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?.SortId}{Attribute?.AttrId}";
        public string FullName => $"{Variety?.Name}" + (Variety != null && Attribute != null ? " " : "") + $"{Attribute?.Name}";

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

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

        public override string ToString() {
            return Listing;
        }

        public int CompareTo(ContractSelection? other) {
            return Listing.CompareTo(other?.Listing);
        } 
    }
}