import { eq, devices, ledgerEvents, type Db } from "@parking/db";
import { registry, formatStampSq as zStamp, type PrinterDevice } from "@parking/devices";
import type { LedgerPayload } from "@parking/shared";
import type { FastifyBaseLogger } from "fastify";
import type { EventLog } from "./event-log.js";

// Shift service (manned mode only). A shift is an operator's accountability period,
// delimited by EXPLICIT marks — not a clock. Represented entirely as signed ledger
// events (no mutable table): `shift_open` … `shift_z_report`. At close, sum the
// `payment` events taken during the shift by tender and print a Z-report.
// See wiki/concepts/shift.md.

export class ShiftAlreadyOpenError extends Error {
  /** The operator who currently holds the open shift (may be someone else). */
  readonly heldBy: string;
  constructor(operator: string, heldBy: string) {
    super(
      heldBy === operator
        ? `operator ${operator} already has an open shift`
        : `another operator (${heldBy}) has an open shift; only one shift may be open at a time`,
    );
    this.name = "ShiftAlreadyOpenError";
    this.heldBy = heldBy;
  }
}
export class NoOpenShiftError extends Error {
  constructor(operator: string) {
    super(`operator ${operator} has no open shift`);
    this.name = "NoOpenShiftError";
  }
}
/** Thrown by the booth money path when NO shift is open site-wide — an operator
 *  must open a shift before any payment/exit can be attributed to a shift. */
export class NoShiftOpenError extends Error {
  constructor() {
    super("no shift is open — open a shift before processing tickets");
    this.name = "NoShiftOpenError";
  }
}

/** A COMPLETED shift, reconstructed from its signed `shift_z_report` (which carries
 *  all the figures in its payload). This is the unit of the shift-history feature.
 *  `id` is the z_report's ledger id (stable, for the UI list key / future deep-link). */
export interface ShiftSummary {
  readonly id: string;
  readonly index: number;
  readonly operator: string;
  readonly startedAt: string;
  readonly endedAt: string;
  readonly cashTotalMinor: number;
  readonly cardTotalMinor: number;
  readonly currency: string | null;
  readonly paymentCount: number;
  readonly ticketTotalMinor: number;
  readonly subscriptionTotalMinor: number;
  readonly subscriptionSalesMinor: number;
  readonly subscriptionWindowMinor: number;
  readonly discountTotalMinor: number;
  readonly openingFloatMinor: number;
  readonly cashAddedMinor: number;
  readonly cashRemovedMinor: number;
  readonly expectedDrawerMinor: number;
}

export interface ShiftReport {
  readonly operator: string;
  readonly startedAt: string;
  readonly endedAt: string;
  readonly cashTotalMinor: number;
  readonly cardTotalMinor: number;
  readonly currency: string | null;
  readonly paymentCount: number;
  // --- Takings split by SOURCE (cash+card combined; the drawer cash/card stay above) ---
  /** Transient TICKET money (the default — any payment not flagged subscription). */
  readonly ticketTotalMinor: number;
  /** All SUBSCRIBER money = monthly sales + out-of-window charges. */
  readonly subscriptionTotalMinor: number;
  /** Subscription SALES only (the prepaid monthly/period fee). */
  readonly subscriptionSalesMinor: number;
  /** Subscriber OUT-OF-WINDOW transient-tariff charges only. */
  readonly subscriptionWindowMinor: number;
  /** Merchant-validation DISCOUNT total given away in the window (leakage — the
   *  cash/card figures above are already NET of it). See validation-discounts.md. */
  readonly discountTotalMinor: number;
  // --- Drawer (physical cash till; carries across shifts) ---
  /** Cash in the drawer at shift start = prior shift's expected closing drawer. */
  readonly openingFloatMinor: number;
  /** Admin cash LOADED into the drawer during the shift (sum of + movements). */
  readonly cashAddedMinor: number;
  /** Admin cash REMOVED from the drawer during the shift (sum of − movements, as +). */
  readonly cashRemovedMinor: number;
  /** Expected drawer at close = opening + cashTaken + added − removed. Carries forward. */
  readonly expectedDrawerMinor: number;
  readonly printed: boolean;
}

/** A drawer movement's admin-review status, derived from its latest `cash_review`. */
export type MovementStatus = "pending" | "authorized" | "denied";

