package com.juick.server;

import com.juick.Message;
import com.juick.User;
import com.juick.server.api.activity.model.Link;
import com.juick.server.api.activity.model.Note;
import com.juick.server.api.activity.model.Person;
import com.juick.server.api.activity.model.activities.Accept;
import com.juick.server.api.activity.model.activities.Create;
import com.juick.service.SocialService;
import com.juick.service.activities.ActivityListener;
import com.juick.service.activities.FollowEvent;
import com.juick.service.activities.UndoFollowEvent;
import com.juick.service.component.*;
import com.juick.util.MessageUtils;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
import org.springframework.web.util.UriComponentsBuilder;

import javax.annotation.Nonnull;
import javax.annotation.PostConstruct;
import javax.inject.Inject;
import java.io.IOException;
import java.net.URI;
import java.util.Collections;

@Component
public class ActivityPubManager implements ActivityListener, NotificationListener {
    private static final Logger logger = LoggerFactory.getLogger(ActivityPubManager.class);
    @Inject
    SignatureManager signatureManager;
    @Inject
    ActivityPubManager activityPubManager;
    @Inject
    SocialService socialService;
    @Value("${ap_base_uri:http://localhost:8080/}")
    private String baseUri;

    private UriComponentsBuilder uri;

    @PostConstruct
    public void init() {
        uri = UriComponentsBuilder.fromUriString(baseUri);
    }

    @Override
    public void processFollowEvent(@Nonnull FollowEvent followEvent) {
        String acct = (String)followEvent.getRequest().getObject();
        logger.info("received follower request to {}", acct);
        User followedUser = socialService.getUserByAccountUri(acct);
        if (!followedUser.isAnonymous()) {
            // automatically accept follower requests
            Person me = (Person) signatureManager.getContext(URI.create(acct));
            Person follower = (Person) signatureManager.getContext(URI.create(followEvent.getRequest().getActor()));
            Accept accept = new Accept();
            accept.setActor(me.getId());
            accept.setObject(followEvent.getRequest());
            try {
                signatureManager.post(me, follower, accept);
                socialService.addFollower(followedUser, follower.getId());
                logger.info("Follower added for {}", followedUser.getName());
            } catch (IOException e) {
                logger.info("activitypub exception", e);
            }
        }
    }

    @Override
    public void undoFollowEvent(UndoFollowEvent event) {
        String actor = event.getActor();
        String me = event.getObject();
        logger.info("{} stopping to follow {}", actor, me);
        User followedUser = socialService.getUserByAccountUri(me);
        if (!followedUser.isAnonymous()) {
            socialService.removeFollower(followedUser, actor);
        }
    }

    @Override
    public void processMessageEvent(MessageEvent messageEvent) {
        Message msg = messageEvent.getMessage();
        User user = msg.getUser();
        String userUri = personUri(user);
        Note note = makeNote(msg);
        Person me = (Person) signatureManager.getContext(URI.create(userUri));
        socialService.getFollowers(user).forEach(acct -> {
            Person follower = (Person) signatureManager.getContext(URI.create(acct));
            Create create = new Create();
            create.setId(note.getId());
            create.setActor(me.getId());
            create.setPublished(note.getPublished());
            create.setObject(note);
            try {
                logger.info("Posting to follower {}", follower.getId());
                signatureManager.post(me, follower, create);
            } catch (IOException e) {
                logger.warn("activitypub exception", e);
            }
        });
    }

    public String inboxUri() {
        return uri.replacePath("/api/inbox").toUriString();
    }

    public String outboxUri(User user) {
        return uri.replacePath(String.format("/u/%s/blog/toc", user.getName())).toUriString();
    }

    public String personUri(User user) {
        return uri.replacePath(String.format("/u/%s", user.getName())).toUriString();
    }

    public String followersUri(User user) {
        return uri.replacePath(String.format("/u/%s/followers/toc", user.getName())).toUriString();
    }

    public String followingUri(User user) {
        return uri.replacePath(String.format("/u/%s/following/toc", user.getName())).toUriString();
    }

    public Note makeNote(Message msg) {
        Note note = new Note();
        note.setId(uri.replacePath(String.format("/m/%d", msg.getMid())).toUriString());
        note.setAttributedTo(personUri(msg.getUser()));
        if (MessageUtils.isReply(msg)) {
            uri.replacePath(String.format("/m/%d#%d", msg.getMid(), msg.getRid())).toUriString();
            note.setInReplyTo(uri.replacePath(String.format("/m/%d#%d", msg.getMid(), msg.getReplyto())).toUriString());
        }
        if (MessageUtils.isPM(msg)) {
            note.setTo(Collections.singletonList(activityPubManager.personUri(msg.getTo())));
        } else {
            note.setTo(Collections.singletonList("https://www.w3.org/ns/activitystreams#Public"));
            note.setCc(Collections.singletonList(followersUri(msg.getUser())));
        }
        note.setPublished(msg.getTimestamp());
        note.setContent(MessageUtils.formatMessage(msg.getText()));
        if (StringUtils.isNotBlank(msg.getAttachmentType())) {
            Link attachment = new Link();
            attachment.setHref(msg.getAttachment().getMedium().getUrl());
            note.setAttachment(attachment);
        }
        return note;
    }

    @Override
    public void processSubscribeEvent(SubscribeEvent subscribeEvent) {

    }

    @Override
    public void processLikeEvent(LikeEvent likeEvent) {

    }

    @Override
    public void processPingEvent(PingEvent pingEvent) {

    }

    @Override
    public void processMessageReadEvent(MessageReadEvent messageReadEvent) {

    }
}