using Data.SeaHavenIndustries;
using Data.SeaHavenIndustries.Enums;
using FluentValidation;
using FluentValidation.Results;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using System.Globalization;
using SeaHaven.DataServices.Interfaces;
using SeaHaven.DataServices.Models;
using SeaHaven.Services.Configuration;
using SeaHaven.Services.DTOs;
using SeaHaven.Services.Helpers;
using SeaHaven.Services.Interfaces;
using SeaHaven.Services.Validation;

namespace SeaHaven.Services.Implementation
{
    public class VendorService : IVendorService
    {
        private const int MaxDirectoryPageSize = 100;
        private static readonly string[] TerminalLegacyStatuses =
            { "completed", "cancelled", "canceled" };

        private readonly IVendorDataService _vendorDataService;
        private readonly IVendorPortalTokenService _vendorTokenService;
        private readonly IZipCodeDistance _zipDistance;
        private readonly FrontendOptions _frontendOptions;
        private readonly ICreateVendorValidation _createValidator;
        private readonly IUpdateVendorValidation _updateValidator;
        private readonly IWorkOrderVendorUpdateValidation _workOrderUpdateValidator;
        private readonly ILogger<VendorService> _logger;

        public VendorService(
            IVendorDataService vendorDataService,
            IVendorPortalTokenService vendorTokenService,
            IZipCodeDistance zipDistance,
            IOptions<FrontendOptions> frontendOptions,
            ICreateVendorValidation createValidator,
            IUpdateVendorValidation updateValidator,
            IWorkOrderVendorUpdateValidation workOrderUpdateValidator,
            ILogger<VendorService> logger)
        {
            _vendorDataService = vendorDataService;
            _vendorTokenService = vendorTokenService;
            _zipDistance = zipDistance;
            _frontendOptions = frontendOptions.Value;
            _createValidator = createValidator;
            _updateValidator = updateValidator;
            _workOrderUpdateValidator = workOrderUpdateValidator;
            _logger = logger;
        }

        public async Task<VendorDTO?> GetVendorByIdAsync(int id)
        {
            var vendor = await _vendorDataService.GetByIdWithDetailsAsync(id);
            return vendor == null ? null : MapToDTO(vendor);
        }

        public async Task<VendorDTO?> GetVendorByIdWithDetailsAsync(int id)
        {
            var vendor = await _vendorDataService.GetByIdWithDetailsAsync(id);
            return vendor == null ? null : MapToDTO(vendor);
        }

        public async Task<IEnumerable<VendorDTO>> GetAllVendorsAsync()
        {
            var vendors = await _vendorDataService.GetAllAsync();
            return vendors.Select(MapToDTO);
        }

        public async Task<PagedResult<VendorDTO>> GetVendorsPagedAsync(
            int page,
            int pageSize,
            string? search = null,
            bool? isActive = true,
            IReadOnlyCollection<string>? companies = null,
            IReadOnlyCollection<string>? trades = null,
            IReadOnlyCollection<string>? locations = null,
            IReadOnlyCollection<string>? jobBuckets = null)
        {
            var (items, totalCount) = await _vendorDataService.GetPagedAsync(
                page,
                pageSize,
                search,
                isActive,
                companies,
                trades,
                locations,
                jobBuckets);
            return new PagedResult<VendorDTO>
            {
                Items = items.Select(MapToDTO).ToList(),
                TotalCount = totalCount,
                Page = page,
                PageSize = pageSize
            };
        }

        // SH-198 legacy per-technician directory contract (GetVendorList): raw
        // pagination semantics are part of the compatibility surface, so pageSize
        // is forwarded unclamped.
        public async Task<PagedResult<VendorDirectoryItemDTO>> GetVendorTechnicianDirectoryPagedAsync(
            int page,
            int pageSize,
            string? search = null,
            bool? isActive = true,
            IReadOnlyCollection<string>? companies = null,
            IReadOnlyCollection<string>? trades = null,
            IReadOnlyCollection<string>? locations = null,
            IReadOnlyCollection<string>? jobBuckets = null,
            CancellationToken cancellationToken = default)
        {
            var (items, totalCount) = await _vendorDataService.GetDirectoryPagedAsync(
                page,
                pageSize,
                search,
                isActive,
                companies,
                trades,
                locations,
                jobBuckets,
                cancellationToken);

