/*
 * Copyright 2004-present the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.security.oauth2.server.resource.authentication;

import java.util.Collection;
import java.util.Map;

import org.jspecify.annotations.Nullable;

import org.springframework.security.authentication.AbstractAuthenticationToken;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.oauth2.core.OAuth2AccessToken;
import org.springframework.security.oauth2.core.OAuth2Token;
import org.springframework.security.oauth2.jwt.Jwt;
import org.springframework.util.Assert;

/**
 * Base class for {@link AbstractAuthenticationToken} implementations that expose common
 * attributes between different OAuth 2.0 Access Token Formats.
 *
 * <p>
 * For example, a {@link Jwt} could expose its {@link Jwt#getClaims() claims} via
 * {@link #getTokenAttributes()} or an &quot;Introspected&quot; OAuth 2.0 Access Token
 * could expose the attributes of the Introspection Response via
 * {@link #getTokenAttributes()}.
 *
 * @author Joe Grandja
 * @since 5.1
 * @see OAuth2AccessToken
 * @see Jwt
 * @see <a target="_blank" href="https://tools.ietf.org/search/rfc7662#section-2.2">2.2
 * Introspection Response</a>
 */
public abstract class AbstractOAuth2TokenAuthenticationToken<T extends OAuth2Token>
		extends AbstractAuthenticationToken {

	private static final long serialVersionUID = 620L;

	private Object principal;

	private Object credentials;

	private T token;

	/**
	 * Sub-class constructor.
	 */
	protected AbstractOAuth2TokenAuthenticationToken(T token) {
		this(token, null);
	}

	/**
	 * Sub-class constructor.
	 * @param authorities the authorities assigned to the Access Token, or {@code null}
	 */
	protected AbstractOAuth2TokenAuthenticationToken(T token,
			@Nullable Collection<? extends GrantedAuthority> authorities) {
		this(token, token, token, authorities);
	}

	protected AbstractOAuth2TokenAuthenticationToken(T token, Object principal, Object credentials,
			@Nullable Collection<? extends GrantedAuthority> authorities) {

		super(authorities);
		Assert.notNull(token, "token cannot be null");
		Assert.notNull(principal, "principal cannot be null");
		this.principal = principal;
		this.credentials = credentials;
		this.token = token;
	}

	protected AbstractOAuth2TokenAuthenticationToken(AbstractOAuth2TokenAuthenticationBuilder<T, ?> builder) {
		super(builder);
		Assert.notNull(builder.credentials, "token cannot be null");
		Assert.notNull(builder.principal, "principal cannot be null");
		this.principal = builder.principal;
		this.credentials = builder.credentials;
		this.token = builder.token;
	}

	@Override
	public Object getPrincipal() {
		return this.principal;
	}

	@Override
	public Object getCredentials() {
		return this.credentials;
	}

	/**
	 * Get the token bound to this {@link Authentication}.
	 */
	public final T getToken() {
		return this.token;
	}

	/**
	 * Returns the attributes of the access token.
	 * @return a {@code Map} of the attributes in the access token.
	 */
	public abstract Map<String, Object> getTokenAttributes();

	/**
	 * A builder for {@link AbstractOAuth2TokenAuthenticationToken} implementations
	 *
	 * @param <B>
	 * @since 7.0
	 */
	public abstract static class AbstractOAuth2TokenAuthenticationBuilder<T extends OAuth2Token, B extends AbstractOAuth2TokenAuthenticationBuilder<T, B>>
			extends AbstractAuthenticationBuilder<B> {

		private Object principal;

		private Object credentials;

		private T token;

		protected AbstractOAuth2TokenAuthenticationBuilder(AbstractOAuth2TokenAuthenticationToken<T> token) {
			super(token);
			this.principal = token.getPrincipal();
			this.credentials = token.getCredentials();
			this.token = token.getToken();
		}

		@Override
		public B principal(@Nullable Object principal) {
			Assert.notNull(principal, "principal cannot be null");
			this.principal = principal;
			return (B) this;
		}

		@Override
		public B credentials(@Nullable Object credentials) {
			Assert.notNull(credentials, "credentials cannot be null");
			this.credentials = credentials;
			return (B) this;
		}

		/**
		 * The OAuth 2.0 Token to use
		 * @param token the token to use
		 * @return the {@link Builder} for further configurations
		 */
		public B token(T token) {
			Assert.notNull(token, "token cannot be null");
			this.token = token;
			return (B) this;
		}

	}

}
