using System;
using System.Collections.Generic;

namespace ChanSort.Api
{
  public class ChannelInfo
  {
    private const int MAX_FAV_LISTS = 16;

    private string uid;
    private string serviceTypeName;

    public virtual bool IsDeleted { get; set; }
    public SignalSource SignalSource { get; set; }
    public string Source { get; set; }
    
    /// <summary>
    /// Index or ID of the data record
    /// </summary>
    public long RecordIndex { get; set; }

    /// <summary>
    /// logical record order (might be different from the index, like old LG TLL files with a linked list of record indices)
    /// </summary>
    public int RecordOrder { get; set; }

    /// <summary>
    /// original program number from the file, except for channels with IsDeleted==true, which will have the value -1
    /// </summary>
    public int OldProgramNr { get; set; }
    /// <summary>
    /// new program number or -1, if the channel isn't assigned a number or has IsDeleted==true
    /// </summary>
    public int NewProgramNr { get; set; }

    public string Name { get; set; }
    public string ShortName { get; set; }
    public bool Skip { get; set; }
    public bool Lock { get; set; }
    public bool Hidden { get; set; }
    public bool? Encrypted { get; set; }
    public string ChannelOrTransponder { get; set; }
    public string Satellite { get; set; }
    public decimal FreqInMhz { get; set; }
    public char Polarity { get; set; }
    public int ServiceId { get; set; }
    public int PcrPid { get; set; }
    public int VideoPid { get; set; }
    public int AudioPid { get; set; }
    public int OriginalNetworkId { get; set; }
    public int TransportStreamId { get; set; }
    public string Provider { get; set; }
    public int SymbolRate { get; set; }
    public int ServiceType { get; set; }
    public string SatPosition { get; set; }
    public Transponder Transponder { get; set; }
    
    /// <summary>
    /// Bitmask in which favorite lists the channel is included
    /// </summary>
    public Favorites Favorites { get; set; }
    /// <summary>
    /// current number of the channel in the various favorite lists (if individual sorting is supported)
    /// </summary>
    public List<int> FavIndex { get; }
    /// <summary>
    /// original number of the channel in the various favorite lists (if individual sorting is supported)
    /// </summary>
    public List<int> OldFavIndex { get; }

    /// <summary>
    /// predefined LCN (logical channel number) assigned by TV firmware or cable/sat operator
    /// </summary>
    public int ProgramNrPreset { get; set; }

    public bool IsNameModified { get; set; }


    /// <summary>
    /// A proxy channel is inserted into the current channel list when there was no match for a reference list channel
    /// </summary>
    public bool IsProxy => this.RecordIndex < 0;
    
    /// <summary>
    /// arbitrary information that can be shown in a UI column to assist in analyzing a file format while coding a plugin
    /// </summary>
    public string Debug { get; private set; }




    #region ctor()
    protected ChannelInfo()
    {
      this.OldProgramNr = -1;
      this.NewProgramNr = -1;
      this.FavIndex = new List<int>(MAX_FAV_LISTS);
      this.OldFavIndex = new List<int>(MAX_FAV_LISTS);
      for (int i = 0; i < MAX_FAV_LISTS; i++)
      {
        this.FavIndex.Add(-1);
        this.OldFavIndex.Add(-1);
      }
      this.Name = "";
      this.ShortName = "";
    }

    /// <summary>
    /// Constructor for existing TV channel
    /// </summary>
    public ChannelInfo(SignalSource source, long index, int oldProgNr, string name) : this()
    {
      this.SignalSource = source;
      this.RecordIndex = index;
      this.RecordOrder = (int)index;
      this.OldProgramNr = oldProgNr;
      this.Name = name;
      this.Encrypted = null;
    }

    /// <summary>
    /// Constructor for reference list channels which no longer exist in TV list
    /// </summary>
    public ChannelInfo(SignalSource source, string uid, int newProgNr, string name) : this()
    {
      this.SignalSource = source;
      this.Uid = uid;
      this.RecordIndex = -1;
      this.RecordOrder = -1;
      this.OldProgramNr = -1;
      this.NewProgramNr = newProgNr;
      this.Name = name;
      this.Encrypted = null;
    }
    #endregion

    #region Uid
    /// <summary>
    /// The Uid is the preferred way of matching channels between the current channel list and a reference list.
    /// The basic format of this string was taken from a command line tool "TllSort" for LG TVs but then expanded beyond that
    /// in order to support the various file formats and the data provided in those.
    /// </summary>
    public string Uid
    {
      get
      {
        if (this.uid == null)
        {
          if ((this.SignalSource & SignalSource.MaskAnalogDigital) == SignalSource.Analog)
            this.uid = "A-0-" + (int) (this.FreqInMhz*20) + "-0";
          else
          {
            if ((this.SignalSource & SignalSource.MaskAntennaCableSat) == SignalSource.Sat)
              this.uid = "S" + /*this.SatPosition + */ "-" + this.OriginalNetworkId + "-" + this.TransportStreamId + "-" + this.ServiceId;
            else if ((this.SignalSource & SignalSource.MaskAntennaCableSat) == SignalSource.Antenna || (this.SignalSource & SignalSource.MaskAntennaCableSat) == SignalSource.Cable)
            {
              // ChannelOrTransponder is needed for DVB-T where the same ONID+TSID+SID can be received from 2 different radio transmitters, but on different frequencies/channels
              this.uid = "C-" + this.OriginalNetworkId + "-" + this.TransportStreamId + "-" + this.ServiceId + "-" + this.ChannelOrTransponder;
            }
            else
              this.uid = this.OriginalNetworkId + "-" + this.TransportStreamId + "-" + this.ServiceId;
          }
        }
        return this.uid;
      }
      set { this.uid = value; }
    }
    #endregion

