package com.company.agentfoundation.integration.wecom;

import com.company.agentfoundation.config.FoundationProperties;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.MediaType;
import org.springframework.stereotype.Service;
import org.springframework.web.reactive.function.client.WebClient;

import java.time.Instant;

@Service
public class WecomClient {
  private static final Logger log = LoggerFactory.getLogger(WecomClient.class);
  private final FoundationProperties properties;
  private final WebClient webClient;

  private volatile String cachedToken;
  private volatile Instant tokenExpireAt = Instant.EPOCH;

  public WecomClient(FoundationProperties properties, WebClient.Builder builder) {
    this.properties = properties;
    this.webClient = builder.baseUrl("https://qyapi.weixin.qq.com").build();
  }

  public void sendText(String toUser, String content) {
    log.info("wecom sendText start toUser={} agentId={} contentPreview={}", toUser, properties.getWecom().getAgentId(), preview(content));
    String token = getAccessToken();
    WecomSendMessageRequest req = new WecomSendMessageRequest();
    req.setToUser(toUser);
    req.setAgentId(properties.getWecom().getAgentId());
    WecomSendMessageRequest.Text text = new WecomSendMessageRequest.Text();
    text.setContent(content);
    req.setText(text);

    WecomApiResponse response = webClient.post()
        .uri(uriBuilder -> uriBuilder.path("/cgi-bin/message/send").queryParam("access_token", token).build())
        .contentType(MediaType.APPLICATION_JSON)
        .bodyValue(req)
        .retrieve()
        .bodyToMono(WecomApiResponse.class)
        .block();

    if (response == null || !response.success()) {
      log.error("wecom sendText failed toUser={} err={}", toUser, response == null ? "null" : response.errmsg());
      throw new IllegalStateException("WeCom send failed: " + (response == null ? "null" : response.errmsg()));
    }
    log.info("wecom sendText success toUser={}", toUser);
  }

  private String getAccessToken() {
    if (cachedToken != null && Instant.now().isBefore(tokenExpireAt)) {
      log.info("wecom gettoken use cached token expireAt={}", tokenExpireAt);
      return cachedToken;
    }

    WecomTokenResponse response = webClient.get()
        .uri(uriBuilder -> uriBuilder.path("/cgi-bin/gettoken")
            .queryParam("corpid", properties.getWecom().getCorpId())
            .queryParam("corpsecret", properties.getWecom().getSecret())
            .build())
        .retrieve()
        .bodyToMono(WecomTokenResponse.class)
        .block();

    if (response == null || !response.success() || response.accessToken() == null) {
      log.error("wecom gettoken failed err={}", response == null ? "null" : response.errmsg());
      throw new IllegalStateException("WeCom gettoken failed: " + (response == null ? "null" : response.errmsg()));
    }

    cachedToken = response.accessToken();
    int expires = response.expiresIn() == null ? 7200 : response.expiresIn();
    tokenExpireAt = Instant.now().plusSeconds(Math.max(300, expires - 120));
    log.info("wecom gettoken success expireAt={}", tokenExpireAt);
    return cachedToken;
  }

  private String preview(String text) {
    if (text == null || text.isBlank()) {
      return "";
    }
    return text.length() <= 80 ? text : text.substring(0, 80) + "...";
  }
}