using PowderCoating.Core.Entities;
using PowderCoating.Core.Enums;

namespace PowderCoating.Application.Services;

/// <summary>
/// Derives sqft/hr throughput rates from a shop's equipment configuration.
/// Used by the AI photo quote prompt (so Claude reasons from real shop speeds)
/// and the Company Settings live preview (so the UI always shows the same rate
/// the AI will use — single formula path, no client-side duplication).
///
/// Both pressure pots and siphon cabinets are nozzle-primary: nozzle size
/// determines throughput and CFM draw. CFM is not used in the rate formula.
///
/// Sources:
///   Pressure pot rates — averaged from two industry standard abrasive blast
///   cleaning reference tables.
///   Siphon cabinet rates — industry reference table for siphon-fed cabinets.
///   Substrate multipliers — relative removal difficulty vs. paint baseline.
/// </summary>
public static class ShopCapabilityCalculator
{
    // ── Public entry points ────────────────────────────────────────────────────

    /// <summary>
    /// Returns the effective blast rate in sqft/hr for company-level operating costs.
    /// BlastRateSqFtPerHourOverride bypasses the formula when set.
    /// </summary>
    public static decimal GetBlastRateSqFtPerHour(CompanyOperatingCosts costs)
    {
        if (costs.BlastRateSqFtPerHourOverride.HasValue && costs.BlastRateSqFtPerHourOverride.Value > 0)
            return costs.BlastRateSqFtPerHourOverride.Value;

        return CalculateBlastRate(costs.BlastNozzleSize, costs.BlastSetupType, costs.PrimaryBlastSubstrate);
    }

    /// <summary>
    /// Returns the effective blast rate in sqft/hr for a named blast setup.
    /// BlastRateSqFtPerHourOverride bypasses the formula when set.
    /// </summary>
    public static decimal GetBlastRateSqFtPerHour(CompanyBlastSetup setup)
    {
        if (setup.BlastRateSqFtPerHourOverride.HasValue && setup.BlastRateSqFtPerHourOverride.Value > 0)
            return setup.BlastRateSqFtPerHourOverride.Value;

        return CalculateBlastRate(setup.BlastNozzleSize, setup.SetupType, setup.PrimarySubstrate);
    }

    /// <summary>
    /// Returns the effective coating application rate in sqft/hr.
    /// Override bypasses the formula when set.
    /// </summary>
    public static decimal GetCoatingRateSqFtPerHour(CompanyOperatingCosts costs)
    {
        if (costs.CoatingRateSqFtPerHourOverride.HasValue && costs.CoatingRateSqFtPerHourOverride.Value > 0)
            return costs.CoatingRateSqFtPerHourOverride.Value;

        return costs.CoatingGunType switch
        {
            CoatingGunType.Corona => 40m,
            CoatingGunType.Tribo  => 35m,
            CoatingGunType.Both   => 40m,
            _ => 40m
        };
    }

    /// <summary>
    /// Returns default equipment field values for a given capability tier, applied
    /// during Setup Wizard tier selection so new shops get reasonable starting values.
    /// CFM defaults reflect typical compressor sizes for each tier; they appear in the
    /// UI for reference but are not used in the rate formula.
    /// </summary>
    public static (BlastSetupType SetupType, decimal Cfm, int NozzleSize, BlastSubstrateType Substrate)
        TierDefaults(ShopCapabilityTier tier) => tier switch
    {
        ShopCapabilityTier.Garage => (BlastSetupType.SiphonCabinet, 7m,   3, BlastSubstrateType.Mixed),
        ShopCapabilityTier.Small  => (BlastSetupType.PressurePot,   49m,  3, BlastSubstrateType.Mixed),
        ShopCapabilityTier.Medium => (BlastSetupType.PressurePot,   90m,  4, BlastSubstrateType.Mixed),
        ShopCapabilityTier.Large  => (BlastSetupType.PressurePot,   150m, 5, BlastSubstrateType.Mixed),
        _ => (BlastSetupType.SiphonCabinet, 7m, 3, BlastSubstrateType.Mixed)
    };

