using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Text;
using System.Web;
using EnVisage.Code;
using EnVisage.Code.BLL;

namespace EnVisage.Models
{
    public class HolidayModel : IValidatableObject
    {
        #region Classes and enums
        public enum HolidayOccurrence
        {
            [DisplayValue("Each")]
            SameDayEveryYear = 0,
            [DisplayValue("First")]
            FirstDayOfWeek = 1,
            [DisplayValue("Second")]
            SecondDayOfWeek = 2,
            [DisplayValue("Third")]
            ThirdDayOfWeek = 3,
            [DisplayValue("Fourth")]
            FourthDayOfWeek = 4,
            [DisplayValue("Last")]
            LastDayOfWeek = 5,
            [DisplayValue("Varies every year")]
            VariesEveryYear = 6,
            [DisplayValue("Only once")]
            OnlyOnce = 7,
        }
        #endregion

        #region Properties
        public Guid Id { get; set; }

        /// <summary>
        /// Gets or sets a name of the holiday.
        /// </summary>
        [Required]
        [DataType(DataType.Text)]
        [StringLength(50)]
        [Display(Name = "Name")]
        public string Name { get; set; }

        /// <summary>
        /// Gets or sets an occurrence of the holiday each year.
        /// </summary>
        [Required]
        [Display(Name = "Occurrence")]
        public HolidayOccurrence? OccurrenceType { get; set; }
        
        /// <summary>
        /// Gets or sets a week day of holiday.
        /// </summary>
        [Display(Name = "Occurrence day of week")]
        public DayOfWeek? OccurrenceWeekDay { get; set; }

        /// <summary>
        /// Gets or sets a day of holiday.
        /// </summary>
        [Display(Name = "Occurrence day of month")]
        [Range(1, 31)]
        public short? OccurrenceMonthDay { get; set; }

        /// <summary>
        /// Gets or sets a month of holiday.
        /// </summary>
        [Display(Name = "of")]
        [Range(1, 12)]
        public short? OccurrenceMonth { get; set; }

        /// <summary>
        /// Gets or sets a value indicating whether a holiday is a working day or not.
        /// </summary>
        [Display(Name = "Working Day")]
        public bool WorkingDay { get; set; }
        
        /// <summary>
        /// Gets or sets a value indicating whether a holiday results in non-working week or not.
        /// </summary>
        [Display(Name = "Non-Work Week")]
        public bool NonWorkingWeek { get; set; }
        
        public bool ShowWeekDayDdl
        {
            get
            {
                return OccurrenceType.HasValue && OccurrenceType.Value == HolidayOccurrence.FirstDayOfWeek &&
                       OccurrenceType.Value == HolidayOccurrence.SecondDayOfWeek &&
                       OccurrenceType.Value == HolidayOccurrence.ThirdDayOfWeek &&
                       OccurrenceType.Value == HolidayOccurrence.FourthDayOfWeek &&
                       OccurrenceType.Value == HolidayOccurrence.LastDayOfWeek &&
                       OccurrenceType.Value == HolidayOccurrence.VariesEveryYear &&
                       OccurrenceType.Value == HolidayOccurrence.OnlyOnce;
            }
        }
        #endregion

        #region Methods
        /// <summary>
        /// Determines whether the specified object is valid.
        /// </summary>
        /// <param name="validationContext">The validation context.</param>
        /// <returns>A collection that holds failed-validation information.</returns>
        public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
        {
            if (OccurrenceType != null)
                switch (OccurrenceType)
                {
                    case HolidayOccurrence.SameDayEveryYear:
                    case HolidayOccurrence.OnlyOnce:
                    case HolidayOccurrence.VariesEveryYear:
                        switch (OccurrenceMonth)
                        {
                            case 1:
                            case 3:
                            case 5:
                            case 7:
                            case 8:
                            case 10:
                            case 12:
                                if (OccurrenceMonthDay > 31)
                                    yield return new ValidationResult(string.Format(Constants.ERROR_RANGE_MAX_VALUE_TEMPLATE, "Occurrence day of month", 31), new[] { "OccurrenceMonthDay" });
                                break;
                            case 2:
                                if (OccurrenceMonthDay > 28)
                                    yield return new ValidationResult(string.Format(Constants.ERROR_RANGE_MAX_VALUE_TEMPLATE, "Occurrence day of month", 28), new[] { "OccurrenceMonthDay" });
                                break;
                            default:
                                if (OccurrenceMonthDay > 30)
                                    yield return new ValidationResult(string.Format(Constants.ERROR_RANGE_MAX_VALUE_TEMPLATE, "Occurrence day of month", 30), new[] { "OccurrenceMonthDay" });
                                break; 
                        }
                        yield break;
                    default:
                        break;
                }
        }

        /// <summary>
        /// Casts a <see cref="Holiday"/> obect to the object of type <see cref="HolidayModel"/>.
        /// </summary>
        /// <param name="obj">A <see cref="Holiday"/> object.</param>
        /// <returns>A <see cref="HolidayModel"/> object filled with data from db.</returns>
        public static explicit operator HolidayModel(Holiday obj)
        {
            if (obj == null)
                return null;
            var model = new HolidayModel
            {
                Id = obj.Id,
                Name = obj.Name,
                NonWorkingWeek = obj.NonWorkingWeek,
                OccurrenceType = (HolidayOccurrence)obj.OccurrenceType,
                OccurrenceMonth = obj.OccurrenceMonth,
                OccurrenceMonthDay = obj.OccurrenceMonthDay,
                OccurrenceWeekDay = (DayOfWeek)obj.OccurrenceWeekDay,
                WorkingDay = obj.WorkingDay
            };
            model.TrimStringProperties();
            return model;
        }

