namespace Zcbot.WindowsNode;

internal sealed class AdapterCatalog
{
    private static readonly Lazy<IReadOnlyList<AdapterDescriptor>> InstalledDescriptors =
        new(DiscoverDescriptors, LazyThreadSafetyMode.ExecutionAndPublication);
    private static readonly JobExecutionGate SharedExecutionGate = new();
    private static readonly ProcessSupervisor SharedProcessSupervisor = new();
    private readonly IReadOnlyDictionary<string, INodeAdapter> adapters;

    internal AdapterCatalog(IEnumerable<INodeAdapter> values)
    {
        adapters = values.ToDictionary(item => item.Capability, StringComparer.Ordinal);
    }

    internal static string AdapterRoot =>
        Path.GetFullPath(Path.Combine(AppContext.BaseDirectory, "adapters"));

    internal static AdapterCatalog CreateDefault(
        JobRepository inbox,
        NodePaths? paths = null)
    {
        var resolvedPaths = paths ?? NodePaths.ForCurrentMachine();
        return new(InstalledDescriptors.Value.Select(item => new ProcessNodeAdapter(
            item, inbox, resolvedPaths, SharedExecutionGate, SharedProcessSupervisor)));
    }

    internal static IReadOnlyList<NodeAdapterContract> InstalledContracts =>
        InstalledDescriptors.Value.Select(item => item.Contract).ToArray();

    internal static IReadOnlyList<string> InstalledCapabilities =>
        InstalledContracts.Select(item => item.Capability).ToArray();

    internal static bool HasActiveExecution => SharedExecutionGate.IsActive;

    internal IReadOnlyCollection<INodeAdapter> All => adapters.Values.ToArray();

    internal INodeAdapter? Find(string capability) =>
        adapters.TryGetValue(capability, out var adapter) ? adapter : null;

    internal void InvalidateRuntime(string runtimeId)
    {
        foreach (var adapter in adapters.Values.Where(
            item => runtimeId.Equals(item.RuntimeId, StringComparison.Ordinal)))
        {
            adapter.InvalidateRuntime();
        }
    }

    private static IReadOnlyList<AdapterDescriptor> DiscoverDescriptors()
    {
        if (!Directory.Exists(AdapterRoot)) return [];
        return Directory.EnumerateDirectories(AdapterRoot)
            .Where(path => File.Exists(Path.Combine(path, "adapter.json")))
            .OrderBy(path => path, StringComparer.OrdinalIgnoreCase)
            .Select(AdapterContractLoader.Load)
            .ToArray();
    }
}