using EnvelopeGenerator.Common;
using Microsoft.Extensions.Primitives;
using System.Reflection.Metadata;
using System.Text;
using static EnvelopeGenerator.Common.Constants;

namespace EnvelopeGenerator.Web.Services
{
    public class EnvelopeService : BaseService
    {
        private ReceiverModel receiverModel;
        private EnvelopeModel envelopeModel;
        private HistoryModel historyModel;
        private DocumentModel documentModel;
        private DocumentStatusModel documentStatusModel;

        public EnvelopeService(IConfiguration Config, LoggingService Logging, DatabaseService database) : base(Config, Logging)
        {
            logger = Logging.LogConfig.GetLogger();

            if (database.Models == null)
            {
                throw new ArgumentNullException("Models not loaded.");
            }

            receiverModel = database.Models.receiverModel;
            envelopeModel = database.Models.envelopeModel;
            historyModel = database.Models.historyModel;
            documentModel = database.Models.documentModel;
            documentStatusModel = database.Models.documentStatusModel;
        }

        public void EnsureValidEnvelopeKey(string envelopeKey)
        {
            logger.Debug("Parsing EnvelopeKey..");

            if (string.IsNullOrEmpty(envelopeKey))
                throw new ArgumentNullException("EnvelopeKey");

            Tuple<string, string> result = Helpers.DecodeEnvelopeReceiverId(envelopeKey);
            logger.Debug("EnvelopeUUID: [{0}]", result.Item1);
            logger.Debug("ReceiverSignature: [{0}]", result.Item2);

            if (string.IsNullOrEmpty(result.Item1))
                throw new ArgumentNullException("EnvelopeUUID");

            if (string.IsNullOrEmpty(result.Item2))
                throw new ArgumentNullException("ReceiverSignature");
        }


        public EnvelopeResponse LoadEnvelope(string pEnvelopeKey)
        {
            Tuple<string, string> result = Helpers.DecodeEnvelopeReceiverId(pEnvelopeKey);
            var envelopeUuid = result.Item1;
            var receiverSignature = result.Item2;
            var receiverId = receiverModel.GetReceiverIdBySignature(receiverSignature);

            Envelope? envelope = envelopeModel.GetByUuid(envelopeUuid);

            if (envelope == null)
            {
                throw new NullReferenceException("Envelope not found");
            }

            if (envelope.Receivers == null)
            {
                throw new NullReferenceException("Receivers for envelope not loaded");
            }

            EnvelopeReceiver? receiver = envelope.Receivers.Where(r => r.Id == receiverId).SingleOrDefault();

            if (receiver == null)
            {
                throw new NullReferenceException("Receiver not found");
            }

            envelope.Documents = FilterElementsByReceiver(envelope, receiverId);

            return new()
            {
                Receiver = receiver,
                Envelope = envelope
            };
        }

        private static List<EnvelopeDocument> FilterElementsByReceiver(Envelope envelope, int receiverId)
        {
            return envelope.Documents.
                Select((document) =>
                {
                    var elements = document.Elements.Where((e) => e.ReceiverId == receiverId);
                    document.Elements = elements.ToList();
                    return document;
                }).
                ToList();
        }

        public List<Envelope> LoadEnvelopes(int pReceiverId)
        {
            return (List<Envelope>)envelopeModel.List(pReceiverId);
        }

        public bool InsertHistoryEntry(EnvelopeHistoryEntry historyEntry)
        {
            return historyModel.Insert(historyEntry);
        }

        public bool InsertHistoryEntrySigned(EnvelopeResponse response)
        {
            return historyModel.Insert(new EnvelopeHistoryEntry()
            {
                ActionDescription = "Dokument wurde signiert",
                ActionDate = DateTime.Now,
                ActionType = EnvelopeHistoryActionType.Signed,
                EnvelopeId = response.Envelope.Id,
                UserReference = response.Receiver.Email
            });
        }

        public bool InsertDocumentStatus(Common.DocumentStatus documentStatus)
        {
            return documentStatusModel.InsertOrUpdate(documentStatus);
        }

        public async Task<string?> EnsureValidAnnotationData(HttpRequest request)
        {
            try
            {
                logger.Debug("Parsing annotation data from request..");

                using MemoryStream ms = new();
                await request.BodyReader.CopyToAsync(ms);
                var bytes = ms.ToArray();

                return Encoding.UTF8.GetString(bytes);
            }
            catch (Exception e)
            {
                logger.Error(e);
                throw new ArgumentNullException("AnnotationData");
            }
        }

        public int EnsureValidDocumentIndex(HttpRequest request)
        {
            if (!request.Query.TryGetValue("index", out StringValues documentIndexStringList))
            {
                logger.Warn("There is no query parameter called index");
                throw new ArgumentNullException("DocumentIndex");
            }

            if (documentIndexStringList.FirstOrDefault() == null)
            {
                logger.Warn("There is no query parameter called index");
                throw new ArgumentNullException("DocumentIndex");
            }

            if (!int.TryParse(documentIndexStringList.First(), out int documentIndex))
            {
                logger.Warn("Invalid document index [{0}]", documentIndexStringList.First());
                throw new ArgumentNullException("DocumentIndex");
            }

            return documentIndex;
        }

        public EnvelopeDocument GetDocument(HttpRequest request, string envelopeKey)
        {
            EnvelopeResponse response = LoadEnvelope(envelopeKey);
            int documentId = EnsureValidDocumentIndex(request);

            logger.Debug("Loading document for Id [{0}]", documentId);

            var document = response.Envelope.Documents.
                Where(d => d.Id == documentId).
                FirstOrDefault();

            if (document == null)
                throw new ArgumentException("DocumentId");

            logger.Debug("Document [{0}] loaded!", documentId);

            return document;
        }

        public async Task UpdateDocument(Stream fileStream, string filePath)
        {
            logger.Debug("Writing document to path [{0}]..", filePath);

            using FileStream fs = new(filePath, FileMode.Open);
            await fileStream.CopyToAsync(fs);

            logger.Debug("Document written!");
        }

        public async Task<byte[]> GetDocumentContents(EnvelopeDocument document)
        {
            logger.Debug("Loading file [{0}]", document.Filepath);
            var bytes = await File.ReadAllBytesAsync(document.Filepath);
            logger.Info("File loaded, size: [{0}]", bytes.Length);

            return bytes;
        }
    }
}