package com.nimbusds.oauth2.sdk;


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

import com.nimbusds.oauth2.sdk.token.BearerAccessToken;
import net.jcip.annotations.Immutable;

import net.minidev.json.JSONObject;

import com.nimbusds.oauth2.sdk.token.AccessToken;
import com.nimbusds.oauth2.sdk.token.RefreshToken;
import com.nimbusds.oauth2.sdk.token.TokenPair;
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 access token.
         */
        private final AccessToken accessToken;
        
        
        /**
         * Optional refresh token.
         */
        private final RefreshToken refreshToken;


        /**
         * Optional custom parameters.
         */
        private final Map<String,Object> customParams;
        
        
        /**
         * Creates a new access token response.
         *
         * @param accessToken  The access token. Must not be {@code null}.
         * @param refreshToken Optional refresh token, {@code null} if none.
         */
        public AccessTokenResponse(final AccessToken accessToken,
                                   final RefreshToken refreshToken) {
                                   
                this(accessToken, refreshToken, null);
        }


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

                if (accessToken == null)
                        throw new IllegalArgumentException("The access token must not be null");

                this.accessToken = accessToken;

                this.refreshToken = refreshToken;

                this.customParams = customParams;
        }


        /**
         * Creates a new access token response.
         *
         * @param tokenPair The access and refresh token pair. Must not be 
         *                  {@code null}.
         */
        public AccessTokenResponse(final TokenPair tokenPair) {
                                   
                this(tokenPair, null);
        }


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

                this(tokenPair.getAccessToken(), tokenPair.getRefreshToken(), customParams);
        }


        @Override
        public boolean indicatesSuccess() {

                return true;
        }
        
        
        /**
         * Gets the access token.
         *
         * @return The access token.
         */
        public AccessToken getAccessToken() {
        
                return accessToken;
        }


        /**
         * Gets the access token as type bearer.
         *
         * @return The bearer access token.
         */
        public BearerAccessToken getBearerAccessToken() {

                // Cast should be safe, only bearer supported at present
                return (BearerAccessToken)accessToken;
        }
        
        
        /**
         * Gets the optional refresh token.
         *
         * @return The refresh token, {@code null} if none.
         */
        public RefreshToken getRefreshToken() {
        
                return refreshToken;
        }


        /**
         * Gets the access and refresh token pair.
         *
         * @return The access and refresh token pair. Must not be {@code null}.
         */
        public TokenPair getTokenPair() {

                return new TokenPair(accessToken, refreshToken);
        }


        /**
         * Gets 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 the JSON object representing 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.
         *
         * @throws SerializeException If this access token response couldn't be
         *                            serialised to a JSON object.
         */
        public JSONObject toJSONObject()
                throws SerializeException {
        
                JSONObject o = accessToken.toJSONObject();

                if (refreshToken != null)
                        o.putAll(refreshToken.toJSONObject());

                if (customParams != null)
                        o.putAll(customParams);
                
                return o;
        }
        
        
        @Override
        public HTTPResponse toHTTPResponse()
                throws SerializeException {
        
                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 {
                
                AccessToken accessToken = AccessToken.parse(jsonObject);
                
                RefreshToken refreshToken = RefreshToken.parse(jsonObject);

                // Get the std param names for the access + refresh token
                Set<String> paramNames = accessToken.getParamNames();

                if (refreshToken != null)
                        paramNames.addAll(refreshToken.getParamNames());

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

                Map<String,Object> customParams = null;

                if (customParamNames.size() > 0) {

                        customParams = new HashMap<>();

                        for (String name: customParamNames) {
                                customParams.put(name, jsonObject.get(name));
                        }
                }
                
                return new AccessTokenResponse(accessToken, refreshToken, 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);
        }
}