using System;
using System.Collections.Generic;
using System.Linq;

namespace DatabaseExport
{
    public class CustomerDetails
    {
        private readonly ISO.CustomerDetails _customerDetails;
        public string Name
        {
            get => _customerDetails.Name;
            set => _customerDetails.Name = value;
        }
        public CustomerDetails()
        {
            _customerDetails = new ISO.CustomerDetails();
            _customerDetails.Name = "(none)";
        }
        public CustomerDetails(ISO.CustomerDetails customerDetails)
        {
            _customerDetails = new ISO.CustomerDetails(customerDetails);
        }
        public ISO.CustomerDetails GetISOCustomer()
        {
            return _customerDetails;
        }
        public override string ToString()
        {
            return Name;
        }
    }
    public class CustomerDetailsList
    {
        private static readonly CustomerDetailsList _customerList = new CustomerDetailsList();
        public static CustomerDetailsList CustomerList => _customerList;

        private void PopulateCustomers()
        {
            if (null != _customers) return;
            _customers = new Dictionary<string, CustomerDetails>();
            foreach (var c in _customerList.GetAllCustomers())
            {
                if (!_customers.ContainsKey(c.Name))
                {
                    _customers.Add(c.Name, c);
                }
            }
        }
        private static readonly object _customerLock = new object();
        private Dictionary<string, CustomerDetails> _customers = null;
        public CustomerDetails[] Customers
        {
            get
            {
                lock (_customerLock)
                {
                    PopulateCustomers();
                }
                var customers = new List<CustomerDetails>(_customers.Values);
                customers.Sort(CompareCustomers);
                return customers.ToArray();
            }
        }
        private static int CompareCustomers(CustomerDetails a, CustomerDetails b)
        {
            if (a == b) { return 0; }
            if (null == a) { return -1; }
            return null == b ? 1 : String.Compare(a.Name, b.Name, StringComparison.Ordinal);
        }

        public CustomerDetails[] GetAllCustomers()
        {
            var list = new List<CustomerDetails>();
            list.Add(new CustomerDetails()); //This is the "(none)" entry
            list.AddRange(ISO.CustomerDetails.GetAllCustomerDetails().Select(cs => new CustomerDetails(cs)));
            return list.ToArray();
        }
        public CustomerDetails GetCustomerDetail(string name)
        {
            var customers = from c in Customers.AsParallel() where c.Name == name select c;
            return customers.Any() ? customers.First() : null;
        }
    }
}