/*
 * Copyright (C) 2008-2017, Juick
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package com.juick.components;

import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.juick.Message;
import com.juick.Tag;
import com.juick.service.CrosspostService;
import com.juick.service.MessagesService;
import org.apache.commons.codec.CharEncoding;
import org.apache.commons.codec.binary.Base64;
import org.apache.commons.io.IOUtils;
import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.tuple.Pair;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.core.env.Environment;
import org.springframework.util.Assert;
import org.springframework.web.socket.TextMessage;
import org.springframework.web.socket.WebSocketSession;
import org.springframework.web.socket.handler.TextWebSocketHandler;

import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import javax.inject.Inject;
import javax.net.ssl.HttpsURLConnection;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.net.URL;
import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;
import java.security.Key;
import java.util.UUID;

/**
 * @author Ugnich Anton
 */
public class Crosspost extends TextWebSocketHandler {
    final static String TWITTERURL = "https://api.twitter.com/1.1/statuses/update.json";
    final static String FBURL = "https://graph.facebook.com/me/feed";
    final static String VKURL = "https://api.vk.com/method/wall.post";

    private static Logger logger = LoggerFactory.getLogger(Crosspost.class);

    private final CrosspostService crosspostService;

    private final String twitter_consumer_key;
    private final String twitter_consumer_secret;
    private ObjectMapper ms;
    @Inject
    MessagesService messagesService;

    public Crosspost(final Environment env, final CrosspostService crosspostService) {
        Assert.notNull(env, "Environment must be initialized");
        Assert.notNull(crosspostService, "CrosspostService must be initialized");

        this.crosspostService = crosspostService;

        twitter_consumer_key = env.getProperty("twitter_consumer_key", StringUtils.EMPTY);
        twitter_consumer_secret = env.getProperty("twitter_consumer_secret", StringUtils.EMPTY);

        ms = new ObjectMapper();
        ms.setSerializationInclusion(JsonInclude.Include.NON_EMPTY);
        ms.setSerializationInclusion(JsonInclude.Include.NON_NULL);
        ms.setSerializationInclusion(JsonInclude.Include.NON_DEFAULT);
    }

    public static String percentEncode(final String s) {
        String ret = StringUtils.EMPTY;
        try {
            ret = URLEncoder.encode(s, CharEncoding.UTF_8).replace("+", "%20").replace("*", "%2A").replace("%7E", "~");
        } catch (UnsupportedEncodingException e) {
        }
        return ret;
    }

    @Override
    protected void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception {
        Message msg = ms.readValue(message.asBytes(), Message.class);
        if (msg.getMid() > 0 && msg.getRid() == 0) {
            Message jmsg = messagesService.getMessage(msg.getMid());
            if (StringUtils.isNotEmpty(crosspostService.getTwitterName(msg.getUser().getUid()))) {
                if (jmsg.getTags().stream().noneMatch(t -> t.getName().equals("notwitter"))) {
                    twitterPost(jmsg);
                }
            }
            // TODO: approve application for facebook crosspost
        }
    }

    public boolean facebookPost(final com.juick.Message jmsg) {
        String token = crosspostService.getFacebookToken(jmsg.getUser().getUid()).orElse(StringUtils.EMPTY);
        if (token.isEmpty()) {
            return false;
        }

        logger.info("FB: #{}", jmsg.getMid());

        String status = getMessageHashTags(jmsg) + "\n" + jmsg.getText();

        boolean ret = false;
        try {
            String body = "access_token="
                    + URLEncoder.encode(token, CharEncoding.UTF_8)
                    + "&message="
                    + URLEncoder.encode(status, CharEncoding.UTF_8)
                    + "&link=http%3A%2F%2Fjuick.com%2F"
                    + jmsg.getMid();

            HttpsURLConnection conn = (HttpsURLConnection) new URL(FBURL).openConnection();
            conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            conn.setRequestProperty("User-Agent", "Juick");
            conn.setRequestProperty("Content-Length", Integer.toString(body.length()));
            conn.setUseCaches(false);
            conn.setDoInput(true);
            conn.setDoOutput(true);
            conn.setRequestMethod("POST");
            conn.connect();

            OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());
            wr.write(body);
            wr.close();

            ret = StringUtils.isNotEmpty(IOUtils.toString(conn.getInputStream(), StandardCharsets.UTF_8));

            conn.disconnect();
        } catch (Exception e) {
            logger.error("fbPost exception", e);
        }
        return ret;
    }

    public boolean vkontaktePost(final com.juick.Message jmsg) {
        Pair<String, String> tokens = crosspostService.getVkTokens(jmsg.getUser().getUid()).orElse(Pair.of(StringUtils.EMPTY, StringUtils.EMPTY));
        if (tokens.getLeft().isEmpty() || tokens.getRight().isEmpty()) {
            return false;
        }

        logger.info("VK: #", jmsg.getMid());

