// Example 3 solution — Ice cream shop demo of Slice with Lambda (C#), after
//
// Lambda extracted (step 1), slid to the top (step 2), method extracted
// below the guard (step 3). The constructor now takes the lambda directly,
// so tests construct with new IceCreamShop(() => 30).
//
// Condensed mechanics: https://sammancoaching.org/refactorings/slice.html
// (where that page says mock, we use a lambda instead).

using System;

public enum Warmth
{
    Cold,
    Warm
}

public enum ThawAmount
{
    None,
    Medium,
    Low
}

public class Thermometer
{
    private readonly Random _rng = new Random();    // stand-in for the hardware

    public byte Read()
    {
        return (byte)_rng.Next(50);                 // raw sensor value
    }
}

public class IceCreamShop
{
    private readonly Func<byte> _readTemperature;   // the thermometer, as a lambda
    private bool _thawedToday;                      // event-style client state

    public IceCreamShop(Func<byte> readTemperature)
    {
        _readTemperature = readTemperature;
    }

    public ThawAmount ThawStock()
    {
        Func<byte> readTemperature = () => _readTemperature();  // lambda at the top
        return ThawStockTail(readTemperature);      // pass the lambda on
    }

    private ThawAmount ThawStockTail(Func<byte> readTemperature)
    {
        if (_thawedToday)                           // guard: client state, stays
        {
            return ThawAmount.None;
        }

        _thawedToday = true;                        // set only after thawing
        byte temperature = readTemperature();       // middle: the stubbed lambda
        Warmth warmth = ToWarmth(temperature);
        if (warmth == Warmth.Warm)                  // tail: complex behaviour below
        {                                           // the extraction point
            return ThawAmount.Medium;
        }
        return ThawAmount.Low;
    }

    private static Warmth ToWarmth(byte temperature)
    {
        return temperature > 25 ? Warmth.Warm : Warmth.Cold;
    }
}