import { describe, it, expect } from 'vitest';
import { loadConfig } from '../src/config/load.js';

describe('loadConfig', () => {
  it('throws when REDIS_URL is unset and names REDIS_URL in the error', () => {
    expect(() => loadConfig({})).toThrowError(/REDIS_URL/);
  });

  it('returns a valid Config with sensible defaults when only REDIS_URL is set in development', () => {
    const config = loadConfig({
      NODE_ENV: 'development',
      REDIS_URL: 'redis://localhost:6379',
    });

    expect(config.NODE_ENV).toBe('development');
    expect(config.REDIS_URL).toBe('redis://localhost:6379');
    expect(config.TELTONIKA_PORT).toBe(5027);
    expect(config.REDIS_TELEMETRY_STREAM).toBe('telemetry:teltonika');
    expect(config.REDIS_STREAM_MAXLEN).toBe(1_000_000);
    expect(config.METRICS_PORT).toBe(9090);
    expect(config.LOG_LEVEL).toBe('info');
    expect(config.STRICT_DEVICE_AUTH).toBe(false);
    expect(config.INSTANCE_ID).toMatch(/^local-[0-9a-f]{8}$/);
  });

  it('parses TELTONIKA_PORT as a number from a string env var', () => {
    const config = loadConfig({
      REDIS_URL: 'redis://localhost:6379',
      TELTONIKA_PORT: '5555',
    });
    expect(config.TELTONIKA_PORT).toBe(5555);
  });

  it('enables STRICT_DEVICE_AUTH when set to "true"', () => {
    const config = loadConfig({
      REDIS_URL: 'redis://localhost:6379',
      STRICT_DEVICE_AUTH: 'true',
    });
    expect(config.STRICT_DEVICE_AUTH).toBe(true);
  });

  it('rejects an invalid NODE_ENV value', () => {
    expect(() =>
      loadConfig({
        REDIS_URL: 'redis://localhost:6379',
        NODE_ENV: 'staging',
      }),
    ).toThrow();
  });

  it('rejects a non-URL REDIS_URL', () => {
    expect(() => loadConfig({ REDIS_URL: 'not-a-url' })).toThrowError(/REDIS_URL/);
  });
});