using Microsoft.AspNetCore.SignalR;
using Microsoft.EntityFrameworkCore;
using vendorApproverBackend.Hubs;
using vendorApproverBackend.Entities;
using vendorApproverBackend.Interfaces;
using vendorApproverBackend.Data;

namespace vendorApproverBackend.Services
{
    public class NotificationSender : INotificationService
    {
        private readonly IHubContext<NotificationHub> _hubContext;
        private readonly DataContext _context;

        public NotificationSender(IHubContext<NotificationHub> hubContext, DataContext context)
        {
            _hubContext = hubContext;
            _context = context;
        }

        public async Task SendNotificationToUser(long userId, NotificationModel notification)
        {
            // Save to database first
            _context.NotificationModels.Add(notification);
            await _context.SaveChangesAsync();

            // Send via SignalR
            await _hubContext.Clients
                .Group($"user_{userId}")
                .SendAsync("ReceiveNotification", notification.ToMap());
        }

        public async Task SendNotificationToUsers(IEnumerable<long> userIds, NotificationModel notification)
        {
            // Save to database first
            _context.NotificationModels.Add(notification);
            await _context.SaveChangesAsync();

            // Send to multiple users
            var tasks = userIds.Select(userId => 
                _hubContext.Clients
                    .Group($"user_{userId}")
                    .SendAsync("ReceiveNotification", notification.ToMap()));

            await Task.WhenAll(tasks);
        }

        public async Task SendNotificationToAllUsers(NotificationModel notification)
        {
            // Save to database first
            _context.NotificationModels.Add(notification);
            await _context.SaveChangesAsync();

            // Send to all connected clients
            await _hubContext.Clients.All.SendAsync("ReceiveNotification", notification.ToMap());
        }

        // NEW METHOD: Send individual notifications to each user in the list
        public async Task SendNotificationToListOfUsers(IEnumerable<long> userIds, NotificationModel notification)
        {
            var notifications = new List<NotificationModel>();
            var sendTasks = new List<Task>();

            foreach (var userId in userIds)
            {
                // Create a separate notification for each user
                var userNotification = new NotificationModel
                {
                    SenderId = notification.SenderId,
                    ReciverId = userId, // Set the specific receiver
                    Subject = notification.Subject,
                    Content = notification.Content,
                    Action = notification.Action,
                    ActionId = notification.ActionId,
                    LogUrl = notification.LogUrl,
                    Status = notification.Status,
                    Timestmp = DateTime.UtcNow
                };

                notifications.Add(userNotification);

                // Prepare SignalR send task
                var sendTask = _hubContext.Clients
                    .Group($"user_{userId}")
                    .SendAsync("ReceiveNotification", userNotification.ToMap());
                
                sendTasks.Add(sendTask);
            }

            // Save all notifications to database
            _context.NotificationModels.AddRange(notifications);
            await _context.SaveChangesAsync();

            // Send all notifications via SignalR
            await Task.WhenAll(sendTasks);
        }
    }
}