import { NextFunction, Request, Response } from "express";
import { Client } from "@elastic/elasticsearch";
import permission from "../interfaces/permission";

if (!process.env.ELASTICSEARCH_INDEX) {
  throw new Error("Require ELASTICSEARCH_INDEX to store log.");
}

const ELASTICSEARCH_INDEX = process.env.ELASTICSEARCH_INDEX;

const LOG_LEVEL_MAP: Record<string, number> = {
  debug: 4,
  info: 3,
  warning: 2,
  error: 1,
  none: 0,
};

const elasticsearch = new Client({
  node: `${process.env.ELASTICSEARCH_PROTOCOL}://${process.env.ELASTICSEARCH_HOST}:${process.env.ELASTICSEARCH_PORT}`,
});
async function logMiddleware(req: Request, res: Response, next: NextFunction) {
  if (!req.url.startsWith("/api/")) return next();

  let data: any;
  const originalJson = res.json;

  res.json = function (v: any) {
    data = v;
    return originalJson.call(this, v);
  };

  const timestamp = new Date().toISOString();
  const start = performance.now();

  req.app.locals.logData = {};

  res.on("finish", async () => {
    try {
      if (!req.url.startsWith("/api/")) return;

      const level = LOG_LEVEL_MAP[process.env.LOG_LEVEL ?? "debug"] || 4;

      if (level === 1 && res.statusCode < 500) return;
      if (level === 2 && res.statusCode < 400) return;
      if (level === 3 && res.statusCode < 200) return;

      // const token = req.headers["authorization"];
      // let rootId = null;

      // try {
      //   rootId = token
      //     ? await new permission().checkRootDna(token, req.app.locals.logData.userId)
      //     : null;
      // } catch (err) {
      //   console.warn("Error fetching rootId:", err);
      // }

      // Get rootId from token
      const rootId = req.app.locals.logData?.orgRootDnaId;

      const obj = {
        logType: res.statusCode >= 500 ? "error" : res.statusCode >= 400 ? "warning" : "info",
        ip: req.ip,
        rootId: rootId ?? null,
        systemName: "KPI",
        startTimeStamp: timestamp,
        endTimeStamp: new Date().toISOString(),
        processTime: performance.now() - start,
        host: req.hostname,
        method: req.method,
        endpoint: req.url,
        responseCode: String(res.statusCode === 304 ? 200 : res.statusCode),
        responseDescription: data?.message,
        input: level === 4 ? JSON.stringify(req.body, null, 2) : undefined,
        output: level === 4 ? JSON.stringify(data, null, 2) : undefined,
        ...req.app.locals.logData,
      };

      // Send log to Elasticsearch
      await elasticsearch.index({
        index: ELASTICSEARCH_INDEX,
        document: obj,
      });
    } catch (err) {
      console.error("Error in logMiddleware:", err);
    }
  });

  return next();
}

export default logMiddleware;