        String status = getMessageHashTags(jmsg) + "\n" + jmsg.getText() + "\nhttp://juick.com/" + jmsg.getMid();

        boolean ret = false;
        try {
            String body = "owner_id=" + tokens.getLeft() + "&access_token=" + URLEncoder.encode(tokens.getRight(), CharEncoding.UTF_8) + "&from_group=1&message=" + URLEncoder.encode(status, CharEncoding.UTF_8);

            HttpsURLConnection conn = (HttpsURLConnection) new URL(VKURL).openConnection();
            conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            conn.setRequestProperty("User-Agent", "Juick");
            conn.setRequestProperty("Content-Length", Integer.toString(body.length()));
            conn.setUseCaches(false);
            conn.setDoInput(true);
            conn.setDoOutput(true);
            conn.setRequestMethod("POST");
            conn.connect();

            OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());
            wr.write(body);
            wr.close();

            ret = StringUtils.isNotEmpty(IOUtils.toString(conn.getInputStream(), StandardCharsets.UTF_8));

            conn.disconnect();
        } catch (Exception e) {
            logger.error("vkPost exception", e);
        }
        return ret;
    }

    public boolean twitterPost(final com.juick.Message jmsg) {
        Pair<String, String> tokens = crosspostService.getTwitterTokens(jmsg.getUser().getUid()).orElse(Pair.of(StringUtils.EMPTY, StringUtils.EMPTY));
        if (tokens.getLeft().isEmpty() || tokens.getRight().isEmpty()) {
            return false;
        }
        String token = percentEncode(tokens.getLeft());
        String token_secret = percentEncode(tokens.getRight());

        logger.info("TWITTER: #{}", jmsg.getMid());

        String status = getMessageHashTags(jmsg) + jmsg.getText();
        if (status.length() > 115) {
            status = status.substring(0, 114) + "…";
        }
        status += " http://juick.com/" + jmsg.getMid();
        status = percentEncode(status);

        boolean ret = false;
        try {
            String nonce = UUID.randomUUID().toString();
            String timestamp = Long.toString(System.currentTimeMillis() / 1000L);
            String signature = percentEncode(twitterSignature(status, nonce, timestamp, token, token_secret));
            String auth = "OAuth "
                    + "oauth_consumer_key=\"" + twitter_consumer_key + "\", "
                    + "oauth_nonce=\"" + nonce + "\", "
                    + "oauth_signature=\"" + signature + "\", "
                    + "oauth_signature_method=\"HMAC-SHA1\", "
                    + "oauth_timestamp=\"" + timestamp + "\", "
                    + "oauth_token=\"" + token + "\", "
                    + "oauth_version=\"1.0\"";

            HttpsURLConnection conn = (HttpsURLConnection) new URL(TWITTERURL).openConnection();
            conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            conn.setRequestProperty("User-Agent", "Juick");
            conn.setRequestProperty("Content-Length", Integer.toString(status.length() + 7));
            conn.setRequestProperty("Authorization", auth);
            conn.setUseCaches(false);
            conn.setDoInput(true);
            conn.setDoOutput(true);
            conn.setRequestMethod("POST");
            conn.connect();

            OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());
            wr.write("status=" + status);
            wr.close();

            ret = IOUtils.toString(conn.getInputStream(), StandardCharsets.UTF_8) != null;

            conn.disconnect();
        } catch (Exception e) {
            logger.error("twitterPost exception", e);
        }
        return ret;
    }

    public String twitterSignature(final String status, final String nonce, final String timestamp, final String token, final String token_secret) {
        try {
            // ALPHABET-SORTED
            String params = "oauth_consumer_key=" + twitter_consumer_key
                    + "&oauth_nonce=" + nonce
                    + "&oauth_signature_method=HMAC-SHA1"
                    + "&oauth_timestamp=" + timestamp
                    + "&oauth_token=" + token
                    + "&oauth_version=1.0"
                    + "&status=" + status;

            String base = "POST&" + percentEncode(TWITTERURL) + "&" + percentEncode(params);
            String key = twitter_consumer_secret + "&" + token_secret;

            Key signingKey = new SecretKeySpec(key.getBytes(), "HmacSHA1");
            Mac mac = Mac.getInstance("HmacSHA1");
            mac.init(signingKey);
            byte[] rawHmac = mac.doFinal(base.getBytes());
            return Base64.encodeBase64String(rawHmac);

        } catch (Exception e) {
            logger.error("twitterSignature exception", e);
        }
        return null;
    }

    public String getMessageHashTags(final com.juick.Message jmsg) {
        String hashtags = StringUtils.EMPTY;
        for (Tag tag : jmsg.getTags()) {
            hashtags += "#" + tag + " ";
        }
        return hashtags;
    }
}