#nullable enable

using System;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.SignalR;
using Volo.Abp.MultiTenancy;
using Volo.Abp.Users;

namespace Sozsoft.Platform.Messenger;

[Authorize]
public class MessengerHub : Hub
{
    private readonly ICurrentTenant _currentTenant;
    private readonly ICurrentUser _currentUser;
    private readonly MessengerAppService _messengerAppService;

    public MessengerHub(
        ICurrentTenant currentTenant,
        ICurrentUser currentUser,
        MessengerAppService messengerAppService)
    {
        _currentTenant = currentTenant;
        _currentUser = currentUser;
        _messengerAppService = messengerAppService;
    }

    public override async Task OnConnectedAsync()
    {
        if (_currentUser.Id.HasValue)
        {
            await Groups.AddToGroupAsync(Context.ConnectionId, UserGroupName(_currentUser.Id.Value));
            await Groups.AddToGroupAsync(Context.ConnectionId, TenantGroupName());
        }

        await base.OnConnectedAsync();
    }

    public override async Task OnDisconnectedAsync(Exception? exception)
    {
        if (_currentUser.Id.HasValue)
        {
            await Groups.RemoveFromGroupAsync(Context.ConnectionId, UserGroupName(_currentUser.Id.Value));
            await Groups.RemoveFromGroupAsync(Context.ConnectionId, TenantGroupName());
        }

        await base.OnDisconnectedAsync(exception);
    }

    public async Task SendMessage(MessengerSendMessageDto input)
    {
        var message = await _messengerAppService.SendMessageAsync(input);

        var targetGroups = message.RecipientIds
            .Append(message.SenderId)
            .Distinct()
            .Select(UserGroupName)
            .ToList();

        await Clients.Groups(targetGroups).SendAsync("MessengerMessageReceived", message);
    }

    public async Task DeleteMessage(Guid messageId)
    {
        var deletedMessage = await _messengerAppService.DeleteMessageAsync(messageId);

        var targetGroups = deletedMessage.RecipientIds
            .Append(deletedMessage.SenderId)
            .Distinct()
            .Select(UserGroupName)
            .ToList();

        await Clients.Groups(targetGroups).SendAsync("MessengerMessageDeleted", deletedMessage);
    }

    private string TenantKey => _currentTenant.Id?.ToString("N") ?? "host";

    private string TenantGroupName() => $"messenger:tenant:{TenantKey}";

    private string UserGroupName(Guid userId) => $"messenger:user:{TenantKey}:{userId:N}";
}