/** One drawer cash movement (cash_in/cash_out) with its review status — the row shape for
 *  the operator's own list and the admin review queue. `status` is derived, not stored. */
export interface DrawerMovement {
  readonly id: string;
  readonly type: "cash_in" | "cash_out";
  /** Positive magnitude; direction is the `type`. */
  readonly amountMinor: number;
  readonly currency: string | null;
  readonly reason: string | null;
  readonly operator: string;
  readonly voucherNo: string | null;
  readonly at: string;
  readonly status: MovementStatus;
  readonly reviewedBy: string | null;
  readonly reviewNote: string | null;
  readonly reviewedAt: string | null;
}

export class InvalidCashMovementError extends Error {
  constructor(msg: string) {
    super(msg);
    this.name = "InvalidCashMovementError";
  }
}

export class ShiftService {
  readonly #db: Db;
  readonly #log: EventLog;
  readonly #logger: FastifyBaseLogger;

  constructor(db: Db, log: EventLog, logger: FastifyBaseLogger) {
    this.#db = db;
    this.#log = log;
    this.#logger = logger;
  }

  /** Current physical drawer balance (cash payments + cash_movements, by time). For
   *  the UI to show "inherited / in the drawer now". */
  drawerBalance(): { balanceMinor: number; currency: string | null } {
    return this.#drawerBalanceAt(new Date().toISOString());
  }

  /** Is there an open shift for this operator? Returns the open `shift_open` row or null. */
  openShiftFor(operator: string) {
    // Scan shift events for this operator; the shift is open if the most recent
    // shift event for them is a `shift_open` (not yet closed by a z_report).
    const rows = this.#db
      .select()
      .from(ledgerEvents)
      .where(eq(ledgerEvents.identity, operator))
      .orderBy(ledgerEvents.index)
      .all()
      .filter((r) => r.type === "shift_open" || r.type === "shift_z_report");
    const last = rows[rows.length - 1];
    return last && last.type === "shift_open" ? last : null;
  }

  /**
   * The SINGLE site-wide open shift, or null. A shift is a site-wide accountability
   * period: at most ONE may be open at a time (so booth takings are unambiguously
   * attributed to one operator). It's open iff the most recent shift event on the
   * whole chain is a `shift_open` (the matching `shift_z_report` hasn't been
   * appended yet). Returns that row so callers can read its operator/startedAt.
   */
  currentOpenShift() {
    const rows = this.#db
      .select()
      .from(ledgerEvents)
      .orderBy(ledgerEvents.index)
      .all()
      .filter((r) => r.type === "shift_open" || r.type === "shift_z_report");
    const last = rows[rows.length - 1];
    return last && last.type === "shift_open" ? last : null;
  }

  /**
   * COMPLETED shift history, newest first. Each closed shift is one signed
   * `shift_z_report` whose payload already holds every figure, so this is a simple
   * read of those rows (no re-summing). Optional filters:
   *   - operator: only this operator's shifts (the `identity` on the z_report).
   *   - from/to:  ISO timestamps; keep shifts whose START falls in [from, to].
   * The open shift (no z_report yet) is intentionally excluded — it's not a
   * completed accountability period. Use `currentOpenShift()` for the live one.
   */
  /**
   * Every operator that HAS a shift (closed z_reports + the open one, if any),
   * distinct + sorted — feeds the admin filter dropdown so it can only ever ask
   * for an operator that exists (the filter is an exact username match).
   */
  listOperators(): string[] {
    const rows = this.#db
      .select()
      .from(ledgerEvents)
      .where(eq(ledgerEvents.type, "shift_z_report"))
      .all();
    const names = new Set<string>();
    for (const r of rows) {
      const op = ((r.payload ?? {}) as { operator?: string }).operator ?? r.identity;
      if (op) names.add(op);
    }
    const open = this.currentOpenShift();
    const openOp = open ? (((open.payload ?? {}) as { operator?: string }).operator ?? open.identity) : null;
    if (openOp) names.add(openOp);
    return [...names].sort((a, b) => a.localeCompare(b));
  }

  listShifts(opts: { operator?: string; from?: string; to?: string } = {}): ShiftSummary[] {
    const rows = this.#db
      .select()
      .from(ledgerEvents)
      .where(eq(ledgerEvents.type, "shift_z_report"))
      .orderBy(ledgerEvents.index)
      .all();

