using System;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.DependencyInjection.Extensions;
using Svrnty.CQRS.Configuration;
using Svrnty.CQRS.Sagas.Abstractions;
using Svrnty.CQRS.Sagas.Abstractions.Persistence;
using Svrnty.CQRS.Sagas.Configuration;
using Svrnty.CQRS.Sagas.Persistence;

namespace Svrnty.CQRS.Sagas;

/// <summary>
/// Extensions for adding saga support to the CQRS pipeline.
/// </summary>
public static class CqrsBuilderExtensions
{
    /// <summary>
    /// Adds saga orchestration support to the CQRS pipeline.
    /// </summary>
    /// <param name="builder">The CQRS builder.</param>
    /// <param name="configure">Optional configuration action.</param>
    /// <returns>The CQRS builder for chaining.</returns>
    public static CqrsBuilder AddSagas(this CqrsBuilder builder, Action<SagaOptions>? configure = null)
    {
        var options = new SagaOptions();
        configure?.Invoke(options);

        builder.Services.Configure<SagaOptions>(opt =>
        {
            opt.DefaultStepTimeout = options.DefaultStepTimeout;
            opt.DefaultMaxRetries = options.DefaultMaxRetries;
            opt.DefaultRetryDelay = options.DefaultRetryDelay;
            opt.AutoCompensateOnFailure = options.AutoCompensateOnFailure;
            opt.StalledSagaCheckInterval = options.StalledSagaCheckInterval;
            opt.StepStalledTimeout = options.StepStalledTimeout;
        });

        // Store configuration
        builder.Configuration.SetConfiguration(options);

        // Register core saga services
        builder.Services.TryAddSingleton<ISagaOrchestrator, SagaOrchestrator>();

        // Register default in-memory state store if not already registered
        builder.Services.TryAddSingleton<ISagaStateStore, InMemorySagaStateStore>();

        return builder;
    }

    /// <summary>
    /// Registers a saga type with the CQRS pipeline.
    /// </summary>
    /// <typeparam name="TSaga">The saga type.</typeparam>
    /// <typeparam name="TData">The saga data type.</typeparam>
    /// <param name="builder">The CQRS builder.</param>
    /// <returns>The CQRS builder for chaining.</returns>
    public static CqrsBuilder AddSaga<TSaga, TData>(this CqrsBuilder builder)
        where TSaga : class, ISaga<TData>
        where TData : class, ISagaData, new()
    {
        builder.Services.AddTransient<TSaga>();
        builder.Services.AddTransient<ISaga<TData>, TSaga>();

        return builder;
    }

    /// <summary>
    /// Uses a custom saga state store implementation.
    /// </summary>
    /// <typeparam name="TStore">The state store implementation type.</typeparam>
    /// <param name="builder">The CQRS builder.</param>
    /// <returns>The CQRS builder for chaining.</returns>
    public static CqrsBuilder UseSagaStateStore<TStore>(this CqrsBuilder builder)
        where TStore : class, ISagaStateStore
    {
        // Remove existing registration
        var descriptor = new ServiceDescriptor(typeof(ISagaStateStore), typeof(TStore), ServiceLifetime.Singleton);
        builder.Services.Replace(descriptor);

        return builder;
    }
}