/**
 * The freight API, booted IN THIS PROCESS — one instance per vitest worker.
 *
 * Each worker is a self-contained shard of the whole topology, so spec files can
 * run in parallel without sharing anything mutable:
 *
 *   shard i = this in-process freight app on :3111+i
 *           + database edr_it_s{i}          (cloned from the seeded template)
 *           + payment-api-it-{i} container  on :3113+i, DB_NAME=edr_it_s{i}
 *           + gateway-mock-it-{i} container on :4600+i
 *           + RabbitMQ vhost payment_s{i}
 *
 * The payment schema lives INSIDE the shard's own database under the usual
 * `edr_payment` name, so every raw `edr_payment.*` query in the specs works
 * unchanged and `paymentDb()` stays an alias for `db()`.
 *
 * Why the app is loaded from `dist/` and not from TypeScript: the freight source
 * is CJS-flavoured — `src/config/database.config.ts` uses `__dirname`,
 * `require.resolve` and an entity glob, none of which survive vitest's ESM
 * transform. `createRequire` anchored at the freight app's own package.json
 * keeps all Nest / typeorm / @tria-plc resolution inside its node_modules, and
 * `dist` is rebuilt by `it.mjs test` on every run so it can never go stale.
 */
import { createRequire } from "node:module";
import { existsSync } from "node:fs";
import { dirname, join } from "node:path";
import { fileURLToPath } from "node:url";
import type { Server } from "node:http";

const here = dirname(fileURLToPath(import.meta.url));
const freightDir = join(here, "..", "..", "apps", "edr-freight-api");
const distMain = join(freightDir, "dist", "main.js");

/**
 * `VITEST_POOL_ID` is 1-based and stable per worker for the life of the run.
 * Absent outside a worker (global-setup, scripts) — that context gets shard 0.
 */
export const SHARD = Math.max(0, Number(process.env.VITEST_POOL_ID ?? "1") - 1);

/**
 * Each service takes a contiguous block of `IT_SHARDS` ports from its base, so
 * the bases must stay far apart — see the PORTS comment in scripts/it.mjs.
 */
const port = (base: string, fallback: number) =>
  Number(process.env[base] ?? fallback) + SHARD;

export const API_PORT = port("IT_API_PORT_BASE", 3111);
export const PAYMENT_API = `http://localhost:${port("IT_PAYMENT_PORT_BASE", 3131)}`;
export const GATEWAY = `http://localhost:${port("IT_GATEWAY_PORT_BASE", 4600)}`;

export const SHARD_DB = `${process.env.IT_DB_PREFIX ?? "edr_it_s"}${SHARD}`;

export const DB_URL =
  `postgres://${process.env.DB_USER ?? "edr_e2e"}:${process.env.DB_PASSWORD ?? "edr_e2e"}` +
  `@${process.env.DB_HOST ?? "localhost"}:${process.env.DB_PORT ?? "5543"}/${SHARD_DB}`;

const RABBIT_URL =
  `amqp://edr:edr_secret@localhost:${process.env.IT_RABBIT_PORT ?? "5772"}` +
  `/payment_s${SHARD}`;

/** Prefix every diagnostic — parallel worker output interleaves. */
export const tag = (msg: string) => `[shard ${SHARD}] ${msg}`;

interface FreightMain {
  createFreightApp: () => Promise<{
    listen: (port: number) => Promise<unknown>;
    getHttpServer: () => Server;
    close: () => Promise<void>;
  }>;
}

let booted: Promise<Server> | undefined;

/**
 * The shard's HTTP server, booted once per worker. supertest takes this
 * directly in place of a base URL, so every call site in client.ts is a
 * one-token change.
 */
export function freightServer(): Promise<Server> {
  return (booted ??= boot());
}

async function boot(): Promise<Server> {
  if (!existsSync(distMain)) {
    throw new Error(
      tag(
        `${distMain} is missing — build the API first ` +
          `(\`pnpm --filter @edr/freight-api run build\`, which \`it.mjs test\` does for you).`,
      ),
    );
  }

  // Must be set BEFORE the require: payment.module.ts reads
  // PAYMENT_RABBITMQ_URL at module-definition time to decide whether
  // RabbitMQModule is in the graph at all, and database.config.ts reads DB_NAME
  // when ConfigModule loads it.
  process.env.DB_NAME = SHARD_DB;
  process.env.PORT = String(API_PORT);
  process.env.PAYMENT_API_URL = PAYMENT_API;
  process.env.PAYMENT_RABBITMQ_URL = RABBIT_URL;

  const { createFreightApp } = createRequire(join(freightDir, "package.json"))(
    "./dist/main.js",
  ) as FreightMain;

  // Postgres and the broker are up before vitest starts, but a shard's payment
  // API may still be finishing its own migrations when the first worker boots.
  // Retry the whole app rather than a connection: a half-initialised Nest app
  // cannot be resumed, only closed and rebuilt.
  let lastErr: unknown;
  for (let attempt = 1; attempt <= 3; attempt++) {
    const app = await createFreightApp().catch((err) => {
      lastErr = err;
      return undefined;
    });
    if (app) {
      try {
        // A real port, not an ephemeral one: payment-api-it-{SHARD} calls back
        // in here for the inbound CBE Unified Bill query (cbe-bill.it.ts).
        await app.listen(API_PORT);
        console.log(tag(`freight-api in-process on :${API_PORT} → ${SHARD_DB}`));
        return app.getHttpServer();
      } catch (err) {
        lastErr = err;
        await app.close().catch(() => {});
      }
    }
    if (attempt < 3) await new Promise((r) => setTimeout(r, 2000 * attempt));
  }

  console.error(tag(`freight-api failed to boot on :${API_PORT} (${SHARD_DB})`), lastErr);
  throw lastErr;
}