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

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

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

        public LCARiskAssmtSurveyForm_AssmtFactor Save(AssmtFactorDTO toBeSave)
        {
            CheckScore(toBeSave);

            var user = GetUserContext();

            if (!AuthorizedLCAs.Contains(toBeSave.LCAID)) throw new Exception("not authorized");
            var entry = _db.Set<LCARiskAssmtSurveyForm_AssmtFactor>().FirstOrDefault(x => x.ID == toBeSave.ID);
            var isEdited = false;
            var assmtFactorIDList = new List<int>();
            if (entry == null)
            {
                if (_db.Set<LCARiskAssmtSurveyForm_AssmtFactor>().Any(x => x.LCAID == toBeSave.LCAID && x.FactorName == toBeSave.FactorName))
                {
                    throw new Exception($"评估因子名称不能重复");
                }

                entry = new LCARiskAssmtSurveyForm_AssmtFactor() 
                { 
                    LCAID = toBeSave.LCAID,
                    FactorName = toBeSave.FactorName,
                    Comment = toBeSave.Comment
                };

                foreach (var factorScore in toBeSave.FactorScores)
                {
                    entry.FactorScores.Add(new LCARiskAssmtSurveyForm_AssmtFactorScore() 
                    {
                        OptionDescription = factorScore.OptionDescription,
                        OptionScore = factorScore.OptionScore,
                        Comment = factorScore.Comment,
                        CreatedBy = user.Id,
                        CreatedDate = DateTime.Now
                    });
                }

                _db.Set<LCARiskAssmtSurveyForm_AssmtFactor>().Add(entry);
                _db.Entry(entry).State = EntityState.Added;
            }
            else
            {
                if (_db.Set<LCARiskAssmtSurveyForm_AssmtFactor>().Any(x => x.ID != entry.ID && x.LCAID == toBeSave.LCAID && x.FactorName == toBeSave.FactorName))
                {
                    throw new Exception($"评估因子名称不能重复");
                }

                entry.FactorName = toBeSave.FactorName;
                entry.Comment = toBeSave.Comment;
                entry.ModifiedBy = user.Id;
                entry.ModifiedDate = DateTime.Now;

                var factorScores = _db.Set<LCARiskAssmtSurveyForm_AssmtFactorScore>().Where(x => x.FactorId == entry.ID).ToList();
                var count = factorScores.Count;

                for (int i = count - 1; i >= 0; i--)
                {
                    var factorScore = factorScores.ElementAt(i);

                    if (!toBeSave.FactorScores.Any(x => x.ID == factorScore.ID))
                    {
                        assmtFactorIDList.Add(factorScore.FactorId);
                        isEdited = true;
                        factorScores.Remove(factorScore);

                        _db.Set<LCARiskAssmtSurveyForm_AssmtFactorScore>().Attach(factorScore);
                        _db.Entry(factorScore).State = EntityState.Deleted;
                    }
                }

                foreach (var factorScore in toBeSave.FactorScores)
                {
                    if (factorScore.ID > 0)
                    {
                        assmtFactorIDList.Add(factorScore.FactorId);
                        isEdited = true;
                        var updatingFactorScore = factorScores.First(fs => fs.ID == factorScore.ID);

                        updatingFactorScore.OptionDescription = factorScore.OptionDescription;
                        updatingFactorScore.OptionScore = factorScore.OptionScore;
                        updatingFactorScore.Comment = factorScore.Comment;
                        updatingFactorScore.ModifiedBy = user.Id;
                        updatingFactorScore.ModifiedDate = DateTime.Now;

                        _db.Set<LCARiskAssmtSurveyForm_AssmtFactorScore>().Attach(updatingFactorScore);
                        _db.Entry(updatingFactorScore).State = EntityState.Modified;
                    }
                    else
                    {
                        var addingFactorScore = new LCARiskAssmtSurveyForm_AssmtFactorScore()
                        {
                            FactorId = entry.ID,
                            OptionDescription = factorScore.OptionDescription,
                            OptionScore = factorScore.OptionScore,
                            Comment = factorScore.Comment,
                            CreatedBy = user.Id,
                            CreatedDate = DateTime.Now
                        };

