namespace DesertPump;

public sealed partial class DesertPumpGame
{
	// The two things that make one click different from the next: pressure, which
	// rewards keeping a rhythm going, and surges, which occasionally pay out several
	// clicks at once.
	//
	// Nothing sits above the class declaration on purpose. s&box turns a comment there
	// into a [Description] attribute, and this type already gets one from the comment
	// over in DesertPumpGame.cs - two of them is warning SB2000.

	// ---- tuning -------------------------------------------------------------
	//
	// Both of these are flat multipliers on manual pumping only. They shift the curve,
	// they don't bend it - nothing here compounds with anything else, which is what
	// separates it from the upgrade tracks that ran the economy away three times over.
	//
	// Measured, not guessed: tools/balance.py mirrors these constants in click_bonus()
	// and reports the cost. As shipped a player clicking flat out finishes in about 37
	// hours against 48 before, and a casual one in 142 against 157. Set PressureMaxBonus
	// to 0 and SurgeMultiplier to 1 to get the old curve back exactly.

	/// <summary>Manual pumps needed to go from cold to full pressure with no decay.</summary>
	public const float PressureClicksToFull = 8f;

	/// <summary>Seconds from full pressure back to nothing once you stop clicking.</summary>
	public const float PressureDecaySeconds = 3.5f;

	/// <summary>Extra litres per click at full pressure, as a fraction of the base.</summary>
	public const float PressureMaxBonus = 0.2f;

	/// <summary>
	/// Chance a manual pump comes up a surge instead. Deliberately rare and large rather
	/// than frequent and small - the same average payout either way, but one reads as an
	/// event worth looking up for and the other reads as the numbers being noisy. At four
	/// clicks a second this is one surge every twelve seconds or so.
	/// </summary>
	public const float SurgeChance = 0.02f;

	/// <summary>What a surge multiplies that one click by.</summary>
	public const float SurgeMultiplier = 7f;

	// ---- state --------------------------------------------------------------

	/// <summary>
	/// 0-1. Rises with every manual pump and bleeds away when you stop, so it reads as
	/// a rhythm you're holding rather than a resource you're spending.
	/// </summary>
	public float Pressure { get; private set; }

	/// <summary>What manual pumping is multiplied by right now.</summary>
	public float PressureBonus => 1f + Pressure * PressureMaxBonus;

	/// <summary>True while pressure is pinned at the top.</summary>
	public bool PressureHot => Pressure >= 0.995f;

	/// <summary>
	/// 0-3. The HUD colours the gauge off this rather than off the raw float, so the
	/// bands stay put if the tuning above moves.
	/// </summary>
	public int PressureStage => Pressure switch
	{
		>= 0.995f => 3,
		>= 0.66f => 2,
		>= 0.33f => 1,
		_ => 0
	};

	/// <summary>"+25%" - what pressure is currently adding.</summary>
	public string PressureBonusText => $"+{(PressureBonus - 1f) * 100f:0}%";

	/// <summary>
	/// Fired instead of <see cref="Pumped"/> when a click comes up a surge, with the
	/// litres it was worth. The two are mutually exclusive - exactly one fires per pump.
	/// </summary>
	public Action<double> Surged { get; set; }

	/// <summary>Surges in this run. Never saved - it's a session curiosity, not progress.</summary>
	public int SurgeCount { get; private set; }

	/// <summary>Bleed pressure off. Called every frame from the main update.</summary>
	void TickPressure()
	{
		if ( Pressure <= 0f )
			return;

		Pressure = Math.Max( 0f, Pressure - Time.Delta / PressureDecaySeconds );
	}

	/// <summary>One manual pump's worth of pressure.</summary>
	void BumpPressure()
	{
		Pressure = Math.Min( 1f, Pressure + 1f / PressureClicksToFull );
	}

	/// <summary>Does this click come up a surge?</summary>
	bool RollSurge() => System.Random.Shared.NextSingle() < SurgeChance;

	/// <summary>
	/// Force the gauge somewhere, for testing the HUD without clicking eight times.
	/// Not reachable from the game itself.
	/// </summary>
	public void SetPressure( float value )
	{
		Pressure = Math.Clamp( value, 0f, 1f );
	}
}