    const out: ShiftSummary[] = [];
    for (const r of rows) {
      const pl = (r.payload ?? {}) as LedgerPayload & {
        operator?: string;
        startedAt?: string;
        endedAt?: string;
        cashTotalMinor?: number;
        cardTotalMinor?: number;
        paymentCount?: number;
        ticketTotalMinor?: number;
        subscriptionTotalMinor?: number;
        subscriptionSalesMinor?: number;
        subscriptionWindowMinor?: number;
        discountTotalMinor?: number;
        openingFloatMinor?: number;
        cashAddedMinor?: number;
        cashRemovedMinor?: number;
        expectedDrawerMinor?: number;
      };
      const operator = pl.operator ?? r.identity ?? "?";
      const startedAt = pl.startedAt ?? r.occurredAt;
      if (opts.operator && operator !== opts.operator) continue;
      if (opts.from && startedAt < opts.from) continue;
      if (opts.to && startedAt > opts.to) continue;
      out.push({
        id: r.id,
        index: r.index,
        operator,
        startedAt,
        endedAt: pl.endedAt ?? r.occurredAt,
        cashTotalMinor: pl.cashTotalMinor ?? 0,
        cardTotalMinor: pl.cardTotalMinor ?? 0,
        currency: pl.currency ?? null,
        paymentCount: pl.paymentCount ?? 0,
        // Split-by-source fields (added 2026-06-21). Old reports lack them → default the
        // subscription buckets to 0 and let ticket absorb the whole take, so the buckets
        // still reconcile to cash+card for a pre-split shift.
        subscriptionSalesMinor: pl.subscriptionSalesMinor ?? 0,
        subscriptionWindowMinor: pl.subscriptionWindowMinor ?? 0,
        subscriptionTotalMinor:
          pl.subscriptionTotalMinor ?? (pl.subscriptionSalesMinor ?? 0) + (pl.subscriptionWindowMinor ?? 0),
        ticketTotalMinor:
          pl.ticketTotalMinor ??
          (pl.cashTotalMinor ?? 0) + (pl.cardTotalMinor ?? 0) - (pl.subscriptionTotalMinor ?? 0),
        // Merchant-validation leakage (added 2026-07-13). Old reports lack it → 0.
        discountTotalMinor: pl.discountTotalMinor ?? 0,
        openingFloatMinor: pl.openingFloatMinor ?? 0,
        cashAddedMinor: pl.cashAddedMinor ?? 0,
        cashRemovedMinor: pl.cashRemovedMinor ?? 0,
        expectedDrawerMinor: pl.expectedDrawerMinor ?? 0,
      });
    }
    // Newest first for the history list.
    return out.reverse();
  }

  /** Require an open shift for the booth money path; returns it or throws. */
  requireOpenShift() {
    const open = this.currentOpenShift();
    if (!open) throw new NoShiftOpenError();
    return open;
  }

  /**
   * The physical drawer balance at `at`: a fold over the SIGNED chain BY TIME (not
   * by operator — a drawer voucher is the admin's, not the shift operator's). Cash
   * payments add to the drawer; card payments never touch it. Drawer movements adjust
   * it via three event types kept side-by-side:
   *   - `cash_in`  (Mandat Arkëtimi): + amountMinor (positive magnitude)
   *   - `cash_out` (Mandat Pagese):   − amountMinor (positive magnitude)
   *   - `cash_movement` (legacy, pre-2026-06-20): a SIGNED amountMinor (+ load / −
   *     removal) — historical chain events that still fold in unchanged.
   * This is what carries across shifts.
   */
  #drawerBalanceAt(at: string): { balanceMinor: number; currency: string | null } {
    const rows = this.#db
      .select()
      .from(ledgerEvents)
      .orderBy(ledgerEvents.index)
      .all()
      .filter(
        (r) =>
          r.occurredAt <= at &&
          (r.type === "payment" ||
            r.type === "cash_in" ||
            r.type === "cash_out" ||
            r.type === "cash_movement"),
      );
    let balanceMinor = 0;
    let currency: string | null = null;
    for (const r of rows) {
      const pl = (r.payload ?? {}) as LedgerPayload;
      const amt = typeof pl.amountMinor === "number" ? pl.amountMinor : 0;
      if (r.type === "payment") {
        // Only CASH enters the till; card settles to the bank.
        if (pl.tender !== "card") balanceMinor += amt;
      } else if (r.type === "cash_in") {
        balanceMinor += Math.abs(amt); // receipt — direction is the type
      } else if (r.type === "cash_out") {
        balanceMinor -= Math.abs(amt); // disbursement — direction is the type
      } else {
        // legacy cash_movement amount is signed (+ load, − removal).
        balanceMinor += amt;
      }
      if (pl.currency) currency = pl.currency;
    }
    return { balanceMinor, currency };
  }

