using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.CSharp;
using Microsoft.CodeAnalysis.CSharp.Syntax;
using Microsoft.CodeAnalysis.Text;
using System.Text;

namespace QWERTYkez.Mensura.Generator;

[Generator]
public class UnitOperatorsGenerator : IIncrementalGenerator
{
    private const string AttributeName = "UnitOperatorsGenerator";

    public void Initialize(IncrementalGeneratorInitializationContext context)
    {
        // Генерируем атрибут
        context.RegisterPostInitializationOutput(ctx =>
        {
            string attributeSource = @"
namespace QWERTYkez.Mensura
{
    [System.AttributeUsage(System.AttributeTargets.Struct, AllowMultiple = false)]
    public sealed class UnitOperatorsGeneratorAttribute : System.Attribute { }
}";
            ctx.AddSource("UnitOperatorsGeneratorAttribute.g.cs", SourceText.From(attributeSource, Encoding.UTF8));
        });

        // Ищем все readonly partial record struct с атрибутом
        var structsProvider = context.SyntaxProvider
            .CreateSyntaxProvider(
                predicate: static (node, _) => IsTargetStruct(node),
                transform: static (ctx, _) => GetStructInfo(ctx))
            .Where(info => info.HasValue)
            .Select((info, _) => info!.Value)
            .Collect();

        context.RegisterSourceOutput(structsProvider, (spc, structs) =>
        {
            foreach (var structInfo in structs)
            {
                string generatedCode = GeneratePartial(structInfo);
                spc.AddSource($"{structInfo.TypeName}.Generated.g.cs", SourceText.From(generatedCode, Encoding.UTF8));
            }
        });
    }

    private static bool IsTargetStruct(SyntaxNode node)
    {
        if (node is not RecordDeclarationSyntax record)
            return false;

        // Должен быть record struct с модификаторами readonly и partial
        if (!record.Modifiers.Any(SyntaxKind.ReadOnlyKeyword) ||
            !record.Modifiers.Any(SyntaxKind.PartialKeyword) ||
            !record.Keyword.IsKind(SyntaxKind.RecordKeyword) ||
            !record.ClassOrStructKeyword.IsKind(SyntaxKind.StructKeyword))
            return false;

        // Проверяем наличие атрибута [UnitOperatorsGenerator]
        foreach (var attrList in record.AttributeLists)
            foreach (var attr in attrList.Attributes)
            {
                string name = attr.Name.ToString();
                if (name == AttributeName || name == AttributeName + "Attribute")
                    return true;
            }
        return false;
    }

    private static StructInfo? GetStructInfo(GeneratorSyntaxContext context)
    {
        var record = (RecordDeclarationSyntax)context.Node;
        var semanticModel = context.SemanticModel;
        if (semanticModel.GetDeclaredSymbol(record) is not INamedTypeSymbol typeSymbol)
            return null;

        string namespaceName = typeSymbol.ContainingNamespace?.ToString();
        if (string.IsNullOrEmpty(namespaceName))
            return null;

        return new StructInfo(namespaceName, typeSymbol.Name);
    }

    private static string GeneratePartial(StructInfo info)
    {
        string typeName = info.TypeName;
        string ns = info.Namespace;

        // Здесь должен быть полный код из вашего файла XXXXXXXXXXXX.cs
        // с заменой {typeName} на {typeName}. Для краткости приведён скелет.
        // Вы должны скопировать сюда всё содержимое вашего второго файла,
        // заменив {typeName} на {typeName}.
        string skeleton = @"
global using {typeName}Extensions = QWERTYkez.Mensura.Units.{typeName}Extensions;
global using {typeName} = QWERTYkez.Mensura.Units.{typeName};

using System.Runtime.Serialization;

namespace QWERTYkez.Mensura.Units;

public class {typeName}Converter : UnitJsonConverter<{typeName}> { }

[JsonConverter(typeof({typeName}Converter))]
public readonly partial record struct {typeName} : IMensuraUnit<{typeName}>, IEquatable<{typeName}>, IMensuraUnit
{
    [JsonInclude, DataMember, JsonPropertyName(""v""), Obsolete] // для JSON / EF на случай сбоев, если пробелма с _Value
    internal double Value { get => _Value; init => _Value = value; }
    internal readonly double _Value;
    internal {typeName}(double value) => _Value = value;

    public override int GetHashCode() => _Value.GetHashCode();
    public int CompareTo({typeName}? other) => _Value.CompareTo(other is null ? 0d : other.Value._Value);
    public int CompareTo({typeName} other) => _Value.CompareTo(other._Value);

    public bool Equals({typeName}? other) => _Value.Equals(other?._Value);


