using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using InABox.Clients;
using InABox.Core;

namespace InABox.Rpc
{
    
    public class RpcClient<TEntity> : BaseClient<TEntity> where TEntity : Entity, new()
    {
        private IRpcClientTransport _transport;

        private ConcurrentDictionary<Guid, ManualResetEventSlim> _events = new ConcurrentDictionary<Guid, ManualResetEventSlim>();
        private ConcurrentDictionary<Guid, RpcMessage> _responses = new ConcurrentDictionary<Guid, RpcMessage>();

        private const int DefaultRequestTimeout = 5 * 60 * 1000; // 5 minutes
        
        public RpcClient(IRpcClientTransport transport)
        {
            
            _transport = transport;
            _transport.OnMessage += Transport_Message;
            if (!_transport.IsConnected())
                _transport.Connect();
        }

        ~RpcClient()
        {
            _transport.OnMessage -= Transport_Message;            
        }
        
        #region TransportManagement

        public override bool IsConnected() => _transport?.IsConnected() == true;
        
        // I'm assuming this is for unexpected messages (notifications, etc)?
        private void Transport_Message(IRpcTransport transport, RpcTransportMessageArgs e)
        {
            RaiseLogEvent(LogType.Error, "", "Message received: ({0}) -> {1}", e.Message.Command, e.Message.Payload);
        }

        public TResult Send<TCommand, TParameters, TResult>(TParameters parameters) 
            where TCommand : IRpcCommand<TParameters,TResult>
            where TParameters : ISerializeBinary
            where TResult : ISerializeBinary, new()
        {
            var request = new RpcMessage()
            {
                Id = new Guid(),
                Command = typeof(TCommand).Name,
                Payload = parameters.WriteBinary(BinarySerializationSettings.Latest)
            };
            var response = Send(request);
            if (response.Error != RpcError.NONE)
                throw new Exception($"Exception in {typeof(TCommand).Name}({request.Id}): {response.Error}");
            var result = Serialization.ReadBinary<TResult>(response.Payload, BinarySerializationSettings.Latest);
            if (result == null)
                throw new Exception($"{typeof(TCommand).Name}({request.Id}) returned NULL");
            return result;
        }
        
        public RpcMessage Send(RpcMessage request, int timeout = DefaultRequestTimeout)
        {
            var start = DateTime.Now;
            var ev = Queue(request.Id);
            _transport.Send(request);
            var result = GetResult(request.Id, ev, timeout);
            return result;
        }

        public ManualResetEventSlim Queue(Guid id)
        {
            var ev = new ManualResetEventSlim();
            _events[id] = ev;
            return ev;
        }

        public RpcMessage GetResult(Guid id, ManualResetEventSlim ev, int timeout)
        {
            if (_responses.TryGetValue(id, out var result))
            {
                _responses.Remove(id, out result);
                _events.Remove(id, out ev);
                return result;
            }

            try
            {
                if (!ev.Wait(timeout))
                {
                    return new RpcMessage() { Id = id, Error = RpcError.TIMEOUT };
                }
            }
            catch (Exception e)
            {
                RaiseLogEvent(LogType.Error, "", e.Message);
                throw;
            }
            
            _responses.Remove(id, out result);
            _events.Remove(id, out ev);
            return result ?? new RpcMessage() { Id =id, Error = RpcError.UNKNOWN };
        }
        
        #endregion
        
        
        #region Client Interface

        public override DatabaseInfo Info()
        {
            var result = _transport.Send<RpcInfoCommand, RpcInfoParameters, RpcInfoResult>(new RpcInfoParameters());
            return result.Info;
        }

        private static string[]? _types;
        public override IEnumerable<string> SupportedTypes()
        {
            _types ??= CoreUtils.Entities
                .Where(x => x.GetInterfaces().Contains(typeof(IPersistent)))
                .Select(x => x.EntityName().Replace(".", "_"))
                .ToArray();
            return _types;
        }
        
        #region Validate & 2FA

        protected override IValidationData DoValidate(string userid, string password, Guid session = default)
        {
            var parameters = new RpcValidateParameters()
            {
                UserID = userid,
                Password = password,
                PIN = "",
                UsePIN = false,
                SessionID = session,
                Platform = ClientFactory.Platform,
                Version = ClientFactory.Version
            };
            return _transport.Send<RpcValidateCommand, RpcValidateParameters, RpcValidateResult>(parameters);
        }

