using MrGameEng.Genetics;
using MrGameEng.Mods;
using Xunit;

namespace MrGameEng.Genetics.Tests;

/// <summary>
/// Verifies <see cref="GeneDef"/> loads through the real <see cref="DefDatabase"/> the way the game
/// loads <c>genes.json</c>: string-named <see cref="GeneKind"/>, parent inheritance and effect maps.
/// </summary>
public sealed class GeneDefLoadTests : IDisposable
{
    private readonly string _root = Directory.CreateTempSubdirectory("mrge-gene-tests-").FullName;

    public void Dispose() => Directory.Delete(_root, recursive: true);

    private DefDatabase Load(string defsJson)
    {
        var modDir = Path.Combine(_root, "mod");
        Directory.CreateDirectory(Path.Combine(modDir, "Defs"));
        File.WriteAllText(Path.Combine(modDir, "Defs", "genes.json"), defsJson);
        var database = new DefDatabase();
        database.RegisterType<GeneDef>("Gene");
        database.Load([new Mod(new ModInfo { Id = "mod" }, modDir)]);
        return database;
    }

    [Fact]
    public void Load_NumericGeneWithParentAndEffects_Resolves()
    {
        var database = Load(
            """
            { "type": "Gene", "defs": [
                { "defName": "BaseGene", "abstract": true, "spread": 0.1, "mutationChance": 0.05 },
                { "defName": "GeneVigor", "parent": "BaseGene", "default": 1.0, "min": 0.1, "max": 3.0,
                  "tags": ["growth"], "effects": { "vigor": "value" } }
            ]}
            """
        );

        var gene = database.Get<GeneDef>("GeneVigor");
        Assert.Equal(GeneKind.Numeric, gene.Kind);
        Assert.Equal(0.1f, gene.Spread); // inherited from parent
        Assert.Equal(0.05f, gene.MutationChance); // inherited
        Assert.Equal(3.0f, gene.Max);
        Assert.Equal(["growth"], gene.Tags);
        Assert.Equal("value", gene.Effects["vigor"]);
        Assert.Single(gene.CompiledEffects); // formula compiles
    }

    [Fact]
    public void Load_DiscreteKindByName_Parses()
    {
        var database = Load(
            """
            { "type": "Gene", "defs": [
                { "defName": "GeneMorph", "kind": "Discrete", "variants": 2,
                  "variantWeights": [0.8, 0.2], "effects": { "variant": "value" } }
            ]}
            """
        );

        var gene = database.Get<GeneDef>("GeneMorph");
        Assert.Equal(GeneKind.Discrete, gene.Kind);
        Assert.Equal(2, gene.Variants);
        Assert.Equal([0.8f, 0.2f], gene.VariantWeights);
    }
}