using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
using ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.PlcFamilies;

namespace ZB.MOM.WW.OtOpcUa.Driver.AbLegacy;

/// <summary>
///     AB Legacy / PCCC driver — SLC 500, MicroLogix, PLC-5, LogixPccc. Implements
///     <see cref="IDriver"/> only at PR 1 time; read / write / discovery / subscribe / probe /
///     host-resolver capabilities ship in PRs 2 and 3.
/// </summary>
public sealed class AbLegacyDriver : IDriver, IDisposable, IAsyncDisposable
{
    private readonly AbLegacyDriverOptions _options;
    private readonly string _driverInstanceId;
    private readonly Dictionary<string, DeviceState> _devices = new(StringComparer.OrdinalIgnoreCase);
    private DriverHealth _health = new(DriverState.Unknown, null, null);

    public AbLegacyDriver(AbLegacyDriverOptions options, string driverInstanceId)
    {
        ArgumentNullException.ThrowIfNull(options);
        _options = options;
        _driverInstanceId = driverInstanceId;
    }

    public string DriverInstanceId => _driverInstanceId;
    public string DriverType => "AbLegacy";

    public Task InitializeAsync(string driverConfigJson, CancellationToken cancellationToken)
    {
        _health = new DriverHealth(DriverState.Initializing, null, null);
        try
        {
            foreach (var device in _options.Devices)
            {
                var addr = AbLegacyHostAddress.TryParse(device.HostAddress)
                    ?? throw new InvalidOperationException(
                        $"AbLegacy device has invalid HostAddress '{device.HostAddress}' — expected 'ab://gateway[:port]/cip-path'.");
                var profile = AbLegacyPlcFamilyProfile.ForFamily(device.PlcFamily);
                _devices[device.HostAddress] = new DeviceState(addr, device, profile);
            }
            _health = new DriverHealth(DriverState.Healthy, DateTime.UtcNow, null);
        }
        catch (Exception ex)
        {
            _health = new DriverHealth(DriverState.Faulted, null, ex.Message);
            throw;
        }
        return Task.CompletedTask;
    }

    public async Task ReinitializeAsync(string driverConfigJson, CancellationToken cancellationToken)
    {
        await ShutdownAsync(cancellationToken).ConfigureAwait(false);
        await InitializeAsync(driverConfigJson, cancellationToken).ConfigureAwait(false);
    }

    public Task ShutdownAsync(CancellationToken cancellationToken)
    {
        _devices.Clear();
        _health = new DriverHealth(DriverState.Unknown, _health.LastSuccessfulRead, null);
        return Task.CompletedTask;
    }

    public DriverHealth GetHealth() => _health;
    public long GetMemoryFootprint() => 0;
    public Task FlushOptionalCachesAsync(CancellationToken cancellationToken) => Task.CompletedTask;

    internal int DeviceCount => _devices.Count;
    internal DeviceState? GetDeviceState(string hostAddress) =>
        _devices.TryGetValue(hostAddress, out var s) ? s : null;

    public void Dispose() => DisposeAsync().AsTask().GetAwaiter().GetResult();
    public async ValueTask DisposeAsync() => await ShutdownAsync(CancellationToken.None).ConfigureAwait(false);

    internal sealed class DeviceState(
        AbLegacyHostAddress parsedAddress,
        AbLegacyDeviceOptions options,
        AbLegacyPlcFamilyProfile profile)
    {
        public AbLegacyHostAddress ParsedAddress { get; } = parsedAddress;
        public AbLegacyDeviceOptions Options { get; } = options;
        public AbLegacyPlcFamilyProfile Profile { get; } = profile;
    }
}