using System;
using System.Collections.Generic;
using System.Data;
using System.Data.OleDb;
using System.Data.SqlClient;
using System.IO;
using System.Windows.Input;
using DTS.Common.Classes.ChannelCodes;
using DTS.Common.Enums;
using DTS.Common.Enums.Channels;
using DTS.Common.Interface.Channels.ChannelCodes;
using DTS.Common.Storage;

namespace ChannelCodes.Model
{
    public class ChannelCode : DTS.Common.Classes.ChannelCodes.ChannelCode, IChannelCode
    {
        //in case this object is held onto longer before cleanup, attempt to empty 
        //private storage
        ~ChannelCode()
        {
            _code = null;
            _name = null;
            PossibleChannels?.Clear();
            PasteCommand = null;
        }


        /// <summary>
        /// whether the current id is valid or not
        /// </summary>
        /// <returns></returns>
        public bool HasValidId()
        {
            return Id >= 0;
        }

        public bool IsBlank()
        {
            return string.IsNullOrEmpty(Name) && string.IsNullOrEmpty(Code);
        }

        /// <summary>
        /// this dates back from when there was a dropdown to select the type of code,
        /// I'm not sure it's used anymore (2019-04-11)
        /// </summary>
        public int SelectedChannelType
        {
            get
            {
                switch (CodeType)
                {
                    case ChannelEnumsAndConstants.ChannelCodeType.ISO:
                        return 0;
                    case ChannelEnumsAndConstants.ChannelCodeType.User:
                        return 1;
                    default:
                        return 0;
                }
            }
            set
            {
                switch (value)
                {
                    case 0: CodeType = ChannelEnumsAndConstants.ChannelCodeType.ISO; break;
                    case 1: CodeType = ChannelEnumsAndConstants.ChannelCodeType.User; break;
                }
            }
        }

        private void RegisterCommands()
        {
            PasteCommand = new PasteCommandClass(PASTE_ID);
            CommandManager.RegisterClassCommandBinding(GetType(),
                new CommandBinding(PasteCommand, Paste));
        }
        public ChannelCode(IChannelCode channelCode)
            : base(channelCode)
        {
            RegisterCommands();
        }

        private void Paste(object sender, ExecutedRoutedEventArgs e)
        {
        }

        public ChannelCode()
        {
            CodeType = ChannelEnumsAndConstants.ChannelCodeType.ISO;
            RegisterCommands();
        }

        public ChannelCode(IDataRecord sqlReader, IDictionary<short, string> channelCodeLookup)
        {
            RegisterCommands();
            Id = Convert.ToInt32(sqlReader["Id"]);
            Code = (string)sqlReader["Code"];
            Name = (string)sqlReader["Name"];
            var codeType = Convert.ToInt16(sqlReader["CodeTypeInt"]);
            if (channelCodeLookup.ContainsKey(codeType))
            {
                var key = channelCodeLookup[codeType];
                switch (key)
                {
                    case ChannelEnumsAndConstants.UserCodeTypeString:
                        CodeType = ChannelEnumsAndConstants.ChannelCodeType.User;
                        break;
                    case ChannelEnumsAndConstants.IsoCodeTypeString:
                        CodeType = ChannelEnumsAndConstants.ChannelCodeType.ISO;
                        break;
                }
            }
        }
        /// <summary>
        /// get all existing channel codes from the db
        /// </summary>
        /// <param name="lookup">a lookup from channel code type (short) to channel code type string as in the db</param>
        /// <returns></returns>
        public static ChannelCode[] GetExistingChannelCodes(IDictionary<short, string> lookup)
        {
            var channelCodes = new List<ChannelCode>();
            using (var cmd = DbOperations.GetSQLCommand(true))
            {
                try
                {
                    cmd.CommandType = CommandType.StoredProcedure;
                    cmd.CommandText = @"sp_ChannelCodesGet";
                    cmd.Parameters.Add(new SqlParameter("@Id", SqlDbType.Int) { Value = null });
                    cmd.Parameters.Add(new SqlParameter("@Code", SqlDbType.NVarChar, 255) { Value = null });
                    cmd.Parameters.Add(new SqlParameter("@Name", SqlDbType.NVarChar, 255) { Value = null });
                    cmd.Parameters.Add(new SqlParameter("@CodeType", SqlDbType.SmallInt) { Value = null });

