parking-webapi/WebApi_data_value/Services/BackgroundService.cs

using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.EntityFrameworkCore;
using System;
using System.Globalization;
using System.Threading;
using System.Threading.Tasks;
using Parking_space_WebAPI.Services;
using WebApi_data_value.Models;
using Microsoft.Extensions.Logging; // 確保引用
using System.Linq;

#region 從進入車輛獲取最新的月租名單
public class ParkingService : BackgroundService
{
    private readonly IServiceScopeFactory _scopeFactory;
    private readonly ILogger<ParkingService> _logger;

    public ParkingService(IServiceScopeFactory scopeFactory, ILogger<ParkingService> logger)
    {
        _scopeFactory = scopeFactory;
        _logger = logger;
    }

    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        await PerformParkingCheckAsync(stoppingToken);
        while (!stoppingToken.IsCancellationRequested)
        {
            await Task.Delay(TimeSpan.FromSeconds(50), stoppingToken); //每50秒執行
            await PerformParkingCheckAsync(stoppingToken);
        }
    }

    private async Task PerformParkingCheckAsync(CancellationToken stoppingToken)
    {
        using (var scope = _scopeFactory.CreateScope())
        {
            var _context = scope.ServiceProvider.GetRequiredService<SqlContext>();

            var now = DateTime.Now;
            var startTime = now.AddHours(-12);   // 獲取最近 12 小時進入的車輛
            var inCars = await _context.yuntech_in_car_table
                .Where(car => car.in_time >= startTime)
                .ToListAsync(stoppingToken);

            // 獲取月租名單
            var monthlyUsers = await _context.yuntech_parking_user_list.ToListAsync(stoppingToken);

            var monthlycar = 0;
            var temporarycar = 0;

            foreach (var car in inCars)
            {
                var matchedUsers = monthlyUsers
                    .Where(user => user.user_license_plate_number == car.license_plate_number)
                    .ToList();

                if (matchedUsers.Count > 0)
                {
                    
                    if (matchedUsers.Count % 2 == 1)
                    {
                        monthlycar++;
                    }
                    else
                    {
                        monthlycar--;
                    }
                }
                else
                {
                    temporarycar++;
                }
            }
            _logger.LogInformation($"月租車位數量: {monthlycar}");
            _logger.LogInformation($"臨停車位數量: {temporarycar}");

           
            await UpdateMonthly(_context, monthlycar, temporarycar, stoppingToken); //更新月租跟臨停
        }
    }

    private async Task UpdateMonthly(SqlContext context, int monthlycar, int temporarycar, CancellationToken stoppingToken)
    {
        
        var monthlyRentData = await context.yuntech_monthly_rent_number
            .FirstOrDefaultAsync(rent => rent.category == "月租", stoppingToken);

        if (monthlyRentData != null)
        {
            monthlyRentData.number = monthlycar.ToString();
        }
        var temporaryRentData = await context.yuntech_monthly_rent_number
            .FirstOrDefaultAsync(rent => rent.category == "臨停", stoppingToken);

        if (temporaryRentData != null)
        {
            temporaryRentData.number = temporarycar.ToString();
        }

        await context.SaveChangesAsync(stoppingToken);
    }
}

#endregion
#region 執行計算剩餘車位並不為負數存入資料庫ParkingLogs

public class ParkingUpdateService : BackgroundService
{
    private readonly IServiceScopeFactory _scopeFactory;

    public ParkingUpdateService(IServiceScopeFactory scopeFactory)
    {
        _scopeFactory = scopeFactory;
    }

    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        while (!stoppingToken.IsCancellationRequested)
        {
            using (var scope = _scopeFactory.CreateScope())
            {
                var _context = scope.ServiceProvider.GetRequiredService<SqlContext>();

                try
                {
                    var yuntech_parking = await _context.yuntech_parking.FirstOrDefaultAsync();
                    if (yuntech_parking != null)
                    {

                        if (Int32.TryParse(yuntech_parking.all_num, out int totalParkingSpaces))
                        {

                            var monthly_rent_data = await _context.yuntech_monthly_rent_number
                                .FirstOrDefaultAsync(rent => rent.category == "月租");
                            int monthlyRentNumber = 0;
                            if (monthly_rent_data != null)
                            {
                                Int32.TryParse(monthly_rent_data.number, out monthlyRentNumber);
                            }


                            var temporary_rent_data = await _context.yuntech_monthly_rent_number
                                .FirstOrDefaultAsync(rent => rent.category == "臨停");
                            int temporaryRentNumber = 0;
                            if (temporary_rent_data != null)
                            {
                                Int32.TryParse(temporary_rent_data.number, out temporaryRentNumber);
                            }


                            int totalOccupiedSpaces = monthlyRentNumber + Math.Abs(temporaryRentNumber); //確保絕對值
                            int remainingSpaces = totalParkingSpaces - totalOccupiedSpaces;

                            // 確保剩餘車位數不為負數
                            yuntech_parking.now_num = Math.Max(remainingSpaces, 0).ToString();


                            await _context.SaveChangesAsync();


                            var log = new ParkingLog
                            {
                                Timestamp = DateTime.Now,
                                TotalParkingSpaces = totalParkingSpaces,
                                RemainingSpaces = Math.Max(remainingSpaces, 0),  // 確保儲存時不為負數
                                MonthlyRentSpaces = monthlyRentNumber,
                                TemporaryRentSpaces = Math.Abs(temporaryRentNumber),
                                DayOfWeek = DateTime.Now.ToString("dddd", new CultureInfo("zh-TW"))
                            };

                            // 儲存資料庫ParkingLogs
                            _context.ParkingLogs.Add(log);
                            await _context.SaveChangesAsync();
                        }
                    }
                }
                catch (Exception ex)
                {
                    // 錯誤顯示
                    Console.WriteLine($"An error occurred: {ex.Message}");
                }
            }

            // 每 30 秒執行一次
            await Task.Delay(TimeSpan.FromSeconds(30), stoppingToken);
        }
    }
}
#endregion