using System;
using System.Collections.Generic;

namespace Svrnty.CQRS.Sagas.Abstractions;

/// <summary>
/// Provides context information during saga step execution.
/// </summary>
public interface ISagaContext
{
    /// <summary>
    /// Unique identifier for this saga instance.
    /// </summary>
    Guid SagaId { get; }

    /// <summary>
    /// Correlation ID for tracing across services.
    /// </summary>
    Guid CorrelationId { get; }

    /// <summary>
    /// The fully qualified type name of the saga.
    /// </summary>
    string SagaType { get; }

    /// <summary>
    /// Index of the current step being executed.
    /// </summary>
    int CurrentStepIndex { get; }

    /// <summary>
    /// Name of the current step being executed.
    /// </summary>
    string CurrentStepName { get; }

    /// <summary>
    /// Results from completed steps, keyed by step name.
    /// </summary>
    IReadOnlyDictionary<string, object?> StepResults { get; }

    /// <summary>
    /// Gets a result from a previous step.
    /// </summary>
    /// <typeparam name="T">The expected result type.</typeparam>
    /// <param name="stepName">The name of the step.</param>
    /// <returns>The result, or default if not found.</returns>
    T? GetStepResult<T>(string stepName);

    /// <summary>
    /// Sets a result for the current step (available to subsequent steps).
    /// </summary>
    /// <typeparam name="T">The result type.</typeparam>
    /// <param name="result">The result value.</param>
    void SetStepResult<T>(T result);
}