OnProfNext/OnProfNext.Server/Controllers/OrderUsersController.cs

using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using OnProfNext.Server.Data;
using OnProfNext.Shared.Models;

namespace OnProfNext.Server.Controllers
{
    [ApiController]
    [Route("api/[controller]")]
    public class OrderUsersController : ControllerBase
    {
        private readonly AppDbContext _context;

        public OrderUsersController(AppDbContext context)
        {
            _context = context;
        }

        //GET: api/orderusers/{orderId}
        [HttpGet("{orderId}")]
        public async Task<ActionResult<IEnumerable<int>>> GetUsersForOrder(int orderId)
        {
            var userIds = await _context.OrderUsers.Where(ou => ou.OrderId == orderId).Select(ou => ou.UserId).ToListAsync();

            return Ok(userIds);
        }

        //POST: api/orderusers
        [HttpPost]
        public async Task<IActionResult> SetUsersForOrder([FromBody] OrderUserAssignmentDto dto)
        {
            var existing = await _context.OrderUsers
                .Where(ou => ou.OrderId == dto.OrderId)
                .ToListAsync();

            _context.OrderUsers.RemoveRange(existing);

            var newRelations = dto.UserIds.Select(uid => new OrderUser
            {
                OrderId = dto.OrderId,
                UserId = uid
            });

            _context.OrderUsers.AddRange(newRelations);
            await _context.SaveChangesAsync();

            return NoContent();
        }

        public class OrderUserAssignmentDto
        {
            public int OrderId { get; set; }
            public List<int> UserIds { get; set; } = new();
        }
    }
}