UniVerse/backend/UniVerse.Infrastructure/Notifications/NotificationService.cs

using Microsoft.Extensions.Logging;
using UniVerse.Application.DTOs.Notifications;
using UniVerse.Application.Interfaces;

namespace UniVerse.Infrastructure.Notifications;

public class NotificationService : INotificationService
{
    private readonly IEnumerable<INotificationProvider> _providers;
    private readonly INotificationScheduler _scheduler;
    private readonly ILogger<NotificationService> _logger;

    public NotificationService(
        IEnumerable<INotificationProvider> providers,
        INotificationScheduler scheduler,
        ILogger<NotificationService> logger)
    {
        _providers = providers;
        _scheduler = scheduler;
        _logger = logger;
    }

    public async Task SendAsync(NotificationMessage message, CancellationToken cancellationToken = default)
    {
        ArgumentException.ThrowIfNullOrWhiteSpace(message.Channel);
        ArgumentException.ThrowIfNullOrWhiteSpace(message.Recipient);
        ArgumentException.ThrowIfNullOrWhiteSpace(message.Subject);
        ArgumentException.ThrowIfNullOrWhiteSpace(message.Body);

        var provider = _providers.FirstOrDefault(p => string.Equals(p.Channel, message.Channel, StringComparison.OrdinalIgnoreCase))
            ?? throw new InvalidOperationException($"Notification provider for channel '{message.Channel}' is not registered.");

        _logger.LogInformation("Dispatching notification through {Channel} to {Recipient}", message.Channel, message.Recipient);
        await provider.SendAsync(message, cancellationToken);
    }

    public Task<ScheduledNotificationResponse> ScheduleAsync(ScheduleNotificationRequest request, CancellationToken cancellationToken = default)
    {
        var message = new NotificationMessage(
            request.Channel,
            request.Recipient,
            request.Subject,
            request.Body,
            request.RecipientName,
            request.Metadata);

        return _scheduler.ScheduleAsync(message, request.SendAt, cancellationToken);
    }
}