/*
 * nimbus-jose-jwt
 *
 * Copyright 2012-2016, Connect2id Ltd.
 *
 * 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
 *
 *    http://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 com.nimbusds.jose;


import java.io.Serializable;
import java.text.ParseException;
import java.util.Map;
import java.util.Objects;

import com.nimbusds.jose.util.JSONObjectUtils;


/**
 * The base abstract class for JSON Web Signature (JWS) secured and JSON Web
 * Encryption (JWE) secured objects serialisable to JSON.
 *
 * @author Vladimir Dzhuvinov
 * @version 2021-10-05
 */
public abstract class JOSEObjectJSON implements Serializable {
        
        
        private static final long serialVersionUID = 1L;


        /**
         * The MIME type of JOSE objects serialised to JSON:
         * {@code application/jose+json; charset=UTF-8}
         */
        public static final String MIME_TYPE_JOSE_JSON = "application/jose+json; charset=UTF-8";


        /**
         * The payload (message), {@code null} if not specified.
         */
        private Payload payload;


        /**
         * Creates a new JOSE object with the specified payload.
         *
         * @param payload The payload, {@code null} if not available (e.g. for
         *                an encrypted JWE object).
         */
        protected JOSEObjectJSON(final Payload payload) {

                this.payload = payload;
        }


        /**
         * Sets the payload of this JOSE object.
         *
         * @param payload The payload, {@code null} if not available (e.g. for 
         *                an encrypted JWE object).
         */
        protected void setPayload(final Payload payload) {

                this.payload = payload;
        }


        /**
         * Returns the payload of this JOSE object.
         *
         * @return The payload, {@code null} if not available (for an encrypted
         *         JWE object that hasn't been decrypted).
         */
        public Payload getPayload() {

                return payload;
        }
        
        
        /**
         * Returns a general JSON object representation of this JOSE secured
         * object.
         *
         * <p>See
         * <a href="https://datatracker.ietf.org/doc/html/rfc7515#section-7.2.1">JWS
         * general serialisation</a> or
         * <a href="https://datatracker.ietf.org/doc/html/rfc7516#section-7.2.1">JWE
         * general serialisation</a>.
         *
         * @return The JSON object.
         *
         * @throws IllegalStateException If the JOSE object is not in a state
         *                               that permits serialisation.
         */
        abstract Map<String, Object> toGeneralJSONObject();
        
        
        /**
         * Returns a flattened JSON object representation of this JOSE secured
         * object. There must be exactly one JWS signature or JWE recipient for
         * a flattened JSON serialisation.
         *
         * <p>See
         * <a href="https://datatracker.ietf.org/doc/html/rfc7515#section-7.2.2">JWS
         * flattened serialisation</a> or
         * <a href="https://datatracker.ietf.org/doc/html/rfc7516#section-7.2.2">JWE
         * flattened serialisation</a>.
         *
         * @return The JSON object.
         *
         * @throws IllegalStateException If the JOSE object is not in a state
         *                               that permits serialisation or there
         *                               is more than one JWS signature or JWE
         *                               recipient.
         */
        abstract Map<String, Object> toFlattenedJSONObject();
        
        
        /**
         * Serialises this JOSE object to a general JOSE object string.
         *
         * <p>See
         * <a href="https://datatracker.ietf.org/doc/html/rfc7515#section-7.2.1">JWS
         * general serialisation</a> or
         * <a href="https://datatracker.ietf.org/doc/html/rfc7516#section-7.2.1">JWE
         * general serialisation</a>.
         *
         * @return The JSON object string.
         *
         * @throws IllegalStateException If the JOSE object is not in a state
         *                               that permits serialisation.
         */
        public abstract String serializeGeneral();
        
        
        /**
         * Serialises this JOSE object to a flattened JSON object string. There
         * must be exactly one JWS signature or JWE recipient for a flattened
         * JSON serialisation.
         *
         * <p>See
         * <a href="https://datatracker.ietf.org/doc/html/rfc7515#section-7.2.2">JWS
         * flattened serialisation</a> or
         * <a href="https://datatracker.ietf.org/doc/html/rfc7516#section-7.2.2">JWE
         * flattened serialisation</a>.
         *
         * @return The JSON object string.
         *
         * @throws IllegalStateException If the JOSE object is not in a state
         *                               that permits serialisation or there
         *                               is more than one JWS signature or JWE
         *                               recipient.
         */
        public abstract String serializeFlattened();
        
        
        /**
         * Parses a JOSE secured object from the specified JSON object
         * representation.
         *
         * @param jsonObject The JSON object to parse. Must not be
         *                   {@code null}.
         *
         * @return The corresponding {@link JWSObjectJSON} or
         *         {@link JWEObjectJSON}.
         *
         * @throws ParseException If the JSON object couldn't be parsed to a
         *                        valid JWS or JWE secured object.
         */
        public static JOSEObjectJSON parse(final Map<String, Object> jsonObject)
                throws ParseException {
                
                if (jsonObject.containsKey("signature") || jsonObject.containsKey("signatures")) {
                        return JWSObjectJSON.parse(jsonObject);
                } else if (jsonObject.containsKey("ciphertext")) {
                        throw new ParseException("JWE JSON not supported", 0); // TODO
                } else {
                        throw new ParseException("Invalid JOSE object", 0);
                }
        }


        /**
         * Parses a JOSE secured object from the specified JSON string.
         *
         * @param json The JSON string to parse. Must not be {@code null}.
         *
         * @return The corresponding {@link JWSObjectJSON} or
         *         {@link JWEObjectJSON}.
         *
         * @throws ParseException If the string couldn't be parsed to a valid 
         *                        JWS or JWE secured object.
         */
        public static JOSEObjectJSON parse(final String json)
                throws ParseException {
                
                Objects.requireNonNull(json);

                return parse(JSONObjectUtils.parse(json));
        }
}