fengling-risk-control/Fengling.RiskControl.Application/Events/RiskAlertTriggeredEventHandler.cs

using Fengling.RiskControl.Application.Services;
using Fengling.RiskControl.Domain.Aggregates.RiskAlerts;
using Fengling.RiskControl.Domain.Events;
using MediatR;

namespace Fengling.RiskControl.Application.Events;

public class RiskAlertTriggeredEventHandler : INotificationHandler<RiskAlertTriggeredEvent>
{
    private const int ALERT_TRIGGER_THRESHOLD = 30;

    private readonly IRiskAlertService _alertService;

    public RiskAlertTriggeredEventHandler(IRiskAlertService alertService)
    {
        _alertService = alertService;
    }

    public async Task Handle(RiskAlertTriggeredEvent notification, CancellationToken cancellationToken)
    {
        if (notification.RiskScore < ALERT_TRIGGER_THRESHOLD)
            return;

        var priority = notification.RiskScore switch
        {
            >= 80 => RiskAlertPriority.Critical,
            >= 60 => RiskAlertPriority.High,
            >= 40 => RiskAlertPriority.Medium,
            _ => RiskAlertPriority.Low
        };

        await _alertService.CreateAlertAsync(
            notification.MemberId,
            notification.AlertType,
            notification.Reason,
            priority);
    }
}