using Fitness_core_BE.Helpers;
using Fitness_core_BE.Interfaces;
using Fitness_core_BE.Interfaces.Services;
using Microsoft.AspNetCore.Http;

namespace Fitness_core_BE.Services
{
    public class PermissionService : IPermissionService
    {
        private readonly UserRoleHelper _userRoleHelper;
        private readonly IStaffRepository _staffRepository;
        private readonly IGymRoleRepository _gymRoleRepository;
        private readonly INavItemRepository _navItemRepository;

        public PermissionService(
            UserRoleHelper userRoleHelper,
            IStaffRepository staffRepository,
            IGymRoleRepository gymRoleRepository,
            INavItemRepository navItemRepository)
        {
            _userRoleHelper = userRoleHelper;
            _staffRepository = staffRepository;
            _gymRoleRepository = gymRoleRepository;
            _navItemRepository = navItemRepository;
        }

        public async Task<PermissionContext> GetPermissionContextAsync(HttpContext httpContext)
        {
            var userId = DataExtractor.GetUserIdFromContext(httpContext);

            // Owner check first: the gym owner always has full access and never touches
            // GymRole/GymRolePermission at all.
            var clientId = await _userRoleHelper.GetOwnedClientId(userId);

            if (clientId.HasValue)
            {
                var allKeys = (await _navItemRepository.GetActiveNavItemsOrdered())
                    .Select(n => n.Key)
                    .ToHashSet();
                return new PermissionContext(IsOwner: true, ClientId: clientId, StaffId: null, AllowedNavKeys: allKeys);
            }

            var staffId = await _userRoleHelper.GetStaffId(userId);
            if (staffId.HasValue)
            {
                var staff = await _staffRepository.GetStaffById(staffId.Value);
                if (staff?.FKGymRoleId is Guid gymRoleId && staff.GymRole?.IsActive == true)
                {
                    var keys = (await _gymRoleRepository.GetPermissionKeys(gymRoleId)).ToHashSet();
                    return new PermissionContext(IsOwner: false, ClientId: null, StaffId: staffId, AllowedNavKeys: keys);
                }

                // Staff with no role assigned yet: dashboard only, not zero -- so forgetting
                // to assign a role (the create-staff flow makes it optional) leaves someone
                // with a blank-but-working dashboard instead of a fully broken login.
                return new PermissionContext(IsOwner: false, ClientId: null, StaffId: staffId, AllowedNavKeys: new HashSet<string> { "dashboard" });
            }

            // Neither owner nor staff (e.g. Customer/Admin token hitting a client-scoped endpoint).
            return new PermissionContext(IsOwner: false, ClientId: null, StaffId: null, AllowedNavKeys: new HashSet<string>());
        }
    }
}