import { describe, it, expect, afterEach, vi } from 'vitest';

// env.ts reads process.env once at module-eval time, so each case re-imports it
// under a controlled environment (resetModules busts the cached module), then
// restores the original process.env immediately so nothing leaks to other tests.
const KEYS = ['DATABASE_URL', 'BETTER_AUTH_SECRET', 'BETTER_AUTH_URL', 'PORT', 'CORS_ORIGINS'];

async function loadEnv(overrides: Record<string, string | undefined>) {
  const saved: Record<string, string | undefined> = {};
  for (const k of KEYS) saved[k] = process.env[k];
  for (const k of KEYS) delete process.env[k];
  for (const [k, v] of Object.entries(overrides)) if (v !== undefined) process.env[k] = v;
  vi.resetModules();
  try {
    const { env } = await import('../src/env');
    return env;
  } finally {
    for (const k of KEYS) {
      if (saved[k] === undefined) delete process.env[k];
      else process.env[k] = saved[k];
    }
  }
}

describe('env', () => {
  afterEach(() => vi.resetModules());

  it('applies every dev default when the vars are unset', async () => {
    const env = await loadEnv({});
    expect(env.DATABASE_URL).toBe('file:./data/app.db');
    expect(env.BETTER_AUTH_SECRET).toBe('dev-insecure-secret-change-me');
    expect(env.BETTER_AUTH_URL).toBe('http://localhost:3000');
    expect(env.PORT).toBe(3000);
    expect(env.WEB_ORIGINS).toEqual(['http://localhost:5173', 'http://localhost:5174']);
  });

  it('reads each override when the var is set (PORT coerced to a number)', async () => {
    const env = await loadEnv({
      DATABASE_URL: 'file:./other.db',
      BETTER_AUTH_SECRET: 'top-secret',
      BETTER_AUTH_URL: 'https://api.example.com',
      PORT: '8080',
    });
    expect(env.DATABASE_URL).toBe('file:./other.db');
    expect(env.BETTER_AUTH_SECRET).toBe('top-secret');
    expect(env.BETTER_AUTH_URL).toBe('https://api.example.com');
    expect(env.PORT).toBe(8080);
    expect(typeof env.PORT).toBe('number');
  });

  it('parses CORS_ORIGINS into WEB_ORIGINS, trimming and dropping empty entries', async () => {
    const env = await loadEnv({ CORS_ORIGINS: ' http://a.example , http://b.example , ' });
    expect(env.WEB_ORIGINS).toEqual(['http://a.example', 'http://b.example']);
  });

  it('falls back to the default origins when CORS_ORIGINS is empty', async () => {
    const env = await loadEnv({ CORS_ORIGINS: '' });
    expect(env.WEB_ORIGINS).toEqual(['http://localhost:5173', 'http://localhost:5174']);
  });
});