using Data.SeaHavenIndustries;
using FluentValidation;
using SeaHaven.DataServices.Dto;
using SeaHaven.DataServices.Interfaces;
using SeaHaven.Services.DTOs;
using SeaHaven.Services.Interfaces;
using SeaHaven.Services.Validation;

namespace SeaHaven.Services.Implementation
{
    /// <summary>
    /// Dispatch service implementation
    /// Contains business logic, validation, and orchestration for Dispatch operations
    /// </summary>
    public class DispatchService : IDispatchService
    {
        private readonly IDispatchDataService _dispatchDataService;
        private readonly ICreateDispatchValidation _createValidator;
        private readonly IUpdateDispatchValidation _updateValidator;

        public DispatchService(
            IDispatchDataService dispatchDataService,
            ICreateDispatchValidation createValidator,
            IUpdateDispatchValidation updateValidator)
        {
            _dispatchDataService = dispatchDataService;
            _createValidator = createValidator;
            _updateValidator = updateValidator;
        }

        public async Task<DispatchDTO?> GetDispatchByIdAsync(int id)
        {
            var dispatch = await _dispatchDataService.GetByIdAsync(id);
            return dispatch == null ? null : MapToDTO(dispatch);
        }

        public async Task<DispatchDTO?> GetDispatchByIdWithDetailsAsync(int id)
        {
            var dispatch = await _dispatchDataService.GetByIdWithDetailsAsync(id);
            return dispatch == null ? null : MapToDTO(dispatch);
        }

        public async Task<IEnumerable<DispatchDTO>> GetAllDispatchesAsync()
        {
            var dispatches = await _dispatchDataService.GetAllAsync();
            return dispatches.Select(MapToDTO);
        }

        public async Task<IEnumerable<DispatchDTO>> GetDispatchesByVendorIdAsync(int vendorId)
        {
            var dispatches = await _dispatchDataService.GetByVendorIdAsync(vendorId);
            return dispatches.Select(MapToDTO);
        }

        public async Task<PagedResult<DispatchDTO>> GetDispatchesPagedAsync(int page, int pageSize, string? search = null, string? status = null)
        {
            var (items, totalCount) = await _dispatchDataService.GetPagedAsync(page, pageSize, search, status);
            return new PagedResult<DispatchDTO>
            {
                Items = items.Select(MapToDTO).ToList(),
                TotalCount = totalCount,
                Page = page,
                PageSize = pageSize
            };
        }

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

            var dispatchNumber = await GenerateNextDispatchNumberAsync();

            var dispatch = new Dispatch
            {
                VendorId = dto.VendorId,
                ScheduledDate = dto.ScheduledDate,
                Status = dto.Status ?? "Pending",
                DispatchNumber = dispatchNumber,
                CreatedDate = DateTime.UtcNow,
                createdby = userId
            };

            var created = await _dispatchDataService.AddAsync(dispatch);
            return MapToDTO(created);
        }

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

            var dispatch = await _dispatchDataService.GetByIdAsync(id);
            if (dispatch == null)
                throw new InvalidOperationException($"Dispatch with ID {id} not found");

            if (dto.VendorId.HasValue) dispatch.VendorId = dto.VendorId.Value;
            if (dto.ScheduledDate.HasValue) dispatch.ScheduledDate = dto.ScheduledDate;
            if (dto.CompletedDate.HasValue) dispatch.CompletedDate = dto.CompletedDate;
            if (dto.Status != null) dispatch.Status = dto.Status;

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

            await _dispatchDataService.UpdateAsync(dispatch);
            return MapToDTO(dispatch);
        }

        public async Task DeleteDispatchAsync(int id, string userId)
        {
            var dispatch = await _dispatchDataService.GetByIdAsync(id);
            if (dispatch == null)
                throw new InvalidOperationException($"Dispatch with ID {id} not found");

            dispatch.IsDeleted = true;
            dispatch.DeleterUserId = userId;
            dispatch.DeletionTime = DateTime.UtcNow;

            await _dispatchDataService.UpdateAsync(dispatch);
        }

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

        public async Task<string> GenerateNextDispatchNumberAsync()
        {
            var count = await _dispatchDataService.CountAsync();
            return $"DISP-{(count + 1):D6}";
        }

        public async Task<int> GetTotalDispatchCountAsync()
        {
            return await _dispatchDataService.CountAsync();
        }

        public async Task<DispatchListResultDTO> GetDispatchListAsync(
            string? search,
            string? status,
            int? vendorId,
            DateTime? dateFrom,
            DateTime? dateTo,
            string? sortBy,
            string? sortDir,
            int page,
            int pageSize,
            CancellationToken cancellationToken)
        {
            var query = new DispatchListQuery
            {
                Search = search,
                Status = status,
                VendorId = vendorId,
                DateFrom = dateFrom,
                DateTo = dateTo,
                SortBy = sortBy,
                SortDir = sortDir,
                Page = page,
                PageSize = pageSize
            };

            var result = await _dispatchDataService.GetListAsync(query, cancellationToken);

            return new DispatchListResultDTO
            {
                Items = result.Items.Select(MapListEntry).ToList(),
                Total = result.Total,
                Page = result.Page,
                PageSize = result.PageSize
            };
        }

        public async Task<DispatchDetailResultDTO?> GetDispatchDetailAsync(int id, CancellationToken cancellationToken)
        {
            var detail = await _dispatchDataService.GetDetailAsync(id, cancellationToken);
            return detail == null ? null : MapDetail(detail);
        }

