using System;

namespace Tapeti.Annotations
{
    /// <inheritdoc />
    /// <summary>
    /// Can be attached to a message class to override or extend the generated routing key.
    /// One of the intended scenarios is for versioning messages, where you want to add for example a
    /// ".v2" postfix but keep the class name itself the same (in a different namespace of course).
    /// </summary>
    /// <remarks>
    /// The implementation of IRoutingKeyStrategy must explicitly add support for this attribute for it to have effect.
    /// The default implementation (TypeNameRoutingKeyStrategy) does, of course. Custom implementations can use
    /// the Tapeti.Helpers.RoutingKeyHelper class to add support and keep up-to-date automatically.
    /// 
    /// When using EnableDeclareDurableQueues to automatically generate the queue bindings, both the sender and receiver must
    /// use a Tapeti version >= 2.5 to support this attribute or the binding will differ from the sent routing key.
    ///
    /// The routing keys are no longer used by Tapeti once the message is in the queue, the message handler
    /// is instead based on the full message class name (thus including namespace), so if the binding is generated in any
    /// other way this remark does not apply and prior versions of Tapeti are compatible.
    /// </remarks>
    [AttributeUsage(AttributeTargets.Class)]
    public class RoutingKeyAttribute : Attribute
    {
        /// <summary>
        /// If specified, the routing key strategy is skipped altogether and this value is used instead.
        /// </summary>
        /// <remarks>
        /// The Prefix and Postfix properties will not have any effect if the Full property is specified.
        /// </remarks>
        public string Full { get; set; }

        /// <summary>
        /// If specified, the value generated by the default routing key strategy is prefixed with this value.
        /// No dot will be added after this prefix, if you want to include it add it as part of the value.
        /// </summary>
        /// <remarks>
        /// This property will not have any effect if the Full property is specified. Can be used in combination with Postfix.
        /// </remarks>
        public string Prefix { get; set; }

        /// <summary>
        /// If specified, the value generated by the default routing key strategy is postfixed with this value.
        /// No dot will be added before this postfix, if you want to include it add it as part of the value.
        /// </summary>
        /// <remarks>
        /// This property will not have any effect if the Full property is specified. Can be used in combination with Prefix.
        /// </remarks>
        public string Postfix { get; set; }
    }
}