using System;
using System.Collections.Generic;
using System.Data.SQLite;
using System.IO;
using System.Text;
using ChanSort.Api;

namespace ChanSort.Loader.DbFile
{
  class DbSerializer : SerializerBase
  {
    private const int BITS_InUse = 0x10000;
    private readonly ChannelList atvChannels = new ChannelList(SignalSource.AnalogCT | SignalSource.TvAndRadio, "Analog");
    private readonly ChannelList dtvChannels = new ChannelList(SignalSource.DvbCT | SignalSource.TvAndRadio, "DVB-C/T");
    private readonly ChannelList satChannels = new ChannelList(SignalSource.DvbS | SignalSource.TvAndRadio, "Satellite");

    #region ctor()
    public DbSerializer(string inputFile) : base(inputFile)
    {
      this.Features.ChannelNameEdit = true;

      this.DataRoot.AddChannelList(this.atvChannels);
      this.DataRoot.AddChannelList(this.dtvChannels);
      this.DataRoot.AddChannelList(this.satChannels);
    }
    #endregion

    #region DisplayName
    public override string DisplayName { get { return "Toshiba *.db Loader"; } }
    #endregion


    #region Load()
    public override void Load()
    {
      string sysDataConnString = "Data Source=" + Path.GetDirectoryName(Path.GetDirectoryName(this.FileName)) +
                                 "\\dvb_type001\\dvbSysData.db";
      using (var sysDataConn = new SQLiteConnection(sysDataConnString))
      {
        sysDataConn.Open();
        using (var cmd = sysDataConn.CreateCommand())
        {
          this.ReadSatellites(cmd);
          this.ReadTransponders(cmd);
        }
      }

      string channelConnString = "Data Source=" + this.FileName;
      using (var channelConn = new SQLiteConnection(channelConnString))
      {
        channelConn.Open();
        using (var cmd = channelConn.CreateCommand())
        {
          this.ReadAnalogChannels(cmd);
          this.ReadDtvChannels(cmd);
          this.ReadSatChannels(cmd);
        }
      }
    }
    #endregion

    #region ReadSatellites()
    private void ReadSatellites(SQLiteCommand cmd)
    {
      cmd.CommandText = "select distinct satellite_id, satellite_name, orbital_position, west_east_flag from satellite";
      using (var r = cmd.ExecuteReader())
      {
        while (r.Read())
        {
          Satellite sat = new Satellite(r.GetInt32(0));
          int pos = r.GetInt32(2);
          sat.OrbitalPosition = string.Format("{0}.{1}{2}", pos / 10, pos % 10, r.GetInt32(3) == 1 ? "E" : "W");
          sat.Name = r.GetString(1) + " " + sat.OrbitalPosition;
          this.DataRoot.AddSatellite(sat);
        }
      }
    }
    #endregion

    #region ReadTransponders()
    private void ReadTransponders(SQLiteCommand cmd)
    {
      cmd.CommandText = "select satellite_id, frequency, polarization, symbol_rate, transponder_number from satellite";
      using (var r = cmd.ExecuteReader())
      {
        while (r.Read())
        {
          int satId = r.GetInt32(0);
          int freq = r.GetInt32(1);
          int id = satId * 1000000 + freq / 1000;
          if (this.DataRoot.Transponder.TryGet(id) != null)
            continue;
          Transponder tp = new Transponder(id);
          tp.FrequencyInMhz = (decimal)freq / 1000;
          tp.Number = r.GetInt32(4);
          tp.Polarity = r.GetInt32(2) == 0 ? 'H' : 'V';
          tp.Satellite = this.DataRoot.Satellites.TryGet(satId);
          tp.SymbolRate = r.GetInt32(3) / 1000;
          this.DataRoot.AddTransponder(tp.Satellite, tp);
        }
      }
    }
    #endregion


    #region ReadAnalogChannels()
    private void ReadAnalogChannels(SQLiteCommand cmd)
    {
      string[] fieldNames = {"channel_handle", "channel_number", "list_bits", "channel_label", "frequency"};
      var sql = this.GetQuery("EuroATVChanList", fieldNames);
      var fields = this.GetFieldMap(fieldNames);
      
      cmd.CommandText = sql;
      using (var r = cmd.ExecuteReader())
      {
        while (r.Read())
          ReadAnalogChannel(r, fields);
      }
    }

    private void ReadAnalogChannel(SQLiteDataReader r, IDictionary<string, int> field)
    {
      var bits = r.GetInt32(field["list_bits"]);
      if ((bits & BITS_InUse) == 0)
        return;

