package gameEngine.views;

import org.lwjgl.BufferUtils;

import javax.swing.*;
import java.awt.*;
import java.awt.Color;
import java.awt.geom.AffineTransform;
import java.awt.image.AffineTransformOp;
import java.awt.image.BufferedImage;
import java.nio.ByteBuffer;
import java.util.HashMap;
import java.util.Map;

public class Font {

    /**
     * Contains the glyphs for each char.
     */
    private final Map<Character, Glyph> glyphs;

    private Texture texture;

    private int fontHeight;

    public Map<Character, Glyph> getGlyphs(){
        return glyphs;
    }
    public Texture getTexture() {
        return texture;
    }
    public int getFontHeight(){
        return fontHeight;
    }


    /**
     * Creates a font from an AWT Font.
     *
     * @param font      The AWT Font
     * @param antiAlias Wheter the font should be antialiased or not
     */
    public Font(java.awt.Font font, boolean antiAlias) {
        glyphs = new HashMap<>();
        createFontTexture(font, antiAlias);
    }

    private void createFontTexture(java.awt.Font font, boolean antiAlias) {
        texture = new Texture();
        /* Loop through the characters to get charWidth and charHeight */
        int imageWidth = 0;
        int imageHeight = 0;

        /* Start at char #32, because ASCII 0 to 31 are just control codes */
        for (int i = 32; i < 256; i++) {
            if (i == 127) {
                /* ASCII 127 is the DEL control code, so we can skip it */
                continue;
            }
            char c = (char) i;
            BufferedImage ch = createCharImage(font, c, antiAlias);
            if (ch == null) {
                /* If char image is null that font does not contain the char */
                continue;
            }

            imageWidth += ch.getWidth();
            imageHeight = Math.max(imageHeight, ch.getHeight());
        }

        fontHeight = imageHeight;

        /* Image for the texture */
        BufferedImage image = new BufferedImage(imageWidth, imageHeight, BufferedImage.TYPE_INT_ARGB);
        Graphics2D g = image.createGraphics();

        int x = 0;

        /* Create image for the standard chars, again we omit ASCII 0 to 31
         * because they are just control codes */
        for (int i = 32; i < 256; i++) {
            if (i == 127) {
                /* ASCII 127 is the DEL control code, so we can skip it */
                continue;
            }
            char c = (char) i;
            BufferedImage charImage = createCharImage(font, c, antiAlias);
            if (charImage == null) {
                /* If char image is null that font does not contain the char */
                continue;
            }

            int charWidth = charImage.getWidth();
            int charHeight = charImage.getHeight();

            /* Create glyph and draw char on image */
            Glyph ch = new Glyph(charWidth, charHeight, x, image.getHeight() - charHeight, 0f);
            g.drawImage(charImage, x, 0, null);
            x += ch.width;
            glyphs.put(c, ch);
        }

        /* Flip image Horizontal to get the origin to bottom left */
        /*AffineTransform transform = AffineTransform.getScaleInstance(1f, -1f);
        transform.translate(0, -image.getHeight());
        AffineTransformOp operation = new AffineTransformOp(transform,
                AffineTransformOp.TYPE_NEAREST_NEIGHBOR);
        image = operation.filter(image, null);*/

        /* Get charWidth and charHeight of image */
        int width = image.getWidth();
        int height = image.getHeight();

        /* Get pixel data of image */
        int[] pixelsRaw = new int[width * height];
        image.getRGB(0, 0, width, height, pixelsRaw, 0, width);

        /* Put pixel data into a ByteBuffer */
        ByteBuffer pixels = BufferUtils.createByteBuffer(width * height * 4);
        for (int i = 0; i < height; i++) {
            for (int j = 0; j < width; j++) {
                /* Pixel as RGBA: 0xAARRGGBB */
                int pixel = pixelsRaw[i * width + j];
                /* Red component 0xAARRGGBB >> 16 = 0x0000AARR */
                pixels.put((byte) ((pixel >> 16) & 0xFF));
                /* Green component 0xAARRGGBB >> 8 = 0x00AARRGG */
                pixels.put((byte) ((pixel >> 8) & 0xFF));
                /* Blue component 0xAARRGGBB >> 0 = 0xAARRGGBB */
                pixels.put((byte) (pixel & 0xFF));
                /* Alpha component 0xAARRGGBB >> 24 = 0x000000AA */
                pixels.put((byte) ((pixel >> 24) & 0xFF));
            }
        }
        /* Do not forget to flip the buffer! */
        pixels.flip();

        texture.setTextureData(width, height, pixels);
        texture.init();
    }

    /**
     * Creates a char image from specified AWT font and char.
     *
     * @param font      The AWT font
     * @param c         The char
     * @param antiAlias Wheter the char should be antialiased or not
     * @return Char image
     */
    private BufferedImage createCharImage(java.awt.Font font, char c, boolean antiAlias) {
        /* Creating temporary image to extract character size */
        BufferedImage image = new BufferedImage(1, 1, BufferedImage.TYPE_INT_ARGB);
        Graphics2D g = image.createGraphics();
        if (antiAlias) {
            g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        }
        g.setFont(font);
        FontMetrics metrics = g.getFontMetrics();
        g.dispose();

        /* Get char charWidth and charHeight */
        int charWidth = metrics.charWidth(c);
        int charHeight = metrics.getHeight();

        /* Check if charWidth is 0 */
        if (charWidth == 0) {
            return null;
        }

        /* Create image for holding the char */
        image = new BufferedImage(charWidth, charHeight, BufferedImage.TYPE_INT_ARGB);
        g = image.createGraphics();
        if (antiAlias) {
            g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        }
        g.setFont(font);

        g.setPaint(Color.RED); //色指定部分
        g.drawString(String.valueOf(c), 0, metrics.getAscent());
        g.dispose();
        return image;
    }

    public void delete() {
        texture.delete();
    }

}