using Fitness_core_BE.DTOs.Auth;
using Fitness_core_BE.Exceptions;
using Fitness_core_BE.Helpers;
using Fitness_core_BE.Interfaces;
using Fitness_core_BE.Interfaces.Services;
using Fitness_core_BE.Models;
using Fitness_core_BE.Infra.UoW;
using Fitness_core_BE.DTOs.Staff;
using System.Text.Json;

namespace Fitness_core_BE.Services.Staff
{
    public class StaffService : IStaffService
    {
        private readonly IStaffRepository _staffRepository;
        private readonly IUnitOfWork _uow;
        private readonly UserRoleHelper _userRoleHelper;
        private readonly IAuthService _authService;
        private readonly IAccessDeviceService _accessDeviceService;
        private readonly IGymRoleRepository _gymRoleRepository;

        public StaffService(IStaffRepository staffRepository, IUnitOfWork uow, UserRoleHelper userRoleHelper, IAuthService authService, IAccessDeviceService accessDeviceService, IGymRoleRepository gymRoleRepository)
        {
            _staffRepository = staffRepository;
            _uow = uow;
            _userRoleHelper = userRoleHelper;
            _authService = authService;
            _accessDeviceService = accessDeviceService;
            _gymRoleRepository = gymRoleRepository;
        }

        public async Task<object> GetAllStaff(object payload, HttpContext httpContext)
        {
            var data = DeserializePayload.Deserialize(payload);
            
            bool includeInactive = data != null && 
                                   data.ContainsKey("includeInactive") && 
                                   data["includeInactive"].GetBoolean();

            var staffList = await _staffRepository.GetAllStaff(includeInactive);

            return await MapStaffListAsync(staffList);
        }

        public async Task<object> GetStaffById(object payload, HttpContext httpContext)
        {
            var data = DeserializePayload.Deserialize(payload);
            
            if (!data!.ContainsKey("staffId"))
            {
                throw new KeyNotFoundException("staffId is required");
            }

            var staffId = Guid.Parse(data["staffId"].GetString()!);
            var staff = await _staffRepository.GetStaffById(staffId);
            
            if (staff == null)
            {
                throw new KeyNotFoundException("Staff not found");
            }
            var callerClientId = await _userRoleHelper.GetClientId(
                DataExtractor.GetUserIdFromContext(httpContext));
            if (staff.FKClientId != callerClientId)
                throw new ForbiddenException("This staff member does not belong to your gym.");

            return await MapStaffAsync(staff);
        }

        public async Task<object> GetStaffByClientId(object payload, HttpContext httpContext)
        {
            var data = DeserializePayload.Deserialize(payload);
            
            if (!data!.ContainsKey("clientId"))
            {
                throw new KeyNotFoundException("clientId is required");
            }

            var clientId = Guid.Parse(data["clientId"].GetString()!);
            var callerClientId = await _userRoleHelper.GetClientId(
                DataExtractor.GetUserIdFromContext(httpContext));
            if (clientId != callerClientId)
                throw new ForbiddenException("You cannot view another gym's staff.");
            
            bool includeInactive = data.ContainsKey("includeInactive") && 
                                   data["includeInactive"].GetBoolean();

            var staffList = await _staffRepository.GetStaffByClientId(clientId, includeInactive);

            return await MapStaffListAsync(staffList);
        }

        public async Task<object> CreateStaff(object payload, HttpContext httpContext)
        {
            await _uow.BeginAsync();
            try
            {
                var data = DeserializePayload.Deserialize(payload);
                
                Guid userId = DataExtractor.GetUserIdFromContext(httpContext);
                Guid clientId = await _userRoleHelper.GetClientId(userId);

                if (!data!.ContainsKey("userName"))
                {
                    throw new KeyNotFoundException("userName is required");
                }

                if (!data.ContainsKey("email"))
                {
                    throw new KeyNotFoundException("email is required");
                }

                if (!data.ContainsKey("phoneNumber"))
                {
                    throw new KeyNotFoundException("phoneNumber is required");
                }

                var user = new User
                {
                    UserName = data["userName"].GetString()!,
                    Email = data["email"].GetString()!,
                    PhoneNumber = data["phoneNumber"].GetString()!
                };

                // Optional -- must belong to this same client, same check AssignStaffRole
                // already does for the post-creation assignment path. Left unset, the new
                // staff member has no dashboard access until a role is assigned later.
                Guid? gymRoleId = null;
                if (data.ContainsKey("gymRoleId") && data["gymRoleId"].ValueKind != JsonValueKind.Null
                    && Guid.TryParse(data["gymRoleId"].GetString(), out var parsedRoleId))
                {
                    var role = await _gymRoleRepository.GetRoleById(parsedRoleId);
                    if (role == null || role.FKClientId != clientId)
                        throw new BadRequestException("That role doesn't belong to your gym.");
                    gymRoleId = parsedRoleId;
                }

                var staff = new Models.Staff
                {
                    FKUserId = userId,
                    FKClientId = clientId,
                    StaffPosition = data.ContainsKey("staffPosition") ? data["staffPosition"].GetString() : null,
                    Department = data.ContainsKey("department") ? data["department"].GetString() : null,
                    FKGymRoleId = gymRoleId,
                };

                var result = await _staffRepository.CreateStaff(staff, user);

                await _uow.SaveChangesAsync();
                await _accessDeviceService.EnsureAccessProfileAsync(
                    clientId, user.UserId, "Staff", user.UserName ?? string.Empty);

