namespace EntitlementBLL.Exceptions;

/// <summary>Thrown by IEntitlementService.EnsureQuotaAsync when a quota-type feature would be
/// exceeded by the requested delta (Layer 8 of the resolution algorithm).</summary>
public class EntitlementQuotaExceededException : Exception
{
    public string FeatureCode  { get; }
    public long   CurrentUsage { get; }
    public long   Quota        { get; }
    public long   Delta        { get; }

    public EntitlementQuotaExceededException(string featureCode, long currentUsage, long quota, long delta)
        : base($"Quota exceeded for feature '{featureCode}': current usage {currentUsage} + delta {delta} > quota {quota}.")
    {
        FeatureCode  = featureCode;
        CurrentUsage = currentUsage;
        Quota        = quota;
        Delta        = delta;
    }
}

/// <summary>Thrown when a subscription, plan, feature, or flag referenced by id/code does not exist.</summary>
public class EntitlementNotFoundException : Exception
{
    public EntitlementNotFoundException(string message) : base(message) { }
}

/// <summary>Thrown when a signed bundle fails ECDSA signature verification or has expired.</summary>
public class EntitlementBundleVerificationException : Exception
{
    public EntitlementBundleVerificationException(string message) : base(message) { }
}

/// <summary>Thrown by IClientProvisioningBLL.CreateClientAsync when the requested ClientCode
/// is already in use (Thread 1 §2.2, narrowed to MCLIENT/MUSER creation).</summary>
public class ClientCodeAlreadyExistsException : Exception
{
    public ClientCodeAlreadyExistsException(string clientCode)
        : base($"ClientCode '{clientCode}' is already in use.") { }
}