using System.Text.Json;

namespace Zcbot.WindowsNode;

internal interface INodeAdapter
{
    string Capability { get; }
    string DisplayName { get; }
    string AdapterVersion { get; }
    IReadOnlyList<string> Features { get; }
    bool HasActiveJobs { get; }
    string RunningDetail { get; }
    AdapterRuntimeStatus DetectRuntime();
    bool ValidateRequest(JsonElement request);
    Task RunAsync(RecoverableJob job);
    void Cancel(Guid jobId);
}

internal sealed class OriginPlotNodeAdapter(JobInboxStore inbox) : INodeAdapter
{
    internal const string CurrentAdapterVersion = "0.5.0";
    internal const string ContractFilename = "origin.plot.v2.json";
    private static readonly NodeAdapterContract Contract =
        NodeAdapterContract.Load(ContractFilename, CurrentAdapterVersion);
    private readonly OriginWorkerRunner runner = new(inbox);

    internal static string CapabilityName => Contract.Capability;

    public string Capability => Contract.Capability;
    public string DisplayName => Contract.DisplayName;
    public string AdapterVersion => CurrentAdapterVersion;
    public IReadOnlyList<string> Features => Contract.Features;
    public bool HasActiveJobs => runner.HasActiveJobs;
    public string RunningDetail => "Origin 正在生成图形";
    public AdapterRuntimeStatus DetectRuntime() => OriginRuntimeProbe.Detect();
    public bool ValidateRequest(JsonElement request) =>
        JobInboxStore.IsValidOriginRequest(request, Features);
    public Task RunAsync(RecoverableJob job) => runner.RunAsync(job);
    public void Cancel(Guid jobId) => runner.Cancel(jobId);
}

internal sealed record NodeAdapterContract(
    string Capability, string DisplayName, IReadOnlyList<string> Features)
{
    internal static NodeAdapterContract Load(string filename, string adapterVersion)
    {
        var path = Path.GetFullPath(
            Path.Combine(AppContext.BaseDirectory, "software-contracts", filename));
        using var document = JsonDocument.Parse(File.ReadAllBytes(path));
        var root = document.RootElement;
        var capability = root.GetProperty("capability").GetString()
            ?? throw new InvalidDataException("Adapter contract capability is missing.");
        var displayName = root.GetProperty("display_name").GetString()
            ?? throw new InvalidDataException("Adapter contract display name is missing.");
        var current = ParseVersion(adapterVersion);
        var features = root.GetProperty("features").EnumerateObject()
            .Where(item => ParseVersion(item.Value.GetString() ?? "0.0.0") <= current)
            .Select(item => item.Name)
            .ToArray();
        return new NodeAdapterContract(capability, displayName, features);
    }

    private static Version ParseVersion(string value) =>
        Version.TryParse(value, out var version) ? version : new Version(0, 0, 0);
}

internal sealed class NodeAdapterRegistry
{
    private readonly IReadOnlyDictionary<string, INodeAdapter> adapters;

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

    internal static NodeAdapterRegistry CreateDefault(JobInboxStore inbox) =>
        new([new OriginPlotNodeAdapter(inbox)]);

    internal static IReadOnlyList<NodeAdapterContract> InstalledContracts { get; } =
    [
        NodeAdapterContract.Load(
            OriginPlotNodeAdapter.ContractFilename,
            OriginPlotNodeAdapter.CurrentAdapterVersion),
    ];

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

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

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