                        _db.Set<LCARiskAssmtSurveyForm_AssmtFactorScore>().Attach(addingFactorScore);
                        _db.Entry(addingFactorScore).State = EntityState.Added;
                    }
                }

                _db.Set<LCARiskAssmtSurveyForm_AssmtFactor>().Attach(entry);
                _db.Entry(entry).State = EntityState.Modified;
                _db.Entry(entry).Property(x => x.LCAID).IsModified = false;
            }

            _db.SaveChanges();
            // 將新增的評估因子更新到顯著性評估項目中
            string sql = $@"
insert into LCARiskAssmtSurveyForm_SignificanceAssmtFactor (SignificanceAssmtID, AssmtFactorID, Score)
select a.SignificanceAssmtID, a.AssmtFactorID, 0 Score
from
(select a.ID AssmtFactorID, s.id SignificanceAssmtID
from LCARiskAssmtSurveyForm_AssmtFactor a, LCARiskAssmtSurveyForm_SignificanceAssmt s
where a.LCAID=@LCAID and s.LCAID=@LCAID) a
left join (
select SignificanceAssmtID, AssmtFactorID
from LCARiskAssmtSurveyForm_SignificanceAssmtFactor
group by SignificanceAssmtID, AssmtFactorID
) c on a.AssmtFactorID=c.AssmtFactorID and a.SignificanceAssmtID=c.SignificanceAssmtID
where c.AssmtFactorID is null or c.SignificanceAssmtID is null
";
            int rows = _db.Database.ExecuteSqlCommand(sql, new SqlParameter("@LCAID", toBeSave.LCAID));
            UpdateLCA_SignificanceAssmts(toBeSave.LCAID, assmtFactorIDList);
            return entry;
        }

        private void CheckScore(AssmtFactorDTO toBeSave)
        {
            if (toBeSave.FactorScores.Any(x => x.OptionScore < 1 || x.OptionScore > 10))
            {
                throw new Exception($"评分范围1~10：{nameof(toBeSave.FactorScores)}");
            }
        }

        public void Delete(int ID)
        {
            var entry = _db.Set<LCARiskAssmtSurveyForm_AssmtFactor>().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;

            _db.SaveChanges();


            // 將刪除的評估因子更新到顯著性評估項目中
            string sql = $@"
delete from LCARiskAssmtSurveyForm_SignificanceAssmtFactor 
where LCARiskAssmtSurveyForm_SignificanceAssmtFactor.AssmtFactorID = @ID
and LCARiskAssmtSurveyForm_SignificanceAssmtFactor.SignificanceAssmtID in (select id from LCARiskAssmtSurveyForm_SignificanceAssmt where LCAID = @LCAID)
";
            object[] parameters = { new SqlParameter("@ID", ID), new SqlParameter("@LCAID", entry.LCAID) };
            int rows = _db.Database.ExecuteSqlCommand(sql, parameters);
            UpdateLCA_SignificanceAssmts(entry.LCAID,new List<int>());
        }

        public void UpdateLCA_SignificanceAssmts(int LCAID,List<int> assmtFacotrIDs)
        {
            var significanceAssmts = _db.LCARiskAssmtSurveyForm_SignificanceAssmts.Where(x => x.LCAID == LCAID).ToList();
            var factors = (from saf in _db.LCARiskAssmtSurveyForm_SignificanceAssmtFactors
                           join sa in _db.LCARiskAssmtSurveyForm_SignificanceAssmts on saf.SignificanceAssmtID equals sa.ID
                           where sa.LCAID == LCAID
                           select saf).ToList();
            var gradingScore = _db.LCAs.Where(x => x.ID == LCAID).First().GradingScore;
            foreach (var factor in factors)
            {
                if (assmtFacotrIDs.Contains(factor.AssmtFactorID))
                    factor.Score = 0;
            }
            foreach (var significanceAssmt in significanceAssmts)
            {
                var thisFactors = factors.Where(x => x.SignificanceAssmtID == significanceAssmt.ID).Select(x => x.Score);
                if (thisFactors.Count() == 0)
                    significanceAssmt.Score = 0;
                else
                    significanceAssmt.Score = thisFactors.Aggregate((m, n) => m * n);
                significanceAssmt.Significance = significanceAssmt.Score >= gradingScore ? 1 : 0;
            }
            _db.SaveChanges();
        }
    }
}