            return new PagedResult<VendorDirectoryItemDTO>
            {
                Items = items.Select(MapToDirectoryItem).ToList(),
                TotalCount = totalCount,
                Page = page,
                PageSize = pageSize
            };
        }

        private static VendorDirectoryItemDTO MapToDirectoryItem(VendorDirectoryRow row) => new()
        {
            Id = row.VendorId,
            CompanyId = row.CompanyId == 0 ? null : row.CompanyId,
            CompanyName = row.CompanyName,
            ContactName = row.ContactName,
            Email = row.Email,
            Phone = row.Phone,
            CompanyPhone = row.CompanyPhone,
            PreferredContact = row.PreferredContact,
            Address = row.Address,
            City = row.City,
            State = row.State,
            Zipcode = row.Zip,
            TradeSpecialties = row.TradeSpecialties,
            GoogleMapsUrl = row.GoogleMapsUrl,
            Notes = row.Notes,
            IsActive = row.IsActive,
            TotalJobs = row.TotalJobs
        };

        // SH-281 company-grouped directory (GetVendorDirectoryList).
        public async Task<PagedResult<VendorDirectoryItemDTO>> GetVendorCompanyDirectoryPagedAsync(
            int page,
            int pageSize,
            string? search = null,
            bool? isActive = true,
            IReadOnlyCollection<string>? companies = null,
            IReadOnlyCollection<string>? trades = null,
            IReadOnlyCollection<string>? locations = null,
            IReadOnlyCollection<string>? jobBuckets = null,
            IReadOnlyCollection<string>? areas = null,
            CancellationToken cancellationToken = default)
        {
            var normalizedPage = Math.Max(1, page);
            var normalizedPageSize = Math.Clamp(pageSize, 1, MaxDirectoryPageSize);
            var areaFilter = await ResolveAreaFilterAsync(areas, cancellationToken);
            var (items, totalCount) = await _vendorDataService.GetCompanyDirectoryPagedAsync(
                normalizedPage,
                normalizedPageSize,
                search,
                isActive,
                companies,
                trades,
                locations,
                jobBuckets,
                areaFilter,
                cancellationToken);

            return new PagedResult<VendorDirectoryItemDTO>
            {
                Items = items.Select(MapToCompanyGroup).ToList(),
                TotalCount = totalCount,
                Page = normalizedPage,
                PageSize = normalizedPageSize
            };
        }

        // SH-278 areas[n] contract: blank entries are ignored; "__unassigned__" selects
        // companies without an Area; other values must be stable positive integer ids
        // of active catalogue rows. Display names, unknown ids and archived ids never
        // error — they simply match nobody. Null means no Area filter was requested.
        private async Task<VendorAreaFilter?> ResolveAreaFilterAsync(
            IReadOnlyCollection<string>? areas,
            CancellationToken cancellationToken)
        {
            var values = areas?
                .Where(value => !string.IsNullOrWhiteSpace(value))
                .Select(value => value.Trim())
                .ToList();

            if (values is not { Count: > 0 })
                return null;

            var includeUnassigned = values.Contains(VendorAreaFilterValues.Unassigned, StringComparer.Ordinal);
            var requestedIds = new HashSet<int>();
            foreach (var value in values)
            {
                if (int.TryParse(value, NumberStyles.None, CultureInfo.InvariantCulture, out var id) && id > 0)
                    requestedIds.Add(id);
            }

            IReadOnlyCollection<int> activeIds = Array.Empty<int>();
            if (requestedIds.Count > 0)
            {
                var activeAreas = await _vendorDataService.GetActiveAreasAsync(cancellationToken);
                activeIds = activeAreas
                    .Select(area => area.Id)
                    .Where(requestedIds.Contains)
                    .ToArray();
            }

            return new VendorAreaFilter
            {
                AreaIds = activeIds,
                IncludeUnassigned = includeUnassigned
            };
        }

