/*
 * opsu! - an open-source osu! client
 * Copyright (C) 2014, 2015 Jeffrey Han
 *
 * opsu! is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * opsu! is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with opsu!.  If not, see <http://www.gnu.org/licenses/>.
 */

package itdelatrisu.opsu.ui;

import itdelatrisu.opsu.GameImage;
import itdelatrisu.opsu.Options;

import java.awt.Font;
import java.awt.FontFormatException;
import java.io.IOException;
import java.util.HashMap;
import java.util.HashSet;

import org.newdawn.slick.SlickException;
import org.newdawn.slick.UnicodeFont;
import org.newdawn.slick.font.effects.ColorEffect;
import org.newdawn.slick.font.effects.Effect;
import org.newdawn.slick.util.Log;
import org.newdawn.slick.util.ResourceLoader;

/**
 * Fonts used for drawing.
 */
public class Fonts {
	public static UnicodeFont DEFAULT, BOLD, XLARGE, LARGE, MEDIUM, SMALL;

	/** Set of all Unicode strings already loaded per font. */
	private static HashMap<UnicodeFont, HashSet<String>> loadedGlyphs = new HashMap<UnicodeFont, HashSet<String>>();

	// This class should not be instantiated.
	private Fonts() {}

	/**
	 * Initializes all fonts.
	 * @throws SlickException if ASCII glyphs could not be loaded
	 * @throws FontFormatException if any font stream data does not contain the required font tables
	 * @throws IOException if a font stream cannot be completely read
	 */
	public static void init() throws SlickException, FontFormatException, IOException {
		float fontBase = 12f * GameImage.getUIscale();
		Font javaFont = Font.createFont(Font.TRUETYPE_FONT, ResourceLoader.getResourceAsStream(Options.FONT_NAME));
		Font font = javaFont.deriveFont(Font.PLAIN, (int) (fontBase * 4 / 3));
		DEFAULT = new UnicodeFont(font);
		BOLD    = new UnicodeFont(font.deriveFont(Font.BOLD));
		XLARGE  = new UnicodeFont(font.deriveFont(fontBase * 3));
		LARGE   = new UnicodeFont(font.deriveFont(fontBase * 2));
		MEDIUM  = new UnicodeFont(font.deriveFont(fontBase * 3 / 2));
		SMALL   = new UnicodeFont(font.deriveFont(fontBase));
		ColorEffect colorEffect = new ColorEffect();
		loadFont(DEFAULT, colorEffect);
		loadFont(BOLD, colorEffect);
		loadFont(XLARGE, colorEffect);
		loadFont(LARGE, colorEffect);
		loadFont(MEDIUM, colorEffect);
		loadFont(SMALL, colorEffect);
	}

	/**
	 * Loads a Unicode font and its ASCII glyphs.
	 * @param font the font to load
	 * @param effect the font effect
	 * @throws SlickException if the glyphs could not be loaded
	 */
	@SuppressWarnings("unchecked")
	private static void loadFont(UnicodeFont font, Effect effect) throws SlickException {
		font.addAsciiGlyphs();
		font.getEffects().add(effect);
		font.loadGlyphs();
	}

	/**
	 * Adds and loads glyphs for a font.
	 * @param font the font to add the glyphs to
	 * @param s the string containing the glyphs to load
	 */
	public static void loadGlyphs(UnicodeFont font, String s) {
		if (s == null || s.isEmpty())
			return;

		// get set of added strings
		HashSet<String> set = loadedGlyphs.get(font);
		if (set == null) {
			set = new HashSet<String>();
			loadedGlyphs.put(font, set);
		} else if (set.contains(s))
			return;  // string already in set

		// load glyphs
		font.addGlyphs(s);
		set.add(s);
		try {
			font.loadGlyphs();
		} catch (SlickException e) {
			Log.warn(String.format("Failed to load glyphs for string '%s'.", s), e);
		}
	}
}