namespace DesertPump;

/// <summary>
/// One pump - one rung of the 108 step ladder. Pure data, built once from the curve
/// below rather than written out by hand.
/// </summary>
/// <remarks>
/// The constants come out of tools/balance.py, which simulates a playthrough. Costs
/// grow 2.88x per pump against roughly 2.43x income growth from the pump itself, and
/// the shop adds the rest on top - so each pump takes slightly longer than the last
/// and each tier lands between one and seven hours. About 55 hours of steady clicking
/// for all twelve tiers, a few hundred at a casual pace.
///
/// Change a constant, re-run the simulation, and look at the shape before shipping it.
/// Two earlier passes at this curve finished the whole game in two minutes.
/// </remarks>
public sealed class PumpModel
{
	// ---- the curve ----------------------------------------------------------
	const double CostFirst = 500.0;      // what pump #2 costs
	const double CostGrowth = 2.88;
	const float ClickFirst = 1f;
	const float ClickGrowth = 1.75f;
	const float IdleFirst = 0.5f;        // litres/sec at pump #2
	const float IdleGrowth = 1.90f;
	const float TankFirst = 30f;
	const float TankGrowth = 1.82f;
	const float PriceFirst = 1f;
	const float PriceGrowth = 1.28f;

	/// <summary>0-based position across all 108 pumps.</summary>
	public int Index { get; init; }

	/// <summary>The tier this belongs to.</summary>
	public PumpTier Tier { get; init; }

	/// <summary>1-9 within its tier.</summary>
	public int Rank { get; init; }

	public string Name { get; init; }

	/// <summary>Coins needed to unlock. The very first pump is free.</summary>
	public double Cost { get; init; }

	/// <summary>Base litres per manual pump, before the Pump Power upgrade.</summary>
	public double PerClick { get; init; }

	/// <summary>Litres per second with no input at all.</summary>
	public double PerSecond { get; init; }

	/// <summary>Base tank size, before the Water Tank upgrade.</summary>
	public double Tank { get; init; }

	/// <summary>Base coins per litre, before the Market Contacts upgrade.</summary>
	public double PricePerLitre { get; init; }

	public Color Tint => Tier.Tint;

	/// <summary>"Tier 3 - 4 of 9"</summary>
	public string Position => $"TIER {Tier.Number} - {Rank} OF {PumpTier.PumpsPerTier}";

	/// <summary>Re-read on hotload so balance edits apply without restarting the editor.</summary>
	[SkipHotload]
	public static readonly PumpModel[] All = Build();

	static PumpModel[] Build()
	{
		var total = PumpTier.TotalPumps;
		var list = new PumpModel[total];

		for ( var i = 0; i < total; i++ )
		{
			var tier = PumpTier.ForPump( i );
			var rank = i % PumpTier.PumpsPerTier;

			list[i] = new PumpModel
			{
				Index = i,
				Tier = tier,
				Rank = rank + 1,
				Name = tier.PumpNames[rank],
				Cost = i == 0 ? 0 : CostFirst * Math.Pow( CostGrowth, i - 1 ),
				PerClick = ClickFirst * Math.Pow( ClickGrowth, i ),
				PerSecond = i == 0 ? 0 : IdleFirst * Math.Pow( IdleGrowth, i - 1 ),
				Tank = TankFirst * Math.Pow( TankGrowth, i ),
				PricePerLitre = PriceFirst * Math.Pow( PriceGrowth, i )
			};
		}

		return list;
	}

	public static int MaxIndex => All.Length - 1;

	public static PumpModel Get( int index ) => All[Math.Clamp( index, 0, MaxIndex )];
}