						setPrefWidth(newWidth);
					} else {
						setPrefWidth(getMinWidth());
					}
				}
			}
		});
		setOnMouseMoved(new EventHandler<MouseEvent>() {
			@Override
			public void handle(MouseEvent event) {
				if(isInDraggableZone(event) || dragging) {
		            setCursor(Cursor.H_RESIZE);
		        }
		        else {
		            setCursor(Cursor.DEFAULT);
		        }
			}
		});
		setOnMouseReleased(new EventHandler<MouseEvent>() {
			@Override
			public void handle(MouseEvent event) {
				dragging = false;
		        setCursor(Cursor.DEFAULT);
			}
		});
	}
	
	private boolean isInDraggableZone(MouseEvent event) {
        return event.getX() < (GUI.RESIZE_MARGIN);
    }
	
	public void disableSettings(boolean value) {
		bpPane.setDisable(value);
		eaPane.setDisable(value);
		mutatorPane.setDisable(value);
		ffPane.setDisable(value);
		nfPane.setDisable(value);
	}
	
	/**
	 * Writes the GUI parameter value back to the resources parameter,
	 * if any changes were made.
	 * 
	 * @return true if the experiment needs to be reset, false otherwise.
	 */
	private boolean applyChanges() {
		boolean reset = false;
		
		for (GUIParameter parameter : parameters) {
			reset |= parameter.applyChange();
		}
		
		return reset;
	}
	
	
}