using Data.SeaHavenIndustries;
using Microsoft.EntityFrameworkCore;
using SeaHaven.DataServices.Interfaces;

namespace SeaHaven.DataServices.Implementation
{
    public class DispatchDataService : IDispatchDataService
    {
        private readonly ApplicationDbContext _context;

        public DispatchDataService(ApplicationDbContext context)
        {
            _context = context;
        }

        public async Task<Dispatch?> GetByIdAsync(int id)
        {
            return await _context.Dispatches.FindAsync(id);
        }

        public async Task<Dispatch?> GetByIdWithDetailsAsync(int id)
        {
            return await _context.Dispatches
                .Include(d => d.Vendor)
                .FirstOrDefaultAsync(d => d.Id == id);
        }

        public async Task<IEnumerable<Dispatch>> GetAllAsync()
        {
            return await _context.Dispatches.ToListAsync();
        }

        public async Task<IEnumerable<Dispatch>> GetByVendorIdAsync(int vendorId)
        {
            return await _context.Dispatches
                .Where(d => d.VendorId == vendorId)
                .ToListAsync();
        }

        public async Task<IEnumerable<Dispatch>> GetByStatusAsync(string status)
        {
            return await _context.Dispatches
                .Where(d => d.Status == status)
                .ToListAsync();
        }

        public async Task<(IEnumerable<Dispatch> Items, int TotalCount)> GetPagedAsync(
            int page, 
            int pageSize, 
            string? search = null, 
            string? status = null)
        {
            var query = _context.Dispatches.AsQueryable();

            if (!string.IsNullOrWhiteSpace(search))
            {
                query = query.Where(d => d.DispatchNumber!.Contains(search));
            }

            if (!string.IsNullOrWhiteSpace(status))
            {
                query = query.Where(d => d.Status == status);
            }

            var totalCount = await query.CountAsync();
            var items = await query
                .OrderByDescending(d => d.CreatedDate)
                .Skip((page - 1) * pageSize)
                .Take(pageSize)
                .ToListAsync();

            return (items, totalCount);
        }

        public async Task<Dispatch> AddAsync(Dispatch dispatch)
        {
            dispatch.CreatedDate = DateTime.Now;
            await _context.Dispatches.AddAsync(dispatch);
            await _context.SaveChangesAsync();
            return dispatch;
        }

        public async Task UpdateAsync(Dispatch dispatch)
        {
            dispatch.LastModificationTime = DateTime.Now;
            _context.Dispatches.Update(dispatch);
            await _context.SaveChangesAsync();
        }

        public async Task DeleteAsync(int id)
        {
            var entity = await GetByIdAsync(id);
            if (entity != null)
            {
                _context.Dispatches.Remove(entity);
                await _context.SaveChangesAsync();
            }
        }

        public async Task<bool> ExistsAsync(int id)
        {
            return await _context.Dispatches.AnyAsync(d => d.Id == id);
        }

        public async Task<string> GenerateNextDispatchNumberAsync()
        {
            return await Task.FromResult($"DISP-{DateTime.Now:yyyyMMdd}-{new Random().Next(1000, 9999)}");
        }

        public async Task<int> CountAsync()
        {
            return await _context.Dispatches.CountAsync();
        }

        public async Task<IEnumerable<Dispatch>> GetByWorkOrderIdAsync(int workOrderId)
        {
            var dispatchIds = await _context.DispatchWorkOrders
                .Where(dwo => dwo.WorkOrderId == workOrderId)
                .Select(dwo => dwo.DispatchId)
                .Distinct()
                .ToListAsync();

            var directIds = await _context.Dispatches
                .Where(d => d.WorkOrderId == workOrderId)
                .Select(d => d.Id)
                .ToListAsync();

            var allIds = dispatchIds.Union(directIds).Distinct().ToList();

            return await _context.Dispatches
                .Where(d => allIds.Contains(d.Id))
                .Include(d => d.Vendor)
                .ToListAsync();
        }

        public async Task<IEnumerable<Dispatch>> GetByWorkOrderIdsAsync(IEnumerable<int> workOrderIds)
        {
            return await _context.Dispatches
                .Where(d => workOrderIds.Contains(d.WorkOrderId ?? 0))
                .Include(d => d.Vendor)
                .ToListAsync();
        }

        public async Task<string> GenerateNextPONumberAsync()
        {
            var lastPO = await _context.Dispatches
                .Where(d => d.PONumber != null)
                .OrderByDescending(d => d.PONumber)
                .Select(d => d.PONumber)
                .FirstOrDefaultAsync();

            int nextPO = 1000;
            if (!string.IsNullOrEmpty(lastPO) && int.TryParse(lastPO, out int lastNum))
            {
                nextPO = lastNum + 1;
            }

            return nextPO.ToString();
        }

        public async Task<IEnumerable<DispatchChecklistItem>> GetChecklistItemsAsync(int dispatchId)
        {
            return await _context.DispatchChecklistItems
                .Where(ci => ci.DispatchId == dispatchId)
                .OrderBy(ci => ci.SortOrder)
                .ToListAsync();
        }

        public async Task<DispatchChecklistItem?> GetChecklistItemByIdAsync(int id)
        {
            return await _context.DispatchChecklistItems.FindAsync(id);
        }

        public async Task AddChecklistItemAsync(DispatchChecklistItem item)
        {
            await _context.DispatchChecklistItems.AddAsync(item);
            await _context.SaveChangesAsync();
        }

        public async Task UpdateChecklistItemAsync(DispatchChecklistItem item)
        {
            _context.DispatchChecklistItems.Update(item);
            await _context.SaveChangesAsync();
        }

        public async Task<IEnumerable<DispatchSignoff>> GetSignoffsAsync(int dispatchId)
        {
            return await _context.DispatchSignoffs
                .Where(s => s.DispatchId == dispatchId)
                .ToListAsync();
        }

        public async Task AddSignoffAsync(DispatchSignoff signoff)
        {
            signoff.SignedAt = DateTime.UtcNow;
            await _context.DispatchSignoffs.AddAsync(signoff);
            await _context.SaveChangesAsync();
        }

        public async Task<bool> HasSignoffTypeAsync(int dispatchId, string signoffType)
        {
            return await _context.DispatchSignoffs
                .AnyAsync(s => s.DispatchId == dispatchId && s.SignoffType == signoffType);
        }

        public async Task<IEnumerable<DispatchWorkOrder>> GetDispatchWorkOrdersAsync(int dispatchId)
        {
            return await _context.DispatchWorkOrders
                .Where(dwo => dwo.DispatchId == dispatchId)
                .Include(dwo => dwo.WorkOrder)
                .ToListAsync();
        }

        public async Task AddDispatchWorkOrderAsync(DispatchWorkOrder dispatchWorkOrder)
        {
            await _context.DispatchWorkOrders.AddAsync(dispatchWorkOrder);
            await _context.SaveChangesAsync();
        }
    }
}