import java.io.File;
import javafx.application.Application;
import javafx.stage.Stage;
import javafx.stage.FileChooser;
import javafx.scene.Scene;
import javafx.scene.paint.Color;
import javafx.scene.text.Font;
import javafx.scene.control.Label;
import javafx.scene.control.Button;
import javafx.scene.control.Alert;
import javafx.scene.layout.HBox;
import javafx.scene.layout.GridPane;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.AnchorPane;
import javafx.scene.layout.Pane;
import javafx.scene.layout.ColumnConstraints;
import javafx.scene.layout.RowConstraints;
import javafx.scene.input.KeyEvent;
import javafx.scene.input.KeyCodeCombination;
import javafx.scene.input.KeyCombination;
import javafx.scene.input.KeyCode;
import javafx.event.EventHandler;
import javafx.event.ActionEvent;

abstract class ActionHandler implements EventHandler<ActionEvent> {}
abstract class KeyHandler implements EventHandler<KeyEvent> {}

abstract class Util {
	static Brett loadBoard(Stage stage) {
		boolean loaded = false;
		Brett board = null;
		while (!loaded) {
			File f = getFile(stage);
			if (f == null)
				return null;

			try {
				board = new Brett(f);
				loaded = true;
			} catch (Exception ex) {
				error(ex.getMessage());
			}
		}

		return board;
	}

	static void error(String msg) {
		Alert alert = new Alert(Alert.AlertType.ERROR, msg);
		alert.showAndWait();
	}

	static File getFile(Stage stage) {
		FileChooser chooser = new FileChooser();
		return chooser.showOpenDialog(stage);
	}
}

class SolutionGrid {
	GridPane grid;

	SolutionGrid(Brett board, SudokuBeholder.Losning solution) {
		grid = new GridPane();
		grid.setMinSize(200, 200);

		// Add labels to grid
		int x = 0;
		int y = 0;
		for (SudokuBeholder.Losning.Verdi val: solution) {
			Label l;
			if (val.tall == -1) {
				l = new Label(" ");
			} else {
				l = new Label(""+val.tall);
			}
			l.setFont(Font.font("Sans-Serif", 16));
			if (val.original) {
				l.setTextFill(Color.web("red"));
			}

			// Rather ugly way of getting pretty lines
			String style = "-fx-border-style: solid;";
			style += "-fx-border-width: 3px;";
			String bColor =  "-fx-border-color: ";
			bColor += "COLY ";
			bColor += (x == board.storrelse - 1 ? "COL " : "transparent ");
			bColor += (y == board.storrelse - 1 ? "COL " : "transparent ");
			bColor += "COLX ";
			if (x % board.antallBokserX == 0 && x != 0) {
				bColor = bColor.replace("COLX", "red");
			} else {
				bColor = bColor.replace("COLX", "grey");
			}
			if (y % board.antallBokserY == 0 && y != 0) {
				bColor = bColor.replace("COLY", "red");
			} else {
				bColor = bColor.replace("COLY", "grey");
			}
			bColor = bColor.replace("COL", "grey");
			style += bColor + ";";

			BorderPane bp = new BorderPane();
			bp.setStyle(style);
			bp.setCenter(l);
			grid.getChildren().add(bp);
			grid.setConstraints(bp, x, y);

			x += 1;
			if (x >= board.storrelse) {
				x = 0;
				y += 1;
			}
		}

		// Set constraints
		double percent = (1.0 / board.storrelse) * 100;
		for (int i = 0; i < board.storrelse; ++i) {
			ColumnConstraints cc = new ColumnConstraints();
			RowConstraints rc = new RowConstraints();

			cc.setPercentWidth(percent);
			rc.setPercentHeight(percent);

			grid.getColumnConstraints().add(cc);
			grid.getRowConstraints().add(rc);
		}
	}

	public Pane getPane() {
		return grid;
	}
}

class SolvedView {
	int index;
	Stage stage;
	Brett board;
	BorderPane root;
	SudokuBeholder sb;

	Label lblNumSolutions;
	Button btnPrev;
	Button btnNext;

	private void drawGrid() {
		Pane grid = new SolutionGrid(board, sb.hent(index)).getPane();
		root.setCenter(grid);
		lblNumSolutions.setText(
			"Solution "+(index+1)+"/"+sb.hentAntallLosninger()
		);
	}

	SolvedView(Stage stage, Brett board, SudokuBeholder sb) {
		index = 0;
		this.stage = stage;
		this.board = board;
		root = new BorderPane();
		this.sb = sb;

		// Menu
		HBox menu = new HBox(12);
		lblNumSolutions = new Label("");
		lblNumSolutions.setPrefHeight(30);
		menu.getChildren().add(lblNumSolutions);

		// Button prev
		btnPrev = new Button("Prev");
		btnPrev.setPrefHeight(30);
		if (sb.hentAntallLosninger() > 1) {
			menu.getChildren().add(btnPrev);
		}
		btnPrev.setOnAction(new ActionHandler() {
			public void handle(ActionEvent evt) {
				if (index < 1)
					return;

				index -= 1;
				drawGrid();
			}
		});

		// Button next
		btnNext = new Button("Next");
		btnNext.setPrefHeight(30);
		if (sb.hentAntallLosninger() > 1) {
			menu.getChildren().add(btnNext);
		}
		btnNext.setOnAction(new ActionHandler() {
			public void handle(ActionEvent evt) {
				if (index >= sb.hentAntallLosninger() - 1)
					return;

				index += 1;
				drawGrid();
			}
		});

		root.setTop(menu);

		drawGrid();
	}

	public void show() {
		stage.getScene().setRoot(root);
		stage.show();
	}
}

class UnsolvedView {
	Stage stage;
	BorderPane root;

	UnsolvedView(Stage stage, Brett board) {
		this.stage = stage;
		root = new BorderPane();

		// Menu
		HBox menu = new HBox(12);

		Button btnSolve = new Button("Solve");
		btnSolve.setPrefHeight(30);
		btnSolve.setOnAction(new ActionHandler() {
			@Override
			public void handle(ActionEvent ae) {
				SudokuBeholder sb = board.los();
				new SolvedView(stage, board, sb).show();
			}
		});
		menu.getChildren().add(btnSolve);

		root.setTop(menu);

		// Grid
		Pane grid = new SolutionGrid(board, board.tilLosning()).getPane();
		root.setCenter(grid);
	}

	public void show() {
		stage.getScene().setRoot(root);
		stage.show();
	}
}

public class Gui extends Application {
	@Override
	public void start(Stage stage) {
		Brett board = Util.loadBoard(stage);
		if (board == null) {
			System.exit(1);
			return;
		}

		stage.setTitle("Sudoku");

		SudokuBeholder.Losning unsolved = board.tilLosning();

		Scene scene = new Scene(new BorderPane(), 500, 500);
		stage.setScene(scene);

		KeyCodeCombination openFileComb = new KeyCodeCombination(
			KeyCode.O,
			KeyCombination.CONTROL_DOWN
		);

		scene.addEventHandler(KeyEvent.KEY_RELEASED, new KeyHandler() {
			@Override
			public void handle(KeyEvent evt) {
				if (openFileComb.match(evt)) {
					Brett board = Util.loadBoard(stage);
					if (board != null)
						new UnsolvedView(stage, board).show();
				}
			}
		});

		new UnsolvedView(stage, board).show();
	}

	public static void main(String[] args) {
		launch();
	}

	public Gui() {
		super();
	}
}