                AuthResponse authResponse;
                try
                {
                    var authPayload = DeserializePayload.Deserialize(payload);

                    Guid roleId = Guid.Parse("08de6a11-9e9f-4401-8a10-6854567b41ed");
                    Guid userTypeId = Guid.Parse("00000000-0000-0000-0000-000000000003");

                    authPayload["userId"] = JsonSerializer.SerializeToElement(user.UserId);
                    authPayload["roleId"] = JsonSerializer.SerializeToElement(roleId);
                    authPayload["userTypeId"] = JsonSerializer.SerializeToElement(userTypeId);
                    // The client portal's request uses "phoneNumber", but Core-Hex-Auth's
                    // RegisterUser only reads "mobileNumber" — without this the auth User row
                    // was silently created with a null phone number.
                    authPayload["mobileNumber"] = JsonSerializer.SerializeToElement(user.PhoneNumber);

                    authResponse = await _authService.RegisterUser(authPayload, httpContext);
                }
                catch (Exception ex)
                {
                    throw new InvalidOperationException($"Auth registration failed: {ex.Message}");
                }

                if (authResponse.StatusCode != 200 || !authResponse.Success)
                {
                    throw new InvalidOperationException($"Auth registration failed: {authResponse.Message}");
                }

                await _uow.CommitAsync();

                // Newly created staff have no password of their own yet — email them a
                // "set your password" link (reuses the auth service's reset-link flow).
                // Non-critical: a failure here must not roll back the created staff member.
                try
                {
                    await _authService.ForgotPassword(
                        new { identifier = user.Email, useResetLink = true, welcome = true },
                        httpContext);
                }
                catch (Exception ex)
                {
                    Console.WriteLine($"Staff set-password email failed (non-critical): {ex.Message}");
                }

                return new
                {
                    staff = await MapStaffAsync(result, user),
                    auth = authResponse
                };
            }
            catch
            {
                await _uow.RollbackAsync();
                throw;
            }
        }

        public async Task<object> UpdateStaff(object payload, HttpContext httpContext)
        {
            await _uow.BeginAsync();
            try
            {
                var data = DeserializePayload.Deserialize(payload);
                
                if (!data!.ContainsKey("staffId"))
                {
                    throw new KeyNotFoundException("staffId is required");
                }

                var staffId = Guid.Parse(data["staffId"].GetString()!);

                // Get existing staff first
                var existingStaff = await _staffRepository.GetStaffById(staffId);
                if (existingStaff == null)
                {
                    throw new KeyNotFoundException("Staff not found");
                }
                var callerClientId = await _userRoleHelper.GetClientId(
                    DataExtractor.GetUserIdFromContext(httpContext));
                if (existingStaff.FKClientId != callerClientId)
                    throw new ForbiddenException("This staff member does not belong to your gym.");

                // Create update object with only provided fields
                var updateStaff = new Models.Staff
                {
                    StaffId = staffId,
                    StaffPosition = data.ContainsKey("staffPosition") ? data["staffPosition"].GetString() : null,
                    Department = data.ContainsKey("department") ? data["department"].GetString() : null,
                    IsActive = data.ContainsKey("isActive") ? data["isActive"].GetBoolean() : existingStaff.IsActive,
                    User = new User
                    {
                        UserName = data.ContainsKey("userName") ? data["userName"].GetString() : null,
                        Email = data.ContainsKey("email") ? data["email"].GetString() : null,
                        PhoneNumber = data.ContainsKey("phoneNumber") ? data["phoneNumber"].GetString() : null
                    }
                };

                var result = await _staffRepository.UpdateStaff(updateStaff);
                await _uow.CommitAsync();

                return await MapStaffAsync(result);
            }
            catch
            {
                await _uow.RollbackAsync();
                throw;
            }
        }

        public async Task<object> DeleteStaff(object payload, HttpContext httpContext)
        {
            await _uow.BeginAsync();
            try
            {
                var data = DeserializePayload.Deserialize(payload);
                
                if (!data!.ContainsKey("staffId"))
                {
                    throw new KeyNotFoundException("staffId is required");
                }

                var staffId = Guid.Parse(data["staffId"].GetString()!);
                await EnsureStaffBelongsToCallerAsync(staffId, httpContext);
                
