#region Copyright & License Information
/*
 * Copyright 2007-2017 The OpenRA Developers (see AUTHORS)
 * This file is part of OpenRA, which is free software. It is made
 * available to you 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. For more
 * information, see COPYING.
 */
#endregion

using System;
using System.Collections.Generic;
using OpenRA.Effects;
using OpenRA.Graphics;
using OpenRA.Scripting;

namespace OpenRA.Mods.Common.Effects
{
	public class Beacon : IEffect, IScriptBindable, IEffectAboveShroud
	{
		static readonly int MaxArrowHeight = 512;

		readonly Player owner;
		readonly WPos position;
		readonly string beaconPalette;
		readonly bool isPlayerPalette;
		readonly string posterPalette;
		readonly Animation arrow;
		readonly Animation circles;
		readonly Animation poster;
		readonly Animation clock;
		readonly int duration;

		int delay;
		int arrowHeight = MaxArrowHeight;
		int arrowSpeed = 50;
		int tick;

		// Player-placed beacons are removed after a delay
		public Beacon(Player owner, WPos position, int duration, string beaconPalette, bool isPlayerPalette,
			string beaconCollection, string arrowSprite, string circleSprite, int delay = 0)
		{
			this.owner = owner;
			this.position = position;
			this.beaconPalette = beaconPalette;
			this.isPlayerPalette = isPlayerPalette;
			this.duration = duration;
			this.delay = delay;

			if (!string.IsNullOrEmpty(arrowSprite))
			{
				arrow = new Animation(owner.World, beaconCollection);
				arrow.Play(arrowSprite);
			}

			if (!string.IsNullOrEmpty(circleSprite))
			{
				circles = new Animation(owner.World, beaconCollection);
				circles.Play(circleSprite);
			}
		}

		// By default, support power beacons are expected to clean themselves up
		public Beacon(Player owner, WPos position, bool isPlayerPalette, string palette, string posterCollection, string posterType, string posterPalette,
			string arrowSequence, string circleSequence, string clockSequence, Func<float> clockFraction, int delay = 0, int duration = -1)
				: this(owner, position, duration, palette, isPlayerPalette, posterCollection, arrowSequence, circleSequence, delay)
		{
			this.posterPalette = posterPalette;

			if (posterType != null)
			{
				poster = new Animation(owner.World, posterCollection);
				poster.Play(posterType);

				if (clockFraction != null)
				{
					clock = new Animation(owner.World, posterCollection);
					clock.PlayFetchIndex(clockSequence, () => Exts.Clamp((int)(clockFraction() * (clock.CurrentSequence.Length - 1)), 0, clock.CurrentSequence.Length - 1));
				}
			}
		}

		void IEffect.Tick(World world)
		{
			if (delay-- > 0)
				return;

			arrowHeight += arrowSpeed;
			var clamped = arrowHeight.Clamp(0, MaxArrowHeight);
			if (arrowHeight != clamped)
			{
				arrowHeight = clamped;
				arrowSpeed *= -1;
			}

			if (arrow != null)
				arrow.Tick();

			if (circles != null)
				circles.Tick();

			if (clock != null)
				clock.Tick();

			if (duration > 0 && duration <= tick++)
				owner.World.AddFrameEndTask(w => w.Remove(this));
		}

		IEnumerable<IRenderable> IEffect.Render(WorldRenderer r) { return SpriteRenderable.None; }

		IEnumerable<IRenderable> IEffectAboveShroud.RenderAboveShroud(WorldRenderer r)
		{
			if (delay > 0)
				yield break;

			if (!owner.IsAlliedWith(owner.World.RenderPlayer))
				yield break;

			var palette = r.Palette(isPlayerPalette ? beaconPalette + owner.InternalName : beaconPalette);

			if (circles != null)
				foreach (var a in circles.Render(position, palette))
					yield return a;

			if (arrow != null)
				foreach (var a in arrow.Render(position + new WVec(0, 0, arrowHeight), palette))
					yield return a;

			if (poster != null)
			{
				foreach (var a in poster.Render(position, r.Palette(posterPalette)))
					yield return a;

				if (clock != null)
					foreach (var a in clock.Render(position, r.Palette(posterPalette)))
						yield return a;
			}
		}
	}
}