using System.IdentityModel.Tokens.Jwt;
using System.Security.Claims;
using HackerNet.Api.Models;
using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Mvc;
using Microsoft.IdentityModel.Tokens;

namespace HackerNet.Api.Controllers;

[ApiController]
[Route("/api/accounts")]
public class AccountsController : ControllerBase
{
  private readonly UserManager<IdentityUser> _userManager;
  private readonly SignInManager<IdentityUser> _signInManager;
  private readonly IUserClaimsPrincipalFactory<IdentityUser> _claimsFactory;
  private readonly TokenValidation _tokenValidation;

  public AccountsController(UserManager<IdentityUser> userManager, SignInManager<IdentityUser> signInManager, IUserClaimsPrincipalFactory<IdentityUser> claimsFactory, TokenValidation tokenValidation)
  {
    _userManager = userManager;
    _signInManager = signInManager;
    _claimsFactory = claimsFactory;
    _tokenValidation = tokenValidation;
  }

  [HttpGet("me")]
  public ActionResult<string> Me()
  {
    return User.Identity.Name;
  }

  [HttpPost]
  public async Task<ActionResult> Signup(SignupLoginViewModel cmd)
  {
    var user = new IdentityUser(cmd.Username);
    var result = await _userManager.CreateAsync(user, cmd.Password);

    if (!result.Succeeded)
    {
      return BadRequest();
    }

    return CreatedAtAction(nameof(Me), null);
  }

  [HttpPost("token")]
  public async Task<ActionResult<string>> Signin(SignupLoginViewModel cmd)
  {
    var user = await _userManager.FindByNameAsync(cmd.Username);

    if (user == null)
    {
      return BadRequest();
    }

    var result = await _signInManager.CheckPasswordSignInAsync(user, cmd.Password, false);

    if (!result.Succeeded)
    {
      return BadRequest();
    }

    var principal = await _claimsFactory.CreateAsync(user);
    var tokenDescriptor = new SecurityTokenDescriptor
    {
      Subject = (ClaimsIdentity)principal.Identity,
      Expires = DateTime.UtcNow.AddDays(7),
      Issuer = _tokenValidation.Issuer,
      Audience = _tokenValidation.Audience,
      SigningCredentials = new SigningCredentials(
        new SymmetricSecurityKey(System.Text.Encoding.UTF8.GetBytes(_tokenValidation.Key))
        , SecurityAlgorithms.HmacSha256Signature)
    };

    return new JwtSecurityTokenHandler().CreateEncodedJwt(tokenDescriptor);
  }
}