CooldownAttribute.cs

using System;
using Ultz.Extensions.Commands.Built;
using Ultz.Extensions.Commands.Cooldown;

namespace Ultz.Extensions.Commands.Attributes.Commands.Cooldown
{
    /// <summary>
    /// Applies a <see cref="Cooldown" /> to the <see cref="Command" />.
    /// </summary>
    [AttributeUsage(AttributeTargets.Method, AllowMultiple = true)]
    public class CooldownAttribute : Attribute
    {
        /// <summary>
        /// Initialises a new <see cref="CooldownAttribute" /> with the specified <see cref="Cooldown" /> properties.
        /// </summary>
        /// <param name="amount"> The amount of uses per given window. </param>
        /// <param name="per"> The bucket time window. </param>
        /// <param name="cooldownMeasure"> The unit of time of the given window. </param>
        /// <param name="bucketType"> The bucket type. Has to be an <see langword="enum" />. </param>
        /// <exception cref="ArgumentOutOfRangeException">
        /// Not a valid cooldown measure.
        /// </exception>
        public CooldownAttribute(int amount, double per, CooldownMeasure cooldownMeasure, object bucketType)
        {
            if (!(bucketType is Enum enumBucketType))
            {
                throw new ArgumentException("Bucket type must be an enum.", nameof(bucketType));
            }

            Amount = amount;
            Per = cooldownMeasure switch
            {
                CooldownMeasure.Milliseconds => TimeSpan.FromMilliseconds(per),
                CooldownMeasure.Seconds => TimeSpan.FromSeconds(per),
                CooldownMeasure.Minutes => TimeSpan.FromMinutes(per),
                CooldownMeasure.Hours => TimeSpan.FromHours(per),
                CooldownMeasure.Days => TimeSpan.FromDays(per),
                _ => throw new ArgumentOutOfRangeException(nameof(cooldownMeasure), "Invalid cooldown measure.")
            };
            BucketType = enumBucketType;
        }

        /// <summary>
        /// Gets the amount of times the <see cref="Command" /> can be used in the given time window.
        /// </summary>
        public int Amount { get; }

        /// <summary>
        /// Gets the time window of this cooldown.
        /// </summary>
        public TimeSpan Per { get; }

        /// <summary>
        /// Gets the <see langword="enum" /> bucket type to use with the <see cref="CooldownBucketKeyGeneratorDelegate" />.
        /// </summary>
        public Enum BucketType { get; }
    }
}