using Fitness_core_BE.DTOs.Rbac;
using Fitness_core_BE.Exceptions;
using Fitness_core_BE.Helpers;
using Fitness_core_BE.Infra.UoW;
using Fitness_core_BE.Interfaces;
using Fitness_core_BE.Interfaces.Services;
using Fitness_core_BE.Models;
using Microsoft.AspNetCore.Http;

namespace Fitness_core_BE.Services
{
    public class GymRoleService : IGymRoleService
    {
        private readonly IGymRoleRepository _gymRoleRepository;
        private readonly INavItemRepository _navItemRepository;
        private readonly UserRoleHelper _userRoleHelper;
        private readonly IUnitOfWork _uow;

        public GymRoleService(
            IGymRoleRepository gymRoleRepository,
            INavItemRepository navItemRepository,
            UserRoleHelper userRoleHelper,
            IUnitOfWork uow)
        {
            _gymRoleRepository = gymRoleRepository;
            _navItemRepository = navItemRepository;
            _userRoleHelper = userRoleHelper;
            _uow = uow;
        }

        public async Task<List<GymRoleDto>> GetRolesAsync(HttpContext httpContext)
        {
            var clientId = await GetOwnerClientId(httpContext);
            var roles = await _gymRoleRepository.GetRolesByClientId(clientId);
            return roles.Select(ToDto).ToList();
        }

        public async Task<GymRoleDto> CreateRoleAsync(CreateGymRoleRequest request, HttpContext httpContext)
        {
            var clientId = await GetOwnerClientId(httpContext);
            var role = new GymRole { FKClientId = clientId, Name = request.Name };
            var created = await _gymRoleRepository.CreateRole(role);
            await _uow.SaveChangesAsync();
            return ToDto(created);
        }

        public async Task<GymRoleDto> UpdateRoleAsync(Guid gymRoleId, UpdateGymRoleRequest request, HttpContext httpContext)
        {
            var clientId = await GetOwnerClientId(httpContext);
            var role = await GetOwnedRole(gymRoleId, clientId);

            if (request.Name != null) role.Name = request.Name;
            if (request.IsActive.HasValue) role.IsActive = request.IsActive.Value;

            var updated = await _gymRoleRepository.UpdateRole(role);
            await _uow.SaveChangesAsync();
            return ToDto(updated);
        }

        public async Task DeleteRoleAsync(Guid gymRoleId, HttpContext httpContext)
        {
            var clientId = await GetOwnerClientId(httpContext);
            var role = await GetOwnedRole(gymRoleId, clientId);
            await _gymRoleRepository.DeleteRole(role);
            await _uow.SaveChangesAsync();
        }

        public async Task<GymRoleDto> SetRolePermissionsAsync(Guid gymRoleId, SetRolePermissionsRequest request, HttpContext httpContext)
        {
            var clientId = await GetOwnerClientId(httpContext);
            var role = await GetOwnedRole(gymRoleId, clientId);
            var requestedKeys = request.NavKeys?.Distinct().ToList() ?? new List<string>();
            var assignableKeys = (await _navItemRepository.GetActiveNavItemsOrdered())
                .Where(item => !item.IsOwnerOnly && item.Key != "dashboard")
                .Select(item => item.Key)
                .ToHashSet();
            var invalidKeys = requestedKeys.Where(key => !assignableKeys.Contains(key)).ToList();
            if (invalidKeys.Count > 0)
                throw new BadRequestException($"Invalid role permission: {string.Join(", ", invalidKeys)}.");

            await _gymRoleRepository.ReplacePermissions(gymRoleId, requestedKeys);
            await _uow.SaveChangesAsync();

            var refreshed = await _gymRoleRepository.GetRoleById(gymRoleId)
                ?? throw new NotFoundException("Role not found.");
            return ToDto(refreshed);
        }

        public async Task AssignStaffRoleAsync(Guid staffId, AssignStaffRoleRequest request, HttpContext httpContext)
        {
            var clientId = await GetOwnerClientId(httpContext);
            var assigned = await _gymRoleRepository.AssignStaffRole(staffId, clientId, request.GymRoleId);
            if (!assigned)
                throw new NotFoundException("Staff member or role not found for this gym.");
            await _uow.SaveChangesAsync();
        }

        // Every public method funnels through here: only a caller who resolves to a Client
        // (the gym owner) can manage roles. Staff — regardless of any nav-section permission
        // they've been granted, including "staff" — are rejected before any GymRole/
        // GymRolePermission data is ever touched.
        private async Task<Guid> GetOwnerClientId(HttpContext httpContext)
        {
            var userId = DataExtractor.GetUserIdFromContext(httpContext);
            return await _userRoleHelper.GetOwnedClientId(userId)
                ?? throw new UnauthorizedAccessException("Only the gym owner can manage roles and permissions.");
        }

        private async Task<GymRole> GetOwnedRole(Guid gymRoleId, Guid clientId)
        {
            var role = await _gymRoleRepository.GetRoleById(gymRoleId)
                ?? throw new NotFoundException("Role not found.");
            if (role.FKClientId != clientId)
                throw new NotFoundException("Role not found.");
            return role;
        }

        private static GymRoleDto ToDto(GymRole role) => new()
        {
            GymRoleId = role.GymRoleId,
            Name = role.Name,
            IsActive = role.IsActive,
            NavKeys = role.Permissions?.Select(p => p.NavItemKey).ToList() ?? new List<string>()
        };
    }
}