  /** Next voucher number for a drawer-voucher type, e.g. `AR-0007` (cash_in) /
   *  `PA-0007` (cash_out). Sequential per type = count of existing events + 1. The
   *  number is human-facing (printed on the slip); the signed chain is the real
   *  record, so a small race only risks a duplicate label, never a lost voucher. */
  #nextVoucherNo(type: "cash_in" | "cash_out"): string {
    const prefix = type === "cash_in" ? "AR" : "PA";
    const count = this.#db.select().from(ledgerEvents).where(eq(ledgerEvents.type, type)).all().length;
    return `${prefix}-${String(count + 1).padStart(4, "0")}`;
  }

  /**
   * Record a drawer cash MOVEMENT — the direction is the event TYPE, not the sign of an
   * amount (a receipt and a disbursement are different financial documents):
   *   - `cash_in`  (Mandat Arkëtimi): cash entered the drawer (+).
   *   - `cash_out` (Mandat Pagese):   cash left the drawer (−).
   * `amountMinor` is always a POSITIVE magnitude. The movement is OPERATOR-RECORDED FREELY
   * (no admin sign-off at creation — 2026-07-01); an admin REVIEWS it after the fact via
   * `reviewMovement` (authorize/deny — a flag that never moves cash). It counts in the
   * drawer immediately (the cash physically moved). Returns the new drawer balance + the
   * assigned voucher number, and prints a slip best-effort. See wiki/concepts/shift.md.
   */
  async recordVoucher(args: {
    type: "cash_in" | "cash_out";
    operator: string;
    amountMinor: number;
    reason: string;
    currency?: string;
  }): Promise<{ type: "cash_in" | "cash_out"; amountMinor: number; voucherNo: string; balanceMinor: number; printed: boolean }> {
    const { type, operator, reason } = args;
    if (!Number.isInteger(args.amountMinor) || args.amountMinor <= 0) {
      throw new InvalidCashMovementError("amountMinor must be a positive integer (minor units)");
    }
    const amountMinor = args.amountMinor;
    const now = new Date().toISOString();
    const voucherNo = this.#nextVoucherNo(type);
    await this.#log.append({
      type,
      source: "manual",
      identity: operator, // who RECORDED the movement (the operator at the booth)
      payload: {
        amountMinor, // positive magnitude — direction is the type
        ...(reason ? { reason } : {}),
        ...(args.currency ? { currency: args.currency } : {}),
        operator,
        voucherNo,
      },
      occurredAt: now,
    });
    const { balanceMinor, currency } = this.#drawerBalanceAt(now);
    const printed = await this.#printVoucher({ type, voucherNo, amountMinor, reason, operator, currency, at: now });
    this.#logger.info(
      `${type} ${voucherNo} ${amountMinor} by ${operator} (${reason || "no reason"}) → drawer ${balanceMinor}`,
    );
    return { type, amountMinor, voucherNo, balanceMinor, printed };
  }

