using Microsoft.EntityFrameworkCore;
using Nuuru.Server.Extensions;
using Nuuru.Server.Models;
using Nuuru.Server.Services;
using System.Collections.Concurrent;

namespace Nuuru.Server.Middleware
{
    public class DailyBointsMiddleware
    {
        private readonly RequestDelegate _next;
        private readonly IServiceScopeFactory _scopeFactory;
        private static readonly ConcurrentDictionary<Guid, byte> _credited = new();
        private static DateTime _lastReset = DateTime.UtcNow.Date;

        public DailyBointsMiddleware(RequestDelegate next, IServiceScopeFactory scopeFactory)
        {
            _next = next;
            _scopeFactory = scopeFactory;
        }

        public async Task InvokeAsync(HttpContext context)
        {
            if (context.User.Identity?.IsAuthenticated == true)
            {
                var userId = context.User.GetUserId();
                if (userId.HasValue)
                {
                    var today = DateTime.UtcNow.Date;
                    if (today > _lastReset)
                    {
                        _credited.Clear();
                        _lastReset = today;
                    }

                    if (_credited.TryAdd(userId.Value, 0))
                    {
                        var uid = userId.Value;
                        _ = Task.Run(async () =>
                        {
                            try
                            {
                                using var scope = _scopeFactory.CreateScope();
                                var bointsService = scope.ServiceProvider.GetRequiredService<IBointsService>();
                                var db = scope.ServiceProvider.GetRequiredService<Data.ApplicationDbContext>();

                                await bointsService.CreditAsync(uid, BointsReason.DailyLogin, 5);

                                // Calculate login streak: count consecutive days with DailyLogin entries
                                var loginDates = await db.BointsLedger
                                    .Where(l => l.UserId == uid && l.Reason == BointsReason.DailyLogin)
                                    .OrderByDescending(l => l.CreatedAt)
                                    .Select(l => l.CreatedAt.Date)
                                    .Distinct()
                                    .Take(8)
                                    .ToListAsync();

                                var streak = 0;
                                var checkDate = DateTime.UtcNow.Date;
                                foreach (var date in loginDates)
                                {
                                    if (date == checkDate) { streak++; checkDate = checkDate.AddDays(-1); }
                                    else break;
                                }
                                var streakBonus = Math.Min(streak, 7);
                                if (streakBonus > 0)
                                    await bointsService.CreditAsync(uid, BointsReason.LoginStreak, streakBonus);
                            }
                            catch
                            {
                                _credited.TryRemove(uid, out _);
                            }
                        });
                    }
                }
            }

            await _next(context);
        }
    }
}