using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using PersonalFinance.Entity;

namespace PersonalFinance
{
    public enum Frequency { None, Once, Daily, Weekly, Monthly, Quarterly, Biannually, Yearly }

    /// <summary>
    /// Scheduling of payments
    ///  - repeated/regular
    ///  - temporary repeated
    ///  - plannig - one times
    /// </summary>
    public class ScheduledItem
    {
        public ScheduledItem()
        {
            LastUse = DateTime.Now.AddDays(-1);
        }

        /// <summary>
        /// Unique scheduling identification number (Primary key)
        /// </summary>
        [Key]
        public int ScheduledItemId { get; set; }

        /// <summary>
        /// Link to payment (Foreign key)
        /// </summary>
        private Payment payment;
        public Payment Payment 
        {
            get { return payment; }
            set
            {
                if (value != null)
                {
                    payment = value;
                }
                else
                {
                    throw new ArgumentNullException("Payment cannot be null.");
                    //throw new NullReferenceException("Payment");
                }
            }
        }

        private Frequency freq;
        /// <summary>
        /// Frequency of payment
        /// </summary>
        public Frequency Frequency {
            get { return freq; }
            set
            {
                if (Frequency.IsDefined(typeof(Frequency), value)){ this.freq = value; }
                else { throw new ArgumentOutOfRangeException("Value is not defined enum from Frequency!"); }
            }
        }

        [Range(typeof(DateTime), "1.1.1950", "31.12.2100")]
        private DateTime? until;
        /// <summary>
        /// Specifies how long to be scheduled
        /// If Frequency if 'Once' date should not be 'null'
        /// /// </summary>
        public DateTime? Until { 
            get { return until; } 
            set {
                if (Frequency == Frequency.Once && value == null)
                {
                    throw new ArgumentNullException("Until null DateTime cannot be combinate with Frequency.Once.");
                }
                else
                {
                    until = value;
                }
            } 
        }

        /// <summary>
        /// Last use cheduled payment in paiments current user - for runnig after long time
        /// </summary>
        [Range(typeof(DateTime), "1.1.1950", "31.12.2100")]
        private DateTime lastUse;
        public DateTime LastUse {
            get { return lastUse; }
            set
            {
                if (value == null) { throw new ArgumentNullException("LastUse cannot be null."); }
                else {  lastUse = value; }
            } 
        }

        public override string ToString()
        {
            if(Until == null){
                return string.Format("ScheduledItem {0}: {1} for Payment {2} last at {3}", ScheduledItemId, Frequency, Payment.PaymentId, LastUse.ToString("dd/MM/yyyy"));
            }else {
                return string.Format("ScheduledItem {0}: {1} until {2} for Payment {3} last at {4}", ScheduledItemId, Frequency, Until, Payment.PaymentId, LastUse.ToString("dd/MM/yyyy"));
            }
        }
    }
}