package cn.home1.oss.lib.security.internal;
   
   import static cn.home1.oss.lib.security.api.GenericUser.isGenericUser;
   
   import com.google.common.collect.ImmutableSet;
   
   import cn.home1.oss.lib.security.api.GenericUser;
   import cn.home1.oss.lib.webmvc.api.TypeSafeToken;
   
  import org.springframework.security.core.Authentication;
  import org.springframework.security.core.GrantedAuthority;
  import org.springframework.security.core.context.SecurityContext;
  import org.springframework.security.core.context.SecurityContextHolder;
  import org.springframework.security.web.authentication.preauth.PreAuthenticatedAuthenticationToken;
  
  import java.util.Collection;
  
  /**
   * Created by zhanghaolun on 16/10/30.
   */
  @SuppressWarnings({"PMD.AbstractNaming", "PMD.AbstractClassWithoutAbstractMethod"})
  public abstract class AuthenticationTokens {
  
    private AuthenticationTokens() {
    }
  
    public static PreAuthenticatedAuthenticationToken authenticated( //
      final PreAuthenticatedAuthenticationToken authentication //
    ) {
      final PreAuthenticatedAuthenticationToken result;
  
      if (authentication == null) {
        result = null;
      } else {
        authentication.setAuthenticated(true);
        authentication.eraseCredentials();
  
        final Object principal = authentication.getPrincipal();
        final Object credentials = authentication.getCredentials();
  
        final GenericUser genericUser = isGenericUser(principal) ? (GenericUser) principal : null;
  
        if (genericUser == null) {
          result = authentication;
        } else {
          genericUser.eraseCredentials();
          final Collection<GrantedAuthority> authorities = genericUser.getAuthorities() != null ? //
            genericUser.getAuthorities() : ImmutableSet.of();
          result = new PreAuthenticatedAuthenticationToken(principal, credentials, authorities);
        }
      }
      return result;
    }
  
    public static String rawToken(final Authentication authentication, final TypeSafeToken<GenericUser> token) {
      // TODO find OAuth2Authentication's header Authorization: Bearer?
  
      final String result;
      if (authentication instanceof PreAuthenticatedAuthenticationToken) {
        final Object principal = authentication.getPrincipal();
        final GenericUser genericUser = isGenericUser(principal) ? (GenericUser) principal : null;
        result = genericUser != null ? (String) authentication.getCredentials() : null;
      } else {
        final GenericUser genericUser = GenericUser.fromPrincipal(authentication);
        result = token.toToken(genericUser);
      }
      return result;
    }
  
    public static Boolean tokenInSecurityContext() {
      final SecurityContext securityContext = SecurityContextHolder.getContext();
      final Authentication authentication = securityContext.getAuthentication();
      return authentication != null && authentication.isAuthenticated();
    }
  
    public static String tokenFromSecurityContext(final TypeSafeToken<GenericUser> token) {
      final SecurityContext securityContext = SecurityContextHolder.getContext();
      final Authentication authentication = securityContext.getAuthentication();
  
      final String result;
      if (authentication != null && authentication.isAuthenticated()) {
        result = AuthenticationTokens.rawToken(authentication, token);
      } else {
        result = null;
      }
  
      return result;
    }
  
    //  public static boolean containsUserInfo(final Authentication authentication) {
    //    final boolean result;
    //    if (authentication == null) {
    //      result = false;
    //    } else if (authentication instanceof OAuth2Authentication) {
    //      final OAuth2Authentication oAuth2Auth = (OAuth2Authentication) authentication;
    //      result = !oAuth2Auth.isClientOnly();
    //    } else if (authentication instanceof AbstractAuthenticationToken) {
    //      // PreAuthenticatedAuthenticationToken
    //      result = isGenericUser(authentication.getPrincipal());
   //    } else {
   //      result = false;
   //    }
   //    return result;
   //  }
 }