package org.wikidata.wdtk.wikibaseapi;

/*
 * #%L
 * Wikidata Toolkit Wikibase API
 * %%
 * Copyright (C) 2014 - 2020 Wikidata Toolkit Developers
 * %%
 * 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.
 * #L%
 */

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.databind.JsonNode;
import okhttp3.OkHttpClient;
import org.wikidata.wdtk.wikibaseapi.apierrors.AssertUserFailedException;
import org.wikidata.wdtk.wikibaseapi.apierrors.MediaWikiApiErrorException;
import se.akerfeldt.okhttp.signpost.OkHttpOAuthConsumer;
import se.akerfeldt.okhttp.signpost.SigningInterceptor;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

/**
 * A connection to the MediaWiki/Wikibase API which uses OAuth
 * for authentication.
 *
 * @author Antonin Delpeuch
 * @author Lu Liu
 */
public class OAuthApiConnection extends ApiConnection {

    private String consumerKey;
    private String consumerSecret;

    private String accessToken;
    private String accessSecret;

    /**
     * Constructs an OAuth connection to the given MediaWiki API endpoint.
     * <p>
     * {@link ApiConnection#isLoggedIn()} will return true
     * until {@link ApiConnection#logout()} is called.
     * <p>
     * NOTICE: The constructor doesn't check if the OAuth credentials
     * (i.e., the consumer key/secret and the access token/secret) are valid.
     * Even if the credentials are valid when calling this constructor,
     * they can be revoked by the user at any time.
     * <p>
     * The validity of the credentials is automatically checked if you use
     * {@link ApiConnection#sendJsonRequest}.
     *
     * @param apiBaseUrl     the MediaWiki API endpoint, such as "https://www.wikidata.org/w/api.php"
     * @param consumerKey    the OAuth 1.0a consumer key
     * @param consumerSecret the OAuth 1.0a consumer secret
     * @param accessToken    the access token obtained via the OAuth process
     * @param accessSecret   the secret key obtained via the OAuth process
     */
    public OAuthApiConnection(String apiBaseUrl,
                              String consumerKey,
                              String consumerSecret,
                              String accessToken,
                              String accessSecret) {
        super(apiBaseUrl, null);
        this.consumerKey = consumerKey;
        this.consumerSecret = consumerSecret;
        this.accessToken = accessToken;
        this.accessSecret = accessSecret;
        loggedIn = true;
    }

    /**
     * Deserializes an existing OAuthApiConnection from JSON.
     *
     * @param apiBaseUrl     the MediaWiki API endpoint, such as "https://www.wikidata.org/w/api.php"
     * @param consumerKey    the OAuth 1.0a consumer key
     * @param consumerSecret the OAuth 1.0a consumer secret
     * @param accessToken    the access token obtained via the OAuth process
     * @param accessSecret   the secret key obtained via the OAuth process
     * @param username       name of the current user
     * @param loggedIn       true if login succeeded.
     * @param tokens         map of tokens used for this session
     * @param connectTimeout the maximum time to wait for when establishing a connection, in milliseconds
     * @param readTimeout    the maximum time to wait for a server response once the connection was established, in milliseconds
     */
    @JsonCreator
    protected OAuthApiConnection(
            @JsonProperty("baseUrl") String apiBaseUrl,
            @JsonProperty("consumerKey") String consumerKey,
            @JsonProperty("consumerSecret") String consumerSecret,
            @JsonProperty("accessToken") String accessToken,
            @JsonProperty("accessSecret") String accessSecret,
            @JsonProperty("username") String username,
            @JsonProperty("loggedIn") boolean loggedIn,
            @JsonProperty("tokens") Map<String, String> tokens,
            @JsonProperty("connectTimeout") int connectTimeout,
            @JsonProperty("readTimeout") int readTimeout) {
        super(apiBaseUrl, tokens);
        this.consumerKey = consumerKey;
        this.consumerSecret = consumerSecret;
        this.accessToken = accessToken;
        this.accessSecret = accessSecret;
        this.username = username;
        this.loggedIn = loggedIn;
        this.connectTimeout = connectTimeout;
        this.readTimeout = readTimeout;
    }

    @Override
    protected OkHttpClient.Builder getClientBuilder() {
        OkHttpOAuthConsumer consumer = new OkHttpOAuthConsumer(consumerKey, consumerSecret);
        consumer.setTokenWithSecret(accessToken, accessSecret);
        return new OkHttpClient.Builder()
                .addInterceptor(new UserAgentInterceptor(customUserAgent))
                .addInterceptor(new SigningInterceptor(consumer));
    }

    /**
     * Forgets the OAuth credentials locally.
     * No requests will be made.
     */
    @Override
    public void logout() {
        consumerKey = null;
        consumerSecret = null;
        accessToken = null;
        accessSecret = null;
        username = "";
        loggedIn = false;
    }

    /**
     * Checks if the OAuth credentials (i.e., consumer key/secret and access token/secret) are still valid.
     * <p>
     * The OAuth credentials can be invalid if the user invoked it.
     * <p>
     * We simply call {@link ApiConnection#checkCredentials()} here.
     * Because for OAuth, the query "action=query&amp;assert=user" returns success
     * if and only if the credentials are still valid. This behaviour is the
     * same when using username/password for logging in.
     * <p>
     * This method throws {@link AssertUserFailedException} if the check failed.
     * This does not update the state of the connection object.
     *
     * @throws MediaWikiApiErrorException if the check failed
     * @throws IOException
     */
    @Override
    public void checkCredentials() throws IOException, MediaWikiApiErrorException {
        super.checkCredentials();
    }

    @Override
    @JsonProperty("username")
    public String getCurrentUser() {
        if (!loggedIn) return "";
        if (username != null && !username.equals("")) return username;

        try {
            Map<String, String> params = new HashMap<>();
            params.put(PARAM_ACTION, "query");
            params.put("meta", "userinfo");
            JsonNode root = sendJsonRequest("POST", params);
            JsonNode nameNode = root.path("query").path("userinfo").path("name");
            if (nameNode.isMissingNode()) {
                throw new AssertUserFailedException("The path \"query/userinfo/name\" doesn't exist in the json response");
            }
            username = nameNode.textValue();
        } catch (IOException | MediaWikiApiErrorException e) {
            logger.warn("An error occurred when retrieving the username with OAuth credentials, the username is set to \"\" automatically: " + e.getMessage());
            username = "";
        }
        return username;
    }

    @JsonProperty("consumerKey")
    public String getConsumerKey() {
        return consumerKey;
    }

    @JsonProperty("consumerSecret")
    public String getConsumerSecret() {
        return consumerSecret;
    }

    @JsonProperty("accessToken")
    public String getAccessToken() {
        return accessToken;
    }

    @JsonProperty("accessSecret")
    public String getAccessSecret() {
        return accessSecret;
    }

}
