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

namespace Polonium.Generators.Generators;
[Generator]
public class TemplateInlineGenerator : AssetProcessGenerator
{
    public override void Execute(GeneratorExecutionContext context)
    {
        if (!(context.SyntaxReceiver is ClassSyntaxReceiver receiver))
            return;
        Compilation compilation = context.Compilation;
        INamedTypeSymbol? templateDefine = compilation.GetTypeByMetadataName("Polonium.Attributes.TemplateDefines.TemplateInline");
        
        foreach (ClassDeclarationSyntax? cls in context.GetClassesWithAttribute(receiver, templateDefine))
        {
            if(!cls.Modifiers.Any(m => m.IsKind(SyntaxKind.PartialKeyword)))
                continue;
            string isStatic = "";
            if(cls.Modifiers.Any(m => m.IsKind(SyntaxKind.StaticKeyword)))
                isStatic = "static";
            StringBuilder sb = new StringBuilder();
            sb
                .AppendLine($"public {isStatic} partial class {cls.Identifier.ToString()}")
                .AppendLine("{");
            HashSet<string> headers = new();
            foreach (AttributeData attr in context.GetAttributes(cls, templateDefine))
            {
                string template = attr.ConstructorArguments[0].Value?.ToString()??string.Empty;
                string dataFile = attr.ConstructorArguments[1].Value?.ToString()??string.Empty;
                string depsString = attr.ConstructorArguments[2].Value?.ToString()??string.Empty;
                string[] deps = depsString.Split(';');
                foreach (string dep in deps)
                    headers.Add(dep);
                AdditionalText? df = context.AdditionalFiles.FirstOrDefault(f => f.Path.EndsWith(dataFile));
                string[] data =(df?.GetText()?.ToString() ?? "").Split('\n');
                foreach (string d in data)
                {
                    if(d.Trim().Equals(""))
                        continue;
                    sb.AppendLine($"    {Format(template, d)}");
                }                
            }

            sb.AppendLine("}");
            StringBuilder hb = new();
            foreach(string header in headers)
            {
                if(header.Trim().Equals(""))
                    continue;
                hb.AppendLine($"using {header};");
            }
            hb.Append(sb);
            Console.WriteLine(hb.ToString());
            context.AddSource($"{cls.Identifier.ToString()}_TemplateInline.g.cs", hb.ToString());
        }
    }
}