    // ── Core formula (single path for all callers) ─────────────────────────────

    /// <summary>
    /// Nozzle-primary blast rate calculation. Nozzle size determines throughput;
    /// setup type routes to the appropriate reference table; substrate adjusts for
    /// removal difficulty. CFM is not used — it is a consequence of nozzle choice,
    /// not an independent variable in throughput.
    /// </summary>
    private static decimal CalculateBlastRate(int nozzle, BlastSetupType setupType, BlastSubstrateType substrate)
    {
        var baseRate = setupType switch
        {
            BlastSetupType.PressurePot   => PressurePotRateByNozzle(nozzle),
            BlastSetupType.SiphonCabinet => SiphonCabinetRateByNozzle(nozzle),
            // Siphon pot: open gravity feed, no enclosure penalty, ~80% of pressure pot
            BlastSetupType.SiphonPot     => Math.Round(PressurePotRateByNozzle(nozzle) * 0.80m, 1),
            // Wet blasting: water-media mix reduces impact velocity, ~60% of dry pressure pot
            BlastSetupType.WetBlasting   => Math.Round(PressurePotRateByNozzle(nozzle) * 0.60m, 1),
            _                            => 0m
        };

        return Math.Round(baseRate * SubstrateMultiplier(substrate), 1);
    }

    /// <summary>
    /// Midpoint cleaning rates for a pressure pot at adequate air supply, by nozzle size.
    /// Averaged from two industry-standard abrasive blast cleaning reference tables.
    ///   #1 (1/16"): 20-35 sqft/hr avg  →  20
    ///   #2 (1/8"):  40-60 sqft/hr avg  →  40
    ///   #3 (3/16"): 60-85 sqft/hr avg  →  75
    ///   #4 (1/4"):  90-110 sqft/hr avg → 115
    ///   #5 (5/16"): 130-160 sqft/hr avg → 175
    ///   #6 (3/8"):  180-230 sqft/hr avg → 245
    ///   #7 (7/16"): 240-300 sqft/hr avg → 325
    ///   #8 (1/2"):  320-400 sqft/hr avg → 430
    /// </summary>
    private static decimal PressurePotRateByNozzle(int nozzle) => nozzle switch
    {
        1 =>  20m,
        2 =>  40m,
        3 =>  75m,
        4 => 115m,
        5 => 175m,
        6 => 245m,
        7 => 325m,
        8 => 430m,
        _ => 100m
    };

    /// <summary>
    /// Midpoint cleaning rates for siphon-fed blast cabinets, by nozzle size.
    /// Source: industry reference table for siphon cabinet production rates.
    ///   #1 (1/16"): 10-25 sqft/hr  →  18
    ///   #2 (1/8"):  25-50 sqft/hr  →  38
    ///   #3 (3/16"): 50-100 sqft/hr →  75
    ///   #4 (1/4"):  100-150 sqft/hr → 125
    ///   #5 (5/16"): 150-225 sqft/hr → 188
    ///   #6 (3/8"):  225-300 sqft/hr → 263
    ///   #7 (7/16"): 300-375 sqft/hr → 338
    ///   #8 (1/2"):  375-450 sqft/hr → 413
    /// </summary>
    private static decimal SiphonCabinetRateByNozzle(int nozzle) => nozzle switch
    {
        1 =>  18m,
        2 =>  38m,
        3 =>  75m,
        4 => 125m,
        5 => 188m,
        6 => 263m,
        7 => 338m,
        8 => 413m,
        _ =>  80m
    };

    /// <summary>
    /// Adjustment for substrate removal difficulty relative to paint (baseline = 1.0).
    /// Powder coat strips faster than paint; rust and scale requires multiple passes.
    /// </summary>
    private static decimal SubstrateMultiplier(BlastSubstrateType substrate) => substrate switch
    {
        BlastSubstrateType.PowderCoat   => 1.25m,
        BlastSubstrateType.Paint        => 1.00m,
        BlastSubstrateType.Mixed        => 0.90m,
        BlastSubstrateType.RustAndScale => 0.70m,
        _ => 0.90m
    };
}