using System;
using System.Collections.Generic;
using System.Linq;
using UnityEngine;

namespace Sensors.ANT
{
    public abstract class AwaitDevice
    {
        public abstract int DeviceId { get; }

        public abstract bool Connected { get; }

        public abstract void Connect(AntDevice device);
    }

    public class AntDevices
    {
        #region singleton

        private static readonly Lazy<AntDevices>
            Lazy =
                new Lazy<AntDevices>
                    (() => new AntDevices());

        public static AntDevices Instance => Lazy.Value;

        #endregion

        public List<AntDevice> ScanResult { get; private set; }

        private List<AwaitDevice> awaitDevices;

        private AntChannel backgroundScanChannel;

        public void StartScan(List<AwaitDevice> devices)
        {
            awaitDevices = devices;
            if (backgroundScanChannel != null) backgroundScanChannel.Close();

            Debug.Log("Looking for ANT + Sensors");
            AntManager.Instance.Init();

            ScanResult = new List<AntDevice>();
            backgroundScanChannel = AntManager.Instance.OpenBackgroundScanChannel(0);
            backgroundScanChannel.onReceiveData += ReceivedBackgroundScanData;
        }

        private void ReceivedBackgroundScanData(byte[] data)
        {
            var deviceType = data[12]; // extended info Device Type byte
            var deviceNumber = data[10] | (data[11] << 8);
            var transType = data[13];

            int period = -1;
            int radioFreq = -1;
            String deviceTypeName ="";

            switch (deviceType)
            {
                case AntplusDeviceType.BikePower:
                    period = 8182;
                    radioFreq = 57;
                    deviceTypeName = "Power";
                    break;
                case AntplusDeviceType.BikeSpeed:
                    period = 8118;
                    radioFreq = 57;
                    deviceTypeName = "Speed";
                    break;
                case AntplusDeviceType.HeartRate:
                    period = 8070;
                    radioFreq = 57;
                    deviceTypeName = "HR";
                    break;
            }

            if (period < 0)
            {
                //Debug.Log($"Device type {deviceType} not supported");
                return;
            }

            if (ScanResult.Any(d => d.deviceNumber == deviceNumber && d.transType == transType))
            {
                return;
            }

            var foundDevice = new AntDevice
            {
                deviceType = deviceType,
                deviceNumber = deviceNumber,
                transType = transType,
                period = period,
                radiofreq = radioFreq
            };

            foundDevice.name = $"{deviceTypeName}(" + foundDevice.deviceNumber + ")";
            Debug.Log($"Found device: {foundDevice.name}");
            ScanResult.Add(foundDevice);

            awaitDevices.FirstOrDefault(d => d.DeviceId == foundDevice.deviceNumber)?.Connect(foundDevice);

            if (awaitDevices.TrueForAll(d => d.Connected))
            {
                Debug.Log("All desired devices found. Closing background scan channel;");
                backgroundScanChannel.Close();
            }
        }
    }
}