abzarasadi/Pages/Admin/Login.cshtml.cs

using AsadiTools.Data;
using Microsoft.AspNetCore.Authentication;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;
using System.ComponentModel.DataAnnotations;
using System.Security.Claims;

namespace AsadiTools.Pages.Admin;

public class LoginModel(AppDbContext db) : PageModel
{
    [BindProperty]
    public InputModel Input { get; set; } = new();
    public string? ErrorMessage { get; private set; }

    public class InputModel
    {
        [Required] public string Username { get; set; } = string.Empty;
        [Required] public string Password { get; set; } = string.Empty;
    }

    public IActionResult OnGet()
    {
        if (User.Identity?.IsAuthenticated == true)
            return RedirectToPage("/Admin/Index");
        return Page();
    }

    public async Task<IActionResult> OnPostAsync()
    {
        if (!ModelState.IsValid) return Page();

        var user = db.AdminUsers.FirstOrDefault(u => u.Username == Input.Username);
        if (user is null || !BCrypt.Net.BCrypt.Verify(Input.Password, user.PasswordHash))
        {
            ErrorMessage = "نام کاربری یا رمز اشتباه است";
            return Page();
        }

        var claims = new List<Claim>
        {
            new(ClaimTypes.Name, user.Username),
            new(ClaimTypes.NameIdentifier, user.Id.ToString()),
        };
        var identity  = new ClaimsIdentity(claims, "AdminCookie");
        var principal = new ClaimsPrincipal(identity);

        await HttpContext.SignInAsync("AdminCookie", principal);
        return RedirectToPage("/Admin/Index");
    }
}