using System;
using Sandbox;

[Perk( Rarity.Legendary, includedAtStart: false, locked: true, alwaysOfferDebug: false )]
public class PerkOnly1HpXpGain : Perk
{
	private enum Mod { XpGainMultiplier };

	private bool _isActive;

	static PerkOnly1HpXpGain()
	{
		Register<PerkOnly1HpXpGain>(
			name: "Near-Death Experience",
			imagePath: "textures/icons/vector/only_1hp_xp_gain.png",
			description: level => $"+{GetValue( level, Mod.XpGainMultiplier, true )}% xp gained while at 1 hp",
			upgradeDescription: level => $"+{GetValue( level - 1, Mod.XpGainMultiplier, true )}%→{GetValue( level, Mod.XpGainMultiplier, true )}% xp gained\nwhile at 1 hp"
		);
	}

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

		ShouldUpdate = true;
		DisplayCooldownColor = new Color( 0.1f, 0.3f, 1f, 0.25f );
	}

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

		if ( !(Player.Health > 1f) )
			Enable();
	}

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

		if( _isActive )
		{
			if ( Player.Health > 1f )
				Disable();
		}
		else
		{
			if ( !(Player.Health > 1f) )
				Enable();
		}
	}

	void Enable()
	{
		Player.Modify( this, PlayerStat.XpGainMultiplier, GetValue( Level, Mod.XpGainMultiplier ), ModifierType.Mult );
		_isActive = true;
		DisplayCooldown = 1f;
		DisplayText = $"{GetValue( Level, Mod.XpGainMultiplier, true )}%";
	}

	void Disable()
	{
		Player.StopModifying( this, PlayerStat.XpGainMultiplier );
		_isActive = false;
		DisplayCooldown = 0f;
		DisplayText = " ";
	}

	private static float GetValue( int level, Mod mod, bool isPercent = false )
	{
		switch ( mod )
		{
			case Mod.XpGainMultiplier:
			default:
				return isPercent
					? 4f + 8f * level
					: 1f + 0.04f + 0.08f * level;
		}
	}
}