using ChatRAG.Models;
using ChatRAG.Services.Contracts;
using ChatRAG.Settings.ChatRAG.Configuration;
using Microsoft.Extensions.Options;
using System.Text;
using System.Text.Json;
using Qdrant.Client;
using Qdrant.Client.Grpc;
using Google.Protobuf;

namespace ChatRAG.Data
{
    public class QdrantProjectDataRepository : IProjectDataRepository
    {
        private readonly HttpClient _httpClient;
        private readonly string _collectionName;
        private readonly ILogger<QdrantProjectDataRepository> _logger;
        private readonly QdrantClient _qdrantClient;
        private volatile bool _collectionInitialized = false;
        private readonly SemaphoreSlim _initializationSemaphore = new(1, 1);

        public QdrantProjectDataRepository(
            IOptions<VectorDatabaseSettings> settings,
            HttpClient httpClient,
            ILogger<QdrantProjectDataRepository> logger)
        {
            var qdrantSettings = settings.Value.Qdrant ?? throw new ArgumentNullException("Qdrant settings not configured");
            _httpClient = httpClient;
            _httpClient.BaseAddress = new Uri($"http://{qdrantSettings.Host}:{qdrantSettings.Port}");
            _collectionName = qdrantSettings.GroupsCollectionName;
            _logger = logger;

            // Inicializa o QdrantClient - use GRPC (porta 6334) para melhor performance
            _qdrantClient = new QdrantClient(qdrantSettings.Host, port: 6334, https: false);

            InitializeAsync().GetAwaiter().GetResult();
        }

        private async Task InitializeAsync()
        {
            try
            {
                if (_collectionInitialized) return;

                await _initializationSemaphore.WaitAsync();

                var exists = await _qdrantClient.CollectionExistsAsync(_collectionName);
                if (!exists)
                {
                    await CreateProjectsCollection();
                }
                _collectionInitialized = true;

            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Erro ao inicializar collection de projetos no Qdrant");
            }
            finally
            {
                _initializationSemaphore.Release();
            }
        }

        public async Task<List<Project>> GetAsync()
        {
            try
            {
                //var scrollRequest = new ScrollPoints
                //{
                //    CollectionName = _collectionName,
                //    Filter = new Filter(), // Filtro vazio
                //    Limit = 1000,
                //    WithPayload = true,
                //    WithVectors = false
                //};

                //var result = await _qdrantClient.ScrollAsync(_collectionName, scrollRequest);
                var result = await _qdrantClient.ScrollAsync(_collectionName, new Filter(), 1000, null, true, false);

                return result.Result.Select(ConvertToProject)
                    .Where(p => p != null)
                    .ToList()!;
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Erro ao recuperar projetos do Qdrant");
                return new List<Project>();
            }
        }

        public async Task<Project?> GetAsync(string id)
        {
            try
            {
                var points = await _qdrantClient.RetrieveAsync(
                    _collectionName,
                    new[] { new PointId { Uuid = id } },
                    withPayload: true,
                    withVectors: false
                );

                var point = points.FirstOrDefault();
                return point != null ? ConvertToProject(point) : null;
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Erro ao buscar projeto {Id} no Qdrant", id);
                return null;
            }
        }

        public async Task CreateAsync(Project newProject)
        {
            try
            {
                var id = string.IsNullOrEmpty(newProject.Id) ? Guid.NewGuid().ToString() : newProject.Id;
                newProject.Id = id;

                var point = new PointStruct
                {
                    Id = new PointId { Uuid= id },
                    Vectors = new float[384], // Vector dummy para projetos
                    Payload =
                    {
                        ["id"] = newProject.Id,
                        ["nome"] = newProject.Nome,
                        ["descricao"] = newProject.Descricao,
                        ["created_at"] = DateTime.UtcNow.ToString("O"),
                        ["entity_type"] = "project"
                    }
                };

                await _qdrantClient.UpsertAsync(_collectionName, new[] { point });
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Erro ao criar projeto no Qdrant");
                throw;
            }
        }

        public async Task UpdateAsync(string id, Project updatedProject)
        {
            try
            {
                updatedProject.Id = id;

                var point = new PointStruct
                {
                    Id = new PointId { Uuid = id },
                    Vectors = new float[384], // Vector dummy
                    Payload =
                    {
                        ["id"] = updatedProject.Id,
                        ["nome"] = updatedProject.Nome,
                        ["descricao"] = updatedProject.Descricao,
                        ["updated_at"] = DateTime.UtcNow.ToString("O"),
                        ["entity_type"] = "project"
                    }
                };

                await _qdrantClient.UpsertAsync(_collectionName, new[] { point });
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Erro ao atualizar projeto {Id} no Qdrant", id);
                throw;
            }
        }

        public async Task SaveAsync(Project project)
        {
            try
            {
                if (string.IsNullOrEmpty(project.Id))
                {
                    await CreateAsync(project);
                }
                else
                {
                    var existing = await GetAsync(project.Id);
                    if (existing == null)
                    {
                        await CreateAsync(project);
                    }
                    else
                    {
                        await UpdateAsync(project.Id, project);
                    }
                }
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Erro ao salvar projeto no Qdrant");
                throw;
            }
        }

        public async Task RemoveAsync(string id)
        {
            try
            {
                await _qdrantClient.DeleteAsync(
                    _collectionName,
                    new[] { new PointId { Uuid = id }.Num }
                );
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Erro ao remover projeto {Id} do Qdrant", id);
                throw;
            }
        }

        private async Task CreateProjectsCollection()
        {
            var vectorParams = new VectorParams
            {
                Size = 384,
                Distance = Distance.Cosine
            };

            await _qdrantClient.CreateCollectionAsync(_collectionName, vectorParams);

            _logger.LogInformation("Collection de projetos '{CollectionName}' criada no Qdrant", _collectionName);
        }

        private static Project? ConvertToProject(RetrievedPoint point)
        {
            try
            {
                if (point.Payload == null) return null;

                return new Project
                {
                    Id = point.Payload.TryGetValue("id", out var idValue) ? idValue.StringValue : point.Id.ToString(),
                    Nome = point.Payload.TryGetValue("nome", out var nomeValue) ? nomeValue.StringValue : "",
                    Descricao = point.Payload.TryGetValue("descricao", out var descValue) ? descValue.StringValue : ""
                };
            }
            catch
            {
                return null;
            }
        }
    }

    public class QdrantScrollResult
    {
        public QdrantScrollData? result { get; set; }
    }

    public class QdrantScrollData
    {
        public QdrantPoint[]? points { get; set; }
    }

    public class QdrantPointResult
    {
        public QdrantPoint? result { get; set; }
    }

    public class QdrantPoint
    {
        public string? id { get; set; }
        public Dictionary<string, object>? payload { get; set; }
    }
}