package de.tims.tictactoe;

import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JOptionPane;
import javax.swing.JPanel;

public class GameLogic implements ActionListener {

	private static final char EMPTY_FIELD = '-';
	private static final char PLAYER_1 = 'x';
	private static final char PLAYER_2 = 'o';
	private char[][] board;
	private final char[] occupiedFields = { PLAYER_1, PLAYER_2 };
	private char currentPlayer = PLAYER_1;
	private boolean gui = false;

	private JButton[][] fields;
	private JPanel contentPanel;

	public GameLogic(int size) {
		if (size < 3) {
			size = 3;
		}
		this.board = new char[size][size];
		this.resetBoard();
	}

	public GameLogic(char[][] board) {
		this.board = board;
	}

	public char[][] getBoard() {
		return this.board;
	}

	public int countFields() {
		return this.board[0].length * this.board.length;
	}

	public void setField(int column, int row, char player) {
		if (this.fieldIsEmpty(column, row)) {
			this.board[column][row] = player;
			if (gui) {
				this.fields[column][row].setText("" + this.getCurrentPlayer());
				this.updateGUI();
			}
		}
	}

	public boolean fieldIsEmpty(int column, int row) {
		for (char field : this.occupiedFields) {
			if (this.board[column][row] == field)
				return false;
		}
		return true;
	}

	public boolean checkForWin(char player) {
		boolean won = false;
		int countFields = 0;

		// check columns
		for (int i = 0; i < this.board.length; i++) {
			for (int j = 0; j < this.board[0].length; j++) {
				if (this.board[j][i] == player)
					countFields++;
			}
			if (countFields == this.board.length)
				return won = true;
			countFields = 0;
		}
		// check rows
		for (int i = 0; i < this.board[0].length; i++) {
			for (int j = 0; j < this.board.length; j++) {
				if (this.board[i][j] == player)
					countFields++;
			}
			if (countFields == this.board.length)
				return won = true;
			countFields = 0;
		}

		// check diagonal left
		for (int i = this.board.length - 1, j = this.board.length - 1; i >= 0; i--, j--) {
			if (this.board[i][j] == player)
				countFields++;
		}
		if (countFields == this.board.length)
			return won = true;
		countFields = 0;

		// check diagonal right
		for (int i = this.board.length - 1, j = 0; i >= 0; i--, j++) {
			if (this.board[i][j] == player)
				countFields++;
		}
		if (countFields == this.board.length)
			return won = true;

		return won;
	}

	public boolean checkEndOfGame() {
		return this.checkForWin(PLAYER_1) || this.checkForWin(PLAYER_2);
	}

	public char getCurrentPlayer() {
		return this.currentPlayer;
	}

	public void switchPlayer() {
		this.currentPlayer = this.currentPlayer == PLAYER_1 ? PLAYER_2 : PLAYER_1;
	}

	public void resetBoard() {
		for (int i = 0; i < this.board.length; i++) {
			for (int j = 0; j < this.board.length; j++) {
				this.board[i][j] = EMPTY_FIELD;
			}
		}
	}

	public JPanel generateGUI() {
		this.fields = new JButton[this.board.length][this.board.length];
		this.contentPanel = new JPanel();
		this.contentPanel.setLayout(new GridLayout(this.board.length, this.board.length));

		for (int i = 0; i < this.fields.length; i++) {
			for (int j = 0; j < this.fields.length; j++) {
				this.fields[i][j] = new JButton();
				this.fields[i][j].addActionListener(this);
				this.contentPanel.add(this.fields[i][j]);
			}
		}
		this.gui = true;
		return this.contentPanel;
	}

	public JButton getGUIField(int column, int row) {
		return this.fields[column][row];
	}

	private void updateGUI() {
		if (this.checkEndOfGame()) {
			for (int i = 0; i < this.fields.length; i++) {
				for (int j = 0; j < this.fields.length; j++) {
					this.fields[i][j].setEnabled(false);
				}
			}
			JOptionPane.showMessageDialog(contentPanel, "Spieler " + this.currentPlayer + " hat gewonnen.");
			this.resetGUI();
		}
		this.switchPlayer();
	}

	private void resetGUI() {
		for (int i = 0; i < this.fields.length; i++) {
			for (int j = 0; j < this.fields.length; j++) {
				this.resetBoard();
				this.fields[i][j].setText("");
				this.fields[i][j].setEnabled(true);
			}
		}
		this.switchPlayer();
	}

	@Override
	public void actionPerformed(ActionEvent e) {
		for (int i = 0; i < this.fields.length; i++) {
			for (int j = 0; j < this.fields[0].length; j++) {
				if (e.getSource() == this.fields[i][j]) {
					this.setField(i, j, currentPlayer);
					this.fields[i][j].getText();
				}
			}
		}
	}

}