using AprsSharp.Parsers.Aprs;
using GeoCoordinatePortable;
using Npgsql;
using NpgsqlTypes;
using skyscraper5.Aprs.AprsSharp;
using skyscraper5.Skyscraper.Scraper.Storage.Utilities;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using skyscraper5.Data.PostgreSql;

namespace skyscraper5.Aprs.AprsStorage
{
	internal class AprsPostgresqlStorage : LX9SESStorage
	{
		private readonly PostgresqlToken _postgresql;

		public AprsPostgresqlStorage(PostgresqlToken postgresql)
		{
			_postgresql = postgresql;
		}

		#region Background Worker
		private Thread _writerThread;
		private delegate void WriterTask(NpgsqlConnection connection);
		private Queue<WriterTask> _writerTasks;
		private void EnqueueTask(WriterTask task)
		{
			if (_writerTasks == null)
			{
				_writerTasks = new Queue<WriterTask>();
			}

			lock (_writerTasks)
			{
				_writerTasks.Enqueue(task);
			}

			if (_writerThread == null)
			{
				_writerThread = new Thread(WriterThreadFunction);
				_writerThread.Priority = ThreadPriority.Highest;
				_writerThread.Name = "PostgreSQL APRS Writer Thread";
				_writerThread.Start();
			}
		}

		private NpgsqlTransaction transaction;
		private void WriterThreadFunction()
		{
			using (NpgsqlConnection connection = new NpgsqlConnection(connectionStringBuilder.ToString()))
			{
				connection.Open();
				transaction = connection.BeginTransaction();
				while (_writerTasks.Count > 0)
				{
					WriterTask task;
					lock (_writerTasks)
					{
						task = _writerTasks.Dequeue();
					}
					task(connection);
				}
				transaction.Commit();
				transaction.Dispose();
				connection.Close();
			}

			_writerThread = null;
		}

		private void CommitTransaction(NpgsqlConnection conn)
		{
			transaction.Commit();
			transaction.Dispose();
			transaction = conn.BeginTransaction();
		}
		#endregion

		private HashSet<string> loadedAprsPositionHistories;
		private HashSet<DatabaseKeyAprsPosition> knownAprsPositions;
		public bool AprsPosition(DateTime currentTime, string packetSender, GeoCoordinate positionCoordinates, string piComment)
		{
			if (positionCoordinates.IsNull)
				return false;
			if (loadedAprsPositionHistories == null)
				loadedAprsPositionHistories = new HashSet<string>();
			if (knownAprsPositions == null)
				knownAprsPositions = new HashSet<DatabaseKeyAprsPosition>();
			if (!loadedAprsPositionHistories.Contains(packetSender))
			{
				FetchAprsPositionHistory(packetSender);
			}

			DatabaseKeyAprsPosition key = new DatabaseKeyAprsPosition(currentTime, packetSender, positionCoordinates.Longitude, positionCoordinates.Latitude);
			if (knownAprsPositions.Contains(key))
				return false;

			EnqueueTask(x => WriteAprsPosition(x, currentTime, packetSender, positionCoordinates, piComment));
			knownAprsPositions.Add(key);
			return true;
		}

		private void WriteAprsPosition(NpgsqlConnection connection, DateTime currentTime, string packetSender, GeoCoordinate positionCoordinates, string piComment)
		{
			NpgsqlCommand command = connection.CreateCommand();
			command.CommandText =
				"INSERT INTO aprs_positions (ctime, sender, lon, lat, comment) " +
				"VALUES (@ctime, @sender, @lon, @lat, @comment)";
			command.Parameters.AddWithValue("@ctime", NpgsqlDbType.Timestamp, currentTime);
			command.Parameters.AddWithValue("@sender", NpgsqlDbType.Varchar, packetSender);
			command.Parameters.AddWithValue("@lon", NpgsqlDbType.Double, positionCoordinates.Longitude);
			command.Parameters.AddWithValue("@lat", NpgsqlDbType.Double, positionCoordinates.Latitude);
			if (piComment != null)
				piComment = piComment.Replace("\0", "");
			command.Parameters.AddWithValue("@comment", NpgsqlDbType.Text, piComment);
			CheckNulls(command.Parameters);
			command.ExecuteNonQuery();
		}

		public static void CheckNulls(NpgsqlParameterCollection collection)
		{
			foreach (NpgsqlParameter o in collection)
			{
				if (o.Value == null)
					o.Value = DBNull.Value;
				else if (o.Value == DBNull.Value)
					continue;
				else
				{
					if (o.NpgsqlDbType == NpgsqlDbType.Text || o.NpgsqlDbType == NpgsqlDbType.Varchar)
					{
						string oValue = (string)o.Value;
						oValue = oValue.Trim('\0');
						o.Value = oValue;
					}
				}
			}
		}