    [JsonIgnore, IgnoreDataMember] public bool IsPositive => _Value >= 0;
    [JsonIgnore, IgnoreDataMember] public bool IsGreaterThanZero => _Value > 0;
    [JsonIgnore, IgnoreDataMember] public bool IsNegative => double.IsNegative(_Value);
    [JsonIgnore, IgnoreDataMember] public bool IsZero => _Value == 0;
    [JsonIgnore, IgnoreDataMember] public bool IsNaN => double.IsNaN(_Value);
    [JsonIgnore, IgnoreDataMember] public bool IsFinite => double.IsFinite(_Value);
    [JsonIgnore, IgnoreDataMember] public bool IsInfinity => double.IsInfinity(_Value);
    [JsonIgnore, IgnoreDataMember] public bool IsPositiveInfinity => double.IsPositiveInfinity(_Value);
    [JsonIgnore, IgnoreDataMember] public bool IsNegativeInfinity => double.IsNegativeInfinity(_Value);


    public static {typeName} Zero { get; } = new(0d);
    public static {typeName} Min { get; } = new(double.MinValue);
    public static {typeName} Max { get; } = new(double.MaxValue);
    public static {typeName} NegativeInfinity { get; } = new(double.NegativeInfinity);
    public static {typeName} PositiveInfinity { get; } = new(double.PositiveInfinity);

    public static bool operator ==({typeName}? T1, {typeName}? T2) => T1.Protected() == T2.Protected();
    public static bool operator !=({typeName}? T1, {typeName}? T2) => T1.Protected() != T2.Protected();

    public static bool operator <({typeName}? T1, {typeName}? T2) => T1.Protected() < T2.Protected();
    public static bool operator <=({typeName}? T1, {typeName}? T2) => T1.Protected() <= T2.Protected();
    public static bool operator >({typeName}? T1, {typeName}? T2) => T1.Protected() > T2.Protected();
    public static bool operator >=({typeName}? T1, {typeName}? T2) => T1.Protected() >= T2.Protected();


    public static {typeName} operator +({typeName} T2) => new(+T2._Value);
    public static {typeName} operator +({typeName} T1, {typeName} T2) => new(T1._Value + T2._Value);
    public static {typeName} operator -({typeName} T2) => new(-T2._Value);
    public static {typeName} operator -({typeName} T1, {typeName} T2) => new(T1._Value - T2._Value);


    // double
    public static {typeName} operator *({typeName} T1, double T2) => new(T1._Value * T2);
    public static {typeName} operator *({typeName} T1, double? T2) => T1 * (T2 ?? 0d);
    public static {typeName} operator *(double T1, {typeName} T2) => new(T1 * T2._Value);
    public static {typeName} operator *(double? T1, {typeName} T2) => (T1 ?? 0d) * T2;
    public static {typeName} operator /({typeName} T1, double T2) => new(T1._Value / T2);
    public static {typeName} operator /({typeName} T1, double? T2) => T1 / (T2 ?? 0d);
    public static double operator /({typeName} T1, {typeName} T2) => T1._Value / T2._Value;

    // sbyte
    public static {typeName} operator *({typeName} T1, sbyte T2) => T1 * T2.ToDouble();
    public static {typeName} operator *({typeName} T1, sbyte? T2) => T1 * T2.ToDouble();
    public static {typeName} operator *(sbyte T1, {typeName} T2) => T1.ToDouble() * T2;
    public static {typeName} operator *(sbyte? T1, {typeName} T2) => T1.ToDouble() * T2;
    public static {typeName} operator /({typeName} T1, sbyte T2) => T1 / T2.ToDouble();
    public static {typeName} operator /({typeName} T1, sbyte? T2) => T1 / T2.ToDouble();

    // short
    public static {typeName} operator *({typeName} T1, short T2) => T1 * T2.ToDouble();
    public static {typeName} operator *({typeName} T1, short? T2) => T1 * T2.ToDouble();
    public static {typeName} operator *(short T1, {typeName} T2) => T1.ToDouble() * T2;
    public static {typeName} operator *(short? T1, {typeName} T2) => T1.ToDouble() * T2;
    public static {typeName} operator /({typeName} T1, short T2) => T1 / T2.ToDouble();
    public static {typeName} operator /({typeName} T1, short? T2) => T1 / T2.ToDouble();

