namespace w4c_workflows.Services;

/// <summary>Describes an executable language in the (extensible) runtime registry.</summary>
public sealed record LanguageInfo(string Id, string DisplayName, string DefaultFunction, string Extension);

/// <summary>
/// The set of languages the engine can execute. This is the single source of
/// truth for YAML validation and the <c>GET /api/languages</c> endpoint; the
/// worker maps each <see cref="LanguageInfo.Id"/> to an executor in step 7.
/// </summary>
public class LanguageRegistry
{
    private readonly IReadOnlyList<LanguageInfo> _languages;

    public LanguageRegistry()
    {
        _languages = new[]
        {
            new LanguageInfo("shell", "Shell", "main", ".sh"),
            new LanguageInfo("javascript", "JavaScript", "handler", ".js"),
            new LanguageInfo("typescript", "TypeScript", "handler", ".ts"),
            new LanguageInfo("csharp", "C#", "Main", ".cs"),
            new LanguageInfo("python", "Python", "main", ".py"),
            new LanguageInfo("agent", "Agent", "run", ""),
        };
    }

    public IReadOnlyList<LanguageInfo> All => _languages;

    public bool IsKnown(string id) => _languages.Any(l => l.Id == id);

    public LanguageInfo? Get(string id) => _languages.FirstOrDefault(l => l.Id == id);
}