/**
 * @fileoverview Process configuration for the Verae Zapier middleware.
 * @module config
 *
 * Loads optional `.env` then exports typed settings used by HTTP, NATS, and workers.
 */

import { readFileSync, existsSync } from 'node:fs';
import { resolve, dirname } from 'node:path';
import { fileURLToPath } from 'node:url';
import { createDebugger } from './debug/logger.js';

const log = createDebugger('app');
const __dirname = dirname(fileURLToPath(import.meta.url));
const rootDir = resolve(__dirname, '..');

/**
 * Load KEY=VALUE pairs from `.env` without overriding existing process.env keys.
 * @returns {void}
 */
export function loadEnvFile() {
  const envPath = resolve(rootDir, '.env');
  if (!existsSync(envPath)) return;

  for (const line of readFileSync(envPath, 'utf8').split('\n')) {
    const trimmed = line.trim();
    if (!trimmed || trimmed.startsWith('#')) continue;
    const eq = trimmed.indexOf('=');
    if (eq === -1) continue;
    const key = trimmed.slice(0, eq).trim();
    const value = trimmed.slice(eq + 1).trim();
    if (!(key in process.env)) {
      process.env[key] = value;
    }
  }
}

loadEnvFile();

/**
 * @param {string|undefined} value
 * @param {boolean} [fallback=false]
 * @returns {boolean}
 */
function bool(value, fallback = false) {
  if (value === undefined) return fallback;
  return ['1', 'true', 'yes', 'on'].includes(String(value).toLowerCase());
}

/**
 * @param {string|undefined} value
 * @param {number} fallback
 * @returns {number}
 */
function int(value, fallback) {
  const parsed = Number.parseInt(value ?? '', 10);
  return Number.isFinite(parsed) ? parsed : fallback;
}

/**
 * Runtime configuration object.
 * @type {{
 *   port: number,
 *   host: string,
 *   veraeApiBaseUrl: string,
 *   mockVerae: boolean,
 *   natsEnabled: boolean,
 *   natsUrl: string,
 *   tokenSecret: string,
 *   jobPollIntervalMs: number,
 *   jobPollMaxAttempts: number,
 *   storePath: string,
 *   upgradeUrl: string,
 *   adminSecret: string,
 * }}
 */
export const config = {
  port: int(process.env.PORT, 3100),
  host: process.env.HOST ?? '0.0.0.0',
  veraeApiBaseUrl: (process.env.VERAE_API_BASE_URL ?? 'http://localhost:8080').replace(
    /\/$/,
    '',
  ),
  mockVerae: bool(process.env.MOCK_VERAE, false),
  natsEnabled: bool(process.env.NATS_ENABLED, false),
  natsUrl: process.env.NATS_URL ?? 'nats://127.0.0.1:4222',
  tokenSecret: process.env.TOKEN_SECRET ?? 'dev-secret-change-me',
  jobPollIntervalMs: int(process.env.JOB_POLL_INTERVAL_MS, 2000),
  jobPollMaxAttempts: int(process.env.JOB_POLL_MAX_ATTEMPTS, 60),
  waitTimeoutMs: int(process.env.WAIT_TIMEOUT_MS, 25000),
  mockJobCompleteMs: int(process.env.MOCK_JOB_COMPLETE_MS, 150),
  storePath: resolve(rootDir, process.env.STORE_PATH ?? './data/store.json'),
  upgradeUrl: process.env.UPGRADE_URL ?? 'https://veraetime.net/billing',
  adminSecret: process.env.ADMIN_SECRET ?? 'change-me-admin',
};

/**
 * Default plan limits. `null` numeric fields mean unlimited.
 * @type {Record<string, {
 *   timestamps: number|null,
 *   verifications: number|null,
 *   batch: boolean,
 *   batchMaxItems: number|null,
 *   requestsPerMinute: number
 * }>}
 */
export const PLAN_LIMITS = {
  free: {
    timestamps: 50,
    verifications: 50,
    batch: false,
    batchMaxItems: 0,
    requestsPerMinute: 30,
  },
  starter: {
    timestamps: 500,
    verifications: 500,
    batch: true,
    batchMaxItems: 10,
    requestsPerMinute: 120,
  },
  pro: {
    timestamps: 5000,
    verifications: 5000,
    batch: true,
    batchMaxItems: 100,
    requestsPerMinute: 600,
  },
  enterprise: {
    timestamps: null,
    verifications: null,
    batch: true,
    batchMaxItems: null,
    requestsPerMinute: 3000,
  },
};

log.info('config loaded', {
  veraeApiBaseUrl: config.veraeApiBaseUrl,
  mockVerae: config.mockVerae,
  natsEnabled: config.natsEnabled,
  natsUrl: config.natsUrl,
  port: config.port,
});