import java.util.*;

import javafx.application.*;
import javafx.stage.*;
import javafx.scene.*;
import javafx.scene.control.*;
import javafx.scene.canvas.*;
import javafx.scene.shape.*;
import javafx.scene.layout.*;
import javafx.scene.paint.*;
import javafx.scene.text.*;
import javafx.event.*;
import javafx.scene.input.*;
import javafx.scene.image.*;
import javafx.geometry.*;

//Main class and GUI

public class Chess extends Application {
	private ArrayList<GameState> gameStateHistory; //Stack of GameBoard states for the move undo.
	private ArrayList<Move> moveHistory;  //Stack of tuples (moves) so they can be displayed.
	private ArrayList<String> moveNotationHistory;  //Stack of move notations.

	//User's first click for a move.
	private Integer clickRow;  //null means no first click made currently.
	private Integer clickColumn;

	private GraphicsContext graphics;
	private TextArea moveHistoryTextArea;

	//Load images
	private static final Image W_ROOK = new Image("img/w_rook_png_shadow_128px.png");
	private static final Image B_ROOK = new Image("img/b_rook_png_shadow_128px.png");
	private static final Image W_KNIGHT = new Image("img/w_knight_png_shadow_128px.png");
	private static final Image B_KNIGHT = new Image("img/b_knight_png_shadow_128px.png");
	private static final Image W_BISHOP = new Image("img/w_bishop_png_shadow_128px.png");
	private static final Image B_BISHOP = new Image("img/b_bishop_png_shadow_128px.png");
	private static final Image W_QUEEN = new Image("img/w_queen_png_shadow_128px.png");
	private static final Image B_QUEEN = new Image("img/b_queen_png_shadow_128px.png");
	private static final Image W_KING = new Image("img/w_king_png_shadow_128px.png");
	private static final Image B_KING = new Image("img/b_king_png_shadow_128px.png");
	private static final Image W_PAWN = new Image("img/w_pawn_png_shadow_128px.png");
	private static final Image B_PAWN = new Image("img/b_pawn_png_shadow_128px.png");

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

	public void start(Stage stage) {
		//Boilerplate code
		VBox root = new VBox();
		Scene scene = new Scene(root);
		stage.setTitle("Chess");
		stage.setScene(scene);

		//Set up canvas for the board
		Canvas board = new Canvas(400, 400);
		graphics = board.getGraphicsContext2D();

		//Setup move history text area
		moveHistoryTextArea = new TextArea();
		moveHistoryTextArea.setFont(Font.font("Courier New", FontWeight.BOLD, 12));
		moveHistoryTextArea.setPrefColumnCount("129. b1Rxb8R+ a1Rxa8R++".length());
		moveHistoryTextArea.setEditable(false);
		moveHistoryTextArea.setPrefHeight(400);
		moveHistoryTextArea.setMinHeight(400);
		moveHistoryTextArea.setMaxHeight(400);

		//Horizontal box for board and move history text area
		HBox hb = new HBox(20, board, moveHistoryTextArea);
		hb.setAlignment(Pos.CENTER);
		root.getChildren().add(hb);

		//Set up buttons
		Button undo = new Button("Undo");
		Button reset = new Button("Reset");
		Button aiMove = new Button("AI move");
		HBox h = new HBox(20, undo, reset, aiMove);
		h.setAlignment(Pos.CENTER);
		h.setPadding(new Insets(10,10,10,10));
		root.getChildren().add(h);

		//Set up empty move history, game history,  notation history.
		gameStateHistory = new ArrayList<GameState>();
		gameStateHistory.add(new GameState()); //Set up the initial board
		moveHistory = new ArrayList<Move>();
		moveNotationHistory = new ArrayList<String>();

		//No clicks yet
		clickRow = clickColumn = null;

		//Set up mouse/click events
		board.setOnMousePressed(this::mouseClick);
		undo.setOnMousePressed(this::undo);
		reset.setOnMousePressed(this::reset);
		aiMove.setOnMousePressed(this::moveAI);

		//Refresh the board
		paintBoard();

		//Fix mysterious broken width and prevent shrinking window
		stage.setWidth(664);
		stage.setMinWidth(stage.getWidth());
		stage.setMinHeight(stage.getHeight());

		stage.show();
	}

	private void paintBoard() {
		for(int x = 0; x < 8; x++) {
			for(int y = 0; y < 8; y++) {
				graphics.setFill((x + y) % 2 == 0 ? Color.BURLYWOOD : Color.FORESTGREEN);
				graphics.fillRect(50*x, 50*y, 50, 50);
				Square s = board().getSquare(x, y);
				if ( s.getType() ==  Square.PAWN && s.isWhite()) graphics.drawImage(W_PAWN, 50*x, 50*y, 50, 50);
				if ( s.getType() ==  Square.PAWN && !s.isWhite()) graphics.drawImage(B_PAWN, 50*x, 50*y, 50, 50);
				if ( s.getType() ==  Square.KNIGHT && s.isWhite()) graphics.drawImage(W_KNIGHT, 50*x, 50*y, 50, 50);
				if ( s.getType() ==  Square.KNIGHT && !s.isWhite()) graphics.drawImage(B_KNIGHT, 50*x, 50*y, 50, 50);
				if ( s.getType() ==  Square.BISHOP && s.isWhite()) graphics.drawImage(W_BISHOP, 50*x, 50*y, 50, 50);
				if ( s.getType() ==  Square.BISHOP && !s.isWhite()) graphics.drawImage(B_BISHOP, 50*x, 50*y, 50, 50);
				if ( s.getType() ==  Square.ROOK && s.isWhite()) graphics.drawImage(W_ROOK, 50*x, 50*y, 50, 50);
				if ( s.getType() ==  Square.ROOK && !s.isWhite()) graphics.drawImage(B_ROOK, 50*x, 50*y, 50, 50);
				if ( s.getType() ==  Square.QUEEN && s.isWhite()) graphics.drawImage(W_QUEEN, 50*x, 50*y, 50, 50);
				if ( s.getType() ==  Square.QUEEN && !s.isWhite()) graphics.drawImage(B_QUEEN, 50*x, 50*y, 50, 50);
				if ( s.getType() ==  Square.KING && s.isWhite()) graphics.drawImage(W_KING, 50*x, 50*y, 50, 50);
				if ( s.getType() ==  Square.KING && !s.isWhite()) graphics.drawImage(B_KING, 50*x, 50*y, 50, 50);
			}
		}
	}

	private GameState board() {
		return gameStateHistory.get(gameStateHistory.size()-1);
	}

	//Reset to the intial game position.
	public void reset(MouseEvent e) {
		//Set up the initial board
		//Clear out clickRo and clickCol
		//Clera out all the histories.

	}

	//AI makes a move
	public void moveAI(MouseEvent e) {
		//Ask the gameState for a list of all legal moves.
		//Get one of those in the list uniformly at random.
//		makeMove(...);
	}

	private void makeMove(Move move) {
		//Clone the gameState object for the current state of the game, tell it to make the move, add it to the move history
		//add the notation for it
		//add the move to the history as well
	}

	//For the human moving
	public void mouseClick(MouseEvent e) {
		//If it is the first click (null check) then record it, updtae the GUI to show highlighting
		//else attempt the move:

//		makeMove(...);
	}

	//Undo button for the most recent move
	public void undo(MouseEvent e) {
		//Pop those 3 history object things and update the GUI.
	}

}