import test from "node:test";
import assert from "node:assert/strict";
import { createRequire } from "node:module";
import { spawnSync } from "node:child_process";
import { mkdtempSync, readFileSync, rmSync } from "node:fs";
import { dirname, join } from "node:path";
import { fileURLToPath } from "node:url";
import { tmpdir } from "node:os";

const require = createRequire(import.meta.url);
const Database = require("better-sqlite3");
const { createBackupService, safeSegment } = require("../server/backup_service.js");
const projectRoot = dirname(dirname(fileURLToPath(import.meta.url)));

function createTestDb(dataDir) {
  const db = new Database(join(dataDir, "rc_timing.sqlite"));
  db.exec(`
    CREATE TABLE app_state (id INTEGER PRIMARY KEY, state_json TEXT NOT NULL, updated_at TEXT NOT NULL);
    CREATE TABLE passings (id INTEGER PRIMARY KEY AUTOINCREMENT, session_id TEXT NOT NULL);
  `);
  db.prepare("INSERT INTO app_state (id, state_json, updated_at) VALUES (1, ?, ?)").run(JSON.stringify({ events: [{ id: "event_1" }] }), "2026-08-31T10:00:00.000Z");
  db.prepare("INSERT INTO passings (session_id) VALUES (?)").run("session_1");
  return db;
}

test("backup service creates consistent SQLite snapshots and metadata", async () => {
  const dataDir = mkdtempSync(join(tmpdir(), "racecore-backup-"));
  const db = createTestDb(dataDir);
  try {
    const service = createBackupService({ db, dataDir, maxBackups: 3, now: () => new Date("2026-08-31T10:15:30.123Z") });
    const backup = await service.createBackup({ reason: "pre_start", sessionId: "session_1", eventId: "event_1" });
    assert.match(backup.fileName, /pre_start__session_1\.sqlite$/);
    assert.equal(backup.reason, "pre_start");
    assert.ok(backup.sizeBytes > 0);

    db.prepare("UPDATE app_state SET state_json = ? WHERE id = 1").run(JSON.stringify({ changed: true }));
    const snapshot = new Database(join(dataDir, "backups", backup.fileName), { readonly: true });
    try {
      assert.deepEqual(JSON.parse(snapshot.prepare("SELECT state_json FROM app_state WHERE id = 1").get().state_json), { events: [{ id: "event_1" }] });
      assert.equal(snapshot.prepare("SELECT COUNT(*) AS count FROM passings").get().count, 1);
    } finally {
      snapshot.close();
    }

    const listed = service.listBackups();
    assert.equal(listed.length, 1);
    assert.equal(listed[0].sessionId, "session_1");
    const metadata = JSON.parse(readFileSync(join(dataDir, "backups", backup.fileName.replace(/\.sqlite$/, ".json")), "utf8"));
    assert.equal(metadata.eventId, "event_1");
  } finally {
    db.close();
    rmSync(dataDir, { recursive: true, force: true });
  }
});

test("backup service keeps only the configured number of snapshots", async () => {
  const dataDir = mkdtempSync(join(tmpdir(), "racecore-backup-retention-"));
  const db = createTestDb(dataDir);
  let index = 0;
  try {
    const service = createBackupService({ db, dataDir, maxBackups: 2, now: () => new Date(1_800_000_000_000 + index++ * 1000) });
    await service.createBackup({ reason: "manual", sessionId: "one" });
    await service.createBackup({ reason: "manual", sessionId: "two" });
    await service.createBackup({ reason: "manual", sessionId: "three" });
    const listed = service.listBackups();
    assert.equal(listed.length, 2);
    assert.ok(listed.some((item) => item.sessionId === "three"));
    assert.ok(!listed.some((item) => item.sessionId === "one"));
  } finally {
    db.close();
    rmSync(dataDir, { recursive: true, force: true });
  }
});

test("local restore validates and replaces a stopped test database with a safety backup", async () => {
  const dataDir = mkdtempSync(join(tmpdir(), "racecore-restore-"));
  let db = createTestDb(dataDir);
  try {
    const service = createBackupService({ db, dataDir, maxBackups: 5 });
    const backup = await service.createBackup({ reason: "manual", sessionId: "session_1" });
    db.prepare("UPDATE app_state SET state_json = ? WHERE id = 1").run(JSON.stringify({ changed: true }));
    db.close();
    db = null;

    const result = spawnSync(process.execPath, [join(projectRoot, "scripts", "restore-backup.js"), backup.fileName, "--confirm"], {
      cwd: projectRoot,
      env: { ...process.env, RC_TIMING_DATA_DIR: dataDir, RC_TIMING_PID_FILE: join(dataDir, "missing.pid") },
      encoding: "utf8",
    });
    assert.equal(result.status, 0, result.stderr || result.stdout);
    const restored = new Database(join(dataDir, "rc_timing.sqlite"), { readonly: true });
    try {
      assert.deepEqual(JSON.parse(restored.prepare("SELECT state_json FROM app_state WHERE id = 1").get().state_json), { events: [{ id: "event_1" }] });
    } finally {
      restored.close();
    }
    const safetyFiles = service.listBackups().filter((item) => item.reason === "pre_restore");
    assert.equal(safetyFiles.length, 1);
  } finally {
    if (db) db.close();
    rmSync(dataDir, { recursive: true, force: true });
  }
});

test("backup file segments are bounded and filesystem safe", () => {
  assert.equal(safeSegment("A final / ../ unsafe"), "a-final-unsafe");
  assert.equal(safeSegment(""), "backup");
});