package com.nimbusds.oauth2.sdk;


import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

import net.jcip.annotations.Immutable;

import net.minidev.json.JSONObject;

import com.nimbusds.oauth2.sdk.token.Tokens;
import com.nimbusds.oauth2.sdk.http.CommonContentTypes;
import com.nimbusds.oauth2.sdk.http.HTTPResponse;


/**
 * Access token response from the Token endpoint.
 *
 * <p>Example HTTP response:
 *
 * <pre>
 * HTTP/1.1 200 OK
 * Content-Type: application/json;charset=UTF-8
 * Cache-Control: no-store
 * Pragma: no-cache
 *
 * {
 *   "access_token"      : "2YotnFZFEjr1zCsicMWpAA",
 *   "token_type"        : "example",
 *   "expires_in"        : 3600,
 *   "refresh_token"     : "tGzv3JOkF0XG5Qx2TlKWIA",
 *   "example_parameter" : "example_value"
 * }
 * </pre>
 *
 * <p>Related specifications:
 *
 * <ul>
 *     <li>OAuth 2.0 (RFC 6749), sections 4.1.4, 4.3.3,  4.4.3 and 5.1.
 * </ul>
 */
@Immutable
public class AccessTokenResponse extends TokenResponse implements SuccessResponse {


        /**
         * The tokens.
         */
        private final Tokens tokens;


        /**
         * Optional custom parameters.
         */
        private final Map<String,Object> customParams;


        /**
         * Creates a new access token response.
         *
         * @param tokens The tokens. Must not be {@code null}.
         */
        public AccessTokenResponse(final Tokens tokens) {

                this(tokens, null);
        }


        /**
         * Creates a new access token response.
         *
         * @param tokens       The tokens. Must not be {@code null}.
         * @param customParams Optional custom parameters, {@code null} if
         *                     none.
         */
        public AccessTokenResponse(final Tokens tokens,
                                   final Map<String,Object> customParams) {

                if (tokens == null)
                        throw new IllegalArgumentException("The tokens must not be null");

                this.tokens = tokens;

                this.customParams = customParams;
        }


        @Override
        public boolean indicatesSuccess() {

                return true;
        }


        /**
         * Returns the tokens.
         *
         * @return The tokens.
         */
        public Tokens getTokens() {

                return tokens;
        }


        /**
         * Returns the custom parameters.
         *
         * @return The custom parameters, as a unmodifiable map, empty map if
         *         none.
         */
        public Map<String,Object> getCustomParams() {

                if (customParams == null)
                        return Collections.emptyMap();

                return Collections.unmodifiableMap(customParams);
        }
        
        
        /**
         * Returns a JSON object representation of this access token response.
         *
         * <p>Example JSON object:
         *
         * <pre>
         * {
         *   "access_token"  : "SlAV32hkKG",
         *   "token_type"    : "Bearer",
         *   "refresh_token" : "8xLOxBtZp8",
         *   "expires_in"    : 3600
         * }
         * </pre>
         *
         * @return The JSON object.
         */
        public JSONObject toJSONObject() {
        
                JSONObject o = tokens.toJSONObject();

                if (customParams != null)
                        o.putAll(customParams);
                
                return o;
        }
        
        
        @Override
        public HTTPResponse toHTTPResponse() {
        
                HTTPResponse httpResponse = new HTTPResponse(HTTPResponse.SC_OK);
                
                httpResponse.setContentType(CommonContentTypes.APPLICATION_JSON);
                httpResponse.setCacheControl("no-store");
                httpResponse.setPragma("no-cache");
                
                httpResponse.setContent(toJSONObject().toString());
                
                return httpResponse;
        }
        
        
        /**
         * Parses an access token response from the specified JSON object.
         *
         * @param jsonObject The JSON object to parse. Must not be {@code null}.
         *
         * @return The access token response.
         *
         * @throws ParseException If the JSON object couldn't be parsed to an
         *                        access token response.
         */
        public static AccessTokenResponse parse(final JSONObject jsonObject)
                throws ParseException {
                
                Tokens tokens = Tokens.parse(jsonObject);

                // Determine the custom param names
                Set<String> paramNames = tokens.getParameterNames();
                Set<String> customParamNames = jsonObject.keySet();
                customParamNames.removeAll(paramNames);

                Map<String,Object> customParams = null;

                if (! customParamNames.isEmpty()) {

                        customParams = new HashMap<>();

                        for (String name: customParamNames) {
                                customParams.put(name, jsonObject.get(name));
                        }
                }
                
                return new AccessTokenResponse(tokens, customParams);
        }
        
        
        /**
         * Parses an access token response from the specified HTTP response.
         *
         * @param httpResponse The HTTP response. Must not be {@code null}.
         *
         * @return The access token response.
         *
         * @throws ParseException If the HTTP response couldn't be parsed to an 
         *                        access token response.
         */
        public static AccessTokenResponse parse(final HTTPResponse httpResponse)
                throws ParseException {
                
                httpResponse.ensureStatusCode(HTTPResponse.SC_OK);
                JSONObject jsonObject = httpResponse.getContentAsJSONObject();
                return parse(jsonObject);
        }
}