		private void FetchAprsPositionHistory(string packetSender)
		{
			using (NpgsqlConnection connection = new NpgsqlConnection(connectionStringBuilder.ToString()))
			{
				connection.Open();
				NpgsqlCommand command = connection.CreateCommand();
				command.CommandText = "SELECT ctime, lon, lat FROM aprs_positions WHERE sender = @sender";
				command.Parameters.AddWithValue("@sender", NpgsqlDbType.Varchar, packetSender);
				NpgsqlDataReader dataReader = command.ExecuteReader();
				while (dataReader.Read())
				{
					DateTime ctime = dataReader.GetDateTime(0);
					double lon = dataReader.GetDouble(1);
					double lat = dataReader.GetDouble(2);
					knownAprsPositions.Add(new DatabaseKeyAprsPosition(ctime, packetSender, lon, lat));
				}
				dataReader.Close();
				command.Dispose();
				connection.Close();
			}

			loadedAprsPositionHistories.Add(packetSender);
		}

		private HashSet<string> knownAprsWeatherReporters;
		private HashSet<DatabaseKeyAprsWeatherReport> knownAprsWeatherReports;
		public bool AprsWeatherReport(DateTime currentTime, string packetSender, WeatherInfo wi)
		{
			if (knownAprsWeatherReporters == null)
				knownAprsWeatherReporters = new HashSet<string>();
			if (knownAprsWeatherReports == null)
				knownAprsWeatherReports = new HashSet<DatabaseKeyAprsWeatherReport>();
			if (!knownAprsWeatherReporters.Contains(packetSender))
				SelectAprsWeatherReports(packetSender);

			DatabaseKeyAprsWeatherReport key = new DatabaseKeyAprsWeatherReport(packetSender, currentTime);
			if (knownAprsWeatherReports.Contains(key))
				return false;

			EnqueueTask(x => WriteAprsWeatherReport(x, currentTime, packetSender, wi));
			knownAprsWeatherReports.Add(key);
			return true;
		}

		private void SelectAprsWeatherReports(string sender)
		{
			using (NpgsqlConnection connection = new NpgsqlConnection(connectionStringBuilder.ToString()))
			{
				connection.Open();
				NpgsqlCommand command = connection.CreateCommand();
				command.CommandText = "SELECT rtime FROM aprs_weather_reports WHERE sender = @sender";
				command.Parameters.AddWithValue("@sender", NpgsqlDbType.Varchar, sender);
				NpgsqlDataReader dataReader = command.ExecuteReader();
				while (dataReader.Read())
				{
					knownAprsWeatherReports.Add(new DatabaseKeyAprsWeatherReport(sender, dataReader.GetDateTime(0)));
				}
				dataReader.Close();
				command.Dispose();
				connection.Close();
			}

			knownAprsWeatherReporters.Add(sender);
		}

		private void WriteAprsWeatherReport(NpgsqlConnection connection, DateTime currentTime, string packetSender, WeatherInfo wi)
		{
			NpgsqlCommand command = connection.CreateCommand();
			command.CommandText =
				"insert into aprs_weather_reports (sender, rtime, lat, lon, has_messaging, ts, comment, wind_direction,\r\n                                  wind_speed, wind_gust, temperature, rainfall_hour, rainfall_day,\r\n                                  rainfall_since_midnight, humidity, barometric_pressure, luminosity, rain_raw, snow) " +
				"values " +
				"(@sender,@rtime,@lat,@lon,@has_messaging,@ts,@comment,@wind_direction,@wind_speed,@wind_gust,@temperature,@rainfall_hour,@rainfall_day,@rainfall_since_midnight,@humidity,@barometric_pressure,@luminosity,@rain_raw,@snow)";
			command.Parameters.AddWithValue("@sender", NpgsqlDbType.Varchar, packetSender);
			command.Parameters.AddWithValue("@rtime", NpgsqlDbType.Timestamp, currentTime);

