using EnvelopeGenerator.Application.Contracts;
using EnvelopeGenerator.Common;
using System.Text;

namespace EnvelopeGenerator.Web.Services
{
    public class EnvelopeService
    {
        private readonly ReceiverModel receiverModel;
        private readonly EnvelopeModel envelopeModel;
        private readonly HistoryModel historyModel;
        
        private readonly DocumentStatusModel documentStatusModel;

        private readonly IConfigService _configService;
        private readonly ILogger<EnvelopeService> _logger;

        public EnvelopeService(DatabaseService database, IConfigService configService, ILogger<EnvelopeService> logger)
        {
            _logger = logger;

            if (database.Models is null)
                throw new ArgumentNullException("Models not loaded.");

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

            _configService = configService;
        }

        public void EnsureValidEnvelopeKey(string envelopeKey)
        {
            _logger.LogInformation("Parsing EnvelopeKey..");

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

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

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

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

        public async Task<EnvelopeResponse> LoadEnvelope(string pEnvelopeKey)
        {
            _logger.LogInformation("Loading Envelope by Key [{0}]", pEnvelopeKey);

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

            _logger.LogInformation("Resolved receiver signature to receiverId [{0}]", receiverId);

            _logger.LogInformation("Loading envelope..");
            Envelope? envelope = envelopeModel.GetByUuid(envelopeUuid);            

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

            _logger.LogInformation("Envelope loaded");

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

            _logger.LogInformation("Envelope receivers found: [{0}]", envelope.Receivers.Count);

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

            if (receiver == null)
            {
                _logger.LogWarning("Receiver [{0}] not found", receiverId);
                throw new NullReferenceException("Receiver not found");
            }

            _logger.LogInformation("Loading documents for receiver [{0}]", receiver.Email);

            // filter elements by receiver
            envelope.Documents = envelope.Documents.Select((document) =>
            {
                document.Elements = document.Elements.Where((e) => e.ReceiverId == receiverId).ToList();
                return document;
            }).ToList();

            //if documenet_path_dmz is existing in config, replace the path with it
            var configResult = await _configService.ReadDefaultAsync();
            if (configResult.IsSuccess && configResult.Data is not null)
            {
                var config = configResult.Data;

                if(config.DocumentPathDmz is not null && config.DocumentPathDmz != string.Empty)
                    foreach(var doc in envelope.Documents)
                    {
                        doc.Filepath = doc.Filepath.Replace(config.DocumentPath , config.DocumentPathDmz);
                    }
            }
            else
            {
                _logger.LogError(string.Join(". ", configResult.Messages));
                throw new InvalidOperationException(String.Join(". ", configResult.Messages));
            }

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

        public List<Envelope> LoadEnvelopes()
        {
            var receivers = receiverModel.ListReceivers();
            List<Envelope> envelopes = new();

            foreach (var receiver in receivers)
            {
                var envs = (List<Envelope>)envelopeModel.List(receiver.Id);
                envelopes.AddRange(envs);
            }

            return envelopes;
        }

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

        public bool ReceiverAlreadySigned(Envelope envelope, int receiverId)
        {
            return historyModel.HasReceiverSigned(envelope.Id, receiverId);     
        }

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

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

                _logger.LogInformation("Annotation data parsed, size: [{0}]", bytes.Length);

                return Encoding.UTF8.GetString(bytes);
            }
            catch (Exception e)
            {
                _logger.LogError(e, "Inner Service Error");
                throw new ArgumentNullException("AnnotationData");
            }
        }

        public async Task<EnvelopeDocument> GetDocument(int documentId, string envelopeKey)
        {
            EnvelopeResponse response = await LoadEnvelope(envelopeKey);

            _logger.LogInformation("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.LogInformation("Document [{0}] loaded!", documentId);

            return document;
        }

        public bool InsertDocumentStatus(Common.DocumentStatus documentStatus)
        {
            _logger.LogInformation("Saving annotation data..");
            return documentStatusModel.InsertOrUpdate(documentStatus);
        }

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

            return bytes;
        }
    }
}