import { eq, ledgerEvents, siteConfig, type Db } from "@parking/db";
import {
  printWithFailover,
  registry,
  type PrinterDevice,
  type PrinterInstance,
  type ReceiptData,
  type TicketHeader,
  printerRoleOf,
} from "@parking/devices";
import type { FastifyBaseLogger } from "fastify";
import { devicesByDirection } from "./device-resolve.js";

// Booth-side printing for the EXIT VOUCHER ("biletë dalje"). When the booth is far
// from the exit, the customer pays at the booth and walks a printed voucher to the
// exit, where they self-scan it. The voucher reprints the SAME ticket id as a
// Code128 barcode (now a paid session) — so the exit reader runs the normal exit
// validation and opens. See wiki/concepts/booth-exit-flow.md, ticket-encoding.md.
//
// This mirrors the entry flow's printer selection + header build, but prints on the
// BOOTH printer (role "booth-receipt") since that's where the operator stands.

/** Park identity for the voucher header, from site_config (all fields optional). */
function ticketHeader(db: Db): TicketHeader | undefined {
  const row = db.select().from(siteConfig).where(eq(siteConfig.id, 1)).get();
  if (!row) return undefined;
  return {
    parkName: row.parkName,
    operatorName: row.operatorName,
    nius: row.nius,
    address: row.address,
    phone: row.phone,
  };
}

/** Build live printer instances for failover selection (entry direction covers the
 *  booth-receipt role too — the booth printer is configured on the entry side). */
function loadPrinters(db: Db): PrinterInstance[] {
  const rows = devicesByDirection(db, "printer", "entry");
  const out: PrinterInstance[] = [];
  for (const row of rows) {
    const driver = registry.get(row.driverId);
    if (!driver) continue;
    const cfg = row.config as Record<string, unknown>;
    const role = printerRoleOf(cfg);
    try {
      out.push({
        id: row.id,
        role,
        failoverRank: typeof cfg.failoverRank === "number" ? cfg.failoverRank : 0,
        device: driver.create(cfg as never) as PrinterDevice,
      });
    } catch {
      // skip a printer whose config won't build
    }
  }
  return out;
}

/** The receipt figures for a paid session, folded from the SIGNED ledger
 *  (authoritative). Null if there's no entry or no payment for this id — the
 *  caller should have validated paid + open before printing. */
function receiptFigures(
  db: Db,
  ticketId: string,
): Omit<ReceiptData, "voucher" | "header"> | null {
  const rows = db
    .select()
    .from(ledgerEvents)
    .where(eq(ledgerEvents.identity, ticketId))
    .orderBy(ledgerEvents.index)
    .all();
  const entry = rows.find((r) => r.type === "vehicle_entry");
  if (!entry) return null;
  // The LATEST payment is the one we receipt (an overstay top-up re-pays).
  let payment: (typeof rows)[number] | undefined;
  for (const r of rows) if (r.type === "payment") payment = r;
  if (!payment) return null;
  const p = (payment.payload ?? {}) as {
    amountMinor?: number;
    currency?: string;
    tender?: "cash" | "card";
    graceExitMin?: number;
    grossMinor?: number;
    validationLines?: { label: string; discountMinor: number }[];
  };
  return {
    ticketId,
    enteredAt: entry.occurredAt,
    paidAt: payment.occurredAt,
    amountMinor: typeof p.amountMinor === "number" ? p.amountMinor : 0,
    currency: p.currency ?? "ALL",
    tender: p.tender === "card" ? "card" : "cash",
    graceExitMin: typeof p.graceExitMin === "number" ? p.graceExitMin : null,
    // Merchant validations, as settled on the signed payment (gross → lines → net).
    grossMinor: typeof p.grossMinor === "number" ? p.grossMinor : null,
    validationLines: Array.isArray(p.validationLines) ? p.validationLines : undefined,
  };
}

/**
 * Print a PAYMENT RECEIPT for a paid session on the booth printer (failing over
 * to the entry dispenser). The receipt is the customer's transparency record:
 * entry time, payment time, duration, amount + tender — folded from the signed
 * ledger. In VOUCHER mode it also carries the scannable ticket-id barcode + the
 * walk-back grace, so the one slip both proves payment AND self-exits at a
 * distant exit reader (this replaces the old barcode-only voucher). In standalone
 * mode (`voucher:false`) it is detail-only, printed at payment when the booth is
 * at the exit. Returns the id of the printer that printed it.
 * Throws NoPrinterAvailableError if none can; throws if the session isn't payable.
 */
export async function printPaymentReceipt(
  db: Db,
  ticketId: string,
  opts: { voucher: boolean },
  logger: FastifyBaseLogger,
): Promise<string> {
  const figures = receiptFigures(db, ticketId);
  if (!figures) {
    throw new Error(`no paid session to receipt for ${ticketId}`);
  }
  const printers = loadPrinters(db);
  const data: ReceiptData = {
    ...figures,
    voucher: opts.voucher,
    header: ticketHeader(db),
  };
  // Prefer the booth printer (operator is at the booth); fall back to the dispenser.
  const printedBy = await printWithFailover(printers, "booth-receipt", (d: PrinterDevice) =>
    d.printReceipt(data),
  );
  logger.info(
    `${opts.voucher ? "exit voucher" : "payment receipt"} for ${ticketId} printed on ${printedBy}`,
  );
  return printedBy;
}

/**
 * Print a SUBSCRIPTION CARD on the booth printer (failing over to the dispenser):
 * a scannable QR of the credential code + holder/validity, so the operator can hand
 * it to the customer. Used on subscription creation and on a "reprint" action.
 * Returns the printer that printed it; throws NoPrinterAvailableError if none can.
 */
export async function printSubscriptionCard(
  db: Db,
  card: { code: string; holderName?: string | null; validFrom?: string | null; validTo?: string | null },
  logger: FastifyBaseLogger,
): Promise<string> {
  const printers = loadPrinters(db);
  const data = {
    code: card.code,
    holderName: card.holderName ?? null,
    validFrom: card.validFrom ?? null,
    validTo: card.validTo ?? null,
    header: ticketHeader(db),
  };
  const printedBy = await printWithFailover(printers, "booth-receipt", (d: PrinterDevice) =>
    d.printSubscriptionCard(data),
  );
  logger.info(`subscription card ${card.code} printed on ${printedBy}`);
  return printedBy;
}

/**
 * Print an ADVISORY "out-of-window" slip when a subscriber enters (or exits) outside
 * their plan's allowed hours. It is NOT a payable ticket and carries NO final amount —
 * the total is computed at the booth on settlement (early-entry AND any late-exit time
 * combined). It just gives the subscriber paper proof that a fee is pending against this
 * occurrence. Albanian (like every customer-facing slip — see i18n.md). Best-effort:
 * the caller swallows failures so a missing printer never blocks the barrier.
 */
export async function printWindowChargeNotice(
  db: Db,
  notice: { occurrenceId: string; holderName?: string | null; at: string; windowOpensMin?: number | null; edge: "entry" | "exit" },
  logger: FastifyBaseLogger,
): Promise<string> {
  const printers = loadPrinters(db);
  const printedBy = await printWithFailover(printers, "booth-receipt", (d: PrinterDevice) =>
    d.printWindowChargeNotice({
      occurrenceId: notice.occurrenceId,
      holderName: notice.holderName ?? null,
      at: notice.at,
      edge: notice.edge,
      windowOpensMin: notice.windowOpensMin ?? null,
      header: ticketHeader(db),
    }),
  );
  logger.info(`out-of-window notice printed for ${notice.occurrenceId} on ${printedBy}`);
  return printedBy;
}