import { readFileSync, existsSync } from "node:fs";
import { resolve } from "node:path";
import { defineConfig } from "vitest/config";
import swc from "unplugin-swc";

/**
 * These are integration tests, not unit tests — they need DATABASE_URL,
 * JWT_SIGNING_SECRET, EDEN_SUPERADMIN_EMAIL/PASSWORD, etc. from the repo
 * root `.env` (gitignored, never read by vitest automatically the way
 * Next/Vite's client env loading does). Parsed by hand here (no `dotenv`
 * dependency needed) and passed through `test.env` so it reaches the
 * worker process(es) vitest actually runs specs in.
 */
function loadRootEnv(): Record<string, string> {
  const envPath = resolve(__dirname, "../../.env");
  if (!existsSync(envPath)) return {};
  const out: Record<string, string> = {};
  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;
    out[trimmed.slice(0, eq).trim()] = trimmed.slice(eq + 1).trim();
  }
  return out;
}

/**
 * Integration test config (eden-qa). Every spec under test/ boots a real,
 * fully-wired Nest app (Test.createTestingModule + AppModule) against a
 * real Postgres — no mocked DB layer, per the eden-qa persona's rule.
 * Timeout is generous (15s default) because some tests hit the DB several
 * times in sequence and hash passwords with Argon2id (intentionally slow).
 */
export default defineConfig({
  // NestJS's DI resolves constructor parameter types from
  // `design:paramtypes` metadata emitted by the TS decorator-metadata
  // transform. Vite's default esbuild transform does NOT implement
  // `emitDecoratorMetadata` (esbuild is a single-file transformer with no
  // type checker to resolve types from) — every @Injectable()/@Controller
  // class would silently receive `undefined` for its dependencies instead
  // of a real instance. Using SWC (which does implement it, matching
  // `tsc`'s behavior) here is the standard fix for testing Nest apps with
  // Vitest — see https://docs.nestjs.com/recipes/swc#vitest.
  plugins: [swc.vite()],
  test: {
    environment: "node",
    include: ["test/**/*.spec.ts"],
    testTimeout: 15000,
    hookTimeout: 15000,
    // Integration tests share one real Postgres connection pool + one
    // seeded super_admin account; running spec files in parallel worker
    // processes risks session/role-cleanup races between files (e.g. two
    // files both minting/deleting similarly-named throwaway roles). Runs
    // sequentially, file by file — still fully real, just not concurrent.
    fileParallelism: false,
    globals: false,
    env: { ...loadRootEnv(), ...process.env },
  },
});