using Microsoft.AspNetCore.Http;
using ODCWeb.DataAccess.Repository.IRepository;
using ODCWeb.Models;
using Syncfusion.XlsIO;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ODCWeb.DataAccess.Repository
{
    public class TemplateService : ITemplateService
    {
        private readonly IUnitOfWork _unitOfWork;

        public TemplateService(IUnitOfWork unitOfWork)
        {
            _unitOfWork = unitOfWork;
        }

        public async Task<(bool isValid, string message)> ValidateTemplate(IFormFile file)
        {
            if (file == null || file.Length == 0)
                return (false, "No file uploaded");

            if (!file.ContentType.Contains("spreadsheet"))
                return (false, "File must be an Excel spreadsheet");

            using (var stream = new MemoryStream())
            {
                await file.CopyToAsync(stream);
                stream.Position = 0; // Reset stream position

                using (ExcelEngine excelEngine = new ExcelEngine())
                {
                    IApplication application = excelEngine.Excel;
                    try
                    {
                        IWorkbook workbook = application.Workbooks.Open(stream);
                        IWorksheet worksheet = workbook.Worksheets[0];
                        var range = worksheet.UsedRange;

                        int firstCol = range.Column;
                        int lastCol = range.End.Column;
                        int firstRow = range.Row;
                        int lastRow = range.End.Row;

                        if (lastCol > 9)
                            return (false, "Template should not exceed column I");

                        if (firstCol != 1)
                            return (false, "Template should start from column A");

                        if (worksheet.PageSetup.PaperSize != ExcelPaperSize.PaperA4)
                            return (false, "Template must be set up for A4 paper size");

                        int rowCount = lastRow - firstRow + 1;
                        if (rowCount > 250)
                            return (false, "Template content must fit on one A4 page");

                        return (true, "Template is valid");
                    }
                    catch (Exception ex)
                    {
                        return (false, $"Invalid template format: {ex.Message}");
                    }
                }
            }
        }
        public async Task<ExcelTemplate> SaveTemplate(IFormFile file, string userId)
        {
            using (var ms = new MemoryStream())
            {
                await file.CopyToAsync(ms);

                // Delete existing templates first
                var existingTemplates = _unitOfWork.ExcelTemplate.GetAll();
                foreach (var templatee in existingTemplates)
                {
                    _unitOfWork.ExcelTemplate.Remove(templatee);
                }
                _unitOfWork.save();

                // Save new template
                var template = new ExcelTemplate
                {
                    Name = file.FileName,
                    FileContent = ms.ToArray(),
                    UploadedDate = DateTime.UtcNow,
                    UploadedBy = userId
                };

                _unitOfWork.ExcelTemplate.Add(template);
                _unitOfWork.save();
                return template;
            }
        }
    }

}