using GB5Shared.DTO.ECM;
using GB5Shared.DTO.Framework.Login;
using GB5Shared.FileImport;
using GB5Shared.FileUpload;
using GB5Shared.QueueReader;
using Microsoft.Extensions.Configuration;
using Newtonsoft.Json;
using PayRollBLL.Employee;
using PayRollDAL.DTO.EmployeeAttachmentImport;
using System;
using System.Data;
using System.IO;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using static GB5Shared.GB5Constant.Constant;

namespace PayRollBLL.EmployeeAttachmentImport
{
    // GB4 parity: EmployeeToUserBulkImportAsynchImport's worker (EmployeeToUserCsvAsynch) —
    // reads the manifest, does the per-row work, writes an import log.
    // Manifest columns expected: EMPLOYEECODE, FILENAME.
    public class EmployeeAttachmentBulkImportJobHandler : IJobQueueHandler
    {
        public string MessageType => EmployeeAttachmentImportBLL.MessageType;

        private readonly IFileToDataTableService _fileToDataTableService;
        private readonly IFileUploadBLL _fileUploadBLL;
        private readonly IEmployeeBLL _employeeBLL;
        private readonly IConfiguration _configuration;

        public EmployeeAttachmentBulkImportJobHandler(
            IFileToDataTableService fileToDataTableService,
            IFileUploadBLL fileUploadBLL,
            IEmployeeBLL employeeBLL,
            IConfiguration configuration)
        {
            _fileToDataTableService = fileToDataTableService;
            _fileUploadBLL = fileUploadBLL;
            _employeeBLL = employeeBLL;
            _configuration = configuration;
        }

        public async Task HandleAsync(string payload, LoginDTO login, long queueId, CancellationToken ct)
        {
            var jobDTO = JsonConvert.DeserializeObject<EmployeeAttachmentBulkImportJobDTO>(payload)
                ?? throw new InvalidOperationException("Invalid EmployeeAttachmentBulkImportJobDTO payload.");

            string manifestPath = EmployeeAttachmentImportBLL.GetManifestPath(_configuration, jobDTO.FileName);
            string attachmentFolder = Path.GetDirectoryName(manifestPath)!;

            ImportFileTypeEnum fileType = Path.GetExtension(manifestPath).TrimStart('.').ToLowerInvariant() == "csv"
                ? ImportFileTypeEnum.Csv
                : ImportFileTypeEnum.Excel;

            DataTable manifest = await _fileToDataTableService.ReadAsync(manifestPath, fileType, ct);

            var log = new StringBuilder();
            int successCount = 0;
            int failureCount = 0;

            foreach (DataRow row in manifest.Rows)
            {
                string employeeCode = Convert.ToString(row["EMPLOYEECODE"]) ?? "";
                string attachmentFileName = Convert.ToString(row["FILENAME"]) ?? "";

                try
                {
                    if (string.IsNullOrWhiteSpace(employeeCode) || string.IsNullOrWhiteSpace(attachmentFileName))
                        throw new InvalidOperationException("EMPLOYEECODE and FILENAME are required.");

                    int employeeId = await _employeeBLL.GetEmployeeIdByCode(employeeCode, login);
                    if (employeeId == -1)
                        throw new InvalidOperationException($"No employee found for EmployeeCode '{employeeCode}'.");

                    string attachmentFilePath = Path.Combine(attachmentFolder, attachmentFileName);
                    if (!File.Exists(attachmentFilePath))
                        throw new InvalidOperationException($"Attachment file not found: {attachmentFilePath}");

                    byte[] fileBytes = await File.ReadAllBytesAsync(attachmentFilePath, ct);

                    var uploadRequest = new FileUploadBase64RequestDTO
                    {
                        FileName = attachmentFileName,
                        Base64Content = Convert.ToBase64String(fileBytes),
                        ObjectId = employeeId,
                        ObjectTypeId = EntityConstant.OBJECTEMPLOYEE
                    };

                    await _fileUploadBLL.FileUploadBase64Async(uploadRequest, login);

                    successCount++;
                    log.AppendLine($"Record saved for {employeeCode} ({attachmentFileName})");
                }
                catch (Exception ex)
                {
                    if (jobDTO.IsSkip == 0)
                        throw;

                    failureCount++;
                    log.AppendLine($"Record not saved for {employeeCode} ({attachmentFileName}) because of {ex.Message}");
                }
            }

            string logPath = Path.Combine(attachmentFolder, $"{Path.GetFileNameWithoutExtension(jobDTO.FileName)}_IMPORT.txt");
            await File.WriteAllTextAsync(logPath,
                $"Total: {manifest.Rows.Count}, Success: {successCount}, Failed: {failureCount}\r\n\r\n{log}", ct);
        }
    }
}