/*
 * opsu! - an open-source osu! client
 * Copyright (C) 2014 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.objects;

import itdelatrisu.opsu.GameScore;
import itdelatrisu.opsu.MusicController;
import itdelatrisu.opsu.OsuHitObject;
import itdelatrisu.opsu.states.Game;
import itdelatrisu.opsu.states.Options;

import org.newdawn.slick.Color;
import org.newdawn.slick.GameContainer;
import org.newdawn.slick.Graphics;
import org.newdawn.slick.Image;
import org.newdawn.slick.SlickException;

/**
 * Data type representing a spinner object.
 */
public class Spinner {
	/**
	 * Images related to spinners.
	 */
	private static Image
		spinnerCircle,          // spinner
		spinnerApproachCircle,  // spinner approach circle (for end time)
		spinnerMetre,           // spinner meter (subimage based on completion ratio)
//		spinnerOsuImage,        // spinner "OSU!" text (complete)
		spinnerSpinImage,       // spinner "SPIN!" text (start)
		spinnerClearImage;      // spinner "CLEAR" text (passed)

	/**
	 * Container dimensions.
	 */
	private static int width, height;

	/**
	 * The associated OsuHitObject.
	 */
	private OsuHitObject hitObject;

	/**
	 * The associated Game object.
	 */
	private Game game;

	/**
	 * The associated GameScore object.
	 */
	private GameScore score;

	/**
	 * The last rotation angle.
	 */
	private float lastAngle = -1f;

	/**
	 * The current number of rotations.
	 */
	private float rotations = 0f;

	/**
	 * The total number of rotations needed to clear the spinner.
	 */
	private float rotationsNeeded;

	/**
	 * Initializes the Spinner data type with images and dimensions.
	 * @param container the game container
	 * @throws SlickException 
	 */
	public static void init(GameContainer container) throws SlickException {
		width  = container.getWidth();
		height = container.getHeight();

		spinnerCircle = new Image("spinner-circle.png").getScaledCopy(height * 9 / 10, height * 9 / 10);
		spinnerApproachCircle = new Image("spinner-approachcircle.png").getScaledCopy(spinnerCircle.getWidth(), spinnerCircle.getHeight());
		spinnerMetre = new Image("spinner-metre.png").getScaledCopy(width, height);
		spinnerSpinImage = new Image("spinner-spin.png");
		spinnerClearImage = new Image("spinner-clear.png");
//		spinnerOsuImage = new Image("spinner-osu.png");
	}

	/**
	 * Constructor.
	 * @param hitObject the associated OsuHitObject
	 * @param game the associated Game object
	 * @param score the associated GameScore object
	 */
	public Spinner(OsuHitObject hitObject, Game game, GameScore score) {
		this.hitObject = hitObject;
		this.game = game;
		this.score = score;

		// calculate rotations needed
		float spinsPerMinute = 100 + (score.getDifficulty() * 15);
		rotationsNeeded = spinsPerMinute * (hitObject.endTime - hitObject.time) / 60000f;
	}

	/**
	 * Draws the spinner to the graphics context.
	 * @param trackPosition the current track position
	 * @param g the graphics context
	 */
	public void draw(int trackPosition, Graphics g) {
		int timeDiff = hitObject.time - trackPosition;
		boolean spinnerComplete = (rotations >= rotationsNeeded);

		// TODO: draw "OSU!" image after spinner ends
		//spinnerOsuImage.drawCentered(width / 2, height / 4);

		// darken screen
		g.setColor(Options.COLOR_BLACK_ALPHA);
		g.fillRect(0, 0, width, height);

		if (timeDiff > 0)
			return;

		// spinner meter (subimage)
		int spinnerMetreY = (spinnerComplete) ? 0 : (int) (spinnerMetre.getHeight() * (1 - (rotations / rotationsNeeded)));
		Image spinnerMetreSub = spinnerMetre.getSubImage(
				0, spinnerMetreY,
				spinnerMetre.getWidth(), spinnerMetre.getHeight() - spinnerMetreY
		);
		spinnerMetreSub.draw(0, height - spinnerMetreSub.getHeight());

