namespace Volcanic.AgenticCore.Extensions.ClaudeCode;

/// <summary>
/// The built-in Claude Code plugins every request disables through <c>enabledPlugins</c>. Built-ins load whatever the
/// setting sources say, and which ones load depends on the CLI version and the account's feature flags, so the set
/// starts with the known ones and learns new ones from <c>system/init</c> (the request is then replayed once).
/// </summary>
public sealed class BuiltinPlugins
{
    public const string Suffix = "@builtin";

    /// <summary>The built-ins known to the CLI versions this provider was tested with.</summary>
    public static readonly IReadOnlyList<string> Known =
    [
        "agents-md@builtin", "telemetry@builtin",
        "cc-plugin-agents-md@builtin", "cc-plugin-claude-test@builtin", "cc-plugin-diff@builtin", "cc-plugin-mermaid@builtin",
        "cc-plugin-mods-guide@builtin", "cc-plugin-plugin-authoring@builtin", "cc-plugin-responsive-mode@builtin",
        "cc-plugin-sec-default@builtin", "cc-plugin-telemetry@builtin", "cc-plugin-tips@builtin", "cc-plugin-you-should-know@builtin",
    ];

    /// <summary>Process-wide: a built-in learned in one session is disabled for every later request.</summary>
    public static BuiltinPlugins Shared { get; } = new();

    private readonly Lock _gate = new();
    private readonly SortedSet<string> _disabled;

    public BuiltinPlugins(IEnumerable<string>? initial = null) =>
        _disabled = new SortedSet<string>(initial ?? Known, StringComparer.Ordinal);

    /// <summary>A sorted snapshot of the plugins to disable.</summary>
    public IReadOnlyList<string> Disabled
    {
        get { lock (_gate) return [.. _disabled]; }
    }

    /// <summary>Adds built-in plugin ids; true when at least one was new.</summary>
    public bool Disable(IEnumerable<string> plugins)
    {
        ArgumentNullException.ThrowIfNull(plugins);
        var added = false;
        lock (_gate)
        {
            foreach (var plugin in plugins)
                if (IsBuiltin(plugin)) added |= _disabled.Add(plugin);
        }
        return added;
    }

    public static bool IsBuiltin(string? source) =>
        source is { Length: > 9 } s && s.EndsWith(Suffix, StringComparison.Ordinal) && !s.Contains('/') && !s.Contains('\\');
}