Files
parking_solution/packages/devices/src/drivers/printer-rongta.ts
T
julian 7366ad19cb feat(printer): USB transport behind the ESC/POS render layer
The ESC/POS printer drivers were TCP-only — every path went through
sendRaw/probe to a raw socket on port 9100. Add a USB transport behind
the existing render layer without touching a single render*() function.

- printer-escpos.ts: sendRawUsb/probeUsb write the same ESC/POS bytes to a
  kernel usblp char device (/dev/usb/lp0) via a plain fs write — no
  libusb/CUPS/native dep (keeps MIT-only + minimal-deps appliance). A
  discriminated Transport + transportFromConfig/sendTo/probeTo dispatch the
  wire; anything not transport:"usb" is TCP, so existing host-only configs
  need no migration. Shared transportField/devicePathField config fields.
- cashino + rongta resolve a Transport once; both are reachability-only over
  USB, and the Rongta's HTTP status page degrades to the open-the-node probe
  over USB (no guessed paper/cover — the standing honesty rule). host/port
  made not-required so a USB printer needs neither.
- Tests: printer-escpos.test.ts (USB writes the exact rendered bytes; probe
  present/absent; transportFromConfig TCP back-compat) + printer-cashino.test.ts
  (USB-configured driver prints to the node, ready/offline).

USB itself is unverified on hardware (the on-site printers are networked);
the appliance-side usblp + udev provisioning is tracked as open-questions #14.

Claude-Session: https://claude.ai/code/session_01Xcm6ikLgGoCxxHrxtjkk5V
2026-06-24 20:32:10 +02:00