        private static VendorDirectoryItemDTO MapToCompanyGroup(VendorCompanyGroup group) => new()
        {
            Id = group.Id,
            CompanyId = group.CompanyId,
            CompanyName = group.CompanyName,
            ContactName = group.ContactName,
            Email = group.Email,
            Phone = group.Phone,
            CompanyPhone = group.CompanyPhone,
            PreferredContact = group.PreferredContact,
            Address = group.Address,
            City = group.City,
            State = group.State,
            Zipcode = group.Zip,
            TradeSpecialties = group.TradeSpecialties,
            GoogleMapsUrl = group.GoogleMapsUrl,
            Notes = group.Notes,
            AreaId = group.AreaId,
            AreaName = group.AreaName,
            IsActive = group.IsActive,
            TotalJobs = group.TotalJobs,
            Technicians = group.Technicians.Select(MapToTechnician).ToList()
        };

        private static VendorDirectoryTechnicianDTO MapToTechnician(VendorCompanyGroupTechnician technician) => new()
        {
            Id = technician.Id,
            ContactName = technician.ContactName,
            Email = technician.Email,
            Phone = technician.Phone,
            PreferredContact = technician.PreferredContact,
            TradeSpecialties = technician.TradeSpecialties,
            IsActive = technician.IsActive,
            TotalJobs = technician.TotalJobs
        };

        public async Task<VendorDTO> CreateVendorAsync(CreateVendorDTO dto, string userId)
        {
            NormalizePhoneFields(dto);
            var validationResult = await _createValidator.ValidateAsync(dto);
            if (!validationResult.IsValid)
            {
                throw new ValidationException(validationResult.Errors);
            }

            var company = await ResolveCompanyAsync(dto.CompanyId, dto.Name, dto, userId);

            var vendor = new Vendor
            {
                CompanyName = dto.Name,
                ContactName = dto.ContactName,
                Email = dto.Email,
                Phone = VendorPhoneNormalizer.NormalizeToCanonical(dto.Phone),
                CompanyPhone = VendorPhoneNormalizer.NormalizeToCanonical(dto.CompanyPhone),
                PreferredContact = dto.PreferredContact,
                Address = dto.Address,
                City = dto.City,
                State = dto.State,
                Zip = dto.Zipcode,
                TradeSpecialties = dto.TradeSpecialties,
                GoogleMapsUrl = dto.GoogleMapsUrl,
                Notes = dto.Notes,
                IsActive = dto.IsActive,
                CompanyId = company?.Id,
                CreatedDate = DateTime.UtcNow,
                createdby = userId
            };

            ApplyCompanyFields(vendor, company);

            var created = await _vendorDataService.AddAsync(vendor);
            return MapToDTO(created);
        }

        public async Task<VendorDTO> UpdateVendorAsync(int id, UpdateVendorDTO dto, string userId)
        {
            NormalizePhoneFields(dto);
            var validationResult = await _updateValidator.ValidateAsync(dto);
            if (!validationResult.IsValid)
            {
                throw new ValidationException(validationResult.Errors);
            }

            var vendor = await _vendorDataService.GetByIdAsync(id);
            if (vendor == null)
                throw new InvalidOperationException($"Vendor with ID {id} not found");

            if (dto.IsActive.HasValue && !dto.IsActive.Value)
            {
                if (dto.ConfirmOpenWorkOrders)
                    await LogConfirmedDeactivationAsync(id, userId);
                else
                    await AssertNoOpenLinkedWorkOrdersAsync(id);
            }

            if (dto.Name != null) vendor.CompanyName = dto.Name;
            if (dto.ContactName != null) vendor.ContactName = dto.ContactName;
            if (dto.Email != null) vendor.Email = dto.Email;
            if (dto.Phone != null) vendor.Phone = VendorPhoneNormalizer.NormalizeToCanonical(dto.Phone);
            if (dto.PreferredContact != null) vendor.PreferredContact = dto.PreferredContact;
            if (dto.TradeSpecialties != null) vendor.TradeSpecialties = dto.TradeSpecialties;
            if (dto.Notes != null) vendor.Notes = dto.Notes;
            if (dto.IsActive.HasValue) vendor.IsActive = dto.IsActive.Value;

