using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Text;

// ReSharper disable once InconsistentNaming

namespace OpenHardwareMonitor.Hardware.Motherboard.Lpc;

internal class LMSensors
{
    private const string HwMonPath = "/sys/class/hwmon/";
    private readonly List<ISuperIO> _superIOs = [];

    public LMSensors()
    {
        if (!Directory.Exists(HwMonPath))
            return;

        foreach (string basePath in Directory.GetDirectories(HwMonPath))
        {
            foreach (string devicePath in new[] { "/device", string.Empty })
            {
                string path = basePath + devicePath;
                string name = null;

                try
                {
                    using StreamReader reader = new(path + "/name");
                    name = reader.ReadLine();
                }
                catch (IOException)
                { }

                switch (name)
                {
                    case "atk0110":
                        _superIOs.Add(new LMChip(Chip.ATK0110, path));
                        break;

                    case "f71858fg":
                        _superIOs.Add(new LMChip(Chip.F71858, path));
                        break;
                    case "f71862fg":
                        _superIOs.Add(new LMChip(Chip.F71862, path));
                        break;
                    case "f71869":
                        _superIOs.Add(new LMChip(Chip.F71869, path));
                        break;
                    case "f71869a":
                        _superIOs.Add(new LMChip(Chip.F71869A, path));
                        break;
                    case "f71882fg":
                        _superIOs.Add(new LMChip(Chip.F71882, path));
                        break;
                    case "f71889a":
                        _superIOs.Add(new LMChip(Chip.F71889AD, path));
                        break;
                    case "f71878ad":
                        _superIOs.Add(new LMChip(Chip.F71878AD, path));
                        break;
                    case "f71889ed":
                        _superIOs.Add(new LMChip(Chip.F71889ED, path));
                        break;
                    case "f71889fg":
                        _superIOs.Add(new LMChip(Chip.F71889F, path));
                        break;
                    case "f71808e":
                        _superIOs.Add(new LMChip(Chip.F71808E, path));
                        break;

                    case "it8705":
                        _superIOs.Add(new LMChip(Chip.IT8705F, path));
                        break;
                    case "it8712":
                        _superIOs.Add(new LMChip(Chip.IT8712F, path));
                        break;
                    case "it8716":
                        _superIOs.Add(new LMChip(Chip.IT8716F, path));
                        break;
                    case "it8718":
                        _superIOs.Add(new LMChip(Chip.IT8718F, path));
                        break;
                    case "it8720":
                        _superIOs.Add(new LMChip(Chip.IT8720F, path));
                        break;

                    case "nct6775":
                        _superIOs.Add(new LMChip(Chip.NCT6771F, path));
                        break;
                    case "nct6776":
                        _superIOs.Add(new LMChip(Chip.NCT6776F, path));
                        break;
                    case "nct6779":
                        _superIOs.Add(new LMChip(Chip.NCT6779D, path));
                        break;
                    case "nct6791":
                        _superIOs.Add(new LMChip(Chip.NCT6791D, path));
                        break;
                    case "nct6792":
                        _superIOs.Add(new LMChip(Chip.NCT6792D, path));
                        break;
                    case "nct6793":
                        _superIOs.Add(new LMChip(Chip.NCT6793D, path));
                        break;
                    case "nct6795":
                        _superIOs.Add(new LMChip(Chip.NCT6795D, path));
                        break;
                    case "nct6796":
                        _superIOs.Add(new LMChip(Chip.NCT6796D, path));
                        break;
                    case "nct6797":
                        _superIOs.Add(new LMChip(Chip.NCT6797D, path));
                        break;
                    case "nct6798":
                        _superIOs.Add(new LMChip(Chip.NCT6798D, path));
                        break;
                    case "nct6799":
                        _superIOs.Add(new LMChip(Chip.NCT6799D, path));
                        break;

                    case "w83627ehf":
                        _superIOs.Add(new LMChip(Chip.W83627EHF, path));
                        break;
                    case "w83627dhg":
                        _superIOs.Add(new LMChip(Chip.W83627DHG, path));
                        break;
                    case "w83667hg":
                        _superIOs.Add(new LMChip(Chip.W83667HG, path));
                        break;
                    case "w83627hf":
                        _superIOs.Add(new LMChip(Chip.W83627HF, path));
                        break;
                    case "w83627thf":
                        _superIOs.Add(new LMChip(Chip.W83627THF, path));
                        break;
                    case "w83687thf":
                        _superIOs.Add(new LMChip(Chip.W83687THF, path));
                        break;
                }
            }
        }
    }

