using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;
using System.Web;
using EnVisage.Models;

namespace EnVisage.Code.BLL
{
    public class TrainingManager : ManagerBase<Training, TrainingModel>
    {
        public TrainingManager(EnVisageEntities dbContext)
            : base(dbContext)
        {
        }

        protected override Training InitInstance()
        {
            return new Training { Id = Guid.NewGuid() };
        }

        protected override Training RetrieveReadOnlyById(Guid key)
        {
            return DataTable.AsNoTracking().FirstOrDefault(t => t.Id == key);
        }

        public override DbSet<Training> DataTable
        {
            get
            {
                return DbContext.Trainings;
            }
        }

        public override Training Save(TrainingModel model)
        {
            //if (!model.traStartDate.HasValue)
            //    throw new ArgumentNullException("model.StartDate");
            //if (!model.EndDate.HasValue)
            //    throw new ArgumentNullException("model.EndDate");
            Dictionary<Guid, decimal> uomValue = new Dictionary<Guid, decimal>();
            using (var db = new EnVisageEntities())
            {
                (from p in db.PeopleResources
                    join ec in db.ExpenditureCategory on p.ExpenditureCategoryId equals ec.Id
                    join uom in db.UOMs on ec.UOMId equals uom.Id
                    where model.Resources.Contains(p.Id)
                    select new { p.Id, uom.UOMValue })
                .ToList().ForEach(x => uomValue.Add(x.Id, x.UOMValue));
            }
            var obj = base.Save(model);
            
            #region Save PeopleResourceTrainings
            if (!Guid.Empty.Equals(model.Id))
            {
                var items2Delete = DbContext.PeopleResourceTrainings.Where(t => t.TrainingId == model.Id);
                foreach (var peopleResourceTraining in items2Delete)
                {
                    DbContext.Entry(peopleResourceTraining).State = EntityState.Deleted;
                }
            }
     
            var weekEndingSetting = DbContext.SystemSettings.FirstOrDefault(t => t.Type == (int)SystemSettingType.FiscalCalendarWeekEnding);
            var weekEndingDay = weekEndingSetting != null
                                    ? (DayOfWeek)Convert.ToInt16(weekEndingSetting.Value)
                                    : DayOfWeek.Saturday;
            var weekEndingDate = model.TrainingStartDate;
            if (weekEndingDate.DayOfWeek != weekEndingDay)
                weekEndingDate = Utils.GetNextDateByWeekDate(weekEndingDate, (short)weekEndingDay, 1, true);
            var rangeEndDate = model.TrainingEndDate;
            if (rangeEndDate.DayOfWeek != weekEndingDay)
                rangeEndDate = Utils.GetNextDateByWeekDate(rangeEndDate, (short)weekEndingDay, 1, true);
            var dt = weekEndingDate.AddDays(-6);
            var businessDays = 0;
            var wkEndDts = 0;
            while (dt <= rangeEndDate)
            {
                if (dt > weekEndingDate)
                {
                    foreach (var res in model.Resources)
                    {
                        var hoursOff = Convert.ToInt32(businessDays * uomValue[res] * model.TrainingTimeAllocated / ((7 - wkEndDts) * 100));
                        if (hoursOff > 0)
                        {
                            DbContext.PeopleResourceTrainings.Add(new PeopleResourceTraining
                            {
                                Id = Guid.NewGuid(),
                                TrainingId = obj.Id,
                                PeopleResourceId = res,
                                WeekEndingDate = weekEndingDate,
                                HoursOff = hoursOff

                            });
                        }
                    }
                    weekEndingDate = weekEndingDate.AddDays(7);
                    businessDays = 0;
                    wkEndDts = 0;
                }
                if (model.TrainingStartDate <= dt && dt <= model.TrainingEndDate)
                    businessDays++;
                if (model.Weekends.Any(t => dt == t))
                {
                    wkEndDts++;
                    if (model.TrainingStartDate <= dt && dt <= model.TrainingEndDate)
                        businessDays--;
                }
                dt = dt.AddDays(1);
            }
            if (wkEndDts != 7)
            {
                foreach (var res in model.Resources)
                {
                    var hoursOff = Convert.ToInt32(businessDays * uomValue[res] * model.TrainingTimeAllocated / ((7 - wkEndDts) * 100));
                    if (hoursOff > 0)
                    {
                        DbContext.PeopleResourceTrainings.Add(new PeopleResourceTraining
                        {
                            Id = Guid.NewGuid(),
                            TrainingId = obj.Id,
                            PeopleResourceId = res,
                            WeekEndingDate = model.TrainingEndDate,
                            HoursOff = 0
                        });
                    }
                }
            }
            #endregion
            
            return obj;
        }

        public static List<TrainingModel> GetTrainings(Guid peopleResourceId)
        {
            if (Guid.Empty.Equals(peopleResourceId))
                return null;
            var Trainings = new Dictionary<Guid, TrainingModel>();
            var prevDate = DateTime.MinValue;
            TrainingModel item = null;
            using (var db = new EnVisageEntities())
            {
                var uomValue = (from p in db.PeopleResources
                                join ec in db.ExpenditureCategory on p.ExpenditureCategoryId equals ec.Id
                                join uom in db.UOMs on ec.UOMId equals uom.Id
                                where p.Id == peopleResourceId
                                select new {uom.Id, uom.UOMValue}).FirstOrDefault();
                if (uomValue == null || uomValue.UOMValue == 0)
                    throw new UOMNotExistsException();

                var records = (from t in db.Trainings
                               join prv in db.PeopleResourceTrainings on t.Id equals prv.TrainingId into g
                               from sub in g.DefaultIfEmpty()
                               where t.PeopleResourceTrainings.Select(x=>x.PeopleResourceId).Contains(peopleResourceId)
                               select
                                   new
                                       {
                                           t.Id,
                                           t.StartDate,
                                           t.EndDate,
                                           t.Name,
                                           t.Cost,
                                           t.PercentAllocated,
                                           t.TrainingType, 
                                           itemId = sub == null ? (Guid?)null : sub.Id,
                                           HoursOff = sub == null ? (int?)null : sub.HoursOff,
                                           WeekEndingDate = sub == null ? (DateTime?)null : sub.WeekEndingDate,
                                       });
                foreach (var training in records.OrderBy(o => o.WeekEndingDate))
                {
                    if (!Trainings.ContainsKey(training.Id))
                    {
                        item = new TrainingModel
                        {
                            Id = training.Id,
                            TrainingStartDate = training.StartDate,
                            TrainingEndDate = training.EndDate,
                            TrainingName = training.Name,
                            TrainingCost = training.Cost,
                            TrainingTypeId = training.TrainingType.Id,
                            TrainingTypeName = training.TrainingType.Name,
                            TrainingTimeAllocated = training.PercentAllocated,
                        };
                        Trainings.Add(item.Id, item);
                    }

                    if (training.itemId.HasValue)
                    {
                        item.PeopleResourceTrainings.Add(new PeopleResourceTrainingModel
                        {
                            Id = training.itemId.Value,
                            WeekEndingDate = training.WeekEndingDate.Value,
                            HoursOff = training.HoursOff.Value,
                            PeopleResourceId = peopleResourceId
                        });
                    }
                }
            }
            return Trainings.Values.ToList();
        }
    }
}