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

namespace Polonium.Generators.Generators;
[Generator]
public class FramePatchGenerator : AssetProcessGenerator
{
    public override void Execute(GeneratorExecutionContext context)
    {
        if(context.SyntaxReceiver is not ClassSyntaxReceiver receiver)
            return;
        Compilation compilation = context.Compilation;
        INamedTypeSymbol? autoPatch = compilation.GetTypeByMetadataName("Polonium.Attributes.AutoPatch");
        INamedTypeSymbol? patchableProperty = compilation.GetTypeByMetadataName("Polonium.Attributes.PatchableProperty");
        foreach (InterfaceInfo inf in GetInterfacesWithAttribute(context, autoPatch))
        {
            
            PropertyDeclarationSyntax? underlying = inf.DeclarationSyntax.Members
                .OfType<PropertyDeclarationSyntax>()
                .FirstOrDefault(m => m.AttributeLists
                    .SelectMany(a => a.Attributes)
                    .Any(a =>
                    {
                        SemanticModel model = compilation.GetSemanticModel(a.SyntaxTree);
                        INamedTypeSymbol? attributeSymbol = model.GetSymbolInfo(a).Symbol?.ContainingType;
                        return SymbolEqualityComparer.Default.Equals(attributeSymbol, patchableProperty);
                    }));
            if (underlying is null)
                continue;
            SemanticModel model = compilation.GetSemanticModel(underlying.SyntaxTree);
            ITypeSymbol? underlyingType = model.GetTypeInfo(underlying.Type).Type;
            ITypeSymbol? hashSet = compilation
                .GetTypeByMetadataName("Polonium.DataStructures.PatchableItems.PatchableHashSet`1");
            ITypeSymbol? dictionary = compilation
                .GetTypeByMetadataName("Polonium.DataStructures.PatchableItems.PatchableDictionary`2");
            string typeString = "";
            StringBuilder sb = new();
            sb
                .AppendLine("using System;")
                .AppendLine("using System.Collections.Generic;")
                .AppendLine("using System.Linq;")
                .AppendLine("using Polonium.Interfaces;")
                .AppendLine("using Polonium.DataStructures.PatchableItems;")
                .AppendLine("using Polonium.Resources.FramePatches;")
                .AppendLine("using Polonium.Resources.FramePatches.Generic;")
                .AppendLine($"namespace {inf.Namespace};");
                
            string lName = inf.InterfaceName[0] == 'I' ? inf.InterfaceName.Substring(1) : inf.InterfaceName;
            if (SymbolEqualityComparer.Default.Equals(underlyingType?.OriginalDefinition, hashSet))
            {
                ITypeSymbol? x1 = (underlyingType as INamedTypeSymbol)?.TypeArguments[0];
                sb
                    .AppendLine($"public partial class {lName}Patch : HashSetFramePatch<{x1?.ToDisplayString()}>")
                    .AppendLine("{")
                    .AppendLine($"    public override void Patch(IPatchableFrame frame)")
                    .AppendLine("    {")
                    .AppendLine($"        if(frame is not {inf.InterfaceFillName} sFrame)")
                    .AppendLine("            return;")
                    .AppendLine($"        switch (sFrame.{underlying.Identifier.ToString()}.UpdateMethod )")
                    .AppendLine("        {")
                    .AppendLine("            case UpdateMethods.None:")
                    .AppendLine("                return;")
                    .AppendLine("            case UpdateMethods.Update:")
                    .AppendLine($"                foreach({x1?.ToDisplayString()} x in Updates)")
                    .AppendLine($"                    sFrame.{underlying.Identifier.ToString()}.Add(x);")
                    .AppendLine("                return;")
                    .AppendLine("            case UpdateMethods.Replace:")
                    .AppendLine($"                sFrame.{underlying.Identifier.ToString()}.Data = Updates;")
                    .AppendLine("                return;")
                    .AppendLine("            case UpdateMethods.Custom:")
                    .AppendLine($"                sFrame.{underlying.Identifier.ToString()}.CustomUpdate(Updates);")
                    .AppendLine("                return;")
                    .AppendLine("            default:")
                    .AppendLine("                  return;")
                    .AppendLine("        }")
                    .AppendLine("    }")
                    .AppendLine("}");
            }
            else if (SymbolEqualityComparer.Default.Equals(underlyingType?.OriginalDefinition, dictionary))
            {
                ITypeSymbol? x1 = (underlyingType as INamedTypeSymbol)?.TypeArguments[0];
                ITypeSymbol? x2 = (underlyingType as INamedTypeSymbol)?.TypeArguments[1];
                sb
                    .AppendLine($"public partial class {lName}Patch : DictionaryFramePatch<{x1?.ToDisplayString()}, {x2?.ToDisplayString()}>")
                    .AppendLine("{")
                    .AppendLine("    public override void Patch(IPatchableFrame frame)")
                    .AppendLine("    {")
                    .AppendLine($"        if(frame is not {inf.InterfaceFillName} sFrame)")
                    .AppendLine("            return;")
                    .AppendLine($"        switch (sFrame.{underlying.Identifier.ToString()}.UpdateMethod )")
                    .AppendLine("        {")
                    .AppendLine("            case UpdateMethods.None:")
                    .AppendLine("                return;")
                    .AppendLine("            case UpdateMethods.Update:")
                    .AppendLine($"                foreach({x1?.ToDisplayString()} x in Updates.Keys)")
                    .AppendLine($"                    sFrame.{underlying.Identifier.ToString()}[x] = Updates[x];")
                    .AppendLine("                return;")
                    .AppendLine("            case UpdateMethods.Replace:")
                    .AppendLine($"                sFrame.{underlying.Identifier.ToString()}.Data = Updates;")
                    .AppendLine("                return;")
                    .AppendLine("            case UpdateMethods.Custom:")
                    .AppendLine($"                sFrame.{underlying.Identifier.ToString()}.CustomUpdate(Updates);")
                    .AppendLine("                return;")
                    .AppendLine("            default:")
                    .AppendLine("                return;")
                    .AppendLine("        }")
                    .AppendLine("    }")
                    .AppendLine("}");
            }

            else
            {
                sb
                    
                    .AppendLine($"public partial class {lName}Patch : FramePatch<{underlyingType?.ToDisplayString()}>")
                    .AppendLine("{")
                    .AppendLine("    public override void Patch(IPatchableFrame frame)")
                    .AppendLine("    {")
                    .AppendLine($"        if(frame is not {inf.InterfaceFillName} sFrame)")
                    .AppendLine("            return;")
                    .AppendLine($"        sFrame.{underlying.Identifier.ToString()} = Updates;")
                    .AppendLine("    }")
                    .AppendLine("}");
            }
            context.AddSource($"{lName}Patch.g.cs", sb.ToString());

        }
    }
}