  /**
   * Admin's post-hoc REVIEW of a recorded cash_in/cash_out. Appends a signed `cash_review`
   * referencing the movement. This is a FLAG ONLY — a `deny` does NOT reverse the movement
   * and does NOT touch the drawer balance (a denial is a judgment about the operator,
   * settled outside the app). Rejects an unknown/ non-movement refId, and a movement that
   * was already decided (one decision per movement; a clean audit trail). Idempotent by
   * design: the drawer fold never reads `cash_review`. See wiki/concepts/shift.md.
   */
  async reviewMovement(args: {
    refId: string;
    decision: "authorize" | "deny";
    reviewedBy: string;
    note?: string;
  }): Promise<{ refId: string; decision: "authorize" | "deny"; reviewedBy: string; at: string }> {
    const { refId, decision, reviewedBy } = args;
    if (decision !== "authorize" && decision !== "deny") {
      throw new InvalidCashMovementError("decision must be authorize or deny");
    }
    const movement = this.#db.select().from(ledgerEvents).where(eq(ledgerEvents.id, refId)).get();
    if (!movement || (movement.type !== "cash_in" && movement.type !== "cash_out")) {
      throw new InvalidCashMovementError("refId is not a cash movement");
    }
    // One decision per movement — reject a re-review so the audit stays unambiguous.
    const already = this.#db
      .select()
      .from(ledgerEvents)
      .where(eq(ledgerEvents.type, "cash_review"))
      .all()
      .some((r) => (r.payload as LedgerPayload | null)?.refId === refId);
    if (already) throw new InvalidCashMovementError("movement already reviewed");

    const now = new Date().toISOString();
    await this.#log.append({
      type: "cash_review",
      source: "manual",
      identity: reviewedBy, // the admin who decided
      payload: {
        refId,
        decision,
        reviewedBy,
        ...(args.note ? { note: args.note } : {}),
      },
      occurredAt: now,
    });
    this.#logger.info(`cash_review ${decision} of ${movement.type} ${refId} by ${reviewedBy}`);
    return { refId, decision, reviewedBy, at: now };
  }

  /**
   * All drawer cash movements (cash_in/cash_out) with their review STATUS, newest first.
   * Status is derived from the latest `cash_review` referencing each movement: none →
   * `pending`, else `authorized`/`denied`. Powers the operator's own list and the admin
   * review queue. `operator` (optional) scopes to one operator's movements (an operator
   * sees only their own; a reviewer sees all). See wiki/concepts/shift.md.
   */
  movementsWithStatus(filter?: { operator?: string; status?: MovementStatus }): DrawerMovement[] {
    const rows = this.#db.select().from(ledgerEvents).orderBy(ledgerEvents.index).all();
    // Latest review decision per movement id.
    const reviewByRef = new Map<string, { decision: "authorize" | "deny"; reviewedBy: string; note?: string; at: string }>();
    for (const r of rows) {
      if (r.type !== "cash_review") continue;
      const pl = (r.payload ?? {}) as LedgerPayload;
      if (!pl.refId || (pl.decision !== "authorize" && pl.decision !== "deny")) continue;
      reviewByRef.set(pl.refId, {
        decision: pl.decision,
        reviewedBy: pl.reviewedBy ?? "",
        ...(pl.note ? { note: pl.note } : {}),
        at: r.occurredAt,
      });
    }
    const out: DrawerMovement[] = [];
    for (const r of rows) {
      if (r.type !== "cash_in" && r.type !== "cash_out") continue;
      const pl = (r.payload ?? {}) as LedgerPayload;
      const operator = (typeof pl.operator === "string" ? pl.operator : null) ?? r.identity ?? "";
      if (filter?.operator && operator !== filter.operator) continue;
      const review = reviewByRef.get(r.id);
      const status: MovementStatus = review ? (review.decision === "authorize" ? "authorized" : "denied") : "pending";
      if (filter?.status && status !== filter.status) continue;
      out.push({
        id: r.id,
        type: r.type,
        amountMinor: typeof pl.amountMinor === "number" ? Math.abs(pl.amountMinor) : 0,
        currency: pl.currency ?? null,
        reason: pl.reason ?? null,
        operator,
        voucherNo: pl.voucherNo ?? null,
        at: r.occurredAt,
        status,
        reviewedBy: review?.reviewedBy ?? null,
        reviewNote: review?.note ?? null,
        reviewedAt: review?.at ?? null,
      });
    }
    // Newest first.
    return out.sort((a, b) => (a.at < b.at ? 1 : a.at > b.at ? -1 : 0));
  }

