using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.Text;

namespace MfGames.Nitride.Generators;

/// <summary>
/// Base class for classes marked with an attribute.
/// </summary>
public abstract class ClassAttributeSourceGeneratorBase<TSyntaxReceiver>
    : ISourceGenerator
    where TSyntaxReceiver : ClassAttributeSyntaxReceiverBase
{
    public void Execute(GeneratorExecutionContext context)
    {
        // Get the  generator infrastructure will create a receiver and
        // populate it we can retrieve the populated instance via the
        // context.
        if (context.SyntaxReceiver is not TSyntaxReceiver syntaxReceiver)
        {
            return;
        }

        // Report any messages.
        foreach (string? message in syntaxReceiver.Messages)
        {
            context.Warning(
                MessageCode.Debug,
                Location.Create(
                    "Temporary.g.cs",
                    TextSpan.FromBounds(0, 0),
                    new LinePositionSpan(
                        new LinePosition(0, 0),
                        new LinePosition(0, 0))),
                "{0}: Syntax Message: {1}",
                this.GetType().Name,
                message);
        }

        // If we didn't find anything, then there is nothing to do.
        if (syntaxReceiver.ReferenceList.Count == 0)
        {
            return;
        }

        // Go through each one.
        foreach (ClassAttributeReference reference in syntaxReceiver
                     .ReferenceList)
        {
            this.GenerateClassFile(context, reference);
        }
    }

    public void Initialize(GeneratorInitializationContext context)
    {
        // Register a factory that can create our custom syntax receiver
        context.RegisterForSyntaxNotifications(
            () => this.CreateSyntaxReceiver(context));
    }

    protected abstract TSyntaxReceiver CreateSyntaxReceiver(
        GeneratorInitializationContext context);

    protected abstract void GenerateClassFile(
        GeneratorExecutionContext context,
        ClassAttributeReference reference);
}