using EnVisage.Code.BLL;
using EnVisage.Models;
using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;
using System.Threading.Tasks;
using System.Web;

namespace EnVisage.Code
{
    public class RateManager 
    {
        private readonly EnVisageEntities _dbContext;
        private readonly bool _isContexLocal = false;

        public RateManager(EnVisageEntities dbContext)
        {
            if (dbContext == null)
            {
                _dbContext = new EnVisageEntities();
                _isContexLocal = true;
            }
            else
            {
                _dbContext = dbContext;
            }
        }
        public void Dispose()
        {
            if (_isContexLocal)
                _dbContext.Dispose();
        }

        #region Public Methods
        /// <summary>
        /// Loads a Rate from the database.
        /// </summary>
        /// <param name="value">Unique identifier of the Rate .</param>
        /// <param name="isReadOnly">Indicates that object will not be saved later in the code. Use <b>false</b> if you need to save an updated object.</param>
        /// <returns>A <see cref="Rate"/> object retrieved from database.</returns>
        public Rate Load(Guid? value, bool isReadOnly = true)
        {
            if (value == null || value == Guid.Empty)
                return new Rate();

            return isReadOnly
                       ? _dbContext.Rates.AsNoTracking().FirstOrDefault(t => t.Id == value)
                       : _dbContext.Rates.Find(value);
        }

        public void Save(RateModel model)
        {
            if (model == null)
                throw new ArgumentNullException("model");

            #region Save Rate data
            Rate dbObj = null;
            if (model.Id != Guid.Empty)
                dbObj = _dbContext.Rates.Find(model.Id);
            if (dbObj == null)
            {
                dbObj = new Rate { Id = Guid.NewGuid() };
            }
            model.CopyTo(dbObj);
            if (model.Id == Guid.Empty)
                _dbContext.Rates.Add(dbObj);
            else
                _dbContext.Entry(dbObj).State = EntityState.Modified;
            #endregion

            #region Update Related Scenarios
            var scenarioManager = new ScenarioManager(_dbContext);
            scenarioManager.ApplyRateAndRecalculateScenarios(dbObj);
            #endregion

            if (_isContexLocal)
                _dbContext.SaveChanges();
        }

		[Obsolete("This method is called in loops - this is not acceptable. Replace with single non-db dictionary loop")]
		public decimal GetRateValue(Guid expenditureCategoryId, DateTime currentDate)
		{
			if(expenditureCategoryId == Guid.Empty)
				throw new ArgumentException("Parameter 'expenditureCatetoryId' can not be Guid.Empty");

			var rate = _dbContext.Rates
				.FirstOrDefault(x => x.Type == (short)EnVisage.Models.RateModel.RateType.Global && x.ExpenditureCategoryId == expenditureCategoryId 
								&& currentDate >= x.StartDate && currentDate <= x.EndDate);

			return rate != null ? rate.Rate1 : 0;
		}
        #endregion
    }
}