using Fitness_core_BE.Interfaces;
using Fitness_core_BE.Interfaces.Services;
using Fitness_core_BE.Models;
using Fitness_core_BE.Infra.UoW;
using System.Text.Json;
using Fitness_core_BE.Helpers;
using Fitness_core_BE.Exceptions;
using Fitness_core_BE.DTOs;

namespace Fitness_core_BE.Services.Document
{
    public class DocumentService : IDocumentService
    {
        private readonly IDocumentRepository _docRepository;
        private readonly IUnitOfWork _uow;

        public DocumentService(IDocumentRepository docRepository, IUnitOfWork uow)
        {
            _docRepository = docRepository;
            _uow = uow;
        }

        public async Task<object> UploadDocument(object payload, HttpContext httpContext)
        {
            await _uow.BeginAsync();
            try
            {
                    Guid userId = DataExtractor.GetUserIdFromContext(httpContext);

                var data = DeserializePayload.Deserialize(payload);

                var files = data["document"].EnumerateArray();
                bool isTicketDoc = data.TryGetValue("IsTicketDoc", out JsonElement isTicketDocElement) && isTicketDocElement.GetBoolean();
                var uploadResults = new List<object>();
                Guid? ticketId = null;
                if (isTicketDoc && data.TryGetValue("TicketId", out JsonElement ticketIdElement))
                {
                    ticketId = ticketIdElement.GetGuid();
                }
                string uploadsRoot = "./desktop";
                

                if (isTicketDoc && ticketId.HasValue)
                {
                    // uploadsRoot = Path.GetFullPath(Path.Combine(AppContext.BaseDirectory, "..", "Uploads", userId.ToString(), ticketId.ToString()));
                    uploadsRoot = Path.GetFullPath(Path.Combine(Directory.GetCurrentDirectory(), "..", "Uploads", userId.ToString(), ticketId.Value.ToString()));

                }
                else
                {
                //     uploadsRoot = Path.GetFullPath(Path.Combine(AppContext.BaseDirectory, "..", "Uploads", userId.ToString()));
                uploadsRoot = Path.GetFullPath(Path.Combine(Directory.GetCurrentDirectory(), "..", "Uploads", userId.ToString()));
                }
                
                if (!Directory.Exists(uploadsRoot))
                {
                    Directory.CreateDirectory(uploadsRoot);
                }

                foreach (var file in files)
                {
                    string lastnum = await _docRepository.GetLastSequnce();
                    string originalFileName = file.GetProperty("FileName").GetString() ?? "document";
                    string extension = Path.GetExtension(originalFileName).ToLowerInvariant();

                    string[] allowedExtensions = { ".pdf", ".jpg", ".jpeg", ".png", ".docx", ".mp4", ".mov", ".avi", ".mkv", ".webm", ".3gp" };
                    if (!allowedExtensions.Contains(extension))
                        throw new BadRequestException("File type not allowed.");

                    string safeTimestamp = DateTime.Now.ToString("yyyyMMdd_HHmmss");
                    string filename = $"{lastnum}_{userId}_{safeTimestamp}{extension}";

                    string baseFile = file.GetProperty("Base64").GetString();
                    if (baseFile.Contains(","))
                        baseFile = baseFile.Substring(baseFile.IndexOf(",") + 1);
                    byte[] fileBytes = Convert.FromBase64String(baseFile);

                    if (fileBytes.Length > 10 * 1024 * 1024)
                        throw new BadRequestException("File too large.");

                    string filePath = Path.Combine(uploadsRoot, filename);
                    await File.WriteAllBytesAsync(filePath, fileBytes);
                    
                    // Extract FileType from the file element
                    var fileData = new Dictionary<string, JsonElement> { { "FileType", file.GetProperty("FileType") } };
                    int docTypeId = DataExtractor.GetRequiredInt(fileData, "FileType");
                    
                    UserDocument documentMeta = new UserDocument { };
                    
                    if (isTicketDoc && ticketId.HasValue)
                    {
                        documentMeta = new UserDocument
                        {
                            UserId = userId,
                            DocumentName = originalFileName,
                            DocumentUrl = $"/Uploads/{userId}/{ticketId.Value}/{Uri.EscapeDataString(filename)}",
                            FkDocumentTypeId = docTypeId,
                        };
                    }
                    else
                    {
                        documentMeta = new UserDocument
                        {
                            UserId = userId,
                            DocumentName = originalFileName,
                            DocumentUrl = $"/Uploads/{userId}/{Uri.EscapeDataString(filename)}",
                            FkDocumentTypeId = docTypeId,
                        };
                    }

                    var savedDocument = await _docRepository.UploadDocumentAsync(documentMeta);
                    await _uow.SaveChangesAsync();
                    uploadResults.Add(new
                    {
                        savedDocument.DocumentId,
                        savedDocument.DocumentName,
                        DocumentURL = savedDocument.DocumentUrl
                    });
                }

                await _uow.CommitAsync();
                return new { Message = "Documents uploaded successfully.", uploadResults };
            }
            catch
            {
                await _uow.RollbackAsync();
                throw;
            }
        }

        public async Task<object> GetDocumentsByUserId(object payload, HttpContext httpContext)
        {
            // TODO: Uncomment for production - Currently using static userId for testing
            // if (!Guid.TryParse(httpContext.User.FindFirst("UserId")?.Value, out Guid userId))
            // {
            //     throw new InvalidOperationException("Invalid UserId in token.");
            // }
            
