MoviesController.cs

using Microsoft.AspNetCore.OData;
using Microsoft.AspNetCore.OData.Routing;
using Microsoft.AspNetCore.OData;
using Microsoft.AspNetCore.OData.Routing;
using WebApiOData.V4.Samples.Models;
using Microsoft.AspNetCore.OData.Routing.Controllers;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.OData.Formatter;

namespace WebApiOData.V4.Samples.Controllers;

public class MoviesController : ODataController
{
	private readonly MoviesContext _db = new();

	public IActionResult Get()
	{
		return Ok(_db.Movies);
	}

	[HttpPost]
	public IActionResult CheckOut(int key)
	{
		var movie = _db.Movies.FirstOrDefault(m => m.ID == key);
		if (movie is null)
		{
			return BadRequest(ModelState);
		}

		if (!TryCheckoutMovie(movie))
		{
			return BadRequest("The movie is already checked out.");
		}

		return Ok(movie);
	}

	[HttpPost]
	public IActionResult Return(int key)
	{
		var movie = _db.Movies.FirstOrDefault(m => m.ID == key);
		if (movie is null)
		{
			return BadRequest(ModelState);
		}

		movie.DueDate = null;

		return Ok(movie);
	}

	// Check out a list of movies.
	[HttpPost]
	public IActionResult CheckOutMany(ODataActionParameters parameters)
	{
		if (!ModelState.IsValid)
		{
			return BadRequest(ModelState);
		}

		// Client passes a list of movie IDs to check out.
		var movieIDs = new HashSet<int>(parameters["MovieIDs"] as IEnumerable<int>);

		// Try to check out each movie in the list.
		var results = new List<Movie>();
		foreach (var movie in _db.Movies.Where(m => movieIDs.Contains(m.ID)))
		{
			if (TryCheckoutMovie(movie))
			{
				results.Add(movie);
			}
		}

		// Return a list of the movies that were checked out.
		return Ok(results);
	}

	[HttpPost]
	[ODataRoute("CreateMovie")]
	public IActionResult CreateMovie(ODataActionParameters parameters)
	{
		if (!ModelState.IsValid)
		{
			return BadRequest(ModelState);
		}

		var title = parameters["Title"] as string;

		var movie = new Movie()
		{
			Title = title,
			ID = _db.Movies.Count + 1,
		};

		_db.Movies.Add(movie);

		return Created(movie);
	}

	protected Movie GetMovieByKey(int key)
	{
		return _db.Movies.FirstOrDefault(m => m.ID == key);
	}

	private static bool TryCheckoutMovie(Movie movie)
	{
		if (movie.IsCheckedOut)
		{
			return false;
		}
		else
		{
			// To check out a movie, set the due date.
			movie.DueDate = DateTime.Now.AddDays(7);
			return true;
		}
	}
}