      ChannelInfo channel = new ChannelInfo(SignalSource.Analog|SignalSource.Tv,
                                            r.GetInt32(field["channel_handle"]),
                                            r.GetInt32(field["channel_number"]),
                                            r.GetString(field["channel_label"]));

      channel.FreqInMhz = (decimal) r.GetInt32(field["frequency"])/1000000;

      this.DataRoot.AddChannel(this.atvChannels, channel);
    }
    #endregion

    #region ReadDtvChannels()
    private void ReadDtvChannels(SQLiteCommand cmd)
    {
      this.ReadDigitalChannels(cmd, "EuroDTVChanList", SignalSource.DvbCT, this.dtvChannels);
    }
    #endregion

    #region ReadSatChannels()
    private void ReadSatChannels(SQLiteCommand cmd)
    {
      this.ReadDigitalChannels(cmd, "EuroSATChanList", SignalSource.DvbS, this.satChannels);
    }
    #endregion

    #region ReadDigitalChannels()
    private void ReadDigitalChannels(SQLiteCommand cmd, string table, SignalSource signalSource, ChannelList channels)
    {
      string[] fieldNames = { "channel_handle", "channel_number", "list_bits", "channel_label", "frequency",
                            "dvb_service_type", "onid", "tsid", "sid", "sat_id", "channel_order" };
      var sql = this.GetQuery(table, fieldNames);
      var fields = this.GetFieldMap(fieldNames);

      cmd.CommandText = sql;
      using (var r = cmd.ExecuteReader())
      {
        while (r.Read())
          ReadDigitalChannel(r, fields, signalSource, channels);
      }
    }
    #endregion

    #region ReadDigitalChannel()
    private void ReadDigitalChannel(SQLiteDataReader r, IDictionary<string, int> field, SignalSource signalSource, ChannelList channels)
    {
      var bits = r.GetInt32(field["list_bits"]);
      if ((bits & BITS_InUse) == 0)
        return;

      var name = r.GetString(field["channel_label"]);
      string longName, shortName;
      this.GetChannelNames(name, out longName, out shortName);
      
      ChannelInfo channel = new ChannelInfo(signalSource,
                                            r.GetInt32(field["channel_handle"]),
                                            r.GetInt32(field["channel_number"]),
                                            longName);
      channel.ShortName = shortName;
      channel.RecordOrder = r.GetInt32(field["channel_order"]);
      channel.FreqInMhz = (decimal)r.GetInt32(field["frequency"]) / 1000;
      int serviceType = r.GetInt32(field["dvb_service_type"]);
      if (serviceType == 1 || serviceType == 25)
        channel.SignalSource |= SignalSource.Tv;
      else if (serviceType == 2)
        channel.SignalSource |= SignalSource.Radio;
      channel.ServiceType = serviceType;
      channel.OriginalNetworkId = r.GetInt32(field["onid"]);
      channel.TransportStreamId = r.GetInt32(field["tsid"]);
      channel.ServiceId = r.GetInt32(field["sid"]);

      if ((signalSource & SignalSource.Sat) != 0)
      {
        int satId = r.GetInt32(field["sat_id"]);
        var sat = this.DataRoot.Satellites.TryGet(satId);
        if (sat != null)
        {
          channel.Satellite = sat.Name;
          channel.SatPosition = sat.OrbitalPosition;
          int tpId = satId*1000000 + (int) channel.FreqInMhz;
          var tp = this.DataRoot.Transponder.TryGet(tpId);
          if (tp != null)
          {
            channel.SymbolRate = tp.SymbolRate;
          }
        }
      }
      this.DataRoot.AddChannel(channels, channel);
    }

    #endregion

    #region GetQuery()
    private string GetQuery(string table, string[] fieldNames)
    {
      string sql = "select ";
      for (int i = 0; i < fieldNames.Length; i++)
      {
        if (i > 0)
          sql += ",";
        sql += fieldNames[i];
      }
      sql += " from " + table;
      return sql;
    }
    #endregion

    #region GetFieldMap()
    private IDictionary<string, int> GetFieldMap(string[] fieldNames)
    {
      Dictionary<string, int> field = new Dictionary<string, int>();
      for (int i = 0; i < fieldNames.Length; i++)
        field[fieldNames[i]] = i;
      return field;
    }
    #endregion

    #region GetChannelNames()
    private void GetChannelNames(string name, out string longName, out string shortName)
    {
      StringBuilder sbLong = new StringBuilder();
      StringBuilder sbShort = new StringBuilder();

      bool inShort = false;
      foreach (char c in name)
      {
        if (c == 0x86)
          inShort = true;
        else if (c == 0x87)
          inShort = false;
        if (c >= 0x80 && c <= 0x9F)
          continue;

        if (inShort)
          sbShort.Append(c);
        sbLong.Append(c);
      }

      longName = sbLong.ToString();
      shortName = sbShort.ToString();
    }
    #endregion


    public override void Save(string tvOutputFile, string csvOutputFile)
    {
      throw new NotImplementedException();
    }

  }
}