namespace JdeScoping.DataSync.Contracts;

/// <summary>
/// Interface for fetching data from source systems (JDE/CMS).
/// </summary>
/// <typeparam name="TEntity">The entity type being fetched.</typeparam>
public interface IDataFetcher<TEntity> where TEntity : class
{
    /// <summary>
    /// Fetches entities from source system as an async stream.
    /// </summary>
    /// <param name="minimumDt">For incremental fetches, only return records modified after this time. Null for full fetch.</param>
    /// <param name="cancellationToken">Cancellation token for graceful shutdown.</param>
    /// <returns>Async enumerable of entities, streamed from source.</returns>
    IAsyncEnumerable<TEntity> FetchAsync(
        DateTime? minimumDt,
        CancellationToken cancellationToken = default);

    /// <summary>
    /// Gets the entity type name for logging purposes.
    /// </summary>
    string EntityTypeName => typeof(TEntity).Name;
}