  /** Open a shift for the operator (explicit start). The opening float is auto-
   *  inherited from the chain = the drawer balance at the start instant. */
  async open(operator: string): Promise<{ startedAt: string; openingFloatMinor: number }> {
    // Site-wide single-open invariant: refuse if ANY shift is open — whether this
    // operator's own (double-open) or another operator's (handover not done). Only
    // one accountability period at a time.
    const current = this.currentOpenShift();
    if (current) throw new ShiftAlreadyOpenError(operator, current.identity ?? operator);
    const startedAt = new Date().toISOString();
    const { balanceMinor: openingFloatMinor } = this.#drawerBalanceAt(startedAt);
    await this.#log.append({
      type: "shift_open",
      source: "manual",
      identity: operator, // the shift's operator; `identity` keys the shift to them
      // Record the inherited opening float on the shift_open so it's reproducible
      // and the next operator's handover figure is fixed in the chain.
      payload: { operator, openingFloatMinor },
      occurredAt: startedAt,
    });
    this.#logger.info(`shift opened for ${operator} (opening float ${openingFloatMinor})`);
    return { startedAt, openingFloatMinor };
  }

  /**
   * Project the drawer/takings figures for a shift's window `[startedAt, asOf]`.
   * Pure read over the signed chain — appends NOTHING — so it backs BOTH the
   * mid-shift X-report (asOf = now, shift still open) and the Z-report at close
   * (asOf = endedAt). The figures are identical projections; only the persistence
   * differs (X = read-only, Z = signed + carried forward).
   */
  #summariseWindow(
    open: typeof ledgerEvents.$inferSelect,
    asOf: string,
  ): Omit<ShiftReport, "printed"> {
    const operator = open.identity ?? "?";
    const startedAt = open.occurredAt;

    // All payments taken in [startedAt, asOf], summed by tender. Payment time =
    // the operator who handled the money (decision: sum by payment time).
    const payments = this.#db
      .select()
      .from(ledgerEvents)
      .where(eq(ledgerEvents.type, "payment"))
      .all()
      .filter((r) => r.occurredAt >= startedAt && r.occurredAt <= asOf);

    let cashTotalMinor = 0;
    let cardTotalMinor = 0;
    // Split by SOURCE: subscription SALES (the prepaid fee), subscriber OUT-OF-WINDOW
    // charges, and everything else = transient TICKET money. Both subscriber kinds roll
    // up into subscriptionTotal; the rest is ticketTotal. The flags ride the signed
    // payment payload (subscriptionSale / subscriptionWindowCharge — see pay-station +
    // the subscription sale path).
    let subscriptionSalesMinor = 0;
    let subscriptionWindowMinor = 0;
    // Merchant-validation leakage: Σ discountMinor across the window's payments. The
    // tender totals are already NET; this is the "given away" figure beside them.
    let discountTotalMinor = 0;
    let currency: string | null = null;
    for (const p of payments) {
      const pl = (p.payload ?? {}) as LedgerPayload & {
        subscriptionSale?: boolean;
        subscriptionWindowCharge?: boolean;
      };
      const amt = typeof pl.amountMinor === "number" ? pl.amountMinor : 0;
      if (pl.tender === "card") cardTotalMinor += amt;
      else cashTotalMinor += amt;
      if (pl.subscriptionSale === true) subscriptionSalesMinor += amt;
      else if (pl.subscriptionWindowCharge === true) subscriptionWindowMinor += amt;
      // (else → transient ticket; derived below as total − subscription)
      if (typeof pl.discountMinor === "number") discountTotalMinor += pl.discountMinor;
      if (pl.currency) currency = pl.currency;
    }
    const subscriptionTotalMinor = subscriptionSalesMinor + subscriptionWindowMinor;
    const ticketTotalMinor = cashTotalMinor + cardTotalMinor - subscriptionTotalMinor;

    // --- Drawer figures ---
    // Opening float was fixed on shift_open (inherited from the chain at start);
    // fall back to a fresh fold if an older shift_open lacks it.
    const openPl = (open.payload ?? {}) as LedgerPayload & { openingFloatMinor?: number };
    const openingFloatMinor =
      typeof openPl.openingFloatMinor === "number"
        ? openPl.openingFloatMinor
        : this.#drawerBalanceAt(startedAt).balanceMinor;

