using System;
using Sandbox;

[Perk( Rarity.Epic, locked: true, minUnlocksReq: 1, alwaysOfferDebug: false, IncludedCategories = new[] { PerkCategory.Aoe, PerkCategory.Explosion })]
public class PerkEnemyExplode : Perk
{
	private enum Mod { NumKillsReq, HpPercent };

	private int _killCounter;

	private const float EXPLOSION_RADIUS = 80f;


	static PerkEnemyExplode()
	{
		Register<PerkEnemyExplode>(
			name: "Combustion",
			imagePath: "textures/icons/vector/enemy_explode.png",
			description: level => $"Every {(int)GetValue( level, Mod.NumKillsReq )}th enemy you kill explodes for {(int)GetValue( level, Mod.HpPercent, true )}% of their max hp as dmg",
			upgradeDescription: level => $"Every [+]{(int)GetValue( level - 1, Mod.NumKillsReq )}th→{(int)GetValue( level, Mod.NumKillsReq )}th[/+] enemy you kill explodes for {(int)GetValue( level - 1, Mod.HpPercent, true )}%→{(int)GetValue( level, Mod.HpPercent, true )}% of their max hp as dmg"
		);
	}

	public override void Start()
	{
		base.Start();

		DisplayCooldownColor = new Color( 1f, 0.2f, 0f, 3f );

		HighlightColor = new Color( 1f, 0.75f, 0.75f );
		HighlightDuration = 0.25f;
		HighlightOpacity = 3f;
	}

	public override void Refresh()
	{
		base.Refresh();

		int numReq = (int)GetValue( Level, Mod.NumKillsReq );
		DisplayText = Player.CombustionActive ? $"✔️" : $"{Math.Max( numReq - _killCounter, 1 ) }";
		DisplayCooldown = Player.CombustionActive ? 1f : Utils.Map( Math.Min( _killCounter, numReq - 1 ), 0, numReq, 0f, 1f );
	}

	public override void Update( float dt )
	{
		base.Update( dt );

		if ( !Player.CombustionActive )
		{
			int numReq = (int)GetValue( Level, Mod.NumKillsReq );
			DisplayText = $"{numReq - _killCounter}";
			DisplayCooldown = Utils.Map( _killCounter, 0, numReq, 0f, 1f );
			DisplayCooldownColor = new Color( 1f, 0.2f, 0f, 3f );
			ShouldUpdate = false;
		}
		else
		{
			DisplayCooldownColor = new Color( 1f, 0.2f, 0.0f, Utils.Map( Utils.FastSin( RealTime.Now * 32f ), -1f, 1f, 0.2f, 2f ) );
		}
	}

	private static float GetValue( int level, Mod mod, bool isPercent = false )
	{
		switch ( mod )
		{
			case Mod.NumKillsReq:
			default:
				return 11 - level;
			case Mod.HpPercent:
				return isPercent
					? 10f + 25f * level
					: 0.10f + 0.25f * level;
		}
	}

	public override void OnKill( Enemy enemy, DamageType damageType, bool countsAsKill )
	{
		base.OnKill( enemy, damageType, countsAsKill );
		if ( !countsAsKill ) return;

		//if ( damageType == DamageType.Explosion )
		//	return;

		_killCounter++;
		int numReq = (int)GetValue( Level, Mod.NumKillsReq );
		if ( _killCounter >= numReq )
		{
			float radius = EXPLOSION_RADIUS * Player.Stats[PlayerStat.RadiusMultiplier] * Player.Stats[PlayerStat.ExplosionSizeMultiplier];
			float damageFactor = GetValue( Level, Mod.HpPercent ) * Player.Stats[PlayerStat.ExplosionDamageMultiplier];

			Player.EnableCombustion( radius, damageFactor );
			// todo: if get +radius perk, update active combustion radius

			ShouldUpdate = true;

			_killCounter = 0;

			Highlight();
		}

		DisplayText = Player.CombustionActive ? $"✔️" : $"{numReq - _killCounter}";
		DisplayCooldown = Player.CombustionActive ? 1f : Utils.Map( _killCounter, 0, numReq, 0f, 1f );
	}

	public override void Remove( bool restart = false )
	{
		base.Remove( restart );

		if( Player.CombustionActive )
			Player.DisableCombustion();
	}
}