// Load environment variables THIS MUST BE AT THE TOP
const path = require("path");
require("dotenv").config({
  path: path.resolve(process.cwd(), `.env.${process.env.NODE_ENV || "development"}`)
});

const InstanceManager = require("../utils/instanceMgr").default;
const winston = require("winston");
const WinstonCloudWatch = require("winston-cloudwatch");
const { isString, isEmpty } = require("lodash");
const { networkInterfaces, hostname } = require("node:os");
const { uploadFileToS3 } = require("./s3");
const { v4 } = require("uuid");

const LOG_LEVELS = {
  error: { level: 0, name: "error" },
  warn: { level: 1, name: "warn" },
  info: { level: 2, name: "info" },
  http: { level: 3, name: "http" },
  verbose: { level: 4, name: "verbose" },
  debug: { level: 5, name: "debug" },
  silly: { level: 6, name: "silly" }
};

const LOG_LENGTH_LIMIT = 256 * 1024; // 256KB

const S3_BUCKET_NAME = InstanceManager({
  imex: "imex-large-log",
  rome: "rome-large-log"
});

const estimateLogSize = (logEntry) => {
  let estimatedSize = 0;
  for (const key in logEntry) {
    if (logEntry.hasOwnProperty(key)) {
      const value = logEntry[key];
      estimatedSize += key.length + (typeof value === "string" ? value.length : JSON.stringify(value).length);
    }
  }
  return estimatedSize;
};

const normalizeLevel = (level) => (level ? level.toLowerCase() : LOG_LEVELS.debug.name);

const createLogger = () => {
  try {
    const isLocal = isString(process.env?.LOCALSTACK_HOSTNAME) && !isEmpty(process.env?.LOCALSTACK_HOSTNAME);
    const logGroupName = isLocal ? "development" : process.env.CLOUDWATCH_LOG_GROUP;

    const winstonCloudwatchTransportDefaults = {
      logGroupName: logGroupName,
      awsOptions: {
        region: InstanceManager({
          imex: "ca-central-1",
          rome: "us-east-2"
        })
      },
      jsonMessage: true
    };

    if (isLocal) {
      winstonCloudwatchTransportDefaults.awsOptions.endpoint = `http://${process.env.LOCALSTACK_HOSTNAME}:4566`;
    }

    const levelFilter = (levels) => {
      return winston.format((info) => {
        if (Array.isArray(levels)) {
          return levels.includes(info.level) ? info : false;
        } else {
          return info.level === levels ? info : false;
        }
      })();
    };

    const getHostNameOrIP = () => {
      // Try to get the hostname first
      const hostName = hostname();
      if (hostName) return hostName;

      const interfaces = networkInterfaces();
      for (const name of Object.keys(interfaces)) {
        for (const iface of interfaces[name]) {
          if (iface.family === "IPv4" && !iface.internal) {
            return iface.address;
          }
        }
      }

      return "127.0.0.1";
    };
    const createProductionTransport = (level, logStreamName, filters) => {
      return new WinstonCloudWatch({
        level,
        logStreamName: logStreamName || level,
        format: levelFilter(filters || level),
        ...winstonCloudwatchTransportDefaults
      });
    };

    const internalHostname = process.env.HOSTNAME || getHostNameOrIP();

    const getDevelopmentTransports = () => [
      new winston.transports.Console({
        level: "silly",
        format: winston.format.combine(
          winston.format.colorize(),
          winston.format.timestamp(),
          winston.format.printf(({ level, message, timestamp, user, record, meta }) => {
            const hostnameColor = `\x1b[34m${internalHostname}\x1b[0m`; // Blue
            const timestampColor = `\x1b[36m${timestamp}\x1b[0m`; // Cyan
            const labelColor = "\x1b[33m"; // Yellow
            const separatorColor = "\x1b[35m|\x1b[0m"; // Magenta for separators

            return `${timestampColor} [${hostnameColor}] [${level}]: ${message} ${
              user ? `${separatorColor} ${labelColor}user:\x1b[0m ${JSON.stringify(user)}` : ""
            } ${record ? `${separatorColor} ${labelColor}record:\x1b[0m ${JSON.stringify(record)}` : ""}${
              meta
                ? `\n${separatorColor} ${labelColor}meta:\x1b[0m ${JSON.stringify(meta, null, 2)} ${separatorColor}`
                : ""
            }`;
          })
        )
      })
    ];

    const getProductionTransports = () => [
      createProductionTransport("error"),
      createProductionTransport("warn"),
      createProductionTransport("info"),
      createProductionTransport("silly", "debug", ["http", "verbose", "debug", "silly"])
    ];

    const winstonLogger = winston.createLogger({
      format: winston.format.json(),
      transports:
        process.env.NODE_ENV === "production"
          ? getProductionTransports()
          : [...getDevelopmentTransports(), ...getProductionTransports()]
    });

    if (isLocal) {
      winstonLogger.debug(
        `CloudWatch set to LocalStack end point: ${winstonCloudwatchTransportDefaults.awsOptions.endpoint}`
      );
    }

    const log = (message, type, user, record, meta, upload) => {
      const logEntry = {
        level: normalizeLevel(type),
        message,
        user,
        record,
        hostname: internalHostname,
        meta
      };

      const uploadLogToS3 = (logEntry, message, type, user) => {
        const uniqueId = v4();
        const dateTimeString = new Date().toISOString().replace(/:/g, "-");
        const logStreamName = `${dateTimeString}-${internalHostname}-${uniqueId}`;
        const logString = JSON.stringify(logEntry);

        uploadFileToS3({ bucketName: S3_BUCKET_NAME, key: logStreamName, content: logString })
          .then(() => {
            log("A log file has been uploaded to S3", "info", "S3", null, {
              logStreamName,
              message: message?.slice(0, 200),
              type,
              user
            });
          })
          .catch((err) => {
            log("Error in S3 Upload", "error", "S3", null, {
              logStreamName,
              message: message?.slice(0, 100),
              type,
              user,
              errorMessage: err?.message?.slice(0, 100)
            });
          });
      };

      const checkAndUploadLog = () => {
        const logString = JSON.stringify(logEntry);
        const logSize = Buffer.byteLength(logString, "utf8");

        if (logSize > LOG_LENGTH_LIMIT * 0.9 || logSize > LOG_LENGTH_LIMIT) {
          uploadLogToS3(logEntry, message, type, user);
          return true;
        }
        return false;
      };

      if (upload || checkAndUploadLog()) return;

      winstonLogger.log(logEntry);
    };

    return {
      log,
      logger: winstonLogger
    };
  } catch (e) {
    console.error("Error setting up enhanced Logger, defaulting to console.: " + e?.message || "");
    return {
      log: console.log,
      logger: console.log,
      LOG_LEVELS
    };
  }
};

module.exports = createLogger();