using MongoDB.Driver;
using System;
using System.Collections.Generic;
using System.Configuration;
using System.Linq.Expressions;
using System.Threading.Tasks;


namespace MongoDb.Extensions
{

	public static class LinqExtensions
	{
		public static IFindFluent<T, T> Where<T>(this IMongoCollection<T> collection, Expression<Func<T, bool>> filter)
		{
			return collection.Find(filter);
		}

		public static T FirstOrDefault<T>(this IMongoCollection<T> collection, Expression<Func<T, bool>> filter)
		{
			var results = collection.Find(filter);

			return results.FirstOrDefault();
		}

		public async static Task<T> FirstOrDefaultAsync<T>(this IMongoCollection<T> collection, Expression<Func<T, bool>> filter)
		{
			var results = await collection.FindAsync(filter);

			if (results == null)
				return default;
			else
				return await results.FirstOrDefaultAsync();
		}

		public async static Task<List<T>> ToListAsync<T>(this IMongoCollection<T> collection, Expression<Func<T, bool>> filter)
		{
			var results = await collection.FindAsync(filter);

			if (results == null)
				return new List<T>();
			else
				return await results.ToListAsync();
		}
	}

	public class MongoDbContext
	{
		public readonly MongoClient Client;

		private readonly IMongoDatabase db;

		public MongoDbContext(string name)
		{
			Client = new MongoClient(ConfigurationManager.ConnectionStrings[name].ConnectionString);

			db = Client.GetDatabase(name);
		}

		public IMongoCollection<T> Table<T>() => db.GetCollection<T>($"{typeof(T).Name}Table");
	}

}