import { z } from 'zod';

/**
 * Environment validation. The process refuses to start with an invalid
 * configuration so misconfiguration is caught at deploy time, not at 3am.
 */
const EnvSchema = z.object({
  NODE_ENV: z.enum(['development', 'test', 'production']).default('development'),
  PORT: z.coerce.number().int().min(1).max(65535).default(3000),
  API_PREFIX: z.string().default('api'),
  CORS_ORIGINS: z.string().default('http://localhost:5173'),
  LOG_LEVEL: z.enum(['fatal', 'error', 'warn', 'info', 'debug', 'trace']).default('info'),

  DATABASE_URL: z.string().min(1),
  DATABASE_MIGRATION_URL: z.string().optional(),
  DATABASE_POOL_MAX: z.coerce.number().int().min(1).max(200).default(20),

  JWT_ACCESS_SECRET: z.string().min(32, 'JWT_ACCESS_SECRET must be at least 32 characters'),
  JWT_ACCESS_TTL: z.string().default('15m'),
  JWT_REFRESH_TTL_DAYS: z.coerce.number().int().min(1).max(365).default(30),
  COOKIE_SECURE: z
    .string()
    .default('false')
    .transform((v) => v === 'true'),
  ENCRYPTION_KEY: z.string().min(10),

  PLATFORM_ADMIN_EMAIL: z.string().email().optional(),
  PLATFORM_ADMIN_PASSWORD: z.string().optional(),

  STORAGE_DRIVER: z.enum(['local', 's3']).default('local'),
  STORAGE_LOCAL_PATH: z.string().default('./storage'),
  S3_BUCKET: z.string().optional(),
  S3_REGION: z.string().optional(),
  S3_ENDPOINT: z.string().optional(),
  S3_ACCESS_KEY_ID: z.string().optional(),
  S3_SECRET_ACCESS_KEY: z.string().optional(),

  MAIL_DRIVER: z.enum(['log', 'smtp']).default('log'),
  SMTP_HOST: z.string().optional(),
  SMTP_PORT: z.coerce.number().optional(),
  SMTP_USER: z.string().optional(),
  SMTP_PASS: z.string().optional(),
  MAIL_FROM: z.string().default('WMS <no-reply@example.com>'),

  AI_PROVIDER: z.enum(['anthropic', 'mock', 'disabled']).default('disabled'),
  ANTHROPIC_API_KEY: z.string().optional(),
  AI_MODEL: z.string().default('claude-sonnet-4-5'),
  AI_MAX_TOKENS: z.coerce.number().int().default(4096),

  /** On-prem: allow webhooks / ERP push to LAN addresses. Keep false for SaaS (SSRF protection). */
  OUTBOUND_ALLOW_PRIVATE_HOSTS: z
    .string()
    .default('false')
    .transform((v) => v === 'true'),

  JOBS_ENABLED: z
    .string()
    .default('true')
    .transform((v) => v !== 'false'),
});

export type Env = z.infer<typeof EnvSchema>;

let cached: Env | null = null;

export function loadEnv(source: NodeJS.ProcessEnv = process.env): Env {
  if (cached) return cached;
  const parsed = EnvSchema.safeParse(source);
  if (!parsed.success) {
    const issues = parsed.error.issues.map((i) => `${i.path.join('.')}: ${i.message}`).join('\n  ');
    throw new Error(`Invalid environment configuration:\n  ${issues}`);
  }
  cached = parsed.data;
  return cached;
}

/** For tests: reset cache and reload with overrides. */
export function resetEnv(overrides: Partial<Record<keyof Env, string>> = {}): Env {
  cached = null;
  return loadEnv({ ...process.env, ...overrides } as NodeJS.ProcessEnv);
}