using Elwig.Models.Entities;
using System;
using System.Collections.Generic;
using System.Linq;

namespace Elwig.Helpers.Billing {
    public class ContractSelection : IComparable<ContractSelection> {

        public WineVar? Variety { get; }
        public WineAttr? Attribute { get; }
        public string Listing => Variety != null || Attribute != null ? $"{Variety?.SortId}{Attribute?.AttrId}" : "";

        public ContractSelection(WineVar? var, WineAttr? attr) {
            Variety = var;
            Attribute = attr;
        }

        public ContractSelection(WineVar var) {
            Variety = var;
        }

        public ContractSelection(WineAttr attr) {
            Attribute = attr;
        }

        public override string ToString() {
            return (Variety != null ? $"{Variety.Name}" : "") + (Attribute != null ? $" {Attribute.Name}" : "");
        }

        public static List<ContractSelection> GetContractsForYear(AppDbContext context, int year) {
            return context.DeliveryParts
                .Where(d => d.Year == year)
                .Select(d => new ContractSelection(d.Variant, d.Attribute))
                .Distinct()
                .ToList()
                .Union(context.WineVarieties.Select(v => new ContractSelection(v)))
                .ToList();
        }

        public int CompareTo(ContractSelection? other) {
            //MessageBox.Show($"{Listing} -- {other.Listing} : {Listing.CompareTo(other.Listing)}");
            return other != null ?
                Listing.CompareTo(other.Listing) :
                throw new ArgumentException();
        } 
    }
}