		// main spinner elements
		spinnerCircle.drawCentered(width / 2, height / 2);
		spinnerApproachCircle.getScaledCopy(1 - ((float) timeDiff / (hitObject.time - hitObject.endTime))).drawCentered(width / 2, height / 2);
		spinnerSpinImage.drawCentered(width / 2, height * 3 / 4);

		if (spinnerComplete) {
			spinnerClearImage.drawCentered(width / 2, height / 4);
			int extraRotations = (int) (rotations - rotationsNeeded);
			if (extraRotations > 0)
				score.drawSymbolNumber(extraRotations * 1000, width / 2, height * 2 / 3, 1.0f);
		}
	}
	
	/**
	 * Calculates and sends the spinner hit result.
	 * @return the hit result (GameScore.HIT_* constants)
	 */
	public int hitResult() {
		// TODO: verify ratios

		int result;
		float ratio = rotations / rotationsNeeded;
		if (ratio >= 1.0f ||
			Options.isModActive(Options.MOD_AUTO) || Options.isModActive(Options.MOD_SPUN_OUT))
			result = GameScore.HIT_300;
		else if (ratio >= 0.8f)
			result = GameScore.HIT_100;
		else if (ratio >= 0.5f)
			result = GameScore.HIT_50;
		else
			result = GameScore.HIT_MISS;

		score.hitResult(hitObject.endTime, result, width / 2, height / 2, Color.transparent, true);
		return result;
	}

	/**
	 * Updates the spinner by a delta interval.
	 * @param overlap true if the next object's start time has already passed
	 * @param delta the delta interval since the last call
	 * @param mouseX the x coordinate of the mouse
	 * @param mouseY the y coordinate of the mouse
	 * @return true if spinner ended
	 */
	public boolean update(boolean overlap, int delta, int mouseX, int mouseY) {
		int trackPosition = MusicController.getPosition();
		if (overlap)
			return true;

		// end of spinner
		if (trackPosition > hitObject.endTime) {
			hitResult();
			return true;
		}

		// spin automatically (TODO: correct rotation angles)
		if (Options.isModActive(Options.MOD_AUTO)) {
			// "auto" mod (fast)
			score.changeHealth(delta / 200f);  // maintain health (TODO)
			rotate(delta / 20f);
			return false;
		} else if (Options.isModActive(Options.MOD_SPUN_OUT)) {
			// "spun out" mod (slow)
			score.changeHealth(delta / 200f);  // maintain health (TODO)
			rotate(delta / 32f);
			return false;
		}

		// not spinning: nothing to do
		if (!game.isInputKeyPressed()) {
			lastAngle = -1f;
			return false;
		}

		// scale angle from [-pi, +pi] to [0, +pi]
		float angle = (float) Math.atan2(mouseY - (height / 2), mouseX - (width / 2));
		if (angle < 0f)
			angle += Math.PI;

		if (lastAngle >= 0f) {  // skip initial clicks
			float angleDiff = Math.abs(lastAngle - angle);
			if (angleDiff < Math.PI / 2) {  // skip huge angle changes...
				score.changeHealth(delta / 200f);  // maintain health (TODO)
				rotate(angleDiff);
			}
		}

		lastAngle = angle;
		return false;
	}

	/**
	 * Rotates the spinner by a number of degrees.
	 * @param degrees the angle to rotate (in radians)
	 */
	private void rotate(float degrees) {
		float newRotations = rotations + (degrees / (float) (2 * Math.PI));

		// added one whole rotation...
		if (Math.floor(newRotations) > rotations) {
			if (newRotations > rotationsNeeded)  // extra rotations
				score.changeScore(1000);
			else
				score.changeScore(100);
		}

		rotations = newRotations;
	}
}