using System.IdentityModel.Tokens.Jwt;
using System.Security.Claims;
using Microsoft.AspNetCore.Components.Authorization;

namespace TaxBaik.Web.Services;

public class CustomAuthenticationStateProvider : AuthenticationStateProvider
{
    private readonly ILocalStorageService _localStorage;
    private readonly AuthService _authService;
    private readonly ILogger<CustomAuthenticationStateProvider> _logger;

    public CustomAuthenticationStateProvider(ILocalStorageService localStorage, AuthService authService, ILogger<CustomAuthenticationStateProvider> logger)
    {
        _localStorage = localStorage;
        _authService = authService;
        _logger = logger;
    }

    public override async Task<AuthenticationState> GetAuthenticationStateAsync()
    {
        try
        {
            var token = await _localStorage.GetItemAsStringAsync("auth_token");

            if (string.IsNullOrEmpty(token))
            {
                return new AuthenticationState(new ClaimsPrincipal(new ClaimsIdentity()));
            }

            if (IsTokenExpired(token))
            {
                _logger.LogWarning("토큰 만료됨");
                await _localStorage.RemoveItemAsync("auth_token");
                return new AuthenticationState(new ClaimsPrincipal(new ClaimsIdentity()));
            }

            var principal = _authService.ValidateToken(token);
            if (principal == null)
            {
                await _localStorage.RemoveItemAsync("auth_token");
                return new AuthenticationState(new ClaimsPrincipal(new ClaimsIdentity()));
            }

            return new AuthenticationState(principal);
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "인증 상태 조회 중 오류 발생");
            return new AuthenticationState(new ClaimsPrincipal(new ClaimsIdentity()));
        }
    }

    public async Task LoginAsync(string token)
    {
        await _localStorage.SetItemAsStringAsync("auth_token", token);
        NotifyAuthenticationStateChanged(GetAuthenticationStateAsync());
    }

    public async Task LogoutAsync()
    {
        await _localStorage.RemoveItemAsync("auth_token");
        NotifyAuthenticationStateChanged(GetAuthenticationStateAsync());
    }

    private bool IsTokenExpired(string token)
    {
        try
        {
            var handler = new JwtSecurityTokenHandler();
            var jwtToken = handler.ReadJwtToken(token);
            return jwtToken.ValidTo < DateTime.UtcNow;
        }
        catch
        {
            return true;
        }
    }
}