    // int
    public static {typeName} operator *({typeName} T1, int T2) => T1 * T2.ToDouble();
    public static {typeName} operator *({typeName} T1, int? T2) => T1 * T2.ToDouble();
    public static {typeName} operator *(int T1, {typeName} T2) => T1.ToDouble() * T2;
    public static {typeName} operator *(int? T1, {typeName} T2) => T1.ToDouble() * T2;
    public static {typeName} operator /({typeName} T1, int T2) => T1 / T2.ToDouble();
    public static {typeName} operator /({typeName} T1, int? T2) => T1 / T2.ToDouble();

    // long
    public static {typeName} operator *({typeName} T1, long T2) => T1 * T2.ToDouble();
    public static {typeName} operator *({typeName} T1, long? T2) => T1 * T2.ToDouble();
    public static {typeName} operator *(long T1, {typeName} T2) => T1.ToDouble() * T2;
    public static {typeName} operator *(long? T1, {typeName} T2) => T1.ToDouble() * T2;
    public static {typeName} operator /({typeName} T1, long T2) => T1 / T2.ToDouble();
    public static {typeName} operator /({typeName} T1, long? T2) => T1 / T2.ToDouble();

    // byte
    public static {typeName} operator *({typeName} T1, byte T2) => T1 * T2.ToDouble();
    public static {typeName} operator *({typeName} T1, byte? T2) => T1 * T2.ToDouble();
    public static {typeName} operator *(byte T1, {typeName} T2) => T1.ToDouble() * T2;
    public static {typeName} operator *(byte? T1, {typeName} T2) => T1.ToDouble() * T2;
    public static {typeName} operator /({typeName} T1, byte T2) => T1 / T2.ToDouble();
    public static {typeName} operator /({typeName} T1, byte? T2) => T1 / T2.ToDouble();

    // ushort
    public static {typeName} operator *({typeName} T1, ushort T2) => T1 * T2.ToDouble();
    public static {typeName} operator *({typeName} T1, ushort? T2) => T1 * T2.ToDouble();
    public static {typeName} operator *(ushort T1, {typeName} T2) => T1.ToDouble() * T2;
    public static {typeName} operator *(ushort? T1, {typeName} T2) => T1.ToDouble() * T2;
    public static {typeName} operator /({typeName} T1, ushort T2) => T1 / T2.ToDouble();
    public static {typeName} operator /({typeName} T1, ushort? T2) => T1 / T2.ToDouble();

    // uint
    public static {typeName} operator *({typeName} T1, uint T2) => T1 * T2.ToDouble();
    public static {typeName} operator *({typeName} T1, uint? T2) => T1 * T2.ToDouble();
    public static {typeName} operator *(uint T1, {typeName} T2) => T1.ToDouble() * T2;
    public static {typeName} operator *(uint? T1, {typeName} T2) => T1.ToDouble() * T2;
    public static {typeName} operator /({typeName} T1, uint T2) => T1 / T2.ToDouble();
    public static {typeName} operator /({typeName} T1, uint? T2) => T1 / T2.ToDouble();

    // ulong
    public static {typeName} operator *({typeName} T1, ulong T2) => T1 * T2.ToDouble();
    public static {typeName} operator *({typeName} T1, ulong? T2) => T1 * T2.ToDouble();
    public static {typeName} operator *(ulong T1, {typeName} T2) => T1.ToDouble() * T2;
    public static {typeName} operator *(ulong? T1, {typeName} T2) => T1.ToDouble() * T2;
    public static {typeName} operator /({typeName} T1, ulong T2) => T1 / T2.ToDouble();
    public static {typeName} operator /({typeName} T1, ulong? T2) => T1 / T2.ToDouble();

    // nint
    public static {typeName} operator *({typeName} T1, nint T2) => T1 * T2.ToDouble();
    public static {typeName} operator *({typeName} T1, nint? T2) => T1 * T2.ToDouble();
    public static {typeName} operator *(nint T1, {typeName} T2) => T1.ToDouble() * T2;
    public static {typeName} operator *(nint? T1, {typeName} T2) => T1.ToDouble() * T2;
    public static {typeName} operator /({typeName} T1, nint T2) => T1 / T2.ToDouble();
    public static {typeName} operator /({typeName} T1, nint? T2) => T1 / T2.ToDouble();