                // Check if hard delete is requested (default is soft delete)
                bool softDelete = !data.ContainsKey("hardDelete") || !data["hardDelete"].GetBoolean();

                var result = await _staffRepository.DeleteStaff(staffId, softDelete);
                
                if (!result)
                {
                    throw new KeyNotFoundException("Staff not found");
                }

                await _uow.CommitAsync();

                return new 
                { 
                    success = true, 
                    message = softDelete 
                        ? "Staff deactivated successfully" 
                        : "Staff deleted successfully",
                    softDelete = softDelete
                };
            }
            catch
            {
                await _uow.RollbackAsync();
                throw;
            }
        }

        public async Task<object> GetPayRate(Guid staffId, HttpContext httpContext)
        {
            await EnsureStaffBelongsToCallerAsync(staffId, httpContext);
            var rate = await _staffRepository.GetActivePayRateAsync(staffId);
            return rate == null
                ? null!
                : new StaffPayRateDto { Id = rate.Id, RateType = rate.RateType, Amount = rate.Amount, EffectiveFrom = rate.EffectiveFrom };
        }

        public async Task<object> UpsertPayRate(Guid staffId, string rateType, decimal amount, HttpContext httpContext)
        {
            await EnsureStaffBelongsToCallerAsync(staffId, httpContext);

            if (rateType != "Monthly" && rateType != "Hourly")
                throw new BadRequestException("rateType must be 'Monthly' or 'Hourly'.");
            if (amount <= 0)
                throw new BadRequestException("amount must be greater than zero.");

            var currentRate = await _staffRepository.GetActivePayRateAsync(staffId);
            if (currentRate != null)
                currentRate.IsActive = false;

            var rate = await _staffRepository.AddPayRateAsync(new Models.StaffPayRate
            {
                Id = Guid.NewGuid(),
                FKStaffId = staffId,
                RateType = rateType,
                Amount = amount,
                EffectiveFrom = DateTime.UtcNow,
                IsActive = true
            });
            await _uow.SaveChangesAsync();
            return new StaffPayRateDto { Id = rate.Id, RateType = rate.RateType, Amount = rate.Amount, EffectiveFrom = rate.EffectiveFrom };
        }

        public async Task<object> GetPayments(Guid staffId, HttpContext httpContext)
        {
            await EnsureStaffBelongsToCallerAsync(staffId, httpContext);
            var payments = await _staffRepository.GetPaymentsAsync(staffId);
            return payments.Select(p => new StaffPaymentDto { Id = p.Id, Amount = p.Amount, Note = p.Note, PaidAt = p.PaidAt }).ToList();
        }

        public async Task<object> RecordPayment(Guid staffId, decimal amount, string? note, HttpContext httpContext)
        {
            await EnsureStaffBelongsToCallerAsync(staffId, httpContext);

            if (amount <= 0)
                throw new BadRequestException("amount must be greater than zero.");

            var payment = new Models.StaffPayment
            {
                Id = Guid.NewGuid(),
                FKStaffId = staffId,
                Amount = amount,
                Note = note,
                PaidAt = DateTime.UtcNow,
                FKPaidByUserId = DataExtractor.GetUserIdFromContext(httpContext)
            };

            await _staffRepository.AddPaymentAsync(payment);
            await _uow.SaveChangesAsync();
            return new StaffPaymentDto { Id = payment.Id, Amount = payment.Amount, Note = payment.Note, PaidAt = payment.PaidAt };
        }

        private async Task EnsureStaffBelongsToCallerAsync(Guid staffId, HttpContext httpContext)
        {
            var userId = DataExtractor.GetUserIdFromContext(httpContext);
            var clientId = await _userRoleHelper.GetClientId(userId);

            var staff = await _staffRepository.GetStaffById(staffId)
                ?? throw new KeyNotFoundException("Staff not found");

            if (staff.FKClientId != clientId)
                throw new ForbiddenException("This staff member does not belong to your gym.");
        }

        private async Task<StaffDto> MapStaffAsync(Models.Staff staff, User? userOverride = null)
        {
            var user = userOverride ?? staff.User;
            var access = await _accessDeviceService.GetAccessStatusAsync(
                staff.FKClientId, staff.FKUserId);
            return new StaffDto
            {
                StaffId = staff.StaffId,
                UserId = staff.FKUserId,
                UserName = user?.UserName,
                Email = user?.Email,
                PhoneNumber = user?.PhoneNumber,
                ClientId = staff.FKClientId,
                ClientName = staff.Client?.ClientName,
                GymRoleId = staff.FKGymRoleId,
                GymRoleName = staff.GymRole?.Name,
                StaffPosition = staff.StaffPosition,
                Department = staff.Department,
                HireDate = staff.HireDate,
                IsActive = staff.IsActive,
                CreatedAt = staff.CreatedAt,
                AccessProfileId = access?.AccessProfileId,
                AccessNumber = access?.AccessNumber,
                AccessProvisionStatus = access?.ProvisionStatus ?? "NotConfigured",
                ActualAccessState = access?.ActualAccessState ?? "Unknown",
                DesiredAccessState = access?.DesiredAccessState ?? "Enabled",
                FingerprintCount = access?.FingerprintCount ?? 0,
                AccessLastError = access?.LastError
            };
        }

        private async Task<List<StaffDto>> MapStaffListAsync(IEnumerable<Models.Staff> staff)
        {
            var result = new List<StaffDto>();
            foreach (var member in staff)
                result.Add(await MapStaffAsync(member));
            return result;
        }
    }
}