            if (dto.CompanyId.HasValue || dto.Name != null || HasCompanyFieldUpdate(dto))
            {
                var company = await ResolveCompanyAsync(
                    dto.CompanyId ?? vendor.CompanyId,
                    dto.Name ?? vendor.CompanyName,
                    dto,
                    userId);
                vendor.CompanyId = company?.Id;
                ApplyCompanyFields(vendor, company);
            }

            vendor.LastModificationTime = DateTime.UtcNow;
            if (int.TryParse(userId, out int userIdInt))
                vendor.LastModifierUserId = userIdInt;

            await _vendorDataService.UpdateAsync(vendor);
            return MapToDTO(vendor);
        }

        public async Task DeleteVendorAsync(int id, string userId, bool confirmOpenWorkOrders)
        {
            var vendor = await _vendorDataService.GetByIdAsync(id);
            if (vendor == null)
                throw new InvalidOperationException($"Vendor with ID {id} not found");

            if (confirmOpenWorkOrders)
                await LogConfirmedDeactivationAsync(id, userId);
            else
                await AssertNoOpenLinkedWorkOrdersAsync(id);

            vendor.IsActive = false;
            vendor.LastModificationTime = DateTime.UtcNow;
            if (int.TryParse(userId, out int userIdInt))
                vendor.LastModifierUserId = userIdInt;

            await _vendorDataService.UpdateAsync(vendor);
        }

        public async Task<bool> VendorExistsAsync(int id)
        {
            return await _vendorDataService.ExistsAsync(id);
        }

        public async Task<int> GetTotalVendorCountAsync()
        {
            return await _vendorDataService.CountAsync();
        }

        public async Task<VendorDeactivationImpactDTO> GetDeactivationImpactAsync(int vendorId)
        {
            if (!await _vendorDataService.ExistsAsync(vendorId))
                throw new InvalidOperationException($"Vendor with ID {vendorId} not found");

            var linked = await _vendorDataService.GetLinkedWorkOrdersAsync(vendorId);
            var openWorkOrders = linked
                .Where(wo => !IsTerminalWorkOrderStatus(wo.LifecycleStatus, wo.Status))
                .Select(MapToLinkedWorkOrderDTO)
                .ToList();

            return new VendorDeactivationImpactDTO
            {
                VendorId = vendorId,
                CanDeactivate = openWorkOrders.Count == 0,
                OpenWorkOrders = openWorkOrders
            };
        }

        public async Task<VendorDTO> UpdateVendorFromWorkOrderAsync(
            int vendorId,
            WorkOrderVendorUpdateDTO dto,
            string userId)
        {
            dto.Phone = VendorPhoneNormalizer.NormalizeToCanonical(dto.Phone);
            var validationResult = await _workOrderUpdateValidator.ValidateAsync(dto);
            if (!validationResult.IsValid)
            {
                throw new ValidationException(validationResult.Errors);
            }

            var vendor = await _vendorDataService.GetByIdAsync(vendorId);
            if (vendor == null)
                throw new InvalidOperationException($"Vendor with ID {vendorId} not found");

            var isAssigned = await _vendorDataService.IsVendorAssignedToWorkOrderAsync(vendorId, dto.WorkOrderId);
            if (!isAssigned)
                throw new InvalidOperationException(
                    $"Vendor {vendorId} is not actively linked to work order {dto.WorkOrderId}.");

            var changes = new List<VendorAuditLog>();
            var now = DateTime.UtcNow;

            void RecordChange(string fieldName, string? oldValue, string? newValue)
            {
                if (!string.Equals(oldValue, newValue, StringComparison.Ordinal))
                {
                    changes.Add(new VendorAuditLog
                    {
                        VendorId = vendorId,
                        WorkOrderId = dto.WorkOrderId,
                        FieldName = fieldName,
                        OldValue = oldValue,
                        NewValue = newValue,
                        Actor = userId,
                        CreatedAt = now
                    });
                }
            }

            if (dto.ContactName != null)
            {
                RecordChange(nameof(Vendor.ContactName), vendor.ContactName, dto.ContactName);
                vendor.ContactName = dto.ContactName;
            }

            if (dto.PreferredContact != null)
            {
                RecordChange(nameof(Vendor.PreferredContact), vendor.PreferredContact, dto.PreferredContact);
                vendor.PreferredContact = dto.PreferredContact;
            }

