// <copyright file="AirGapSyncServiceCollectionExtensions.cs" company="StellaOps">
// Copyright (c) StellaOps. Licensed under AGPL-3.0-or-later.
// </copyright>

using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.DependencyInjection.Extensions;
using Microsoft.Extensions.Logging;
using StellaOps.AirGap.Sync.Services;
using StellaOps.AirGap.Sync.Stores;
using StellaOps.AirGap.Sync.Transport;
using StellaOps.Determinism;
using StellaOps.HybridLogicalClock;

namespace StellaOps.AirGap.Sync;

/// <summary>
/// Extension methods for registering air-gap sync services.
/// </summary>
public static class AirGapSyncServiceCollectionExtensions
{
    /// <summary>
    /// Adds air-gap sync services to the service collection.
    /// </summary>
    /// <param name="services">The service collection.</param>
    /// <param name="nodeId">The node identifier for this instance.</param>
    /// <returns>The service collection for chaining.</returns>
    public static IServiceCollection AddAirGapSyncServices(
        this IServiceCollection services,
        string nodeId)
    {
        ArgumentException.ThrowIfNullOrWhiteSpace(nodeId);

        // Core services
        services.TryAddSingleton<IConflictResolver, ConflictResolver>();
        services.TryAddSingleton<IHlcMergeService, HlcMergeService>();
        services.TryAddSingleton<IAirGapBundleImporter, AirGapBundleImporter>();

        // Register in-memory HLC state store for offline operation
        services.TryAddSingleton<IHlcStateStore, InMemoryHlcStateStore>();

        // Register HLC clock with node ID
        services.TryAddSingleton<IHybridLogicalClock>(sp =>
        {
            var timeProvider = sp.GetService<TimeProvider>() ?? TimeProvider.System;
            var stateStore = sp.GetRequiredService<IHlcStateStore>();
            var logger = sp.GetRequiredService<ILogger<HybridLogicalClock.HybridLogicalClock>>();
            return new HybridLogicalClock.HybridLogicalClock(timeProvider, nodeId, stateStore, logger);
        });

        // Register deterministic GUID provider
        services.TryAddSingleton<IGuidProvider>(SystemGuidProvider.Instance);

        // File-based store (can be overridden)
        services.TryAddSingleton<IOfflineJobLogStore, FileBasedOfflineJobLogStore>();

        // Offline HLC manager
        services.TryAddSingleton<IOfflineHlcManager, OfflineHlcManager>();

        // Bundle exporter
        services.TryAddSingleton<IAirGapBundleExporter, AirGapBundleExporter>();

        // Bundle DSSE signer (OMP-010)
        services.TryAddSingleton<IAirGapBundleDsseSigner, AirGapBundleDsseSigner>();

        return services;
    }

    /// <summary>
    /// Adds air-gap sync services with custom options.
    /// </summary>
    /// <param name="services">The service collection.</param>
    /// <param name="nodeId">The node identifier for this instance.</param>
    /// <param name="configureOptions">Action to configure file-based store options.</param>
    /// <returns>The service collection for chaining.</returns>
    public static IServiceCollection AddAirGapSyncServices(
        this IServiceCollection services,
        string nodeId,
        Action<FileBasedOfflineJobLogStoreOptions> configureOptions)
    {
        // Configure file-based store options
        services.Configure(configureOptions);

        return services.AddAirGapSyncServices(nodeId);
    }

    /// <summary>
    /// Adds the air-gap sync service for importing bundles to the central scheduler.
    /// </summary>
    /// <param name="services">The service collection.</param>
    /// <returns>The service collection for chaining.</returns>
    /// <remarks>
    /// This requires ISyncSchedulerLogRepository to be registered separately,
    /// as it depends on the Scheduler.Persistence module.
    /// </remarks>
    public static IServiceCollection AddAirGapSyncImportService(this IServiceCollection services)
    {
        services.TryAddScoped<IAirGapSyncService, AirGapSyncService>();
        return services;
    }

    /// <summary>
    /// Adds file-based transport for job sync bundles.
    /// </summary>
    /// <param name="services">The service collection.</param>
    /// <returns>The service collection for chaining.</returns>
    public static IServiceCollection AddFileBasedJobSyncTransport(this IServiceCollection services)
    {
        services.TryAddSingleton<IJobSyncTransport, FileBasedJobSyncTransport>();
        return services;
    }

    /// <summary>
    /// Adds file-based transport for job sync bundles with custom options.
    /// </summary>
    /// <param name="services">The service collection.</param>
    /// <param name="configureOptions">Action to configure transport options.</param>
    /// <returns>The service collection for chaining.</returns>
    public static IServiceCollection AddFileBasedJobSyncTransport(
        this IServiceCollection services,
        Action<FileBasedJobSyncTransportOptions> configureOptions)
    {
        services.Configure(configureOptions);
        return services.AddFileBasedJobSyncTransport();
    }

    /// <summary>
    /// Adds Router-based transport for job sync bundles.
    /// </summary>
    /// <param name="services">The service collection.</param>
    /// <returns>The service collection for chaining.</returns>
    /// <remarks>
    /// Requires IRouterJobSyncClient to be registered separately.
    /// </remarks>
    public static IServiceCollection AddRouterJobSyncTransport(this IServiceCollection services)
    {
        services.TryAddSingleton<IJobSyncTransport, RouterJobSyncTransport>();
        return services;
    }

    /// <summary>
    /// Adds Router-based transport for job sync bundles with custom options.
    /// </summary>
    /// <param name="services">The service collection.</param>
    /// <param name="configureOptions">Action to configure transport options.</param>
    /// <returns>The service collection for chaining.</returns>
    public static IServiceCollection AddRouterJobSyncTransport(
        this IServiceCollection services,
        Action<RouterJobSyncTransportOptions> configureOptions)
    {
        services.Configure(configureOptions);
        return services.AddRouterJobSyncTransport();
    }
}