    public IReadOnlyList<ISuperIO> SuperIO
    {
        get { return _superIOs; }
    }

    public void Close()
    {
        foreach (ISuperIO superIO in _superIOs)
        {
            if (superIO is LMChip lmChip)
                lmChip.Close();
        }
    }

    private class LMChip : ISuperIO
    {
        private readonly FileStream[] _fanStreams;
        private readonly FileStream[] _temperatureStreams;

        private readonly FileStream[] _voltageStreams;
        private string _path;

        public LMChip(Chip chip, string path)
        {
            _path = path;
            Chip = chip;

            string[] voltagePaths = Directory.GetFiles(path, "in*_input");
            Voltages = new float?[voltagePaths.Length];
            _voltageStreams = new FileStream[voltagePaths.Length];
            for (int i = 0; i < voltagePaths.Length; i++)
                _voltageStreams[i] = new FileStream(voltagePaths[i], FileMode.Open, FileAccess.Read, FileShare.ReadWrite);

            string[] temperaturePaths = Directory.GetFiles(path, "temp*_input");
            Temperatures = new float?[temperaturePaths.Length];
            _temperatureStreams = new FileStream[temperaturePaths.Length];
            for (int i = 0; i < temperaturePaths.Length; i++)
                _temperatureStreams[i] = new FileStream(temperaturePaths[i], FileMode.Open, FileAccess.Read, FileShare.ReadWrite);

            string[] fanPaths = Directory.GetFiles(path, "fan*_input");
            Fans = new float?[fanPaths.Length];
            _fanStreams = new FileStream[fanPaths.Length];
            for (int i = 0; i < fanPaths.Length; i++)
                _fanStreams[i] = new FileStream(fanPaths[i], FileMode.Open, FileAccess.Read, FileShare.ReadWrite);

            Controls = Array.Empty<float?>();
        }

        public Chip Chip { get; }

        public float?[] Controls { get; }

        public float?[] Fans { get; }

        public float?[] Temperatures { get; }

        public float?[] Voltages { get; }

        public byte? ReadGpio(int index)
        {
            return null;
        }

        public void WriteGpio(int index, byte value)
        { }

        public string GetReport()
        {
            return null;
        }

        public void SetControl(int index, byte? value)
        { }

        public void Update()
        {
            for (int i = 0; i < Voltages.Length; i++)
            {
                string s = ReadFirstLine(_voltageStreams[i]);
                try
                {
                    Voltages[i] = 0.001f *
                                  long.Parse(s, CultureInfo.InvariantCulture);
                }
                catch
                {
                    Voltages[i] = null;
                }
            }

            for (int i = 0; i < Temperatures.Length; i++)
            {
                string s = ReadFirstLine(_temperatureStreams[i]);
                try
                {
                    Temperatures[i] = 0.001f *
                                      long.Parse(s, CultureInfo.InvariantCulture);
                }
                catch
                {
                    Temperatures[i] = null;
                }
            }

            for (int i = 0; i < Fans.Length; i++)
            {
                string s = ReadFirstLine(_fanStreams[i]);
                try
                {
                    Fans[i] = long.Parse(s, CultureInfo.InvariantCulture);
                }
                catch
                {
                    Fans[i] = null;
                }
            }
        }

        private static string ReadFirstLine(Stream stream)
        {
            StringBuilder sb = new();
            try
            {
                stream.Seek(0, SeekOrigin.Begin);
                int b = stream.ReadByte();
                while (b is not -1 and not 10)
                {
                    sb.Append((char)b);
                    b = stream.ReadByte();
                }
            }
            catch
            { }

            return sb.ToString();
        }

        public void Close()
        {
            foreach (FileStream stream in _voltageStreams)
                stream.Close();

            foreach (FileStream stream in _temperatureStreams)
                stream.Close();

            foreach (FileStream stream in _fanStreams)
                stream.Close();
        }
    }
}