            if (dto.Phone != null)
            {
                var normalized = VendorPhoneNormalizer.NormalizeToCanonical(dto.Phone);
                RecordChange(nameof(Vendor.Phone), vendor.Phone, normalized);
                vendor.Phone = normalized;
            }

            if (dto.Email != null)
            {
                RecordChange(nameof(Vendor.Email), vendor.Email, dto.Email);
                vendor.Email = dto.Email;
            }

            if (dto.Notes != null)
            {
                RecordChange(nameof(Vendor.Notes), vendor.Notes, dto.Notes);
                vendor.Notes = dto.Notes;
            }

            vendor.LastModificationTime = now;
            if (int.TryParse(userId, out int userIdInt))
                vendor.LastModifierUserId = userIdInt;

            await _vendorDataService.UpdateWithAuditLogsAsync(vendor, changes);

            return MapToDTO(vendor);
        }

        private async Task<VendorCompany?> ResolveCompanyAsync(
            int? requestedCompanyId,
            string? companyName,
            object dto,
            string userId)
        {
            if (requestedCompanyId.HasValue)
            {
                var byId = await _vendorDataService.GetCompanyByIdAsync(requestedCompanyId.Value);
                if (byId != null)
                {
                    ApplyCompanyUpdates(byId, companyName, dto, userId);
                    await _vendorDataService.UpdateCompanyAsync(byId);
                    return byId;
                }

                throw new ValidationException(new[]
                {
                    new ValidationFailure(
                        nameof(CreateVendorDTO.CompanyId),
                        $"No vendor company exists with ID {requestedCompanyId.Value}.")
                });
            }

            if (string.IsNullOrWhiteSpace(companyName))
                return null;

            var normalizedName = companyName.Trim().ToLowerInvariant();
            var existing = await _vendorDataService.GetCompanyByNormalizedNameAsync(normalizedName);
            if (existing != null)
            {
                ApplyCompanyUpdates(existing, companyName, dto, userId);
                await _vendorDataService.UpdateCompanyAsync(existing);
                return existing;
            }

            string? companyPhone = null;
            string? email = null;
            string? address = null;
            string? city = null;
            string? state = null;
            string? zip = null;
            string? mapsUrl = null;

            if (dto is CreateVendorDTO create)
            {
                companyPhone = VendorPhoneNormalizer.NormalizeToCanonical(create.CompanyPhone);
                email = create.Email;
                address = create.Address;
                city = create.City;
                state = create.State;
                zip = create.Zipcode;
                mapsUrl = create.GoogleMapsUrl;
            }
            else if (dto is UpdateVendorDTO update)
            {
                companyPhone = VendorPhoneNormalizer.NormalizeToCanonical(update.CompanyPhone);
                email = update.Email;
                address = update.Address;
                city = update.City;
                state = update.State;
                zip = update.Zipcode;
                mapsUrl = update.GoogleMapsUrl;
            }

            var company = new VendorCompany
            {
                Name = companyName.Trim(),
                NormalizedName = normalizedName,
                CompanyPhone = companyPhone,
                Email = email,
                Address = address,
                City = city,
                State = state,
                Zip = zip,
                GoogleMapsUrl = mapsUrl,
                CreatedDate = DateTime.UtcNow,
                createdby = userId
            };

            return await _vendorDataService.AddCompanyAsync(company);
        }

        private static void ApplyCompanyFields(Vendor vendor, VendorCompany? company)
        {
            if (company == null)
                return;

            if (company.CompanyPhone != null) vendor.CompanyPhone = company.CompanyPhone;
            if (company.Address != null) vendor.Address = company.Address;
            if (company.City != null) vendor.City = company.City;
            if (company.State != null) vendor.State = company.State;
            if (company.Zip != null) vendor.Zip = company.Zip;
            if (company.GoogleMapsUrl != null) vendor.GoogleMapsUrl = company.GoogleMapsUrl;
        }

        private static bool HasCompanyFieldUpdate(UpdateVendorDTO dto) =>
            dto.CompanyPhone != null ||
            dto.Address != null ||
            dto.City != null ||
            dto.State != null ||
            dto.Zipcode != null ||
            dto.GoogleMapsUrl != null;