    // Drawer movements within the window, split into added (+) and removed (−).
    // Three side-by-side types: cash_in (+), cash_out (−), and the legacy signed-±
    // cash_movement. All carry a POSITIVE magnitude except legacy, which is signed.
    const movements = this.#db
      .select()
      .from(ledgerEvents)
      .all()
      .filter(
        (r) =>
          (r.type === "cash_in" || r.type === "cash_out" || r.type === "cash_movement") &&
          r.occurredAt >= startedAt &&
          r.occurredAt <= asOf,
      );
    let cashAddedMinor = 0;
    let cashRemovedMinor = 0;
    for (const m of movements) {
      const pl = (m.payload ?? {}) as LedgerPayload;
      const amt = typeof pl.amountMinor === "number" ? pl.amountMinor : 0;
      if (m.type === "cash_in") cashAddedMinor += Math.abs(amt);
      else if (m.type === "cash_out") cashRemovedMinor += Math.abs(amt);
      else if (amt >= 0) cashAddedMinor += amt; // legacy + load
      else cashRemovedMinor += -amt; // legacy − removal, store as positive magnitude
      if (pl.currency) currency = pl.currency;
    }

    // Expected drawer = opening + cash taken + added − removed. At close this is the
    // figure the NEXT shift inherits as its opening float.
    const expectedDrawerMinor = openingFloatMinor + cashTotalMinor + cashAddedMinor - cashRemovedMinor;

    return {
      operator,
      startedAt,
      endedAt: asOf,
      cashTotalMinor,
      cardTotalMinor,
      currency,
      paymentCount: payments.length,
      ticketTotalMinor,
      subscriptionTotalMinor,
      subscriptionSalesMinor,
      subscriptionWindowMinor,
      discountTotalMinor,
      openingFloatMinor,
      cashAddedMinor,
      cashRemovedMinor,
      expectedDrawerMinor,
    };
  }

  /**
   * Mid-shift X-report: a READ-ONLY "so far" snapshot of the open shift's takings +
   * drawer, computed as of now. Appends nothing (it's not an accountability mark —
   * the Z-report at close is). Returns null when no shift is open. The same
   * projection the Z-report prints, so the operator sees exactly what their close
   * will show. See wiki/concepts/shift.md.
   */
  currentReport(): (Omit<ShiftReport, "printed"> & { asOf: string }) | null {
    const open = this.currentOpenShift();
    if (!open) return null;
    const asOf = new Date().toISOString();
    return { ...this.#summariseWindow(open, asOf), asOf };
  }

  /** Close the operator's open shift: sum payments in the window, sign + print the Z-report. */
  async close(operator: string): Promise<ShiftReport> {
    const open = this.openShiftFor(operator);
    if (!open) throw new NoOpenShiftError(operator);
    const endedAt = new Date().toISOString();

    const report = this.#summariseWindow(open, endedAt);
    const {
      startedAt,
      cashTotalMinor,
      cardTotalMinor,
      currency,
      paymentCount,
      ticketTotalMinor,
      subscriptionTotalMinor,
      subscriptionSalesMinor,
      subscriptionWindowMinor,
      discountTotalMinor,
      openingFloatMinor,
      cashAddedMinor,
      cashRemovedMinor,
      expectedDrawerMinor,
    } = report;

    await this.#log.append({
      type: "shift_z_report",
      source: "manual",
      identity: operator,
      payload: {
        operator,
        startedAt,
        endedAt,
        cashTotalMinor,
        cardTotalMinor,
        currency: currency ?? undefined,
        paymentCount,
        ticketTotalMinor,
        subscriptionTotalMinor,
        subscriptionSalesMinor,
        subscriptionWindowMinor,
        discountTotalMinor,
        openingFloatMinor,
        cashAddedMinor,
        cashRemovedMinor,
        expectedDrawerMinor,
      },
    });

    const printed = await this.#printZReport(report);

    this.#logger.info(
      `shift closed for ${operator}: cash ${cashTotalMinor} card ${cardTotalMinor} (${paymentCount} payments); ` +
        `drawer open ${openingFloatMinor} +${cashAddedMinor} −${cashRemovedMinor} → expected ${expectedDrawerMinor}`,
    );
    return { ...report, printed };
  }

