using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using Shogi.Contracts.Types;
using Shogi.Api.Repositories.CouchModels;
using System.Collections.ObjectModel;
using System.Text;
using Session = Shogi.Domain.Session;

namespace Shogi.Api.Repositories
{
	public interface IGameboardRepository
	{
		Task CreateBoardState(Session session);
		Task CreateUser(Models.User user);
		Task<Collection<SessionMetadata>> ReadSessionMetadatas();
		Task<Session?> ReadSession(string name);
		Task UpdateSession(SessionMetadata session);
		Task<SessionMetadata?> ReadSessionMetaData(string name);
		Task<Models.User?> ReadUser(string userName);
	}

	public class GameboardRepository
	{
		/// <summary>
		/// Returns session, board state, and user documents, grouped by session.
		/// </summary>
		private static readonly string View_SessionWithBoardState = "_design/session/_view/session-with-boardstate";
		/// <summary>
		/// Returns session and user documents, grouped by session.
		/// </summary>
		private static readonly string View_SessionMetadata = "_design/session/_view/session-metadata";
		private static readonly string View_User = "_design/user/_view/user";
		private const string ApplicationJson = "application/json";
		private readonly HttpClient client;
		private readonly ILogger<GameboardRepository> logger;

		public GameboardRepository(IHttpClientFactory clientFactory, ILogger<GameboardRepository> logger)
		{
			client = clientFactory.CreateClient("couchdb");
			this.logger = logger;
		}

		//public async Task<Collection<SessionMetadata>> ReadSessionMetadatas()
		//{
		//	var queryParams = new QueryBuilder { { "include_docs", "true" } }.ToQueryString();
		//	var response = await client.GetAsync($"{View_SessionMetadata}{queryParams}");
		//	var responseContent = await response.Content.ReadAsStringAsync();
		//	var result = JsonConvert.DeserializeObject<CouchViewResult<JObject>>(responseContent);
		//	if (result != null)
		//	{
		//		var groupedBySession = result.rows.GroupBy(row => row.id);
		//		var sessions = new List<SessionMetadata>(result.total_rows / 3);
		//		foreach (var group in groupedBySession)
		//		{
		//			/**
  //         * A group contains 3 elements.
  //         * 1) The session metadata.
  //         * 2) User document of Player1.
  //         * 3) User document of Player2.
  //         */
		//			var session = group.FirstOrDefault()?.doc.ToObject<SessionDocument>();
		//			var player1 = group.Skip(1).FirstOrDefault()?.doc.ToObject<UserDocument>();
		//			var player2Doc = group.Skip(2).FirstOrDefault()?.doc;
		//			if (session != null && player1 != null && player2Doc != null)
		//			{
		//				var player2 = IsUserDocument(player2Doc)
		//					? new Models.User(player2Doc.ToObject<UserDocument>()!)
		//					: null;
		//				//sessions.Add(new SessionMetadata(session.Name, session.IsPrivate, player1.Id, player2?.Id));
		//			}
		//		}
		//		return new Collection<SessionMetadata>(sessions);
		//	}
		//	return new Collection<SessionMetadata>(Array.Empty<SessionMetadata>());
		//}

		private static bool IsUserDocument(JObject player2Doc)
		{
			return player2Doc?.SelectToken(nameof(CouchDocument.DocumentType))?.Value<WhichDocumentType>() == WhichDocumentType.User;
		}

		//public async Task<Session?> ReadSession(string name)
		//{
		//	static Domain.ValueObjects.Piece? MapPiece(Piece? piece)
		//	{
		//		return piece == null
		//			? null
		//			: Domain.ValueObjects.Piece.Create(piece.WhichPiece, piece.Owner, piece.IsPromoted);
		//	}

		//	var queryParams = new QueryBuilder
		//	{
		//		{ "include_docs", "true" },
		//		{ "startkey", JsonConvert.SerializeObject(new [] {name}) },
		//		{ "endkey", JsonConvert.SerializeObject(new object [] {name, int.MaxValue}) }
		//	}.ToQueryString();
		//	var query = $"{View_SessionWithBoardState}{queryParams}";
		//	logger.LogInformation("ReadSession() query: {query}", query);
		//	var response = await client.GetAsync(query);
		//	var responseContent = await response.Content.ReadAsStringAsync();
		//	var result = JsonConvert.DeserializeObject<CouchViewResult<JObject>>(responseContent);
		//	if (result != null && result.rows.Length > 2)
		//	{
		//		var group = result.rows;
		//		/**
  //       * A group contains multiple elements.
  //       * 0) The session metadata.
  //       * 1) User documents of Player1.
  //       * 2) User documents of Player1.
  //       *   2.a) If the Player2 document doesn't exist, CouchDB will return the SessionDocument instead :(
  //       * Everything Else) Snapshots of the boardstate after every player move.
  //       */
		//		var session = group[0].doc.ToObject<SessionDocument>();
		//		var player1 = group[1].doc.ToObject<UserDocument>();
		//		var player2Doc = group[2].doc;
		//		var boardState = group.Last().doc.ToObject<BoardStateDocument>();

