using System;
using System.Text.Json;
using System.Threading;

namespace Barsik
{
	/// <summary>
	/// Parses output of "sensors" command and puts CPU core temperatures into
	/// registers
	/// </summary>
	class SensorsMonitoringUnit : BaseMonitoringUnit
	{
		const string CORE_STR = "Core{0} Temp:";

		public SensorsMonitoringUnit(JsonElement config, RegistersContainer registers) : base(config, registers)
		{
		}

		public override void Run()
		{
			int cores = config.GetProperty("Cores").GetInt32();
			var multiplier = config.GetProperty("Multiplier").GetDouble();
			while (true)
			{
				System.Diagnostics.ProcessStartInfo procStartInfo = new System.Diagnostics.ProcessStartInfo("sensors");
				procStartInfo.RedirectStandardOutput = true;
				procStartInfo.UseShellExecute = false;
				procStartInfo.CreateNoWindow = true;
				using (System.Diagnostics.Process proc = new System.Diagnostics.Process())
				{
					proc.StartInfo = procStartInfo;
					proc.Start();
					while (!proc.HasExited)
					{
						Thread.Sleep(100);
					}
					string result = proc.StandardOutput.ReadToEnd();
					var lines = result.Split('\n');
					// lines in output will be of format:
					// Core0 Temp:   +29.0°C  
					// and there could be several lines for one core
					// so let's take all of them and use maximal value as core temp
					float[] t = new float[cores];
					for (int i = 0; i < cores; i++)
					{
						t[i] = 0;
					}
					for (int i = 0; i < lines.Length; i++)
					{
						for (int j = 0; j < cores; j++)
						{
							string toFind = string.Format(CORE_STR, j);
							if (lines[i].Contains(toFind))
							{
								var value = ExtractValue(lines[i].Substring(toFind.Length));
								t[j] = Math.Max(t[j], value);
							}
						}
					}
					// fill register data starting from baseAddress
					for (int i = 0; i < cores; i++)
					{
						registers[baseAddress + i] = (int)(t[i] * multiplier);
					}
				}
				Thread.Sleep(2000);
			}
		}

		bool Good(char c)
		{
			if (c == '-' || c == '+' || c == '.') return true;
			if (c >= '0' && c <= '9') return true;
			return false;
		}

		private float ExtractValue(string v)
		{
			int pos = 0;
			while (pos < v.Length && !Good(v[pos])) pos++;
			int pos2 = pos;
			while (pos2 < v.Length && Good(v[pos2])) pos2++;
			float res;
			float.TryParse(v.Substring(pos, pos2 - pos), out res);
			return res;
		}
	}
}