  /** Print the Z-report on a booth-receipt printer (best-effort; the signed event
   *  is the record — a failed print doesn't undo the close). */
  async #printZReport(r: Omit<ShiftReport, "printed">): Promise<boolean> {
    const printer = await this.#boothPrinter();
    if (!printer) {
      this.#logger.warn(`no booth-receipt printer — Z-report for ${r.operator} not printed (event is recorded)`);
      return false;
    }
    const cur = r.currency ?? "";
    const money = (m: number) => (m / 100).toFixed(2);
    // Customer/operator-facing print is Albanian (see i18n.md — printed slips are not
    // governed by the UI language), with human dates "19 Qershor 2026 10:48:25".
    const lines = [
      `Operatori: ${r.operator}`,
      `Nga:  ${zStamp(r.startedAt)}`,
      `Deri: ${zStamp(r.endedAt)}`,
      "",
      `Pagesa: ${r.paymentCount}`,
      `Para në dorë: ${money(r.cashTotalMinor)} ${cur}`,
      `Kartë:        ${money(r.cardTotalMinor)} ${cur}`,
      "",
      "-- Arkëtime sipas burimit --",
      `Bileta:       ${money(r.ticketTotalMinor)} ${cur}`,
      // Abonime is the subscription TOTAL; only the out-of-window part is broken out.
      // (subscriptionSalesMinor stays in the signed payload — it's just not printed.)
      `Abonime:       ${money(r.subscriptionTotalMinor)} ${cur}`,
      `Jashtë orarit: ${money(r.subscriptionWindowMinor)} ${cur}`,
      // Merchant-validation leakage — printed only when the shift actually gave any
      // (older slips stay byte-identical). The takings above are already NET of it.
      ...(r.discountTotalMinor > 0 ? [`Zbritje (validime): ${money(r.discountTotalMinor)} ${cur}`] : []),
      "",
      "-- Arka --",
      `Gjëndje fillestare:    ${money(r.openingFloatMinor)} ${cur}`,
      `Para të grumbulluara:  ${money(r.cashTotalMinor)} ${cur}`,
      `Arkëtime:              ${money(r.cashAddedMinor)} ${cur}`,
      `Pagesa:                ${money(r.cashRemovedMinor)} ${cur}`,
      `Gjëndje aktuale:       ${money(r.expectedDrawerMinor)} ${cur}`,
    ];
    try {
      await printer.printReport({ title: "RAPORT TURNI", lines });
      return true;
    } catch (err) {
      this.#logger.warn(`Z-report print failed for ${r.operator}: ${(err as Error).message} (event recorded)`);
      return false;
    }
  }

  /** Print a drawer-voucher slip (Mandat Arkëtimi / Mandat Pagese). Best-effort —
   *  the signed event is the record; a failed print doesn't undo the voucher.
   *  Albanian, like every customer/operator-facing slip (see i18n.md). */
  async #printVoucher(v: {
    type: "cash_in" | "cash_out";
    voucherNo: string;
    amountMinor: number;
    reason: string;
    operator: string;
    currency: string | null;
    at: string;
  }): Promise<boolean> {
    const printer = await this.#boothPrinter();
    if (!printer) {
      this.#logger.warn(`no booth-receipt printer — ${v.type} ${v.voucherNo} not printed (event recorded)`);
      return false;
    }
    const cur = v.currency ?? "";
    const money = (m: number) => (m / 100).toFixed(2);
    const title = v.type === "cash_in" ? "MANDAT ARKËTIMI" : "MANDAT PAGESE";
    const lines = [
      `Mandat Nr.: ${v.voucherNo}`,
      `Data: ${zStamp(v.at)}`,
      "",
      `Shuma: ${money(v.amountMinor)} ${cur}`,
      `Arsyeja: ${v.reason || "-"}`,
      "",
      `Regjistroi:   ${v.operator}`,
    ];
    try {
      await printer.printReport({ title, lines });
      return true;
    } catch (err) {
      this.#logger.warn(`${v.type} ${v.voucherNo} print failed: ${(err as Error).message} (event recorded)`);
      return false;
    }
  }

  /** First enabled booth-receipt printer, or any enabled printer. */
  async #boothPrinter(): Promise<PrinterDevice | null> {
    const rows = await this.#db.select().from(devices).where(eq(devices.category, "printer")).all();
    const enabled = rows.filter((r) => r.enabled);
    const booth = enabled.find((r) => (r.config as { role?: string }).role === "booth-receipt") ?? enabled[0];
    if (!booth) return null;
    const driver = registry.get(booth.driverId);
    if (!driver) return null;
    try {
      return driver.create(booth.config as never) as PrinterDevice;
    } catch {
      return null;
    }
  }
}