using System.Collections.Concurrent;
using System.Diagnostics.CodeAnalysis;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;

namespace RPG.Services.Core.Session;
public class SessionManager
{
    private readonly ConcurrentDictionary<ulong, RPGSession> _sessions;
    private readonly IServiceProvider _serviceProvider;
    private readonly ILogger _logger;

    public SessionManager(IServiceProvider serviceProvider, ILogger<SessionManager> logger)
    {
        _sessions = [];
        _serviceProvider = serviceProvider;
        _logger = logger;
    }

    public TSession? Create<TSession>(ulong id) where TSession : RPGSession
    {
        if (_sessions.ContainsKey(id)) return null;

        TSession session = ActivatorUtilities.CreateInstance<TSession>(_serviceProvider, id);

        _sessions[id] = session;
        _logger.LogInformation("New session (id={id}) registered", id);

        return session;
    }

    public bool TryGet<TSession>(ulong id, [NotNullWhen(true)] out TSession? session) where TSession : RPGSession
    {
        if (_sessions.TryGetValue(id, out RPGSession? value))
        {
            session = (TSession)value;
            return true;
        }

        session = null;
        return false;
    }

    public void Remove(RPGSession session)
    {
        if (_sessions.TryRemove(session.SessionId, out _))
        {
            session.Dispose();
            _logger.LogInformation("Session with id {id} was unregistered", session.SessionId);
        }
    }
}