using GB5Shared.DTO.PubSub;

namespace GB5Shared.RuleEngine
{
    /// <summary>
    /// Evaluates a condition expression string against an <see cref="OutboxEventMessage"/>.
    /// Injected into EventSubBLL to filter MACTION rows before queueing.
    ///
    /// Expression format: "LHS operator RHS"
    ///   LHS: top-level property of OutboxEventMessage OR Payload.JsonFieldName
    ///   Operators: == != > &lt; >= &lt;=
    ///   RHS: literal value (number, string — no quotes needed)
    ///
    /// Examples:
    ///   "ObjectTypeId == 5"
    ///   "Payload.Amount > 100000"
    ///   "Payload.Status == Approved"
    ///
    /// Returns true when the expression is null/empty (pass-through — preserves existing behaviour).
    /// </summary>
    public interface IConditionEvaluator
    {
        /// <summary>
        /// Evaluates <paramref name="expression"/> against <paramref name="message"/>.
        /// Returns <c>true</c> when the condition passes or expression is null/empty.
        /// Returns <c>false</c> when the condition fails.
        /// Never throws — logs and returns <c>true</c> on parse error (fail-open to preserve existing delivery).
        /// </summary>
        bool Evaluate(string? expression, OutboxEventMessage message);
    }
}