                    var reader = cmd.ExecuteReader();
                    while (reader.Read())
                    {
                        channelCodes.Add(new ChannelCode(reader, lookup));
                    }
                }
                finally
                {
                    cmd.Connection.Dispose();
                }
            }
            return channelCodes.ToArray();
        }
        /// <summary>
        /// retrieves all channel codes and returns as a list
        /// </summary>
        public static IList<IChannelCode> ChannelCodes
        {
            get
            {
                var lookup = ChannelCodeType.GetChannelCodeTypeLookup();
                var channelCodes = new List<IChannelCode>();
                channelCodes.AddRange(GetExistingChannelCodes(lookup));
                channelCodes.AddRange(ISOChannelCodes);

                return channelCodes;
            }
        }

        private static readonly object RefreshLock = new object();

        public Dictionary<string, string> PossibleChannels { get; private set; }


        private static IList<IChannelCode> _isoChannelCodes;

        /// <summary>
        /// retrieves a list of iso channel codes from the db
        /// </summary>
        public static IList<IChannelCode> ISOChannelCodes
        {
            get
            {
                if (null != _isoChannelCodes) return _isoChannelCodes;
                //we only need to fetch these values once, they're not going to change.
                var channelCodes = new List<IChannelCode>();

                lock (RefreshLock)
                {
                    var sourceFile = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "ISOPossibleChannels.txt");
                    using (StreamReader sr = File.OpenText(sourceFile))
                    {
                        string s = string.Empty;
                        while ((s = sr.ReadLine()) != null)
                        {
                            var splitString = s.Split(',');
                            var isoCode = splitString[0];
                            var textL1 = splitString[1];
                            var newChannelCode = new ChannelCode()
                            {
                                Code = isoCode,
                                Name = textL1,
                                CodeType = ChannelEnumsAndConstants.ChannelCodeType.ISO
                            };
                            if (!channelCodes.Contains(newChannelCode))
                            {
                                channelCodes.Add(newChannelCode);
                            }
                        }
                    }
                }
                _isoChannelCodes = channelCodes;
                return _isoChannelCodes;
            }
        }

        /// <summary>
        /// not used?  maybe was a part of migration?
        /// </summary>
        /// <param name="reader"></param>
        /// <param name="field"></param>
        /// <returns></returns>
        protected static long GetLong(OleDbDataReader reader, string field)
        {
            return DBNull.Value == reader[field] ? long.MinValue : Convert.ToInt64(reader[field]);
        }
        /// <summary>
        /// not used, maybe was a part of migration?
        /// </summary>
        /// <param name="reader"></param>
        /// <param name="field"></param>
        /// <returns></returns>
        protected static DateTime GetDate(OleDbDataReader reader, string field)
        {
            return DBNull.Value != reader[field] ? (DateTime)reader[field] : DateTime.MinValue;
        }

        /// <summary>
        /// deletes channel code
        /// deleting a channel code only removes it from the lookup, doesn't remove it from any existing channels
        /// </summary>
        public void Delete()
        {
            _ = DbOperations.ChannelCodesDelete(Id, null, null, null);
        }
        /// <summary>
        /// commits any channel codes to the db
        /// this only affects the channel code lookup, not any existing channels
        /// </summary>
        /// <param name="lookup"></param>
        public void Save(IDictionary<ChannelEnumsAndConstants.ChannelCodeType, short> lookup)
        {
            var restrictedLookup = (IReadOnlyDictionary<ChannelEnumsAndConstants.ChannelCodeType, short>)lookup;
            _ = DbOperations.ChannelCodesUpdate(restrictedLookup, this);
        }
        /// <summary>
        /// inserts a new channel code into the db
        /// </summary>
        /// <param name="lookup"></param>
        public void Insert(IDictionary<ChannelEnumsAndConstants.ChannelCodeType, short> lookup)
        {
            var restrictedLookup = (IReadOnlyDictionary<ChannelEnumsAndConstants.ChannelCodeType, short>)lookup;
            var hr = DbOperations.ChannelCodesInsert(restrictedLookup, this, out var id);
            if (0 == hr)
            {
                Id = id;
            }
        }
    }
}