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

namespace Esiur.Proxy
{
    [Generator]
    public class ResourceGenerator : ISourceGenerator
    {
        public void Initialize(GeneratorInitializationContext context)
        {
            // Register receiver
            context.RegisterForSyntaxNotifications(() => new ResourceGeneratorReceiver());
        }

        public void Execute(GeneratorExecutionContext context)
        {

            if (!(context.SyntaxContextReceiver is ResourceGeneratorReceiver receiver))
                return;

            try
            {
                //#if DEBUG
                //            if (!Debugger.IsAttached)
                //            {
                //                Debugger.Launch();
                //            }
                //#endif

                //var toImplement = receiver.Classes.Where(x => x.Fields.Length > 0);

                foreach (var ci in receiver.Classes)
                {
                    var code = @$"using Esiur.Resource; 
using Esiur.Core; 
namespace { ci.ClassSymbol.ContainingNamespace.ToDisplayString() } {{
";

                    if (ci.ImplementInterface)
                        code += $"public partial class {ci.Name} {{";
                    else
                    {
                        code += @$"public partial class {ci.Name} : IResource {{
public Instance Instance {{ get; set; }}
public event DestroyedEvent OnDestroy;
public virtual void Destroy() {{ OnDestroy?.Invoke(this); }}
";

                        if (!ci.ImplementTrigger)
                            code += "public AsyncReply<bool> Trigger(ResourceTrigger trigger) => new AsyncReply<bool>(true);\r\n";
                    }

                    foreach (var f in ci.Fields)
                    {
                        var fn = f.Name;
                        var pn = fn.Substring(0, 1).ToUpper() + fn.Substring(1);

                        // copy attributes 
                        var attrs = string.Join(" ", f.GetAttributes().Select(x => $"[{x.ToString()}]"));
                        code += $"{attrs} public {f.Type} {pn} {{ get => {fn}; set {{ {fn} = value; Instance?.Modified(); }} }}\r\n";
                    }

                    code += "}}\r\n";

                    //System.IO.File.WriteAllText("c:\\gen\\" + ci.Name + "_esiur.cs", code);
                    context.AddSource(ci.Name + "_esiur.cs", code);
                }
            }
            catch //(Exception ex)
            {
                //System.IO.File.AppendAllText("c:\\gen\\error.log", ex.ToString() + "\r\n");
            }
        }
    }
}