        private static void ApplyCompanyUpdates(
            VendorCompany company,
            string? companyName,
            object dto,
            string userId)
        {
            if (!string.IsNullOrWhiteSpace(companyName))
            {
                company.Name = companyName.Trim();
                company.NormalizedName = company.Name.ToLowerInvariant();
            }

            if (dto is CreateVendorDTO create)
            {
                if (create.CompanyPhone != null) company.CompanyPhone = create.CompanyPhone;
                if (create.Address != null) company.Address = create.Address;
                if (create.City != null) company.City = create.City;
                if (create.State != null) company.State = create.State;
                if (create.Zipcode != null) company.Zip = create.Zipcode;
                if (create.GoogleMapsUrl != null) company.GoogleMapsUrl = create.GoogleMapsUrl;
            }
            else if (dto is UpdateVendorDTO update)
            {
                if (update.CompanyPhone != null) company.CompanyPhone = update.CompanyPhone;
                if (update.Address != null) company.Address = update.Address;
                if (update.City != null) company.City = update.City;
                if (update.State != null) company.State = update.State;
                if (update.Zipcode != null) company.Zip = update.Zipcode;
                if (update.GoogleMapsUrl != null) company.GoogleMapsUrl = update.GoogleMapsUrl;
            }

            company.LastModificationTime = DateTime.UtcNow;
            if (int.TryParse(userId, out int userIdInt))
                company.LastModifierUserId = userIdInt;
        }

        private static void NormalizePhoneFields(CreateVendorDTO dto)
        {
            dto.Phone = VendorPhoneNormalizer.NormalizeToCanonical(dto.Phone);
            dto.CompanyPhone = VendorPhoneNormalizer.NormalizeToCanonical(dto.CompanyPhone);
        }

        private static void NormalizePhoneFields(UpdateVendorDTO dto)
        {
            dto.Phone = VendorPhoneNormalizer.NormalizeToCanonical(dto.Phone);
            dto.CompanyPhone = VendorPhoneNormalizer.NormalizeToCanonical(dto.CompanyPhone);
        }

        // SH-44's story is about not *silently* orphaning active work. When the caller
        // confirms past the guard, the work orders it chose to leave open are recorded.
        private async Task LogConfirmedDeactivationAsync(int vendorId, string userId)
        {
            var linked = await _vendorDataService.GetLinkedWorkOrdersAsync(vendorId);
            var openCount = linked.Count(wo => !IsTerminalWorkOrderStatus(wo.LifecycleStatus, wo.Status));
            if (openCount == 0) return;

            _logger.LogWarning(
                "Vendor {VendorId} deactivated by user {UserId} with {OpenWorkOrderCount} open work orders, confirmed by the caller.",
                vendorId,
                userId,
                openCount);
        }

        // Guard for the unconfirmed path only. SH-44 and SH-82 left "blocks or requires
        // explicit confirmation" to be settled with the team; SH-254 settles it as
        // explicit confirmation, so a caller that has not confirmed is still blocked.
        private async Task AssertNoOpenLinkedWorkOrdersAsync(int vendorId)
        {
            var linked = await _vendorDataService.GetLinkedWorkOrdersAsync(vendorId);
            var openWorkOrders = linked
                .Where(wo => !IsTerminalWorkOrderStatus(wo.LifecycleStatus, wo.Status))
                .Select(MapToLinkedWorkOrderDTO)
                .ToList();

            if (openWorkOrders.Count > 0)
            {
                throw new VendorDeactivationBlockedException(
                    "Vendor cannot be deactivated while linked work orders are open or scheduled.",
                    openWorkOrders);
            }
        }

        private static bool IsTerminalWorkOrderStatus(LifecycleStatus? lifecycleStatus, string? legacyStatus)
        {
            if (lifecycleStatus == LifecycleStatus.Completed || lifecycleStatus == LifecycleStatus.Canceled)
                return true;

            if (!string.IsNullOrWhiteSpace(legacyStatus) &&
                TerminalLegacyStatuses.Contains(legacyStatus.Trim().ToLowerInvariant()))
                return true;

