package dev.kske.chess.io;

import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;

import javax.imageio.ImageIO;

import dev.kske.chess.board.Piece;

/**
 * Project: <strong>Chess</strong><br>
 * File: <strong>TextureUtil.java</strong><br>
 * Created: <strong>01.07.2019</strong><br>
 *
 * @since Chess v0.1-alpha
 * @author Kai S. K. Engelbart
 */
public class TextureUtil {

	private static Map<String, Image> textures = new HashMap<>(),
		scaledTextures = new HashMap<>();

	static {
		loadPieceTextures();
		scaledTextures.putAll(textures);
	}

	private TextureUtil() {}

	/**
	 * Loads a piece texture fitting to a piece object.
	 *
	 * @param piece The piece from which the texture properties are taken
	 * @return The fitting texture
	 */
	public static Image getPieceTexture(Piece piece) {
		String key = piece.getClass().getSimpleName().toLowerCase() + "_"
			+ piece.getColor().toString().toLowerCase();
		return scaledTextures.get(key);
	}

	/**
	 * Scales all piece textures to fit the current tile size.
	 *
	 * @param tileSize the new width and height of the piece textures
	 */
	public static void scalePieceTextures(int tileSize) {
		scaledTextures.clear();
		textures.forEach(
			(key, img) -> scaledTextures.put(key, img.getScaledInstance(tileSize, tileSize, Image.SCALE_SMOOTH))
		);
	}

	/**
	 * Loads an image from a file in the resource folder.
	 *
	 * @param fileName The name of the image resource
	 * @return The loaded image
	 */
	private static Image loadImage(String fileName) {
		BufferedImage in = null;
		try {
			in = ImageIO.read(TextureUtil.class.getResourceAsStream(fileName));
		} catch (IOException e) {
			e.printStackTrace();
		}
		return in;
	}

	/**
	 * Load every PNG file inside the res/pieces directory.
	 * The filenames without extensions are used as keys in the map textures.
	 */
	private static void loadPieceTextures() {
		Arrays
			.asList(
				"king_white",
				"king_black",
				"queen_white",
				"queen_black",
				"rook_white",
				"rook_black",
				"knight_white",
				"knight_black",
				"bishop_white",
				"bishop_black",
				"pawn_white",
				"pawn_black"
			)
			.forEach(
				name -> textures.put(name, loadImage("/pieces/" + name + ".png"))
			);
	}
}