using GB5Shared.ActionProcessor;
using System.Threading;
using System.Threading.Tasks;

namespace FrameworkBLL.ActionProcessor.Handlers
{
    /// <summary>
    /// Defines a contract for executing an action based on ActionType.
    /// Each implementation handles a specific action type
    /// (Email, SMS, Webhook, Notification, Report, etc.).
    ///
    /// Implementations are typically registered in Dependency Injection
    /// as Singleton services.
    /// </summary>
    public interface IActionHandler
    {
        /// <summary>
        /// Gets the integer ActionType handled by this implementation.
        ///
        /// Standard ActionType mapping:
        /// 0 = Email
        /// 1 = SMS
        /// 2 = Webhook
        /// 3 = Correspondence (document/template delivery)
        /// 4 = Report
        /// 5 = EIP Notification (SignalR push to active conversation session)
        /// </summary>
        int ActionType { get; }

    /// <summary>
    /// Executes the action asynchronously.
    /// </summary>
    /// <param name="dto">Action event data containing payload and execution context.</param>
    /// <param name="ct">Optional cancellation token.</param>
    /// <returns>Execution result indicating success, retry, or permanent failure.</returns>
    Task<ActionResult> HandleAsync(ActionEventDto dto, CancellationToken ct = default);
    }

    /// <summary>
    /// Resolves the correct IActionHandler implementation
    /// based on the provided ActionType.
    /// </summary>
    public interface IActionHandlerResolver
    {
        /// <summary>
        /// Returns the handler associated with the given ActionType.
        /// Returns null if no handler is registered for that type.
        /// </summary>
        /// <param name="actionType">Integer representing the action type.</param>
        /// <returns>IActionHandler instance or null if not found.</returns>
        IActionHandler? Resolve(int actionType);
    }
}