    #region ToString(), Equals(), GetHashCode()

    public override string ToString()
    {
      string nr = this.NewProgramNr != -1 ? this.NewProgramNr.ToString() : "@" + this.RecordIndex;
      return nr + ": " + this.Name;
    }

    public override bool Equals(object obj)
    {
      //ChannelInfo that = obj as ChannelInfo;
      //return that != null && this.Uid == that.Uid && this.OldProgramNr == that.OldProgramNr;
      return ReferenceEquals(this, obj);
    }

    public override int GetHashCode()
    {
      return this.Uid.GetHashCode() + this.OldProgramNr;
    }

    #endregion

    #region NetworkName, NetworkOperator
    public string NetworkName
    {
      get
      {
        var network = LookupData.Instance.GetNetwork(this.OriginalNetworkId);
        return network == null ? null : network.Name;
      }
    }

    public string NetworkOperator
    {
      get
      {
        var network = LookupData.Instance.GetNetwork(this.OriginalNetworkId);
        return network == null ? null : network.Operator;
      }
    }
    #endregion

    #region ServiceTypeName

    public string ServiceTypeName
    {
      get { return this.serviceTypeName ?? (this.serviceTypeName = LookupData.Instance.GetServiceTypeDescription(this.ServiceType)); }
      set { this.serviceTypeName = value; }
    }
    #endregion

    #region ParseFavString()
    public static Favorites ParseFavString(string value)
    {
      Favorites favMask = 0;
      foreach (Favorites fav in Enum.GetValues(typeof (Favorites)))
      {
        foreach (char c in value)
        {
          if (c == fav.ToString()[0])
          {
            favMask |= fav;
            break;
          }
        }
      }
      return favMask;
    }
    #endregion

    #region AddDebug()
    public void AddDebug(byte val)
    {
      if (this.Debug == null)
        this.Debug = val.ToString("x2");
      else
        this.Debug += " " + val.ToString("x2");
    }

    public void AddDebug(ushort val)
    {
      if (this.Debug == null)
        this.Debug = val.ToString("x4");
      else
        this.Debug += " " + val.ToString("x4");
    }

    public void AddDebug(uint val)
    {
      if (this.Debug == null)
        this.Debug = val.ToString("x8");
      else
        this.Debug += " " + val.ToString("x8");
    }

    public void AddDebug(byte[] data, int offset, int len)
    {
      for (int i = 0; i < len; i++)
        this.AddDebug(data[offset + i]);
    }

    public void AddDebug(string val)
    {
      if (this.Debug == null)
        this.Debug = val;
      else
        this.Debug += " " + val;
    }
    #endregion

    #region UpdateRawData()
    /// <summary>
    /// called during the saving procedure to update the external channel list data with the changes made by the user
    /// </summary>
    public virtual void UpdateRawData()
    {
    }
    #endregion

    #region ChangeEncoding()
    /// <summary>
    /// for file formats that allow characters in local code pages, this method should re-parse the raw data bytes for the given encoding
    /// </summary>
    /// <param name="encoding"></param>
    public virtual void ChangeEncoding(System.Text.Encoding encoding)
    {
    }
    #endregion

    #region GetPosition(), SetPosition(), ChangePosition()

    /// <summary>
    /// Gets the new channel number in the main channel list (index=0) or the various favorite lists (1-x)
    /// </summary>
    public int GetPosition(int subListIndex)
    {
      return subListIndex == 0 ? this.NewProgramNr : this.FavIndex[subListIndex - 1];
    }

    /// <summary>
    /// Gets the original channel number in the main channel list (index=0) or the various favorite lists (1-x)
    /// </summary>
    public int GetOldPosition(int subListIndex)
    {
      return subListIndex == 0 ? this.OldProgramNr : this.OldFavIndex[subListIndex - 1];
    }

    /// <summary>
    /// Sets the new channel number in the main channel list (index=0) or the various favorite lists (1-x)
    /// </summary>
    public void SetPosition(int subListIndex, int newPos)
    {
      if (subListIndex == 0)
        this.NewProgramNr = newPos;
      else
      {
        this.FavIndex[subListIndex - 1] = newPos;
        int mask = 1 << (subListIndex - 1);
        if (newPos == -1)
          this.Favorites &= (Favorites)~mask;
        else
          this.Favorites |= (Favorites)mask;
      }
    }

    /// <summary>
    /// Sets the original channel number in the main channel list (index=0) or the various favorite lists (1-x)
    /// </summary>
    public void SetOldPosition(int subListIndex, int oldPos)
    {
      if (subListIndex == 0)
        this.OldProgramNr = oldPos;
      else
        this.OldFavIndex[subListIndex - 1] = oldPos;
    }

    /// <summary>
    /// Internal helper method to adjust the main or favorite program number by a delta value
    /// </summary>
    internal void ChangePosition(int subListIndex, int delta)
    {
      if (subListIndex == 0)
        this.NewProgramNr += delta;
      else
        this.FavIndex[subListIndex - 1] += delta;      
    }
    #endregion
  }
}