using FluentAssertions;
using Xunit;

namespace BucketChain.Test;

public sealed class FireTests
{
    private const double InitialSize = 12.34D;
    private const double GrowRate = 0.85D;
    private const int Times = 17;
    
    [Fact]
    public void Construction_Simple()
    {
        var fire = new Fire(InitialSize, default(double));

        fire.FireSize.Should().Be(InitialSize, "has not grown yet");
        fire.Extinguished.Should().BeFalse("size > 0");
    }

    [Fact]
    public void BurnHigher()
    {
        var fire = new Fire(InitialSize, GrowRate);
        fire.BurnHigher();

        fire.FireSize.Should().Be(InitialSize + GrowRate, "grow happened once");
        fire.Extinguished.Should().BeFalse();
    }
    
    [Fact]
    public void BurnHigher_Multiple()
    {
        var fire = new Fire(InitialSize, GrowRate);
        for (var i = 0; i < Times; i++)
        {
            fire.BurnHigher();
        }

        fire.FireSize.Should().BeApproximately(InitialSize + GrowRate * Times, 
            2E-14, $"grow happened {Times} times");
        fire.Extinguished.Should().BeFalse();
    }

    [Fact]
    public void GetHitByWater_Simple()
    {
        var fire = new Fire(InitialSize, default);
        
        fire.GetHitByWater(InitialSize - 1);
        fire.FireSize.Should().Be(1);
        fire.Extinguished.Should().BeFalse("not yet extinguished");
        
        fire.GetHitByWater(1D);
        fire.Extinguished.Should().BeTrue("now extinguished");
    }
    
    [Fact]
    public void GetHitByWater_Complex()
    {
        var fire = new Fire(InitialSize, GrowRate);
        
        fire.GetHitByWater(InitialSize - 1);
        fire.Extinguished.Should().BeFalse("not yet extinguished");
        
        fire.BurnHigher();
        
        fire.GetHitByWater(1D);
        fire.Extinguished.Should().BeFalse("not yet extinguished, because it grew");
        
        fire.GetHitByWater(1D);
        fire.Extinguished.Should().BeTrue("now extinguished");
    }

    [Theory]
    [InlineData(10, "🔥 10")]
    [InlineData(1.23, "🔥 1")]
    [InlineData(1.83, "🔥 2")]
    [InlineData(0, "🔥 0")]
    public void StringRepresentation(double size, string expected)
    {
        var fire = new Fire(size, default(double));

        fire.ToString()
            .Should().Be(expected);
    }
}