// src/services/logger.server.ts
/**
 * SERVER-SIDE LOGGER
 * This file configures and exports a singleton `pino` logger instance for
 * server-side use, adhering to ADR-004 for structured JSON logging.
 */
import pino from 'pino';

const isProduction = process.env.NODE_ENV === 'production';
const isTest = process.env.NODE_ENV === 'test';

export const logger = pino({
  level: isProduction ? 'info' : 'debug',
  // Use pino-pretty for human-readable logs in development, and JSON in production.
  // Disable transport in tests to prevent worker thread issues.
  transport:
    isProduction || isTest
      ? undefined
      : {
          target: 'pino-pretty',
          options: {
            colorize: true,
            translateTime: 'SYS:standard',
            ignore: 'pid,hostname', // These are useful in production, but noisy in dev.
          },
        },
  // As per ADR-004, we centralize sanitization here.
  // This automatically redacts sensitive fields from all log objects.
  // The paths target keys within objects passed to the logger.
  redact: {
    paths: [
      'req.headers.authorization',
      'req.headers.cookie',
      '*.body.password',
      '*.body.newPassword',
      '*.body.currentPassword',
      '*.body.confirmPassword',
      '*.body.refreshToken',
      '*.body.token',
    ],
    censor: '[REDACTED]',
  },
});

const debugModules = (process.env.DEBUG_MODULES || '').split(',').map((s) => s.trim());

export const createScopedLogger = (moduleName: string) => {
  // If DEBUG_MODULES contains "ai-service" or "*", force level to 'debug'
  const isDebugEnabled = debugModules.includes('*') || debugModules.includes(moduleName);

  return logger.child({
    module: moduleName,
    level: isDebugEnabled ? 'debug' : logger.level,
  });
};