            Guid userId = Guid.Parse("5b664468-9ba5-4e6e-b73a-97c9a791c9a0");

            List<UserDocument> docResults = await _docRepository.GetDocumentsByUserId(userId);

            if (docResults == null || docResults.Count == 0)
                return new List<object>();

            string uploadsRoot = Path.GetFullPath(Path.Combine(Directory.GetCurrentDirectory(), ".."));

            var documents = new List<object>();

            foreach (var doc in docResults)
            {
                if (string.IsNullOrEmpty(doc.DocumentUrl))
                    continue;

                string relativePath = doc.DocumentUrl.Replace("/", Path.DirectorySeparatorChar.ToString());
                Console.WriteLine("Relative Path: " + relativePath);

                string filePath = uploadsRoot + relativePath;
                Console.WriteLine("File Path: " + filePath);

                if (!File.Exists(filePath))
                    continue; // Skip missing files safely

                byte[] fileBytes = await File.ReadAllBytesAsync(filePath);

                documents.Add(new
                {
                    FileName = doc.DocumentName,
                    FileType = Path.GetExtension(doc.DocumentName),
                    doc.DocumentUrl,
                    doc.DocumentType.DocumentType,
                    Data = Convert.ToBase64String(fileBytes)
                });
            }

            return documents;
        }

        public async Task<object> GetDocumentById(object payload, HttpContext httpContext)
        {
            var data = DeserializePayload.Deserialize(payload);
            var documentId = DataExtractor.GetRequiredInt(data, "documentId");
            var document = await _docRepository.GetDocumentById(documentId);

            if (document != null && !string.IsNullOrEmpty(document.DocumentUrl))
            {
                string uploadsRoot = Path.GetFullPath(Path.Combine(Directory.GetCurrentDirectory(), ".."));
                Console.WriteLine("Uploads Root: " + uploadsRoot);
                
                string relativePath = document.DocumentUrl.Replace("/", Path.DirectorySeparatorChar.ToString());
                Console.WriteLine("Relative Path: " + relativePath);

                string filePath = uploadsRoot + relativePath;
                Console.WriteLine("File Path: " + filePath);

                if (!File.Exists(filePath))
                    throw new FileNotFoundException("Document file not found.");

                byte[] fileBytes = await File.ReadAllBytesAsync(filePath);

                return new
                {
                    FileName = document.DocumentName,
                    FileType = Path.GetExtension(document.DocumentName),
                    document.DocumentUrl,
                    document.DocumentType.DocumentType,
                    Data = Convert.ToBase64String(fileBytes)
                };
            }

            throw new InvalidOperationException("Document not found or invalid document data.");
        }

        public async Task<object> RemoveDocument(object payload, HttpContext httpContext)
        {
            await _uow.BeginAsync();
            try
            {
                var data = DeserializePayload.Deserialize(payload);
                var documentId = DataExtractor.GetRequiredInt(data, "documentId");
                var result = await _docRepository.RemoveDocument(documentId);
                
                if (!result)
                {
                    throw new NotFoundException("Document not found");
                }

                await _uow.CommitAsync();
                
                return new { success = true, message = "Document removed successfully" };
            }
            catch
            {
                await _uow.RollbackAsync();
                throw;
            }
        }

        public async Task<DocumentDownloadModel> GetFileBytesById(int documentId)
        {
            var document = await _docRepository.GetDocumentById(documentId);

            if (document == null || string.IsNullOrEmpty(document.DocumentUrl))
                throw new NotFoundException("Document record not found.");

            string uploadsRoot = Path.GetFullPath(Path.Combine(Directory.GetCurrentDirectory(), ".."));
            string relativePath = document.DocumentUrl.Replace("/", Path.DirectorySeparatorChar.ToString());
            string filePath = uploadsRoot + relativePath;

            if (!File.Exists(filePath))
                throw new FileNotFoundException("Physical file is missing on the server.");

            byte[] fileBytes = await File.ReadAllBytesAsync(filePath);

            return new DocumentDownloadModel
            {
                FileName = document.DocumentName,
                FileType = Path.GetExtension(document.DocumentName),
                FileData = fileBytes
            };
        }
    }
}