using System;
using System.IO;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using OfficeOpenXml;
using WebApi_data_value.Models; 
using Microsoft.EntityFrameworkCore;

namespace Parking_space_WebAPI.Services
{
    public class ExcelGenerationService : BackgroundService
    {
        private readonly IServiceProvider _serviceProvider;
        private readonly string _saveDirectory = @"C:\Users\ste92\Desktop\parking-e\excel"; // 指定儲存 Excel 的資料夾

        public ExcelGenerationService(IServiceProvider serviceProvider)
        {
            _serviceProvider = serviceProvider;
        }

        protected override async Task ExecuteAsync(CancellationToken stoppingToken)
        {
            while (!stoppingToken.IsCancellationRequested)
            {
                await GenerateAndSaveExcel();
                await Task.Delay(TimeSpan.FromHours(1), stoppingToken); // 每小時執行一次
                //await Task.Delay(TimeSpan.FromMinutes(2), stoppingToken); // 每 2 分鐘執行一次
            }
        }

        private async Task GenerateAndSaveExcel()
        {
            using (var scope = _serviceProvider.CreateScope())
            {
                var _context = scope.ServiceProvider.GetRequiredService<SqlContext>();

                // 從資料庫讀取數據
                var parkingSpaces = await _context.yuntech_parking.ToListAsync();
                var monthlyRent = await _context.yuntech_monthly_rent_number
                    .FirstOrDefaultAsync(x => x.category == "月租");
                var temporaryParking = await _context.yuntech_monthly_rent_number
                    .FirstOrDefaultAsync(x => x.category == "臨停");

                if (parkingSpaces != null && monthlyRent != null && temporaryParking != null)
                {
                    // 生成 Excel 文件
                    var fileBytes = GenerateExcel(parkingSpaces, monthlyRent, temporaryParking);

                    // 文件名帶上當前時間
                    var fileName = $"ParkingSpaces_{DateTime.Now:yyyyMMddHHmmss}.xlsx";
                    var filePath = Path.Combine(_saveDirectory, fileName);

                    // 保存文件
                    await File.WriteAllBytesAsync(filePath, fileBytes);
                }
            }
        }

        private byte[] GenerateExcel(IEnumerable<Yuntech_parking> parkingData, Yuntech_monthly_rent_number monthlyRent, Yuntech_monthly_rent_number temporaryParking)
        {
            using var package = new ExcelPackage();
            var worksheet = package.Workbook.Worksheets.Add("Yuntech Parking");

            // 設定標題
            worksheet.Cells[1, 1].Value = "總車位";
            worksheet.Cells[1, 2].Value = "剩餘車位";
            worksheet.Cells[1, 3].Value = "月租車數量";
            worksheet.Cells[1, 4].Value = "臨停數量";

            // 添加下載時間
            worksheet.Cells[1, 6].Value = "下載時間";
            worksheet.Cells[2, 6].Value = DateTime.Now.ToString("yyyy/MM/dd HH:mm:ss");

            var row = 2;
            foreach (var item in parkingData)
            {
                worksheet.Cells[row, 1].Value = item.all_num;
                worksheet.Cells[row, 2].Value = item.now_num;
                row++;
            }

            // 添加月租車與臨停車數據
            worksheet.Cells[2, 3].Value = monthlyRent.number;
            worksheet.Cells[2, 4].Value = temporaryParking.number;

            return package.GetAsByteArray();
        }
    }
}