using Bibblan.Models;
using Bibblan.ViewModels;
using Dapper;
using Microsoft.Extensions.Options;
using Npgsql;

namespace Bibblan.Business.Services
{

    public class BookFilter
    {
        public int? Author;
    }

    public class DatabaseService
    {
        BibblanOptions settings;
        public DatabaseService(IOptions<BibblanOptions> options) {
            settings = options.Value;
        }

        public IEnumerable<Books> GetBooks(int count, BookFilter filter = null)
        {
            var conn = new NpgsqlConnection(settings.BibblanConnection);
            var query = "select * from books";
            if(filter != null)
            {
                query += " where ";
                if(filter.Author != null)
                {
                    query += $"id in (select book from books_authors_link where author = {filter.Author})";
                }
            }
            return conn.Query<Books>(query).Take(count).ToList();
        }

        public IEnumerable<AuthorVm> GetAuthors(int count)
        {
            var query = "select a.id, a.name, count(bal.*) as bookcount\r\nfrom authors a\r\nleft join books_authors_link bal on a.id  = bal.author\r\ngroup by a.id , a.name ";
            var conn = new NpgsqlConnection(settings.BibblanConnection);
            return conn.Query<AuthorVm>(query).Take(count).ToList();

        }
    }
}