import { Injectable, Logger } from '@nestjs/common';

/**
 * 企业微信群机器人 Webhook 出站（单向告警，与智能机器人长连接无关）。
 * @see https://developer.work.weixin.qq.com/document/path/91770
 */
@Injectable()
export class WecomWebhookAlertService {
  private readonly logger = new Logger(WecomWebhookAlertService.name);

  isEnabled(): boolean {
    return (
      process.env.WECOM_ALERT_ENABLED === 'true' &&
      !!(process.env.WECOM_ALERT_WEBHOOK_URL || '').trim()
    );
  }

  async sendMarkdown(content: string): Promise<boolean> {
    if (!this.isEnabled()) return false;
    const url = (process.env.WECOM_ALERT_WEBHOOK_URL || '').trim();
    try {
      const res = await fetch(url, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({
          msgtype: 'markdown',
          markdown: { content: content.slice(0, 4000) },
        }),
      });
      const data = (await res.json().catch(() => ({}))) as {
        errcode?: number;
        errmsg?: string;
      };
      if (!res.ok || (data.errcode != null && data.errcode !== 0)) {
        this.logger.warn(
          `wecom webhook failed: HTTP ${res.status} errcode=${data.errcode} ${data.errmsg ?? ''}`,
        );
        return false;
      }
      return true;
    } catch (e) {
      this.logger.warn(
        `wecom webhook network error: ${e instanceof Error ? e.message : String(e)}`,
      );
      return false;
    }
  }
}