using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;
using System.Web;
using Weee.DAL;
using Weee.Models;
using Weee.ViewModels.DataTransferObject;

namespace Weee.Service
{
    public class WasteMaterialDataService : WeeeLCADataService
    {
        public WasteMaterialDataService(WeeeDataContext db)
        : base(db)
        {
        }

        public IQueryable<LCARiskAssmtSurveyForm_WasteMaterial> GetList(int LCAID)
        {
            if (!AuthorizedLCAs.Contains(LCAID)) throw new Exception("not authorized");
            return _db.Set<LCARiskAssmtSurveyForm_WasteMaterial>().Where(x => x.LCAID == LCAID)
                .OrderByDescending(x => x.ID);
        }

        public LCARiskAssmtSurveyForm_WasteMaterial Save(LCARiskAssmtSurveyForm_WasteMaterial toBeSave, out decimal totalQuantity)
        {
            var user = GetUserContext();

            if (!AuthorizedLCAs.Contains(toBeSave.LCAID)) throw new Exception("not authorized");
            var entry = _db.Entry(toBeSave);
            var list = GetList(toBeSave.LCAID).Select(x => new { x.ID, x.TotalQuantity }).ToList();
            var lca = GetLCA(toBeSave.LCAID);

            CheckMaterialName(toBeSave);

            if (toBeSave.ID == 0)
            {
                toBeSave.CreatedBy = user.Id;
                toBeSave.CreatedDate = DateTime.Now;
                entry.State = EntityState.Added;

                totalQuantity = list.Sum(x => x.TotalQuantity);
            }
            else
            {
                toBeSave.ModifiedBy = user.Id;
                toBeSave.ModifiedDate = DateTime.Now;
                entry.State = EntityState.Modified;
                entry.Property(x => x.LCAID).IsModified = false;

                totalQuantity = list.Where(x => x.ID != toBeSave.ID).Sum(x => x.TotalQuantity);
            }

            totalQuantity += toBeSave.TotalQuantity;
            lca.WasteMaterialTotalQuantity = totalQuantity;

            _db.SaveChanges();

            return toBeSave;
        }

        public LCA UpdateLCA(int LCAID, LCAWasteMaterialDTO ToBeSave)
        {
            if (!AuthorizedLCAs.Contains(LCAID)) throw new Exception("not authorized");

            var lca = base.GetLCA(LCAID);

            lca.WasteMaterialTotalQuantity = ToBeSave.WasteMaterialTotalQuantity;
            lca.WasteMaterialShippingDistance = ToBeSave.WasteMaterialShippingDistance;
            lca.WasteMaterialTKM1 = ToBeSave.WasteMaterialTKM1;
            lca.WasteMaterialNumOfBarrels = ToBeSave.WasteMaterialNumOfBarrels;
            lca.WasteMaterialWeight = ToBeSave.WasteMaterialWeight;
            lca.WasteMaterialWorkingDays = ToBeSave.WasteMaterialWorkingDays;
            lca.WasteMaterialTotalOutputKg = ToBeSave.WasteMaterialTotalOutputKg;
            lca.WasteMaterialTotalOutputT = ToBeSave.WasteMaterialTotalOutputT;
            lca.WasteMaterialTreatmentPlantShippingDistance = ToBeSave.WasteMaterialTreatmentPlantShippingDistance;
            lca.WasteMaterialTKM2 = ToBeSave.WasteMaterialTKM2;

            _db.SaveChanges();

            return lca;
        }

        private void CheckMaterialName(LCARiskAssmtSurveyForm_WasteMaterial toBeSave)
        {
            if (_db.Set<LCARiskAssmtSurveyForm_WasteMaterial>().Any(i => i.LCAID == toBeSave.LCAID && i.MaterialName == toBeSave.MaterialName && (toBeSave.ID == 0 || toBeSave.ID != i.ID)))
            {
                throw new Exception($"物品名称不得重複：{nameof(toBeSave.MaterialName)}");
            }
        }

        public void Delete(int ID)
        {
            var entry = _db.Set<LCARiskAssmtSurveyForm_WasteMaterial>().Where(x => x.ID == ID).Single();
            var LCA = GetLCA(entry.LCAID);
            if (LCA.Status != LCAStatus.New && LCA.Status != LCAStatus.Processing) throw new Exception("Business logic error , should not delete data in this status: " + LCA.Status.ToString());

            var ToBeDelete = _db.Entry(entry);
            ToBeDelete.State = EntityState.Deleted;

            var left = GetList(entry.LCAID).Where(x => x.ID != ID);

            LCA.WasteMaterialTotalQuantity = left.Count() > 0 ? left.Sum(x => x.TotalQuantity) : 0;

            _db.SaveChanges();
        }
    }
}