/*******************************************************************************
 * Copyright 2015 See AUTHORS file.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 ******************************************************************************/

package com.badlogic.gdx.scenes.scene2d.ui;

import static com.badlogic.gdx.math.Interpolation.*;
import static com.badlogic.gdx.scenes.scene2d.actions.Actions.*;

import com.badlogic.gdx.Files;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.math.Interpolation;
import com.badlogic.gdx.scenes.scene2d.Stage;
import com.badlogic.gdx.utils.Array;
import com.badlogic.gdx.utils.Timer;
import com.badlogic.gdx.utils.Timer.Task;

/** Keeps track of an application's tooltips.
 * @author Nathan Sweet */
public class TooltipManager {
	static private TooltipManager instance;
	static private Files files;

	/** Seconds from when an actor is hovered to when the tooltip is shown. Default is 2. Call {@link #hideAll()} after changing to
	 * reset internal state. */
	public float initialTime = 2;
	/** Once a tooltip is shown, this is used instead of {@link #initialTime}. Default is 0. */
	public float subsequentTime = 0;
	/** Seconds to use {@link #subsequentTime}. Default is 1.5. */
	public float resetTime = 1.5f;
	/** If false, tooltips will not be shown. Default is true. */
	public boolean enabled = true;
	/** If false, tooltips will be shown without animations. Default is true. */
	public boolean animations = true;
	/** The maximum width of a {@link TextTooltip}. The label will wrap if needed. Default is Integer.MAX_VALUE. */
	public float maxWidth = Integer.MAX_VALUE;
	/** The distance from the mouse position to offset the tooltip actor. Default is 15,19. */
	public float offsetX = 15, offsetY = 19;
	/** The distance from the tooltip actor position to the edge of the screen where the actor will be shown on the other side of
	 * the mouse cursor. Default is 7. */
	public float edgeDistance = 7;

	final Array<Tooltip> shown = new Array();

	float time = initialTime;
	final Task resetTask = new Task() {
		public void run () {
			time = initialTime;
		}
	};

	Tooltip showTooltip;
	final Task showTask = new Task() {
		public void run () {
			if (showTooltip == null) return;

			Stage stage = showTooltip.targetActor.getStage();
			if (stage == null) return;
			stage.addActor(showTooltip.container);
			showTooltip.container.toFront();
			shown.add(showTooltip);

			showTooltip.container.clearActions();
			showAction(showTooltip);

			if (!showTooltip.instant) {
				time = subsequentTime;
				resetTask.cancel();
			}
		}
	};

	public void touchDown (Tooltip tooltip) {
		showTask.cancel();
		if (tooltip.container.remove()) resetTask.cancel();
		resetTask.run();
		if (enabled || tooltip.always) {
			showTooltip = tooltip;
			Timer.schedule(showTask, time);
		}
	}

	public void enter (Tooltip tooltip) {
		showTooltip = tooltip;
		showTask.cancel();
		if (enabled || tooltip.always) {
			if (time == 0 || tooltip.instant)
				showTask.run();
			else
				Timer.schedule(showTask, time);
		}
	}

	public void hide (Tooltip tooltip) {
		showTooltip = null;
		showTask.cancel();
		if (tooltip.container.hasParent()) {
			shown.removeValue(tooltip, true);
			hideAction(tooltip);
			resetTask.cancel();
			Timer.schedule(resetTask, resetTime);
		}
	}

	/** Called when tooltip is shown. Default implementation sets actions to animate showing. */
	protected void showAction (Tooltip tooltip) {
		float actionTime = animations ? (time > 0 ? 0.5f : 0.15f) : 0.1f;
		tooltip.container.setTransform(true);
		tooltip.container.getColor().a = 0.2f;
		tooltip.container.setScale(0.05f);
		tooltip.container.addAction(parallel(fadeIn(actionTime, fade), scaleTo(1, 1, actionTime, Interpolation.fade)));
	}

	/** Called when tooltip is hidden. Default implementation sets actions to animate hiding and to remove the actor from the stage
	 * when the actions are complete. A subclass must at least remove the actor. */
	protected void hideAction (Tooltip tooltip) {
		tooltip.container
			.addAction(sequence(parallel(alpha(0.2f, 0.2f, fade), scaleTo(0.05f, 0.05f, 0.2f, Interpolation.fade)), removeActor()));
	}

	public void hideAll () {
		resetTask.cancel();
		showTask.cancel();
		time = initialTime;
		showTooltip = null;

		for (Tooltip tooltip : shown)
			tooltip.hide();
		shown.clear();
	}

	/** Shows all tooltips on hover without a delay for {@link #resetTime} seconds. */
	public void instant () {
		time = 0;
		showTask.run();
		showTask.cancel();
	}

	static public TooltipManager getInstance () {
		if (files == null || files != Gdx.files) {
			files = Gdx.files;
			instance = new TooltipManager();
		}
		return instance;
	}
}