using Bot.Rasa.Agents;
using Bot.Rasa.Intents;
using Bot.Rasa.Models;
using Bot.Rasa.Sessions;
using DotNetToolkit;
using EntityFrameworkCore.BootKit;
using Microsoft.EntityFrameworkCore;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using Newtonsoft.Json.Serialization;
using RestSharp;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;

namespace Bot.Rasa.Consoles
{
    public static class RequestExtension
    {
        public static AIResponse TextRequest(this RasaAi rasa, Database dc, AIRequest request)
        {
            AIResponse aiResponse = new AIResponse();
            RasaResponse response = null;

            // Merge input contexts
            var contexts = dc.Table<SessionContext>()
                .Where(x => x.SessionId == rasa.SessionId && x.Lifespan > 0)
                .ToList()
                .Select(x => new AIContext { Name = x.Context.ToLower(), Lifespan = x.Lifespan })
                .ToList();

            contexts.AddRange(request.Contexts.Select(x => new AIContext { Name = x.Name.ToLower(), Lifespan = x.Lifespan }));
            contexts = contexts.OrderBy(x => x.Name).ToList();

            // search all potential intents which input context included in contexts
            var intents = rasa.agent.Intents.Where(it =>
            {
                if (contexts.Count == 0)
                {
                    return it.Contexts.Count() == 0;
                }
                else
                {
                    return it.Contexts.Count() > 0 && 
                        it.Contexts.Count(x => contexts.Select(ctx => ctx.Name).Contains(x.Name.ToLower())) == it.Contexts.Count;
                }
            }).OrderByDescending(x => x.Contexts.Count).ToList();

            // Max contexts match
            foreach(var it in intents)
            {
                request.Contexts = it.Contexts.Select(x => new AIContext { Name = x.Name.ToLower() })
                    .OrderBy(x => x.Name)
                    .ToList();
                string contextId = $"{String.Join(',', request.Contexts.Select(x => x.Name))}".GetMd5Hash();

                string modelName = dc.Table<ContextModelMapping>().FirstOrDefault(x => x.ContextId == contextId)?.ModelName;

                // need training
                if (String.IsNullOrEmpty(modelName))
                {
                    dc.DbTran(() =>
                    {
                        modelName = TrainWithContexts(rasa, dc, request, contextId);
                    });
                }

                var client = new RestClient($"{RasaAi.Options.HostUrl}");

                var rest = new RestRequest("parse", Method.POST);
                string json = JsonConvert.SerializeObject(new { Project = rasa.agent.Id, Q = request.Query.First(), Model = modelName },
                    new JsonSerializerSettings
                    {
                        ContractResolver = new CamelCasePropertyNamesContractResolver()
                    });
                rest.AddParameter("application/json", json, ParameterType.RequestBody);

                var result = client.Execute<RasaResponse>(rest);

                if(result.Data.Intent != null)
                {
                    response = result.Data;
                    break;
                }
            };

            var intent = (dc.Table<Intent>().Where(x => x.Name == response.Intent.Name)
                .Include(x => x.Responses).ThenInclude(x => x.Contexts)
                .Include(x => x.Responses).ThenInclude(x => x.Parameters)
                .Include(x => x.Responses).ThenInclude(x => x.Messages)).First();

            var intentResponse = ArrayHelper.GetRandom(intent.Responses);
            aiResponse.Id = Guid.NewGuid().ToString();
            aiResponse.Lang = rasa.agent.Language;
            aiResponse.Status = new AIResponseStatus { };
            aiResponse.SessionId = rasa.SessionId;
            aiResponse.Timestamp = DateTime.UtcNow;
            intentResponse.Messages.Where(x => x.Type == AIResponseMessageType.Text)
                .ToList()
                .ForEach(msg =>
                {
                    msg.Speech = ArrayHelper.GetRandom(msg.Speech.Substring(2, msg.Speech.Length - 4).Split("\",\"").ToList());
                });

            aiResponse.Result = new AIResponseResult
            {
                Source = "agent",
                ResolvedQuery = request.Query.First(),
                Action = intentResponse.Action,
                Parameters = new Dictionary<string, object>(),
                Score = response.Intent.Confidence,
                Metadata = new AIResponseMetadata { IntentId = intent.Id, IntentName = intent.Name },
                Fulfillment = new AIResponseFulfillment
                {
                    Messages = intentResponse.Messages.Select(x => (object)x).ToList()
                }
            };

            // Merge context lifespan
            // override if exists, otherwise add, delete if lifespan is zero
            dc.DbTran(() =>
            {
                var sessionContexts = dc.Table<SessionContext>().Where(x => x.SessionId == rasa.SessionId).ToList();

                // minus 1 round
                sessionContexts.Where(x => !intentResponse.Contexts.Select(ctx => ctx.Name).Contains(x.Context))
                    .ToList()
                    .ForEach(ctx => ctx.Lifespan = ctx.Lifespan - 1);

                intentResponse.Contexts.ForEach(ctx =>
                {
                    var session1 = sessionContexts.FirstOrDefault(x => x.Context == ctx.Name);

                    if (session1 != null)
                    {
                        if (ctx.Lifespan == 0)
                        {
                            dc.Table<SessionContext>().Remove(session1);
                        }
                        else
                        {
                            session1.Lifespan = ctx.Lifespan;
                        }
                    }
                    else
                    {
                        dc.Table<SessionContext>().Add(new SessionContext
                        {
                            SessionId = rasa.SessionId,
                            Context = ctx.Name,
                            Lifespan = ctx.Lifespan
                        });
                    }
                });
            });

            aiResponse.Result.Contexts = dc.Table<SessionContext>()
                .Where(x => x.SessionId == rasa.SessionId)
                .Select(x => new AIContext { Name = x.Context, Lifespan = x.Lifespan })
                .ToArray();

            return aiResponse;
        }

        /// <summary>
        /// Need two categories at least
        /// </summary>
        /// <param name="console"></param>
        /// <param name="dc"></param>
        /// <param name="request"></param>
        /// <param name="contextId"></param>
        /// <returns></returns>
        public static string TrainWithContexts(this RasaAi console, Database dc, AIRequest request, String contextId)
        {
            var corpus = console.agent.GrabCorpus(dc, request.Contexts);

            corpus.UserSays.Add(new UserSay
            {
                Intent = "Welcome",
                Text = "Hi"
            });

            corpus.UserSays.Add(new UserSay
            {
                Intent = "Welcome",
                Text = "Hey"
            });

            corpus.UserSays.Add(new UserSay
            {
                Intent = "Welcome",
                Text = "Hello"
            });

            string json = JsonConvert.SerializeObject(new { rasa_nlu_data = corpus },
                new JsonSerializerSettings
                {
                    ContractResolver = new CamelCasePropertyNamesContractResolver()
                });

            var client = new RestClient($"{RasaAi.Options.HostUrl}");
            var rest = new RestRequest("train", Method.POST);
            rest.AddQueryParameter("project", console.agent.Id);
            rest.AddParameter("application/json", json, ParameterType.RequestBody);

            var response = client.Execute(rest);
            var result = JObject.Parse(response.Content);

            if (response.IsSuccessful)
            {
                string modelName = result["info"].Value<String>().Split(": ")[1];

                dc.Table<ContextModelMapping>().Add(new ContextModelMapping
                {
                    AgentId = console.agent.Id,
                    ModelName = modelName,
                    ContextId = contextId
                });

                return modelName;
            }
            else
            {
                Console.WriteLine(result["error"]);

                return String.Empty;
            }
        }
    }
}