    // nuint
    public static {typeName} operator *({typeName} T1, nuint T2) => T1 * T2.ToDouble();
    public static {typeName} operator *({typeName} T1, nuint? T2) => T1 * T2.ToDouble();
    public static {typeName} operator *(nuint T1, {typeName} T2) => T1.ToDouble() * T2;
    public static {typeName} operator *(nuint? T1, {typeName} T2) => T1.ToDouble() * T2;
    public static {typeName} operator /({typeName} T1, nuint T2) => T1 / T2.ToDouble();
    public static {typeName} operator /({typeName} T1, nuint? T2) => T1 / T2.ToDouble();

    // float
    public static {typeName} operator *({typeName} T1, float T2) => T1 * T2.ToDouble();
    public static {typeName} operator *({typeName} T1, float? T2) => T1 * T2.ToDouble();
    public static {typeName} operator *(float T1, {typeName} T2) => T1.ToDouble() * T2;
    public static {typeName} operator *(float? T1, {typeName} T2) => T1.ToDouble() * T2;
    public static {typeName} operator /({typeName} T1, float T2) => T1 / T2.ToDouble();
    public static {typeName} operator /({typeName} T1, float? T2) => T1 / T2.ToDouble();

    // decimal
    public static {typeName} operator *({typeName} T1, decimal T2) => T1 * T2.ToDouble();
    public static {typeName} operator *({typeName} T1, decimal? T2) => T1 * T2.ToDouble();
    public static {typeName} operator *(decimal T1, {typeName} T2) => T1.ToDouble() * T2;
    public static {typeName} operator *(decimal? T1, {typeName} T2) => T1.ToDouble() * T2;
    public static {typeName} operator /({typeName} T1, decimal T2) => T1 / T2.ToDouble();
    public static {typeName} operator /({typeName} T1, decimal? T2) => T1 / T2.ToDouble();

#if NET7_0_OR_GREATER
    // Int128
    public static {typeName} operator *({typeName} T1, Int128 T2) => T1 * T2.ToDouble();
    public static {typeName} operator *({typeName} T1, Int128? T2) => T1 * T2.ToDouble();
    public static {typeName} operator *(Int128 T1, {typeName} T2) => T1.ToDouble() * T2;
    public static {typeName} operator *(Int128? T1, {typeName} T2) => T1.ToDouble() * T2;
    public static {typeName} operator /({typeName} T1, Int128 T2) => T1 / T2.ToDouble();
    public static {typeName} operator /({typeName} T1, Int128? T2) => T1 / T2.ToDouble();

    // UInt128
    public static {typeName} operator *({typeName} T1, UInt128 T2) => T1 * T2.ToDouble();
    public static {typeName} operator *({typeName} T1, UInt128? T2) => T1 * T2.ToDouble();
    public static {typeName} operator *(UInt128 T1, {typeName} T2) => T1.ToDouble() * T2;
    public static {typeName} operator *(UInt128? T1, {typeName} T2) => T1.ToDouble() * T2;
    public static {typeName} operator /({typeName} T1, UInt128 T2) => T1 / T2.ToDouble();
    public static {typeName} operator /({typeName} T1, UInt128? T2) => T1 / T2.ToDouble();
#endif

    public static explicit operator {typeName}(double val) => Unsafe.As<double, {typeName}>(ref val);
    public static explicit operator double({typeName} unit) => unit._Value;


    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public {typeName} Abs() => new(Math.Abs(_Value));

    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    internal R Pow2_Internal<R>() where R : struct, IMensuraUnit, IEquatable<R> => (_Value * _Value).ToUnit<R>();

    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    internal R Sqrt_Internal<R>() where R : struct, IMensuraUnit, IEquatable<R> => Math.Sqrt(_Value).ToUnit<R>();
}

public static class {typeName}Extensions
{
    public static double Protected(this {typeName}? unit) => unit is null ? 0d : unit.Value._Value;
}
";
        return skeleton.Replace("{typeName}", typeName).Replace("{ns}", ns);
    }

    private readonly struct StructInfo(string ns, string name)
    {
        public string Namespace { get; } = ns;
        public string TypeName { get; } = name;
    }
}