        private static DispatchListEntryDTO MapListEntry(DispatchListItemDTO d)
        {
            return new DispatchListEntryDTO
            {
                Id = d.Id,
                DispatchNumber = d.DispatchNumber,
                PONumber = d.PONumber,
                NTEAmount = d.NTEAmount,
                Status = d.Status,
                DispatchedAt = d.DispatchedAt,
                ScheduledDate = d.ScheduledDate,
                CompletedDate = d.CompletedDate,
                AcknowledgedAt = d.AcknowledgedAt,
                VerifiedAt = d.VerifiedAt,
                VendorId = d.VendorId,
                VendorName = d.VendorName,
                WorkOrderId = d.WorkOrderId,
                PrimaryWOInternalNumber = d.PrimaryWOInternalNumber,
                PrimaryWOTitle = d.PrimaryWOTitle,
                LocationName = d.LocationName,
                WorkOrderCount = d.WorkOrderCount,
                PendingUpliftCount = d.PendingUpliftCount
            };
        }

        private static DispatchDetailResultDTO MapDetail(DispatchDetailDTO d)
        {
            return new DispatchDetailResultDTO
            {
                Id = d.Id,
                DispatchNumber = d.DispatchNumber,
                PONumber = d.PONumber,
                NTEAmount = d.NTEAmount,
                Description = d.Description,
                Status = d.Status,
                ScheduledDate = d.ScheduledDate,
                CompletedDate = d.CompletedDate,
                DispatchedAt = d.DispatchedAt,
                AcknowledgedAt = d.AcknowledgedAt,
                VerifiedAt = d.VerifiedAt,
                VerifiedBy = d.VerifiedBy,
                EmailSent = d.EmailSent,
                WorkOrderId = d.WorkOrderId,
                Vendor = d.Vendor == null ? null : new DispatchDetailVendorResultDTO
                {
                    Id = d.Vendor.Id,
                    CompanyName = d.Vendor.CompanyName,
                    ContactName = d.Vendor.ContactName,
                    Email = d.Vendor.Email,
                    Phone = d.Vendor.Phone,
                    Address = d.Vendor.Address,
                    City = d.Vendor.City,
                    State = d.Vendor.State,
                    Zip = d.Vendor.Zip,
                    TradeSpecialties = d.Vendor.TradeSpecialties
                },
                PrimaryLocation = d.PrimaryLocation == null ? null : new DispatchDetailLocationResultDTO
                {
                    Id = d.PrimaryLocation.Id,
                    Name = d.PrimaryLocation.Name,
                    Address1 = d.PrimaryLocation.Address1,
                    City = d.PrimaryLocation.City,
                    State = d.PrimaryLocation.State,
                    Zip = d.PrimaryLocation.Zip
                },
                WorkOrders = d.WorkOrders.Select(w => new DispatchDetailLinkedWorkOrderDTO
                {
                    WorkOrderId = w.WorkOrderId,
                    InternalWONumber = w.InternalWONumber,
                    Title = w.Title,
                    Priority = w.Priority,
                    Status = w.Status,
                    LocationName = w.LocationName,
                    Trade = w.Trade,
                    SubTrade = w.SubTrade,
                    Problem = w.Problem
                }).ToList(),
                Checklist = d.Checklist.Select(c => new DispatchDetailChecklistDTO
                {
                    Id = c.Id,
                    ItemText = c.ItemText,
                    IsCompleted = c.IsCompleted,
                    CompletedBy = c.CompletedBy,
                    CompletedAt = c.CompletedAt,
                    SortOrder = c.SortOrder,
                    WorkOrderId = c.WorkOrderId
                }).ToList(),
                Signoffs = d.Signoffs.Select(s => new DispatchDetailSignoffDTO
                {
                    Id = s.Id,
                    SignoffType = s.SignoffType,
                    Name = s.Name,
                    Signature = s.Signature,
                    SignatureMethod = s.SignatureMethod,
                    SignedAt = s.SignedAt
                }).ToList(),
                Comments = d.Comments.Select(c => new DispatchDetailCommentDTO
                {
                    Id = c.Id,
                    Commenttext = c.Commenttext,
                    Commenter = c.Commenter,
                    CommentType = c.CommentType,
                    RecordType = c.RecordType,
                    CreatedDate = c.CreatedDate,
                    UserId = c.UserId,
                    UserName = c.UserName
                }).ToList(),
                UpliftRequests = d.UpliftRequests.Select(u => new DispatchDetailUpliftDTO
                {
                    Id = u.Id,
                    CurrentNTE = u.CurrentNTE,
                    RequestedNTE = u.RequestedNTE,
                    Delta = u.Delta,
                    VendorReason = u.VendorReason,
                    Status = u.Status,
                    RequiredTier = u.RequiredTier,
                    RequestedByVendorName = u.RequestedByVendorName,
                    RequestedAt = u.RequestedAt,
                    DecidedAt = u.DecidedAt,
                    DecisionNote = u.DecisionNote,
                    DecidedByName = u.DecidedByName
                }).ToList(),
                AuditLog = d.AuditLog.Select(a => new DispatchDetailAuditLogDTO
                {
                    Id = a.Id,
                    Action = a.Action,
                    FieldName = a.FieldName,
                    OldValue = a.OldValue,
                    NewValue = a.NewValue,
                    CreatedAt = a.CreatedAt,
                    UserId = a.UserId,
                    UserName = a.UserName
                }).ToList()
            };
        }

        private DispatchDTO MapToDTO(Dispatch dispatch)
        {
            return new DispatchDTO
            {
                Id = dispatch.Id,
                DispatchNumber = dispatch.DispatchNumber,
                Status = dispatch.Status,
                VendorId = dispatch.VendorId,
                VendorName = dispatch.Vendor?.CompanyName,
                ScheduledDate = dispatch.ScheduledDate,
                CompletedDate = dispatch.CompletedDate,
                CreatedDate = dispatch.CreatedDate,
                CreatedBy = dispatch.createdby
            };
        }
    }
}