using Amphora;
using System;

namespace Susurrus.XAudio2
{
    /// <summary>
    /// Interprets failures that carry the name of the call that failed in Ref and its HRESULT in Bits.
    /// </summary>
    public class HResultFailureKind : FailureKind
    {
        public const int InvalidArgument = unchecked((int)0x80070057);
        public const int OutOfMemory = unchecked((int)0x8007000E);
        public const int InvalidCall = unchecked((int)0x88960001);
        public const int DeviceInvalidated = unchecked((int)0x88960004);

        public HResultFailureKind(string name) : base(name)
        {
        }

        public Status Fail(string call, int hresult)
        {
            if (call == null)
            {
                throw new ArgumentNullException(nameof(call));
            }

            return Status.FromWire(this, call, hresult);
        }

        /// <summary>
        /// Returns the HRESULT the failed <paramref name="status"/>, which has to be of this kind, carries.
        /// </summary>
        public int HResultOf(in Status status)
        {
            if (status.Kind != this)
            {
                ThrowWrongKind(status.Kind);
            }

            return (int)status.Bits;
        }

        /// <summary>
        /// Returns the name of the call that failed in <paramref name="status"/>, which has to be of this kind.
        /// </summary>
        public string CallOf(in Status status)
        {
            if (status.Kind != this)
            {
                ThrowWrongKind(status.Kind);
            }

            return (string)status.Ref;
        }

        public override string Describe(in Status status, object context)
        {
            int hresult = HResultOf(in status);
            string call = CallOf(in status);
            string hex = "0x" + hresult.ToString("X8");

            switch (hresult)
            {
                case InvalidArgument:
                    return $"{call} was given an invalid argument ({hex}).";
                case OutOfMemory:
                    return $"{call} ran out of memory ({hex}).";
                case InvalidCall:
                    return $"{call} isn't allowed in the engine's current state ({hex}).";
                case DeviceInvalidated:
                    return $"{call} failed because the audio device went away or can't be used ({hex}).";
                default:
                    return $"{call} failed with HRESULT {hex}.";
            }
        }
    }
}