using Amphora;
using System;
using UnitTestSharp;
using static Susurrus.UnitTests.TestSounds;

namespace Susurrus.UnitTests
{
    public class DecodedSoundTests : TestFixture
    {
        public class CtorTests : TestFixture
        {
            public void AssignsAllFourComponents()
            {
                byte[] bytes = new byte[8];
                DecodedSound sound = new DecodedSound(new ByteView(bytes), sampleRate: 22050, channelCount: 2,
                    format: SampleFormat.Float32);

                CheckTrue(sound.Samples.IsOver(bytes));
                CheckEqual(22050, sound.SampleRate);
                CheckEqual(2, sound.ChannelCount);
                CheckEqual(SampleFormat.Float32, sound.Format);
            }

            public void KeepsTheWindowOfTheViewItWasGiven()
            {
                ByteView window = new ByteView(new byte[10], startIndex: 2, endIndex: 6);
                DecodedSound sound = new DecodedSound(window, sampleRate: 44100, channelCount: 1,
                    format: SampleFormat.Pcm16);

                CheckEqual(2, sound.Samples.StartIndex);
                CheckEqual(6, sound.Samples.EndIndex);
                CheckEqual(2, sound.FrameCount);
            }

            public void AcceptsNoSamples()
            {
                CheckEqual(0, new DecodedSound(Silence(0), 44100, 1, SampleFormat.Pcm16).FrameCount);
            }

            public void RejectsADefaultView()
            {
                CheckThrow(typeof(ArgumentException));
                new DecodedSound(default(ByteView), 44100, 1, SampleFormat.Pcm16);
            }

            public void RejectsZeroSampleRate()
            {
                CheckThrow(typeof(ArgumentOutOfRangeException));
                new DecodedSound(Silence(2), sampleRate: 0, channelCount: 1, format: SampleFormat.Pcm16);
            }

            public void RejectsZeroChannels()
            {
                CheckThrow(typeof(ArgumentOutOfRangeException));
                new DecodedSound(Silence(2), sampleRate: 44100, channelCount: 0, format: SampleFormat.Pcm16);
            }

            public void RejectsAnUndefinedFormat()
            {
                CheckThrow(typeof(ArgumentOutOfRangeException));
                new DecodedSound(Silence(2), sampleRate: 44100, channelCount: 1, format: (SampleFormat)99);
            }

            public void RejectsBytesThatEndMidFrame()
            {
                CheckThrow(typeof(ArgumentException));
                new DecodedSound(Silence(6), sampleRate: 44100, channelCount: 2, format: SampleFormat.Pcm16);
            }
        }

        public class FrameCountTests : TestFixture
        {
            public void CountsEachFrameOnceAcrossChannels()
            {
                CheckEqual(3, new DecodedSound(Silence(24), 44100, channelCount: 2, format: SampleFormat.Float32)
                    .FrameCount);
            }

            public void CountsPcm16Frames()
            {
                CheckEqual(5, new DecodedSound(Silence(10), 44100, channelCount: 1, format: SampleFormat.Pcm16)
                    .FrameCount);
            }
        }

        public class DurationTests : TestFixture
        {
            public void IsFramesDividedByTheSampleRate()
            {
                CheckEqual(TimeSpan.FromSeconds(0.5), new DecodedSound(Silence(22050 * 2), sampleRate: 44100,
                    channelCount: 1, format: SampleFormat.Pcm16).Duration);
            }

            public void TruncatesToWholeTicks()
            {
                CheckEqual(TimeSpan.FromTicks(3333333), new DecodedSound(Silence(2), sampleRate: 3,
                    channelCount: 1, format: SampleFormat.Pcm16).Duration);
            }

            public void IsZeroWithNoSamples()
            {
                CheckEqual(TimeSpan.Zero, new DecodedSound(Silence(0), 44100, 1, SampleFormat.Pcm16).Duration);
            }
        }

        public class GetBytesPerSampleTests : TestFixture
        {
            public void Pcm16IsTwo()
            {
                CheckEqual(2, DecodedSound.GetBytesPerSample(SampleFormat.Pcm16));
            }

            public void Float32IsFour()
            {
                CheckEqual(4, DecodedSound.GetBytesPerSample(SampleFormat.Float32));
            }

            public void RejectsAnUndefinedFormat()
            {
                CheckThrow(typeof(ArgumentOutOfRangeException));
                DecodedSound.GetBytesPerSample((SampleFormat)99);
            }
        }
    }
}