using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using YamlDotNet.Core;
using YamlDotNet.RepresentationModel;
using YamlDotNet.Serialization;

namespace ReFuel.Gltf.Tests;

[DebuggerDisplay("{Kind,nq} path={DocumentUnderTestPath}")]
public class GltfTestDocument(FileInfo documentUnderTestPath) : IDisposable
{
    public FileInfo DocumentUnderTestPath { get; } = documentUnderTestPath;
    public FileInfo? SummaryDocumentFile { get; init; } = FindSummary(documentUnderTestPath);
    public DirectoryInfo WorkingDirectory { get; init; } = documentUnderTestPath.Directory ?? new DirectoryInfo(Environment.CurrentDirectory);
    public GltfDocumentKind Kind { get; init; } = documentUnderTestPath.Extension.ToLowerInvariant() switch
    {
        ".gltf" => GltfDocumentKind.Json,
        ".glb" => GltfDocumentKind.Binary,
        _ => GltfDocumentKind.Any,
    };

    public FileStream? Stream { get; private set; }
    public GltfDocument? DocumentUnderTest { get; private set; }
    public YamlDocument? SummaryDocument { get; private set; }
    public ValidationDocument? ValidationDocument { get; private set; }

    public bool HasValidation => SummaryDocumentFile != null;

    public GltfDocument Parse()
    {
        Stream = DocumentUnderTestPath.OpenRead();
        return DocumentUnderTest = GltfDocument.Open(Stream);
    }

    [MemberNotNullWhen(true, nameof(ValidationDocument))]
    public bool LoadValidationDocument()
    {
        if (SummaryDocumentFile == null)
            return false;

        using StreamReader reader = new StreamReader(SummaryDocumentFile.OpenRead());
        ValidationDocument = Deserializer.Deserialize<ValidationDocument>(reader.ReadToEnd());

        return true;
    }

    public void Dispose()
    {
        DocumentUnderTest?.Dispose();
        DocumentUnderTest = null;

        Stream?.Dispose();
        Stream = null;
    }

    private static FileInfo? FindSummary(FileInfo documentUnderTest)
    {
        return
            documentUnderTest.Directory?
            .EnumerateFiles()
            .FirstOrDefault(x => string.Equals(x.Name, "conversion.yaml", StringComparison.InvariantCultureIgnoreCase));
    }

    public override string ToString()
    {
        string kind = Kind switch
        {
            GltfDocumentKind.Json => "Gltf JSON",
            GltfDocumentKind.Binary => "Gltf Binary",
            _ => "Unknown Gltf",
        };

        return $"{kind} \"{DocumentUnderTestPath.Name}\" HasValidation={(HasValidation ? "Yes" : "No")}";
    }

    private static IDeserializer Deserializer { get; }

    static GltfTestDocument()
    {
        Deserializer = new DeserializerBuilder()
            .IgnoreUnmatchedProperties()
            .Build();
    }
}