import { randomUUID } from "node:crypto";
import { beforeEach, describe, expect, it } from "vitest";
import { deviceEvents as deviceEventsTable, ledgerEvents, sessions, type Db } from "@parking/db";
import { createTestDb } from "@parking/db/testing";
import { flagDuplicateEntryPlate } from "./snapshot.js";
import { makeLog, silentLogger } from "./test-helpers.js";
import type { EventLog } from "./event-log.js";

// Entry-side duplicate-plate reconciliation (2026-07-04): when ANPR recognizes a plate on
// a fresh transient entry and that plate is already OPEN under another RECENT session,
// the same car most likely minted a second ticket (a motion radar dropped the stationary
// car → the button re-armed). We sign ONE entry.duplicatePlate anomaly for the operator
// to void. Post-hoc + advisory: recognition never gates the (already-open) barrier —
// exactly the non-blocking role the plate can play here.

let db: Db;
let log: EventLog;

const PLATE = "AA111BB";
const OLD = "11111111111";
const NEW = "22222222222";

beforeEach(() => {
  ({ db } = createTestDb());
  log = makeLog(db);
});

/** Seed the prior entry's unsigned plate-read telemetry (what recognizePlate records). */
function seedPriorRead(opts: { identity?: string; plate?: string; direction?: string; agoMs?: number } = {}) {
  db.insert(deviceEventsTable).values({
    id: randomUUID(),
    deviceId: "cam-entry",
    category: "camera",
    kind: "read",
    detail: {
      identity: opts.identity ?? OLD,
      direction: opts.direction ?? "entry",
      plate: opts.plate ?? PLATE,
      snapshotId: "snap-old",
      source: "entry-exit-snapshot",
    },
    occurredAt: new Date(Date.now() - (opts.agoMs ?? 60_000)).toISOString(),
  }).run();
}

function seedSession(id: string, state: "open" | "closed") {
  db.insert(sessions).values({
    id,
    identity: id,
    source: "ticket",
    enteredAt: new Date(Date.now() - 60_000).toISOString(),
    state,
  }).run();
}

const flag = () =>
  flagDuplicateEntryPlate({ db, log, identity: NEW, plate: PLATE, snapshotId: "snap-new", logger: silentLogger() });

const anomalies = () =>
  db.select().from(ledgerEvents).all().filter((r) => r.type === "anomaly");

describe("flagDuplicateEntryPlate", () => {
  it("same plate OPEN under another recent session → signs ONE entry.duplicatePlate anomaly", async () => {
    seedPriorRead();
    seedSession(OLD, "open");
    await flag();
    expect(anomalies()).toHaveLength(1);
    const a = anomalies()[0];
    expect(a.identity).toBe(NEW); // keyed to the NEW (suspect) ticket
    expect(a.payload).toMatchObject({
      reasonCode: "entry.duplicatePlate",
      duplicateEntrySuspected: true,
      plate: PLATE,
      otherIdentity: OLD,
      snapshotId: "snap-new",
    });
  });

  it("prior session already CLOSED → no anomaly (that car drove off; a re-visit is legit)", async () => {
    seedPriorRead();
    seedSession(OLD, "closed");
    await flag();
    expect(anomalies()).toHaveLength(0);
  });

  it("prior read outside the window → no anomaly (stale coincidence, not a double press)", async () => {
    seedPriorRead({ agoMs: 30 * 60_000 }); // beyond the 15-min default window
    seedSession(OLD, "open");
    await flag();
    expect(anomalies()).toHaveLength(0);
  });

  it("own read (same identity) never flags itself", async () => {
    seedPriorRead({ identity: NEW });
    seedSession(NEW, "open");
    await flag();
    expect(anomalies()).toHaveLength(0);
  });

  it("different plate / exit-side reads are ignored", async () => {
    seedPriorRead({ plate: "ZZ999ZZ" });
    seedPriorRead({ direction: "exit" });
    seedSession(OLD, "open");
    await flag();
    expect(anomalies()).toHaveLength(0);
  });
});