            return false;
        }

        private static LinkedWorkOrderDTO MapToLinkedWorkOrderDTO(LinkedWorkOrderInfo info) => new()
        {
            WorkOrderId = info.WorkOrderId,
            WorkOrderNumber = info.WorkOrderNumber,
            WorkOrderTitle = info.WorkOrderTitle,
            Status = info.Status,
            ScheduledDate = info.ScheduledDate,
            DispatchId = info.DispatchId
        };

        private VendorDTO MapToDTO(Vendor vendor)
        {
            return new VendorDTO
            {
                Id = vendor.Id,
                Name = vendor.CompanyName,
                CompanyId = vendor.CompanyId,
                ContactName = vendor.ContactName,
                Email = vendor.Email,
                Phone = vendor.Phone,
                CompanyPhone = vendor.CompanyPhone,
                PreferredContact = vendor.PreferredContact,
                Address = vendor.Address,
                City = vendor.City,
                State = vendor.State,
                Zipcode = vendor.Zip,
                TradeSpecialties = vendor.TradeSpecialties,
                GoogleMapsUrl = vendor.GoogleMapsUrl,
                Notes = vendor.Notes,
                IsActive = vendor.IsActive,
                TotalJobs = vendor.Dispatches == null
                    ? vendor.TotalJobs
                    : CountDistinctWorkOrders(vendor)
            };
        }

        private static int CountDistinctWorkOrders(Vendor vendor)
        {
            if (vendor.Dispatches == null)
                return 0;

            return vendor.Dispatches
                .SelectMany(dispatch =>
                {
                    var linked = dispatch.DispatchWorkOrders?.Select(item => item.WorkOrderId)
                        ?? Enumerable.Empty<int>();
                    return dispatch.WorkOrderId.HasValue
                        ? linked.Append(dispatch.WorkOrderId.Value)
                        : linked;
                })
                .Distinct()
                .Count();
        }

        public async Task<IEnumerable<VendorDropdownItemDTO>> GetDropdownAsync(string? trade, string? siteZip, CancellationToken cancellationToken)
        {
            var vendors = await _vendorDataService.GetActiveVendorsAsync(cancellationToken);

            var result = vendors.Select(v =>
            {
                var distance = _zipDistance.GetDistanceMiles(siteZip, v.Zip);
                var addr = new[] { v.Address, v.City, v.State, v.Zip }
                    .Where(s => !string.IsNullOrWhiteSpace(s));
                return new VendorDropdownItemDTO
                {
                    Id = v.Id,
                    CompanyName = v.CompanyName,
                    ContactName = v.ContactName,
                    PreferredContact = v.PreferredContact,
                    TradeSpecialties = v.TradeSpecialties,
                    Address = string.Join(", ", addr),
                    DistanceMiles = distance.HasValue ? Math.Round(distance.Value, 1) : (double?)null
                };
            }).ToList();

            if (!string.IsNullOrWhiteSpace(trade))
            {
                var tradeMatched = result.Where(v => (v.TradeSpecialties ?? "").Contains(trade)).ToList();
                var rest = result.Where(v => !(v.TradeSpecialties ?? "").Contains(trade)).ToList();
                result = tradeMatched.Concat(rest).ToList();
            }

            if (!string.IsNullOrWhiteSpace(siteZip))
            {
                result = result.OrderBy(v => v.DistanceMiles ?? 99999).ToList();
            }

            return result;
        }

        public async Task<VendorFacetsDTO> GetFacetsAsync(bool? isActive, CancellationToken cancellationToken)
        {
            // Companies and Locations are sourced from company-owned VendorCompany fields
            // (status semantics aligned to the directory union). Trades come from the
            // SH-249 server-owned canonical Trade reference data — a stable list that
            // does not derive from technician TradeSpecialties free text, so it is
            // populated even on an empty database and independent of the status filter.
            var companies = await _vendorDataService.GetCompaniesForFacetsAsync(isActive, cancellationToken);
            var canonicalTrades = await _vendorDataService.GetActiveTradesAsync(cancellationToken);
            var activeAreas = await _vendorDataService.GetActiveAreasAsync(cancellationToken);