		//		if (session != null && player1 != null && boardState != null)
		//		{
		//			var player2 = IsUserDocument(player2Doc)
		//					? new Models.User(player2Doc.ToObject<UserDocument>()!)
		//					: null;
		//			var metaData = new SessionMetadata(session.Name, session.IsPrivate, player1.Id, player2?.Id);
		//			var shogiBoardState = new BoardState(boardState.Board.ToDictionary(kvp => kvp.Key, kvp => MapPiece(kvp.Value)));
		//			//return new Session(shogiBoardState, metaData);
		//		}
		//	}
		//	return null;
		//}

		//public async Task<SessionMetadata?> ReadSessionMetaData(string name)
		//{
		//	var queryParams = new QueryBuilder
		//	{
		//		{ "include_docs", "true" },
		//		{ "startkey", JsonConvert.SerializeObject(new [] {name}) },
		//		{ "endkey", JsonConvert.SerializeObject(new object [] {name, int.MaxValue}) }
		//	}.ToQueryString();
		//	var response = await client.GetAsync($"{View_SessionMetadata}{queryParams}");
		//	var responseContent = await response.Content.ReadAsStringAsync();
		//	var result = JsonConvert.DeserializeObject<CouchViewResult<JObject>>(responseContent);
		//	if (result != null && result.rows.Length > 2)
		//	{
		//		var group = result.rows;
		//		/**
  //       * A group contains 3 elements.
  //       * 1) The session metadata.
  //       * 2) User document of Player1.
  //       * 3) User document of Player2.
  //       */
		//		var session = group[0].doc.ToObject<SessionDocument>();
		//		var player1 = group[1].doc.ToObject<UserDocument>();
		//		var player2Doc = group[2].doc;
		//		if (session != null && player1 != null)
		//		{
		//			var player2 = IsUserDocument(player2Doc)
		//					? new Models.User(player2Doc.ToObject<UserDocument>()!)
		//					: null;
		//			return new SessionMetadata(session.Name, session.IsPrivate, player1.Id, player2?.Id);
		//		}
		//	}
		//	return null;
		//}

		/// <summary>
		/// Saves a snapshot of board state and the most recent move.
		/// </summary>
		public async Task CreateBoardState(Session session)
		{
			var boardStateDocument = new BoardStateDocument(session.Name, session);
			var content = new StringContent(JsonConvert.SerializeObject(boardStateDocument), Encoding.UTF8, ApplicationJson);
			var response = await client.PostAsync(string.Empty, content);
			response.EnsureSuccessStatusCode();
		}

		//public async Task<bool> CreateSession(SessionMetadata session)
		//{
		//	var sessionDocument = new SessionDocument(session);
		//	var sessionContent = new StringContent(JsonConvert.SerializeObject(sessionDocument), Encoding.UTF8, ApplicationJson);
		//	var postSessionDocumentTask = client.PostAsync(string.Empty, sessionContent);

		//	var boardStateDocument = new BoardStateDocument(session.Name, new Session());
		//	var boardStateContent = new StringContent(JsonConvert.SerializeObject(boardStateDocument), Encoding.UTF8, ApplicationJson);

		//	if ((await postSessionDocumentTask).IsSuccessStatusCode)
		//	{
		//		var response = await client.PostAsync(string.Empty, boardStateContent);
		//		return response.IsSuccessStatusCode;
		//	}

		//	return false;
		//}

		//public async Task UpdateSession(SessionMetadata session)
		//{
		//	// GET existing session to get revisionId.
		//	var readResponse = await client.GetAsync(session.Name);
		//	readResponse.EnsureSuccessStatusCode();
		//	var sessionDocument = JsonConvert.DeserializeObject<SessionDocument>(await readResponse.Content.ReadAsStringAsync());

		//	// PUT the document with the revisionId.
		//	var couchModel = new SessionDocument(session)
		//	{
		//		RevisionId = sessionDocument?.RevisionId
		//	};
		//	var content = new StringContent(JsonConvert.SerializeObject(couchModel), Encoding.UTF8, ApplicationJson);
		//	var response = await client.PutAsync(couchModel.Id, content);
		//	response.EnsureSuccessStatusCode();
		//}

		//public async Task<bool> PutJoinPublicSession(PutJoinPublicSession request)
		//{
		//  var content = new StringContent(JsonConvert.SerializeObject(request), Encoding.UTF8, MediaType);
		//  var response = await client.PutAsync(JoinSessionRoute, content);
		//  var json = await response.Content.ReadAsStringAsync();
		//  return JsonConvert.DeserializeObject<PutJoinPublicSessionResponse>(json).JoinSucceeded;
		//}

		//public async Task<string> PostJoinPrivateSession(PostJoinPrivateSession request)
		//{
		//  var content = new StringContent(JsonConvert.SerializeObject(request), Encoding.UTF8, MediaType);
		//  var response = await client.PostAsync(JoinSessionRoute, content);
		//  var json = await response.Content.ReadAsStringAsync();
		//  var deserialized = JsonConvert.DeserializeObject<PostJoinPrivateSessionResponse>(json);
		//  if (deserialized.JoinSucceeded)
		//  {
		//    return deserialized.SessionName;
		//  }
		//  return null;
		//}
	}
}