DeutschLernen/GermanApp/Presentation/Controllers/AuthController.cs

using GermanApp.Application.DTOs.Auth;
using GermanApp.Application.Interfaces;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using System.IdentityModel.Tokens.Jwt;
using System.Net;
using System.Security.Claims;

namespace GermanApp.Presentation.Controllers;

/// <summary>
/// Controller for authentication endpoints.
/// Part of the Presentation layer.
/// </summary>
[ApiController]
[Route("api/[controller]")]
public class AuthController : ControllerBase
{
    private readonly IAuthService _authService;

    public AuthController(IAuthService authService)
    {
        _authService = authService;
    }

    /// <summary>
    /// Register a new user.
    /// </summary>
    /// <param name="registerDto">Registration data</param>
    /// <returns>Authentication response with JWT token</returns>
    [HttpPost("register")]
    [AllowAnonymous]
    [ProducesResponseType(typeof(AuthResponse), (int)HttpStatusCode.OK)]
    [ProducesResponseType(typeof(string), (int)HttpStatusCode.BadRequest)]
    public async Task<IActionResult> Register([FromBody] RegisterDto registerDto)
    {
        try
        {
            var result = await _authService.RegisterAsync(registerDto);
            return Ok(result);
        }
        catch (InvalidOperationException ex)
        {
            return BadRequest(ex.Message);
        }
        catch (Exception ex)
        {
            return StatusCode((int)HttpStatusCode.InternalServerError, ex.Message);
        }
    }

    /// <summary>
    /// Login an existing user.
    /// </summary>
    /// <param name="loginDto">Login data</param>
    /// <returns>Authentication response with JWT token</returns>
    [HttpPost("login")]
    [AllowAnonymous]
    [ProducesResponseType(typeof(AuthResponse), (int)HttpStatusCode.OK)]
    [ProducesResponseType(typeof(string), (int)HttpStatusCode.Unauthorized)]
    public async Task<IActionResult> Login([FromBody] LoginDto loginDto)
    {
        try
        {
            var result = await _authService.LoginAsync(loginDto);
            return Ok(result);
        }
        catch (UnauthorizedAccessException ex)
        {
            return Unauthorized(ex.Message);
        }
        catch (Exception ex)
        {
            return StatusCode((int)HttpStatusCode.InternalServerError, ex.Message);
        }
    }

    /// <summary>
    /// Get current authenticated user information.
    /// </summary>
    /// <returns>Current user information</returns>
    [HttpGet("me")]
    [Authorize]
    [ProducesResponseType(typeof(AuthResponse), (int)HttpStatusCode.OK)]
    [ProducesResponseType((int)HttpStatusCode.Unauthorized)]
    public async Task<IActionResult> GetCurrentUser()
    {
        try
        {
            // Get user ID from JWT claim
            // Note: JWT "sub" claim is mapped by ASP.NET Core JWT middleware to ClaimTypes.NameIdentifier
            // (http://schemas.xmlsoap.org/ws/2005/05/identity/claims/nameidentifier)
            var userIdClaim = User.FindFirst(ClaimTypes.NameIdentifier) ?? User.FindFirst("sub");
            if (userIdClaim == null || !int.TryParse(userIdClaim.Value, out var userId) || userId == 0)
                return Unauthorized();

            var user = await _authService.GetCurrentUserAsync(userId);
            if (user == null)
                return Unauthorized();

            return Ok(new AuthResponse
            {
                UserId = user.Id,
                Username = user.Username,
                Email = user.Email
            });
        }
        catch (Exception ex)
        {
            return StatusCode((int)HttpStatusCode.InternalServerError, ex.Message);
        }
    }

    /// <summary>
    /// Refresh the access token using a refresh token.
    /// </summary>
    /// <param name="refreshToken">The refresh token</param>
    /// <returns>New access token and refresh token</returns>
    [HttpPost("refresh")]
    [ProducesResponseType(typeof(RefreshTokenResponse), (int)HttpStatusCode.OK)]
    [ProducesResponseType(typeof(string), (int)HttpStatusCode.Unauthorized)]
    [ProducesResponseType(typeof(string), (int)HttpStatusCode.BadRequest)]
    public async Task<IActionResult> Refresh([FromBody] string refreshToken)
    {
        try
        {
            var result = await _authService.RefreshTokenAsync(refreshToken);
            return Ok(result);
        }
        catch (UnauthorizedAccessException ex)
        {
            return Unauthorized(ex.Message);
        }
        catch (Exception ex)
        {
            return StatusCode((int)HttpStatusCode.InternalServerError, ex.Message);
        }
    }

    /// <summary>
    /// Revoke a refresh token.
    /// </summary>
    /// <param name="refreshToken">The refresh token to revoke</param>
    /// <returns>Success or error response</returns>
    [HttpPost("revoke-refresh")]
    [Authorize]
    [ProducesResponseType((int)HttpStatusCode.OK)]
    [ProducesResponseType(typeof(string), (int)HttpStatusCode.Unauthorized)]
    [ProducesResponseType(typeof(string), (int)HttpStatusCode.BadRequest)]
    public async Task<IActionResult> RevokeRefreshToken([FromBody] string refreshToken)
    {
        try
        {
            await _authService.RevokeRefreshTokenAsync(refreshToken);
            return Ok(new { message = "Refresh token revoked successfully" });
        }
        catch (UnauthorizedAccessException ex)
        {
            return Unauthorized(ex.Message);
        }
        catch (Exception ex)
        {
            return StatusCode((int)HttpStatusCode.InternalServerError, ex.Message);
        }
    }
}