using System.Diagnostics;
using static CommonHelpers.Log;

namespace SteamController.Devices
{
    public partial class SteamController : IDisposable
    {
        public const ushort VendorID = 0x28DE;
        public const ushort ProductID = 0x1205;
        private const int ReadTimeout = 50;
        public const int MaxFailures = 10;

        private hidapi.HidDevice neptuneDevice;
        private Stopwatch stopwatch = new Stopwatch();
        private TimeSpan? lastUpdate;
        private int failures;
        public long ElapsedMilliseconds { get => stopwatch.ElapsedMilliseconds; }
        public double DeltaTime { get; private set; }

        internal SteamController()
        {
            InitializeButtons();
            InitializeActions();

            OpenDevice();

            stopwatch.Start();
        }

        ~SteamController()
        {
            Dispose();
        }

        public void Dispose()
        {
            GC.SuppressFinalize(this);
            using (neptuneDevice) { }
        }

        public bool Updated { get; private set; }

        private void OpenDevice()
        {
            using (neptuneDevice) { }
            neptuneDevice = new hidapi.HidDevice(VendorID, ProductID, 64);
            neptuneDevice.OpenDevice();
        }

        internal void Fail(bool immediately = false)
        {
            foreach (var action in AllActions)
                action.Reset();

            // Try to re-open every MaxFailures
            failures++;
            if (failures % MaxFailures == 0 || immediately)
            {
                OpenDevice();
                failures = 0;
            }
        }

        private void BeforeUpdate(byte[] buffer)
        {
            foreach (var action in AllActions)
                action.BeforeUpdate(buffer);
        }

        internal void BeforeUpdate()
        {
            var ts = stopwatch.Elapsed;
            DeltaTime = lastUpdate is not null ? (ts - lastUpdate.Value).TotalSeconds : 0.0;
            DeltaTime = Math.Min(DeltaTime, 0.1); // max update is 100ms
            lastUpdate = ts;

            LizardButtons = true;
            LizardMouse = true;

            try
            {
                byte[] data = neptuneDevice.Read(ReadTimeout);
                if (data == null)
                {
                    Fail();
                    Updated = false;
                    return;
                }

                BeforeUpdate(data);
                Updated = true;
            }
            catch (hidapi.HidDeviceInvalidException)
            {
                // Steam might disconnect device
                Fail();
                Updated = false;
            }
            catch (Exception e)
            {
                TraceException("STEAM", "BeforeUpdate", e);
                Fail();
                Updated = false;
            }
        }

        internal void Update()
        {
            foreach (var action in AllActions)
                action.Update();

            try
            {
                UpdateLizardButtons();
                UpdateLizardMouse();
            }
            catch (hidapi.HidDeviceInvalidException)
            {
                // Steam might disconnect device
                Fail();
            }
            catch (Exception e)
            {
                // Steam have disconnected device, which triggered exception
                if (e.Message == "Could not send report to hid device. Error: -1")
                    DebugException("STEAM", "Update", e);
                else
                    TraceException("STEAM", "Update", e);
                Fail();
            }
        }
    }
}