package com.juick.service;

import java.net.URI;
import java.util.Collections;

import javax.inject.Inject;

import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Component;
import org.springframework.web.client.RestClientException;
import org.springframework.web.client.RestTemplate;
import org.springframework.web.util.UriComponentsBuilder;

import com.juick.www.api.webfinger.model.Account;
import com.juick.www.api.webfinger.model.Link;

import rocks.xmpp.addr.Jid;

@Component
public class WebfingerService {
    private static final Logger logger = LoggerFactory.getLogger("ActivityPub");

    private final RestTemplate restClient;
    @Inject
    public WebfingerService(final RestTemplate restClient) {
        this.restClient = restClient;
    }
    public URI discoverAccountURI(String acct, MediaType linkType) {
        Jid acctId = Jid.of(acct);
        URI resourceUri = UriComponentsBuilder.fromPath("/.well-known/webfinger").host(acctId.getDomain())
                .scheme("https").queryParam("resource", "acct:" + acct).build().toUri();
        HttpHeaders headers = new HttpHeaders();
        headers.setAccept(Collections.singletonList(MediaType.valueOf("application/jrd+json")));
        HttpEntity<Void> webfingerRequest = new HttpEntity<>(headers);
        try {
            ResponseEntity<Account> response = restClient.exchange(resourceUri, HttpMethod.GET, webfingerRequest,
                    Account.class);
            if (response.getStatusCode().is2xxSuccessful()) {
                var account = response.getBody();
                for (Link l : account.links()) {
                    if (l.rel().equals("self") && l.type().equals(linkType.toString())) {
                        return URI.create(l.href());
                    }
                }
            }
        } catch (RestClientException e) {
            logger.warn("Cannot discover person {}: {}", acct, e.getMessage());
        }
        return URI.create(StringUtils.EMPTY);
    }
}