            var companyFacets = companies
                .Where(c => !string.IsNullOrWhiteSpace(c.Name))
                .GroupBy(c => c.Name!.Trim(), StringComparer.OrdinalIgnoreCase)
                .Select(group => group.First())
                .OrderBy(c => c.Name, StringComparer.OrdinalIgnoreCase)
                .Select(c => new VendorFacetCompanyDTO
                {
                    Name = c.Name,
                    CompanyId = c.Id,
                    CompanyPhone = c.CompanyPhone,
                    Email = c.Email,
                    PreferredContact = null,
                    Address = c.Address,
                    City = c.City,
                    State = c.State,
                    Zip = c.Zip,
                    GoogleMapsUrl = c.GoogleMapsUrl
                });

            var trades = canonicalTrades.Select(t => t.Name).ToList();

            // Exact Location label rule (mirrors the directory filter): City/State
            // whenever either structured value is present, otherwise Address.
            // Address-only companies are therefore represented in the facets.
            var locations = companies
                .Where(c => !string.IsNullOrWhiteSpace(c.City)
                    || !string.IsNullOrWhiteSpace(c.State)
                    || !string.IsNullOrWhiteSpace(c.Address))
                .Select(c => new VendorFacetLocationDTO
                {
                    City = c.City,
                    State = c.State,
                    Label = !string.IsNullOrWhiteSpace(c.City) || !string.IsNullOrWhiteSpace(c.State)
                        ? string.Join(", ", new[] { c.City?.Trim(), c.State?.Trim() }
                            .Where(value => !string.IsNullOrWhiteSpace(value)))
                        : c.Address!.Trim()
                })
                .DistinctBy(location => location.Label, StringComparer.OrdinalIgnoreCase)
                .OrderBy(location => location.Label);

            // SH-278: the active Area catalogue, A–Z case-insensitive, independent of the
            // status filter and of whether any company currently uses an Area. Clients
            // prepend the "__unassigned__" option themselves.
            var areas = activeAreas
                .OrderBy(area => area.Name, StringComparer.OrdinalIgnoreCase)
                .Select(area => new VendorFacetAreaDTO { Id = area.Id, Name = area.Name })
                .ToList();

            return new VendorFacetsDTO
            {
                Companies = companyFacets,
                Trades = trades,
                Areas = areas,
                Locations = locations,
                JobBuckets = new[]
                {
                    new VendorJobBucketDTO { Id = "under-50", Label = "Under 50" },
                    new VendorJobBucketDTO { Id = "50-99", Label = "50–99" },
                    new VendorJobBucketDTO { Id = "100-149", Label = "100–149" },
                    new VendorJobBucketDTO { Id = "150-plus", Label = "150+" }
                }
            };
        }

        public async Task<VendorPortalTokenDTO?> GetPortalTokenAsync(int vendorId, CancellationToken cancellationToken)
        {
            if (!await _vendorDataService.ExistsAsync(vendorId))
                return null;

            var token = await _vendorTokenService.GetOrCreateActiveTokenAsync(vendorId, cancellationToken);
            return BuildPortalTokenResponse(token);
        }

        public async Task<VendorPortalTokenDTO?> RotatePortalTokenAsync(int vendorId, CancellationToken cancellationToken)
        {
            if (!await _vendorDataService.ExistsAsync(vendorId))
                return null;

            var token = await _vendorTokenService.RotateAsync(vendorId, cancellationToken);
            return BuildPortalTokenResponse(token);
        }

        public async Task<bool> RevokePortalTokenAsync(int vendorId, CancellationToken cancellationToken)
        {
            if (!await _vendorDataService.ExistsAsync(vendorId))
                return false;

            await _vendorTokenService.RevokeAllAsync(vendorId, cancellationToken);
            return true;
        }

        private VendorPortalTokenDTO BuildPortalTokenResponse(VendorPortalTokenStateDTO token)
        {
            var frontendBase = _frontendOptions.FrontendBaseUrl?.TrimEnd('/') ?? "";
            return new VendorPortalTokenDTO
            {
                Token = token.Token,
                IssuedAt = token.IssuedAt,
                ExpiresAt = token.ExpiresAt,
                LastUsedAt = token.LastUsedAt,
                PortalUrl = $"{frontendBase}/v/{token.Token}/dashboard"
            };
        }
    }
}