Buecherwurm/Catalogue.cs

using System;
using System.Collections.Generic;
using System.Text.Json;

namespace Bücherwurm
{
    class Catalogue
    {
        private List<Book> Books {get; set;}

        private int NextId {get; set;}

        public Catalogue()
        {
            Books = new List<Book>();
            NextId = 1;
        }

        public void Import(string JsonString)
        {
            var intermediateBooks = JsonSerializer.Deserialize<List<Book>>(JsonString);
            foreach (var ibook in intermediateBooks)
            {
                ibook.OverwriteNullId(NextId);
                NextId = NextId + 1;
            }
            Books = intermediateBooks;
        }

        public void Add(string Title, string Author,
            string Country, string ILink, string Link,
            string Language, int Pages, int Year)
        {
            Books.Add(new Book(NextId, Title, Author, Country, ILink, Link, Language, Pages, Year));
            NextId = NextId++;
        }

        public void Remove(int BookID)
        {
            Books.RemoveAll(book => book.BookId == BookID);
        }

        public List<Book> GetBooks()
        {
            return Books;
        }

        public Book LookupBook(int BookId)
        {
            return Books.Find(book => book.BookId == BookId);
        }
    }
}