Add authentication controller.

Marechai.Server/Controllers/AuthController.cs

@@ -0,0 +1,56 @@
+using System.Linq;
+using System.Threading.Tasks;
+using Marechai.Data.Models;
+using Marechai.Database.Models;
+using Marechai.Server.Services;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Identity;
+using Microsoft.AspNetCore.Mvc;
+
+namespace Marechai.Server.Controllers;
+
+[ApiController]
+[Route("auth")]
+public class AuthController
+    (UserManager<ApplicationUser> userManager, MarechaiContext context, TokenService tokenService) : ControllerBase
+{
+    [HttpPost]
+    [Route("login")]
+    [ProducesResponseType(typeof(AuthResponse),
+                          StatusCodes.Status200OK,
+                          Description =
+                              "Authenticates a user with email and password, returning an access token if successful.")]
+    [ProducesResponseType(StatusCodes.Status400BadRequest)]
+    [ProducesResponseType(StatusCodes.Status401Unauthorized)]
+    [ProducesResponseType(StatusCodes.Status500InternalServerError)]
+    [AllowAnonymous]
+    [Produces("application/json")]
+    [Consumes("application/json")]
+    public async Task<ActionResult<AuthResponse>> Authenticate([FromBody] AuthRequest request)
+    {
+        if(!ModelState.IsValid) return BadRequest(ModelState);
+
+        ApplicationUser managedUser = await userManager.FindByEmailAsync(request.Email);
+
+        if(managedUser == null) return Unauthorized("Bad credentials");
+
+        bool isPasswordValid = await userManager.CheckPasswordAsync(managedUser, request.Password);
+
+        if(!isPasswordValid) return Unauthorized("Bad credentials");
+
+        ApplicationUser userInDb = context.Users.FirstOrDefault(u => u.Email == request.Email);
+
+        if(userInDb is null) return Unauthorized();
+
+        string accessToken = tokenService.CreateToken(userInDb, await userManager.GetRolesAsync(managedUser));
+        await context.SaveChangesAsync();
+
+        return Ok(new AuthResponse
+        {
+            Message   = "",
+            Succeeded = true,
+            Token     = accessToken
+        });
+    }
+}