			GeoCoordinate positionCoordinates = new GeoCoordinate();
			if (wi.Position != null)
			{
				if (!wi.Position.Coordinates.IsNull)
					positionCoordinates = wi.Position.Coordinates;
			}
			command.Parameters.AddWithValue("@lat", NpgsqlDbType.Double, positionCoordinates.IsNull ? DBNull.Value : positionCoordinates.Latitude);
			command.Parameters.AddWithValue("@lon", NpgsqlDbType.Double, positionCoordinates.IsNull ? DBNull.Value : positionCoordinates.Longitude);
			command.Parameters.AddWithValue("@has_messaging", NpgsqlDbType.Boolean, wi.HasMessaging);
			command.Parameters.AddWithValue("@ts", NpgsqlDbType.TimestampTz, wi.Timestamp?.DateTime.ToUniversalTime());
			command.Parameters.AddWithValue("@comment", NpgsqlDbType.Text, wi.Comment.Replace("\0", ""));
			command.Parameters.AddWithValue("@wind_direction", NpgsqlDbType.Integer, wi.WindDirection);
			command.Parameters.AddWithValue("@wind_speed", NpgsqlDbType.Integer, wi.WindSpeed);
			command.Parameters.AddWithValue("@wind_gust", NpgsqlDbType.Integer, wi.WindGust);
			command.Parameters.AddWithValue("@temperature", NpgsqlDbType.Integer, wi.Temperature);
			command.Parameters.AddWithValue("@rainfall_hour", NpgsqlDbType.Integer, wi.Rainfall1Hour);
			command.Parameters.AddWithValue("@rainfall_day", NpgsqlDbType.Integer, wi.Rainfall24Hour);
			command.Parameters.AddWithValue("@rainfall_since_midnight", NpgsqlDbType.Integer, wi.RainfallSinceMidnight);
			command.Parameters.AddWithValue("@humidity", NpgsqlDbType.Integer, wi.Humidity);
			command.Parameters.AddWithValue("@barometric_pressure", NpgsqlDbType.Integer, wi.BarometricPressure);
			command.Parameters.AddWithValue("@luminosity", NpgsqlDbType.Integer, wi.Luminosity);
			command.Parameters.AddWithValue("@rain_raw", NpgsqlDbType.Integer, wi.RainRaw);
			command.Parameters.AddWithValue("@snow", NpgsqlDbType.Integer, wi.Snow);
			CheckNulls(command.Parameters);
			command.ExecuteNonQuery();
		}

		private HashSet<string> knownAprsStationCapabilities;
		public bool AprsStationCapabilities(string packetSender, StationCapabilities stationCapabilities)
		{
			if (knownAprsStationCapabilities == null)
				knownAprsStationCapabilities = new HashSet<string>();
			if (knownAprsStationCapabilities.Contains(packetSender))
				return false;

			bool inDb = TestForAprsStationCapabilities(packetSender);
			if (inDb)
			{
				knownAprsStationCapabilities.Add(packetSender);
				return false;
			}

			EnqueueTask(x => WriteAprsStationCapabilities(x, packetSender, stationCapabilities));
			knownAprsStationCapabilities.Add(packetSender);
			return true;
		}

		private void WriteAprsStationCapabilities(NpgsqlConnection connection, string packetSender, StationCapabilities stationCapabilities)
		{
			NpgsqlCommand command = connection.CreateCommand();
			command.CommandText =
				"INSERT INTO aprs_station_capabilities (sender, isl_gate, local_stations, message_count) " +
				"VALUES (@sender, @isl_gate, @local_stations, @message_count)";
			command.Parameters.AddWithValue("@sender", NpgsqlDbType.Varchar, packetSender);
			command.Parameters.AddWithValue("@isl_gate", NpgsqlDbType.Boolean, stationCapabilities.IsIGate);
			command.Parameters.AddWithValue("@local_stations", NpgsqlDbType.Integer, stationCapabilities.LocalStations);
			command.Parameters.AddWithValue("@message_count", NpgsqlDbType.Integer, stationCapabilities.MessageCount);
			command.ExecuteNonQuery();
		}

		private bool TestForAprsStationCapabilities(string sender)
		{
			bool result;
			using (NpgsqlConnection conn = new NpgsqlConnection(connectionStringBuilder.ToString()))
			{
				conn.Open();
				NpgsqlCommand command = conn.CreateCommand();
				command.CommandText = "SELECT dateadded FROM aprs_station_capabilities WHERE sender = @sender";
				command.Parameters.AddWithValue("@sender", NpgsqlDbType.Varchar, sender);
				NpgsqlDataReader dataReader = command.ExecuteReader();
				result = dataReader.Read();
				dataReader.Close();
				command.Dispose();
				conn.Close();
			}

			return result;
		}

		class CachedGpsSentence
		{
			public CachedGpsSentence(DateTime currentTime, string packetSender, double? course, double? magneticVariation, double? speed)
			{
				CurrentTime = currentTime;
				PacketSender = packetSender;
				Course = course;
				MagneticVariation = magneticVariation;
				Speed = speed;
			}

			public DateTime CurrentTime { get; }
			public string PacketSender { get; }
			public double? Course { get; }
			public double? MagneticVariation { get; }
			public double? Speed { get; }

			public override bool Equals(object? obj)
			{
				return obj is CachedGpsSentence sentence &&
					   CurrentTime == sentence.CurrentTime &&
					   PacketSender == sentence.PacketSender;
			}

			public override int GetHashCode()
			{
				return HashCode.Combine(CurrentTime, PacketSender);
			}
		}

		public bool AprsGpsSentence(DateTime currentTime, string packetSender, double? course, double? magneticVariation,
			double? speed)
		{
			CachedGpsSentence cgs = new CachedGpsSentence(currentTime, packetSender, course, magneticVariation, speed);
			if (TestForAprsGpsSentence(cgs))
			{
				return false;
			}

