Radicade/Server/Rooms/Lists/AlgorithmicListsAPI.cs

using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using RadicadeServer.DB;
using RadicadeServer.RecNet.Enums;
using RadicadeServer.RecNet.Enums.Rooms;
using RadicadeServer.RecNet.Rooms;

namespace RadicadeServer.Lists
{
	[Route("lists/algorithmiclists")]
	public class AlgorithmicListsAPI : Controller
	{
		private const int Rooms = 1;

		private const int RowSize = 20;

		RecDBContext db;

		public AlgorithmicListsAPI(RecDBContext context)
		{
			this.db = context;
		}

		[HttpGet("{list}")]
		public async Task<IActionResult> GetAlgorithmicList(string list, [FromQuery] int? type)
		{
			var echoed = type is >= 0 and <= 255 ? type.Value : Rooms;

			return Ok(new AlgorithmicList
			{
				Type = echoed,
				Entities = (await GetRowIds(list)).Select(roomId => new AlgorithmicListEntity
				{
					Id = roomId.ToString(),
					Context = null,
				}).ToList(),
			});
		}

		private async Task<List<long>> GetRowIds(string? list)
		{
			var key = (list ?? string.Empty).Trim().ToLowerInvariant();

			var rooms = await db.Rooms
				.Where(x => x.Accessibility == Accessibility.Public
					&& x.State == RoomState.Active
					&& !x.IsDorm)
				.ToListAsync();

			if (key == "new")
			{
				return rooms
					.OrderByDescending(x => x.PublishedAt)
					.ThenBy(x => x.RoomId)
					.Take(RowSize)
					.Select(x => x.RoomId)
					.ToList();
			}

			var visits = await db.RoomStats
				.Select(x => new { x.RoomId, x.VisitCount })
				.ToDictionaryAsync(x => x.RoomId, x => x.VisitCount);

			return rooms
				.OrderByDescending(x => visits.TryGetValue(x.RoomId, out var count) ? count : 0)
				.ThenBy(x => x.RoomId)
				.Take(RowSize)
				.Select(x => x.RoomId)
				.ToList();
		}
	}

	public class AlgorithmicList
	{
		public int Type { get; set; }

		public List<AlgorithmicListEntity> Entities { get; set; } = new();
	}

	public class AlgorithmicListEntity
	{
		public string Id { get; set; } = "";

		public string? Context { get; set; }
	}
}