package com.xuqm.push.service;

import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.stereotype.Component;
import org.springframework.web.client.RestTemplate;
import org.springframework.web.util.UriComponentsBuilder;

import java.util.Map;
import java.util.Optional;

@Component
public class ImPresenceClient {

    private final RestTemplate restTemplate = new RestTemplate();
    private final ObjectMapper objectMapper;

    @Value("${push.im-service-base-url:http://im-service:8082}")
    private String imServiceBaseUrl;

    @Value("${push.internal-token:xuqm-internal-token}")
    private String internalToken;

    public ImPresenceClient(ObjectMapper objectMapper) {
        this.objectMapper = objectMapper;
    }

    public Optional<PresenceStatus> resolveToken(String token) {
        try {
            HttpHeaders headers = internalHeaders();
            HttpEntity<String> request = new HttpEntity<>(
                    objectMapper.writeValueAsString(Map.of("token", token)),
                    headers);
            String body = restTemplate.postForObject(
                    imServiceBaseUrl + "/api/im/internal/presence/resolve-token",
                    request,
                    String.class);
            return parse(body);
        } catch (Exception ignored) {
            return Optional.empty();
        }
    }

    public Optional<PresenceStatus> userStatus(String appId, String userId) {
        try {
            HttpHeaders headers = internalHeaders();
            HttpEntity<Void> request = new HttpEntity<>(headers);
            String uri = UriComponentsBuilder.fromHttpUrl(imServiceBaseUrl + "/api/im/internal/presence/users/{userId}")
                    .queryParam("appId", appId)
                    .build(userId)
                    .toString();
            String body = restTemplate.exchange(
                    uri,
                    org.springframework.http.HttpMethod.GET,
                    request,
                    String.class).getBody();
            return parse(body);
        } catch (Exception ignored) {
            return Optional.empty();
        }
    }

    private HttpHeaders internalHeaders() {
        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.APPLICATION_JSON);
        headers.set("X-Internal-Token", internalToken);
        return headers;
    }

    private Optional<PresenceStatus> parse(String body) throws Exception {
        if (body == null || body.isBlank()) {
            return Optional.empty();
        }
        JsonNode data = objectMapper.readTree(body).path("data");
        if (data.isMissingNode() || data.isNull()) {
            return Optional.empty();
        }
        return Optional.of(new PresenceStatus(
                data.path("appId").asText(null),
                data.path("userId").asText(null),
                data.path("online").asBoolean(false),
                data.path("lastSeenAt").asLong(0L)));
    }

    public record PresenceStatus(String appId, String userId, boolean online, long lastSeenAt) {}
}