using System.Collections.Generic;
using JetBrains.Annotations;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using TBF.Rig;
using TBF.Rig.RegisterReaders.PoseidonCmdStartStop;
using CmdPoseidonReader = TBF.Rig.RegisterReaders.PoseidonCmdStartStop.PoseidonReader;

namespace TBFTests.Rig.RegisterReaders.PoseidonCmdStartStop
{
    [TestClass]
    [TestSubject(typeof(PoseidonReadCycle))]
    public class PoseidonReadCycleTest
    {
        private sealed class FakeReader : IPoseidonReadOperation
        {
            private readonly int iterationsToComplete;
            private int iterations;
            public FakeReader(string name, int iterationsToComplete) { Name = name; this.iterationsToComplete = iterationsToComplete; }
            public string Name { get; private set; }
            public int StartCount { get; private set; }
            public CmdPoseidonReader.CurrentPoseidonOp CurrentOp { get; private set; }
            public bool IsNotStarted { get { return CurrentOp == CmdPoseidonReader.CurrentPoseidonOp.None; } }
            public bool IsFinished { get { return CurrentOp == CmdPoseidonReader.CurrentPoseidonOp.Done || CurrentOp == CmdPoseidonReader.CurrentPoseidonOp.Error; } }
            public bool HasError { get { return CurrentOp == CmdPoseidonReader.CurrentPoseidonOp.Error; } }
            public void Start(bool readStart) { StartCount++; CurrentOp = readStart ? CmdPoseidonReader.CurrentPoseidonOp.ReadDataStream_Start : CmdPoseidonReader.CurrentPoseidonOp.ReadDataStream_End; }
            public Event Run()
            {
                if (CurrentOp == CmdPoseidonReader.CurrentPoseidonOp.ReadDataStream_Start || CurrentOp == CmdPoseidonReader.CurrentPoseidonOp.ReadDataStream_End)
                { CurrentOp = CmdPoseidonReader.CurrentPoseidonOp.ReadDatastream_Running; return Event.Busy; }
                if (CurrentOp == CmdPoseidonReader.CurrentPoseidonOp.ReadDatastream_Running && ++iterations >= iterationsToComplete)
                { CurrentOp = CmdPoseidonReader.CurrentPoseidonOp.Done; return Event.Done; }
                return Event.Busy;
            }
        }

        [TestMethod]
        public void RunIteration_FullBench_ArmsEachReaderOnce()
        {
            var readers = new List<IPoseidonReadOperation>();
            for (int i = 1; i <= 48; i++) readers.Add(new FakeReader("PoseidonPos" + i, 1 + i % 3));
            for (int i = 0; i < 5; i++) PoseidonReadCycle.RunIteration(readers, true);
            foreach (FakeReader reader in readers) Assert.AreEqual(1, reader.StartCount, reader.Name);
        }

        [TestMethod]
        public void RunIteration_ReducedBench_DoesNotRestartCompletedReader()
        {
            var readers = new List<IPoseidonReadOperation> { new FakeReader("Pos1", 1), new FakeReader("Pos2", 3) };
            for (int i = 0; i < 5; i++) PoseidonReadCycle.RunIteration(readers, false);
            foreach (FakeReader reader in readers) Assert.AreEqual(1, reader.StartCount, reader.Name);
        }

        [TestMethod]
        public void StartThenStop_PhasesArmTheSameReaderOncePerPhase()
        {
            var reader = new FakeReader("Pos1", 1);
            var readers = new List<IPoseidonReadOperation> { reader };
            var startPhase = new PoseidonReadPhaseRunner(true);

            // START phase completes.
            startPhase.RunIteration(readers);
            startPhase.RunIteration(readers);
            Assert.AreEqual(CmdPoseidonReader.CurrentPoseidonOp.Done, reader.CurrentOp);

            // A new STOP phase re-arms the terminal reader exactly once.
            var stopPhase = new PoseidonReadPhaseRunner(false);
            stopPhase.RunIteration(readers);
            stopPhase.RunIteration(readers);

            Assert.AreEqual(2, reader.StartCount);
            Assert.AreEqual(CmdPoseidonReader.CurrentPoseidonOp.Done, reader.CurrentOp);
        }

        [TestMethod]
        public void InputJson_ZeroReading_WithDecimalCommaOrDot_IsValid()
        {
            foreach (string reading in new[] { "00000,0", "00000.0" })
            {
                double value;
                Assert.IsTrue(CmdPoseidonReader.TryParseCliReading(reading, out value));
                Assert.AreEqual(0d, value);
            }
        }

        [TestMethod]
        public void CliReadResponse_RequiresNfcAndCompletedReading()
        {
            string reason;
            var data = new JsonDataFromPoseidon { NfcTagDetected = true, ReadingComplete = true, Reading = "00000.0" };
            Assert.IsTrue(CmdPoseidonReader.TryValidateCliReadResponse(data, out reason));
            data.ReadingComplete = false;
            Assert.IsFalse(CmdPoseidonReader.TryValidateCliReadResponse(data, out reason));
        }
    }
}