using System.Collections.Generic;
using System.Collections.Immutable;
using System.Linq;
using System.Text;
using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.Text;

namespace Godot.Sharp.Extended.Generators;

[Generator]
public class ActionGenerator : IIncrementalGenerator
{
    public void Initialize(IncrementalGeneratorInitializationContext context)
    {
        var projectFile = context.AdditionalTextsProvider
            .Where(file => file.Path.EndsWith("project.godot"))
            .Select((file, token) => file.GetText())
            .Collect();

        context.RegisterSourceOutput(projectFile, GenerateCode);
    }

    private void GenerateCode(SourceProductionContext ctx, ImmutableArray<SourceText> texts)
    {
        var memberCode = new StringBuilder();
        foreach (var text in texts)
        {
            if (text == null) continue;
            var content = text.ToString();
            var inputs = GetActions(content);
            var fields = inputs.Select(keyData => $$"""\tpublic static StringName {{keyData.ToPascalCase()}} = "{{keyData}}";""");

            foreach (var field in fields) memberCode.AppendLine(field);
        }

        var code = $$"""
                     // <auto-generated />

                     using System;
                     using Godot;

                     namespace Godot.Sharp.Extended.Generators;

                     public partial class Actions
                     {
                        {{memberCode}}
                     }
                     """;
        ctx.AddSource("Godot.Sharp.Extended.Generators.Actions.g.cs", SourceText.From(code, Encoding.UTF8));
    }

    public List<string> GetActions(string content)
    {
        var results = new List<string>();
        var inputSection = false;
        foreach (var line in content.Split(['\n']))
        {
            if (line.Equals("[input]"))
                inputSection = true;
            else if (line.StartsWith("[") && inputSection) break;

            if (!inputSection) continue;

            var kv = line.Split(['='], 2);
            if (kv.Length == 2) results.Add(kv[0].Trim());
        }

        return results;
    }
}