/**
 * @file Two dashboards started at the same instant on a FRESH database must
 * both come up: server/db.js runs its probe-then-ALTER migrations under one
 * cross-process lock, so the second waits and then finds every column already
 * there instead of dying on "duplicate column name".
 * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
 */

const { it } = require("node:test");
const assert = require("node:assert/strict");
const fs = require("node:fs");
const os = require("node:os");
const path = require("node:path");
const { spawn } = require("node:child_process");

const DB_MODULE = path.join(__dirname, "..", "db.js");

function openDb(dbPath, dataDir) {
  return new Promise((resolve) => {
    const child = spawn(process.execPath, ["-e", `require(${JSON.stringify(DB_MODULE)})`], {
      env: { ...process.env, DASHBOARD_DB_PATH: dbPath, DASHBOARD_DATA_DIR: dataDir },
      stdio: ["ignore", "ignore", "pipe"],
    });
    let err = "";
    child.stderr.on("data", (d) => (err += d));
    child.on("exit", (code) => resolve({ code, err }));
  });
}

it("lets several processes open one fresh database at once", async () => {
  for (let round = 0; round < 3; round++) {
    const dir = fs.mkdtempSync(path.join(os.tmpdir(), "db-concurrent-"));
    try {
      const results = await Promise.all(
        Array.from({ length: 4 }, () => openDb(path.join(dir, "dashboard.db"), dir))
      );
      for (const r of results) assert.equal(r.code, 0, r.err.split("\n").slice(0, 6).join("\n"));
    } finally {
      fs.rmSync(dir, { recursive: true, force: true });
    }
  }
});