        protected override IValidationData DoValidate(string pin, Guid session = default)
        {
            var ticks = DateTime.Now.ToUniversalTime().Ticks.ToString();
            var parameters = new RpcValidateParameters()
            {
                UserID = Encryption.Encrypt(ticks, "wCq9rryEJEuHIifYrxRjxg", true),
                Password = Encryption.Encrypt(ticks, "7mhvLnqMwkCAzN+zNGlyyg", true),
                PIN = pin,
                UsePIN = true,
                SessionID = session,
                Platform = ClientFactory.Platform,
                Version = ClientFactory.Version
            };
            return _transport.Send<RpcValidateCommand, RpcValidateParameters, RpcValidateResult>(parameters);
        }

        protected override IValidationData DoValidate(Guid session = default)
        {
            var parameters = new RpcValidateParameters()
            {
                UserID = "",
                Password = "",
                PIN = "",
                UsePIN = false,
                SessionID = session,
                Platform = ClientFactory.Platform,
                Version = ClientFactory.Version
            };
            return _transport.Send<RpcValidateCommand, RpcValidateParameters, RpcValidateResult>(parameters);
        }
        
        protected override bool DoCheck2FA(string code, Guid? session)
        {
            var parameters = new RpcCheck2FAParameters()
            {
                Code = code,
                SessionId = session ?? Guid.Empty,
            };
            var result = _transport.Send<RpcCheck2FACommand, RpcCheck2FAParameters, RpcCheck2FAResult>(parameters);
            return result.Valid;
        }
        
        #endregion

        protected override CoreTable DoQuery(Filter<TEntity>? filter, Columns<TEntity>? columns, SortOrder<TEntity>? sort = null)
        {
            var parameters = new RpcQueryParameters()
            {
                Queries = new RpcQueryDefinition[]
                {
                    new RpcQueryDefinition()
                    {
                        Type = typeof(TEntity),
                        Filter = filter,
                        Columns = columns,
                        Sort = sort
                    }
                }
            };
            var result = _transport.Send<RpcQueryCommand, RpcQueryParameters, RpcQueryResult>(parameters);
            return result.Tables[0].Table;
        }

        protected override TEntity[] DoLoad(Filter<TEntity>? filter = null, SortOrder<TEntity>? sort = null)
        {
            return DoQuery(filter, null, sort).Rows.Select(r => r.ToObject<TEntity>()).ToArray();
        }
        
        
        protected override Dictionary<string, CoreTable> DoQueryMultiple(Dictionary<string, IQueryDef> queries)
        {
            var result = new Dictionary<String, CoreTable>();
            
            var parameters = new RpcQueryParameters()
            {
                Queries = queries.Select(kvp =>
                    new RpcQueryDefinition()
                    {
                        Key = kvp.Key,
                        Type = kvp.Value.Type,
                        Filter = kvp.Value.Filter,
                        Columns = kvp.Value.Columns,
                        Sort = kvp.Value.SortOrder
                    }
                ).ToArray()
            };
            var response = _transport.Send<RpcQueryCommand, RpcQueryParameters, RpcQueryResult>(parameters);

            foreach (var key in response.Tables)
                result[key.Key] = key.Table;

            return result;
        }

        protected override void DoSave(TEntity entity, string auditnote)
        {
            DoSave(new TEntity[] { entity }, auditnote);
        }

        protected override void DoSave(IEnumerable<TEntity> entities, string auditnote)
        {
            var items = entities.ToArray();
            var parameters = new RpcSaveParameters()
            {
                Type = typeof(TEntity),
                Items = items
            };
            var result = _transport.Send<RpcSaveCommand, RpcSaveParameters, RpcSaveResult>(parameters);
            for (int i=0; i< result.Deltas.Length; i++)
            {
                items[i].SetObserving(false);
                foreach (var (key, value) in result.Deltas[i])
                {
                    if (CoreUtils.TryGetProperty<TEntity>(key, out var property))
                        CoreUtils.SetPropertyValue(items[i], key, CoreUtils.ChangeType(value, property.PropertyType));
                }
                items[i].CommitChanges();
                items[i].SetObserving(true);
            }
        }

        protected override void DoDelete(TEntity entity, string auditnote)
        {
            DoDelete(new TEntity[] { entity }, auditnote);
        }

        protected override void DoDelete(IList<TEntity> entities, string auditnote)
        {
            var parameters = new RpcDeleteParameters()
            {
                Type = typeof(TEntity),
                IDs = entities.Select(x=>x.ID).ToArray(),
                AuditNote = auditnote
            };
            _transport.Send<RpcDeleteCommand, RpcDeleteParameters, RpcDeleteResult>(parameters);
        }

        
        protected override bool DoPing()
        {
            try
            {
                _transport.Send<RpcPingCommand, RpcPingParameters, RpcPingResult>(new RpcPingParameters());
                return true;
            }
            catch (Exception e)
            {
                return false;
            }
            
        }
        
        #endregion
    }
}