#nullable enable

using System;

namespace ShrinkEventBus
{
    public sealed class ShrinkEventBusBuilder
    {
        internal ShrinkBusKey Key { get; private set; } = ShrinkBusKey.Game;
        internal ShrinkBusOptions Options { get; private set; } = ShrinkBusOptions.Inline();
        internal Action<IShrinkEvent, Type, ShrinkBusKey>? PostObserver { get; private set; }

        public ShrinkEventBusBuilder WithKey(ShrinkBusKey key)
        {
            Key = key;
            return this;
        }

        public ShrinkEventBusBuilder WithOptions(ShrinkBusOptions options)
        {
            Options = (options ?? throw new ArgumentNullException(nameof(options))).CloneValidated();
            return this;
        }

        public IShrinkEventBus Build() => Options.Scheduler == ShrinkBusSchedulerKind.Inline
            ? new ShrinkInlineEventBusInstance(this)
            : new ShrinkEventBusInstance(this);

        internal ShrinkEventBusBuilder WithPostObserver(
            Action<IShrinkEvent, Type, ShrinkBusKey> observer)
        {
            PostObserver = observer ?? throw new ArgumentNullException(nameof(observer));
            return this;
        }
    }
}