			EnqueueTask(x => WriteAprsGpsSentence(x,cgs));
			return true;
		}

		private void WriteAprsGpsSentence(NpgsqlConnection conn, CachedGpsSentence cgs)
		{
			NpgsqlCommand command = conn.CreateCommand();
			command.CommandText = "insert into aprs_gps_sentences (callsign, calltime, course, magnetic_variation, speed) values (@sign,@time,@course,@magnetic_variation, @speed)";
			command.Parameters.AddWithValue("@sign", NpgsqlDbType.Varchar, cgs.PacketSender);
			command.Parameters.AddWithValue("@time", NpgsqlDbType.Timestamp, cgs.CurrentTime);
			command.Parameters.AddWithValue("@course", NpgsqlDbType.Double, cgs.Course);
			command.Parameters.AddWithValue("@magnetic_variation", NpgsqlDbType.Double, cgs.MagneticVariation);
			command.Parameters.AddWithValue("@speed", NpgsqlDbType.Double, cgs.Speed);
			int v = command.ExecuteNonQuery();
			if (v >= 0)
			{
				_gpsSentences.Add(cgs);
			}
		}

		private HashSet<CachedGpsSentence> _gpsSentences;
		private bool TestForAprsGpsSentence(CachedGpsSentence cgs)
		{
			if (_gpsSentences == null)
				_gpsSentences = new HashSet<CachedGpsSentence>();
			if (_gpsSentences.Contains(cgs))
				return true;

			using (NpgsqlConnection conn = new NpgsqlConnection(connectionStringBuilder.ToString()))
			{
				conn.Open();
				NpgsqlCommand command = conn.CreateCommand();
				command.CommandText = "SELECT dateadded FROM aprs_gps_sentences WHERE callsign = @sign AND calltime = @time";
				command.Parameters.AddWithValue("@sign", NpgsqlDbType.Varchar, cgs.PacketSender);
				command.Parameters.AddWithValue("@time", NpgsqlDbType.Timestamp, cgs.CurrentTime);
				NpgsqlDataReader dataReader = command.ExecuteReader();
				bool result = dataReader.Read();
				dataReader.Close();
				conn.Close();

				if (result)
				{
					_gpsSentences.Add(cgs);
				}

				return result;
			}
		}

		public void AprsMessage(string sender, DateTime currentTime, string receiver, string message)
		{
			EnqueueTask(x => WriteAprsMessage(x, sender, currentTime, receiver, message));
		}

		private void WriteAprsMessage(NpgsqlConnection connection, string sender, DateTime currentTime, string receiver, string message)
		{
			int ctime_sort = SelectAprsMessageCtimeSort(connection, currentTime);

			NpgsqlCommand command = connection.CreateCommand();
			command.CommandText =
				"INSERT INTO aprs_messages (ctime,ctime_sort,sender,receiver,message) " +
				"VALUES (@ctime,@ctime_sort,@sender,@receiver,@message)";
			command.Parameters.AddWithValue("@ctime", NpgsqlDbType.Timestamp, currentTime);
			command.Parameters.AddWithValue("@ctime_sort", NpgsqlDbType.Integer, ctime_sort);
			command.Parameters.AddWithValue("@sender", NpgsqlDbType.Varchar, sender);
			command.Parameters.AddWithValue("@receiver", NpgsqlDbType.Varchar, receiver);
			command.Parameters.AddWithValue("@message", NpgsqlDbType.Text, message.Replace("\0", ""));
			CheckNulls(command.Parameters);
			command.ExecuteNonQuery();
		}

		private int SelectAprsMessageCtimeSort(NpgsqlConnection connection, DateTime currentTime)
		{
			int result = 0;
			NpgsqlCommand command = connection.CreateCommand();
			command.CommandText = "SELECT MAX(ctime_sort) FROM aprs_messages WHERE ctime = @ctime";
			command.Parameters.AddWithValue("@ctime", NpgsqlDbType.Timestamp, currentTime);
			NpgsqlDataReader dataReader = command.ExecuteReader();
			if (dataReader.Read())
			{
				if (!dataReader.IsDBNull(0))
				{
					result = dataReader.GetInt32(0);
					result++;
				}
			}
			dataReader.Close();
			return result;
		}
	}
}