import "server-only";

import { createHmac } from "node:crypto";
import {
  defaultDingTalkRobotNotificationConfig,
  normalizeDingTalkRobotNotificationConfig,
  type DingTalkRobotNotificationConfig,
} from "./dingtalk-robot-config";

function buildSignedWebhookUrl(webhookUrl: string, secret: string) {
  const normalizedUrl = String(webhookUrl || "").trim();
  const normalizedSecret = String(secret || "").trim();

  if (!normalizedSecret) {
    return normalizedUrl;
  }

  const timestamp = Date.now().toString();
  const stringToSign = `${timestamp}\n${normalizedSecret}`;
  const sign = createHmac("sha256", normalizedSecret)
    .update(stringToSign, "utf8")
    .digest("base64");

  const url = new URL(normalizedUrl);
  url.searchParams.set("timestamp", timestamp);
  url.searchParams.set("sign", sign);
  return url.toString();
}

function buildMarkdownText(params: { title: string; content: string }) {
  const normalizedTitle = String(params.title || "").trim();
  const normalizedContent = String(params.content || "")
    .replace(/\r\n?/g, "\n")
    .trim();
  const sentAt = new Intl.DateTimeFormat("zh-CN", {
    timeZone: "Asia/Shanghai",
    year: "numeric",
    month: "2-digit",
    day: "2-digit",
    hour: "2-digit",
    minute: "2-digit",
    second: "2-digit",
    hour12: false,
  }).format(new Date());

  return [
    `### ${normalizedTitle}`,
    "",
    normalizedContent,
    "",
    `> 发送时间：${sentAt}`,
  ].join("\n");
}

export function assertDingTalkRobotNotificationConfigReady(
  config: DingTalkRobotNotificationConfig,
) {
  if (!config.enabled) {
    throw new Error("钉钉群机器人通知未启用");
  }

  if (!config.webhookUrl) {
    throw new Error("钉钉群机器人 Webhook 未配置");
  }
}

export async function sendDingTalkRobotNotification(params: {
  config: DingTalkRobotNotificationConfig;
  title: string;
  content: string;
}) {
  const config = normalizeDingTalkRobotNotificationConfig(params.config);
  assertDingTalkRobotNotificationConfigReady(config);

  const title = String(params.title || "").trim();
  const content = String(params.content || "").trim();

  if (!title) {
    throw new Error("通知标题不能为空");
  }

  if (!content) {
    throw new Error("通知内容不能为空");
  }

  const requestUrl = buildSignedWebhookUrl(config.webhookUrl, config.secret);
  const response = await fetch(requestUrl, {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
    },
    body: JSON.stringify({
      msgtype: "markdown",
      markdown: {
        title,
        text: buildMarkdownText({ title, content }),
      },
      at: {
        isAtAll: false,
      },
    }),
    signal: AbortSignal.timeout(15_000),
  });

  const responseText = await response.text();
  let responseData: any = null;

  try {
    responseData = responseText ? JSON.parse(responseText) : null;
  } catch {
    responseData = responseText;
  }

  if (!response.ok) {
    throw new Error(
      `钉钉群机器人请求失败：${response.status} ${response.statusText}`,
    );
  }

  if (
    responseData &&
    typeof responseData === "object" &&
    "errcode" in responseData &&
    responseData.errcode !== 0
  ) {
    throw new Error(
      String(responseData.errmsg || "钉钉群机器人返回失败"),
    );
  }

  return {
    ok: true,
    response: responseData,
    configUsed: {
      ...defaultDingTalkRobotNotificationConfig,
      ...config,
      secret: config.secret ? "***" : "",
    },
  };
}