import { z } from 'zod';

const configSchema = z.object({
  NODE_ENV: z.enum(['development', 'test', 'production']).default('development'),
  PORT: z.coerce.number().int().min(1).max(65535).default(8080),
  LOG_LEVEL: z.enum(['fatal', 'error', 'warn', 'info', 'debug', 'trace', 'silent']).default('info'),
  STAFF_RUNTIME_MODE: z.enum(['standalone', 'platform']).default('standalone'),
  DATABASE_URL: z.string().url(),
  REDIS_URL: z.string().url().optional(),
  PLATFORM_GATEWAY_URL: z.string().url().optional(),
  PLATFORM_JWT_ISSUER: z.string().url().optional(),
  PLATFORM_JWT_AUDIENCE: z.string().optional(),
  PLATFORM_JWKS_URL: z.string().url().optional(),
  STANDALONE_TENANT_ID: z.string().regex(/^[0-9A-HJKMNP-TV-Z]{26}$/),
  STANDALONE_ACTOR_ID: z.string().regex(/^[0-9A-HJKMNP-TV-Z]{26}$/),
});

export type AppConfig = z.infer<typeof configSchema>;

export function loadConfig(env: NodeJS.ProcessEnv = process.env): AppConfig {
  const config = configSchema.parse(env);
  if (config.NODE_ENV === 'production' && config.STAFF_RUNTIME_MODE === 'standalone') {
    throw new Error('STAFF_RUNTIME_MODE=standalone is not allowed in production');
  }
  if (config.STAFF_RUNTIME_MODE === 'platform') {
    const required = [
      'PLATFORM_GATEWAY_URL',
      'PLATFORM_JWT_ISSUER',
      'PLATFORM_JWT_AUDIENCE',
      'PLATFORM_JWKS_URL',
    ] as const;
    for (const key of required)
      if (!config[key]) throw new Error(`${key} is required in platform mode`);
  }
  return config;
}