        /// <summary>
        /// Copies data from model to DAL object.
        /// </summary>
        /// <param name="holiday">A target DAL object.</param>
        public void CopyTo(Holiday holiday)
        {
            if (holiday == null)
                throw new ArgumentNullException();
            
            holiday.Name = Name;
            holiday.OccurrenceMonth = OccurrenceMonth ?? 1;
            holiday.OccurrenceMonthDay = OccurrenceMonthDay ?? 1;
            holiday.OccurrenceType = (short)(OccurrenceType ?? HolidayOccurrence.SameDayEveryYear);
            holiday.OccurrenceWeekDay = (short)(OccurrenceWeekDay ?? DayOfWeek.Monday);
            holiday.WorkingDay = WorkingDay;
            holiday.NonWorkingWeek = NonWorkingWeek;
        }

        public static DateTime GetHolidayDate(HolidayOccurrence occurrenceType, short month, short day, short weekDay)
        {
            DateTime date = DateTime.Today;
            switch (occurrenceType)
            {
                case HolidayOccurrence.OnlyOnce:
                case HolidayOccurrence.VariesEveryYear:
                case HolidayOccurrence.SameDayEveryYear:
                    return new DateTime(DateTime.Today.Year, month, day);
                case HolidayOccurrence.FirstDayOfWeek:
                    date = Utils.GetNextDateByWeekDate (new DateTime(DateTime.Today.Year, month, 1), weekDay, 1);
                    break;
                case HolidayOccurrence.SecondDayOfWeek:
                    date = Utils.GetNextDateByWeekDate(new DateTime(DateTime.Today.Year, month, 1), weekDay, 2);
                    break;
                case HolidayOccurrence.ThirdDayOfWeek:
                    date = Utils.GetNextDateByWeekDate(new DateTime(DateTime.Today.Year, month, 1), weekDay, 3);
                    break;
                case HolidayOccurrence.FourthDayOfWeek:
                    date = Utils.GetNextDateByWeekDate(new DateTime(DateTime.Today.Year, month, 1), weekDay, 4);
                    break;
                case HolidayOccurrence.LastDayOfWeek:
                    date = Utils.GetLastDateByWeekDate(new DateTime(DateTime.Today.Year, month, 1), weekDay);
                    break;
            }
            return date;
        }
        #endregion
    }

    public class HolidayDetailsModel
    {
        #region Properties
        public Guid Id { get; set; }

        /// <summary>
        /// Gets or sets a name of the holiday.
        /// </summary>
        [DataType(DataType.Text)]
        [Display(Name = "Name")]
        public string Name { get; set; }

        /// <summary>
        /// Gets or sets an occurrence of the holiday each year.
        /// </summary>
        [Display(Name = "Occurrence")]
        public string Occurrence { get; set; }

        /// <summary>
        /// Gets or sets a value indicating whether a holiday is a working day or not.
        /// </summary>
        [Display(Name = "Working Day")]
        public bool WorkingDay { get; set; }

        /// <summary>
        /// Gets or sets a value indicating whether a holiday results in non-working week or not.
        /// </summary>
        [Display(Name = "Non-Work Week")]
        public bool NonWorkingWeek { get; set; }
        #endregion

        #region Methods
        /// <summary>
        /// Casts a <see cref="Holiday"/> obect to the object of type <see cref="HolidayDetailsModel"/>.
        /// </summary>
        /// <param name="obj">A <see cref="Holiday"/> object.</param>
        /// <returns>A <see cref="HolidayDetailsModel"/> object filled with data from db.</returns>
        public static explicit operator HolidayDetailsModel(Holiday obj)
        {
            if (obj == null)
                return null;
            var model = new HolidayDetailsModel
            {
                Id = obj.Id,
                Name = obj.Name,
                NonWorkingWeek = obj.NonWorkingWeek,
                WorkingDay = obj.WorkingDay
            };
            var sb = new StringBuilder();
            sb.Append(((HolidayModel.HolidayOccurrence) obj.OccurrenceType).ToDisplayValue() + " ");
            switch ((HolidayModel.HolidayOccurrence) obj.OccurrenceType)
            {
                case HolidayModel.HolidayOccurrence.OnlyOnce:
                    case HolidayModel.HolidayOccurrence.SameDayEveryYear:
                    case HolidayModel.HolidayOccurrence.VariesEveryYear:
                    switch (obj.OccurrenceMonthDay % 10)
                    {
                        case 2:
                            sb.Append("2nd ");
                            break;
                        case 3:
                            sb.Append("3rd ");
                            break;
                        default:
                            sb.Append(obj.OccurrenceMonthDay + "th ");
                            break;

                    }
                    sb.Append("of " +
                              new DateTime(DateTime.Today.Year, obj.OccurrenceMonth, 1).ToString("MMMM") + " every year");
                    break;
                default:
                    sb.Append(" " + ((DayOfWeek)obj.OccurrenceWeekDay).ToString() + " of " +
                              new DateTime(DateTime.Today.Year, obj.OccurrenceMonth, 1).ToString("MMMM") + " every year");
                    break;
            }
            model.Occurrence = sb.ToString();
            model.TrimStringProperties();
            return model;
        }
        #endregion
    }
}