/**
 * Centralized structured logging for ForkFolio.
 *
 * - Emits newline-delimited JSON to stdout (collected by Docker, rotated by the
 *   json-file log driver, and forwarded to OpenObserve by Fluent Bit).
 * - `log.*` helpers accept console-style arguments, so existing
 *   `console.error('Message:', err)` call sites translate 1:1 while Error
 *   objects are serialized with their stack trace under the `err` key.
 * - `httpLogger` is Express middleware that logs one line per HTTP request.
 *
 * Environment variables:
 *   LOG_LEVEL  trace | debug | info | warn | error | fatal | silent (default: info)
 */
const crypto = require('crypto');
const util = require('util');
const pino = require('pino');
const pinoHttp = require('pino-http');

const logger = pino({
  level: process.env.LOG_LEVEL || 'info',
  base: { app: 'forkfolio' },
  timestamp: pino.stdTimeFunctions.isoTime,
  formatters: {
    // Use readable level names ("info") instead of numeric levels (30)
    level: (label) => ({ level: label })
  },
  redact: {
    paths: ['password', '*.password', 'token', '*.token', 'apiKey', '*.apiKey'],
    censor: '[REDACTED]'
  }
});

/**
 * Builds a console-compatible log function for the given pino level.
 * The first Error argument is attached as `err`; remaining arguments are
 * formatted into the message exactly like console.log would format them.
 */
function consoleStyle(level) {
  return (...args) => {
    const err = args.find((a) => a instanceof Error);
    const rest = err ? args.filter((a) => a !== err) : args;
    const msg = util.format(...rest);
    if (err) {
      // Drop the trailing "Message:" colon since the error is attached separately
      logger[level]({ err }, msg.replace(/:\s*$/, ''));
    } else {
      logger[level](msg);
    }
  };
}

const log = {
  debug: consoleStyle('debug'),
  info: consoleStyle('info'),
  warn: consoleStyle('warn'),
  error: consoleStyle('error')
};

// Static asset requests are high-volume and low-value; skip them in request logs
const STATIC_ASSET_RE = /\.(?:js|css|png|jpe?g|gif|svg|ico|webp|woff2?|ttf|map|json|html)$/i;

const httpLogger = pinoHttp({
  logger,
  genReqId: (req, res) => {
    const id = req.headers['x-request-id'] || crypto.randomUUID();
    res.setHeader('X-Request-Id', id);
    return id;
  },
  autoLogging: {
    ignore: (req) => STATIC_ASSET_RE.test((req.url || '').split('?')[0])
  },
  customLogLevel: (req, res, err) => {
    if (err || res.statusCode >= 500) return 'error';
    if (res.statusCode >= 400) return 'warn';
    return 'info';
  },
  // Keep request logs compact and never record headers (Authorization, cookies)
  serializers: {
    req: (req) => ({
      id: req.id,
      method: req.method,
      url: req.url,
      ip: (req.headers && req.headers['x-forwarded-for']) || req.remoteAddress
    }),
    res: (res) => ({ statusCode: res.statusCode })
  }
});

module.exports = { logger, log, httpLogger };