335 lines
12 KiB
TypeScript

import { request as httpRequest } from "node:http";
import type {
Device,
DeviceHealth,
MonitorableDevice,
PrinterDevice,
PrinterStatus,
PrintReport,
SubscriptionCardData,
TicketData,
WindowChargeNoticeData,
} from "../interfaces.js";
import type { ConfigField, DeviceConfig, PrinterDriver } from "../registry.js";
import { hostField, portField, stubLog } from "./common.js";
import {
devicePathField,
probeTo,
renderReceipt,
renderReport,
renderSubscriptionCard,
renderTicket,
renderWindowChargeNotice,
sendTo,
transportField,
transportFromConfig,
type Transport,
} from "./printer-escpos.js";
// Rongta 80mm thermal printer driver (network OR USB). Rongta RP-series printers
// (and the many OEM clones that share their firmware) speak ESC/POS over a raw TCP
// socket on port 9100 — the JetDirect/RAW convention — or over a local USB usblp
// char device. The ESC/POS rendering + transport are shared with the other ESC/POS
// clones in ./printer-escpos.ts (config.transport picks the wire); what is unique to
// Rongta — and lives here — is LIVE STATUS via the board's own status web page. That
// page is a NETWORK feature: a USB Rongta degrades to reachability-only monitoring
// (see readStatus). There is no auth on the print socket; like the other field
// devices a networked unit lives on the isolated device VLAN.
// See wiki/entities/rongta-printer.md and wiki/concepts/network-isolation.md.
//
// ROLES + FAILOVER: a lane has more than one printer. Each instance declares a
// `role` (entry-dispenser at the lane / booth-receipt in the booth) and a
// `failoverRank`. The entry flow prints on the highest-rank healthy printer for
// the wanted role and falls back to the next — so if the outside dispenser is
// offline, the booth printer prints the entry ticket as a backup. The driver
// itself is role-agnostic; the role/rank live in config and the caller (server)
// owns the failover selection. See wiki/concepts/printer-roles-failover.md.
// --- live status via the device's own status web page -------------------------
// The Rongta board serves /prn_stat.htm, a small HTML table where the DEVICE has
// already decoded the ESC/POS status bits into labelled Yes/No rows. We scrape
// that rather than send raw `DLE EOT` ourselves: on this clone the DLE EOT reply
// bytes don't follow the canonical bit layout (verified on hardware), so trusting
// the device's own decode is the safe choice. See printer-status-monitoring.md.
// A clone that does NOT serve this page (e.g. the Cashino) uses its own driver
// with a plain reachability probe — it must not pretend to report paper/cover.
/** The fault flags the status page reports (a subset of PrinterStatus). */
type StatusFlag =
| "coverOpen"
| "cutterError"
| "paperEnd"
| "paperNearEnd"
| "offline";
type StatusFlags = Partial<Record<StatusFlag, boolean>>;
/** Label text on the status page (NBSP/space-normalised, lowercased) → our key. */
const STATUS_FIELDS: Record<string, StatusFlag> = {
"cover is open": "coverOpen",
"cutter error": "cutterError",
"paper end": "paperEnd",
"paper near end": "paperNearEnd",
"printer off-line": "offline",
};
/** GET the status page over HTTP and return the raw HTML. */
function fetchStatusPage(
host: string,
httpPort: number,
timeoutMs: number,
): Promise<string> {
return new Promise((resolve, reject) => {
const req = httpRequest(
{
host,
port: httpPort,
path: "/prn_stat.htm",
method: "GET",
timeout: timeoutMs,
},
(res) => {
let data = "";
res.on("data", (c) => (data += c));
res.on("end", () =>
res.statusCode === 200
? resolve(data)
: reject(new Error(`status page HTTP ${res.statusCode}`)),
);
},
);
req.on("error", reject);
req.on("timeout", () => req.destroy(new Error("status page timeout")));
req.end();
});
}
/**
* Parse /prn_stat.htm into boolean flags. Each fault is a `<TD>label</TD>
* <TD>Yes|No</TD>` pair. Returns only the recognised fields; a missing field is
* left undefined so the caller can detect an unexpected page (fail safe, not a
* false "ok").
*/
function parseStatusPage(html: string): StatusFlags {
const out: StatusFlags = {};
const rowRe = /<TD[^>]*>([^<]*?)<\/TD>\s*<TD[^>]*>([^<]*?)<\/TD>/gi;
let m: RegExpExecArray | null;
while ((m = rowRe.exec(html))) {
if (m[1] === undefined || m[2] === undefined) continue;
const label = m[1]
.replace(/&nbsp;/gi, " ")
.replace(/\s+/g, " ")
.trim()
.toLowerCase();
const value = m[2]
.replace(/&nbsp;/gi, " ")
.trim()
.toLowerCase();
const key = STATUS_FIELDS[label];
if (key && (value === "yes" || value === "no")) {
out[key] = value === "yes";
}
}
return out;
}
class RongtaPrinter implements PrinterDevice, MonitorableDevice {
readonly driverId = "rongta";
readonly #transport: Transport;
readonly #host: string;
readonly #httpPort: number;
readonly #timeout: number;
constructor(config: DeviceConfig) {
this.#transport = transportFromConfig(config);
// Kept for the HTTP status page (TCP only); empty on a USB printer.
this.#host = config.host ? String(config.host) : "";
this.#httpPort = config.httpPort ? Number(config.httpPort) : 80;
this.#timeout = config.timeoutMs ? Number(config.timeoutMs) : 3000;
}
async connect(): Promise<void> {
await this.healthCheck();
}
async disconnect(): Promise<void> {
stubLog(this.driverId, "disconnect");
}
async healthCheck(): Promise<DeviceHealth> {
try {
await probeTo(this.#transport, this.#timeout);
return { status: "ready" };
} catch (err) {
return { status: "offline", detail: (err as Error).message };
}
}
async printTicket(data: TicketData): Promise<void> {
await sendTo(this.#transport, renderTicket(data), this.#timeout);
stubLog(this.driverId, `printed ticket ${data.ticketId}`);
}
async printReport(report: PrintReport): Promise<void> {
await sendTo(this.#transport, renderReport(report), this.#timeout);
stubLog(
this.driverId,
`printed report "${report.title}" (${report.lines.length} lines)`,
);
}
async printSubscriptionCard(data: SubscriptionCardData): Promise<void> {
await sendTo(this.#transport, renderSubscriptionCard(data), this.#timeout);
stubLog(this.driverId, `printed subscription card ${data.code}`);
}
async printReceipt(data: import("../interfaces.js").ReceiptData): Promise<void> {
await sendTo(this.#transport, renderReceipt(data), this.#timeout);
stubLog(
this.driverId,
`printed ${data.voucher ? "voucher" : "receipt"} ${data.ticketId}`,
);
}
async printWindowChargeNotice(data: WindowChargeNoticeData): Promise<void> {
await sendTo(this.#transport, renderWindowChargeNotice(data), this.#timeout);
stubLog(this.driverId, `printed out-of-window slip ${data.occurrenceId}`);
}
/**
* Live operator-actionable status, scraped from the device's own status page.
* The board decodes the ESC/POS status bits itself, so we trust its Yes/No
* over hand-decoding this clone's non-standard DLE EOT reply.
*
* - status page unreachable → offline (the same signal as a dead printer),
* - page reachable but a recognised field missing → degraded (don't claim
* "ready" off a page we didn't fully understand — fail safe),
* - any fault flag true → degraded,
* - otherwise → ready.
*/
async readStatus(): Promise<PrinterStatus> {
const checkedAt = new Date().toISOString();
// The status page is an HTTP feature of the network board; a USB printer has no
// such page. Degrade to the reachability floor (open the char device) and report
// ready/offline only — never a guessed paper/cover state, same honesty rule as
// the Cashino. (A USB Rongta is effectively a Cashino for monitoring purposes.)
if (this.#transport.kind === "usb") {
try {
await probeTo(this.#transport, this.#timeout);
return { status: "ready", checkedAt };
} catch (err) {
return { status: "offline", detail: (err as Error).message, checkedAt };
}
}
let html: string;
try {
html = await fetchStatusPage(this.#host, this.#httpPort, this.#timeout);
} catch (err) {
return { status: "offline", detail: (err as Error).message, checkedAt };
}
const flags = parseStatusPage(html);
const expected: StatusFlag[] = [
"coverOpen",
"cutterError",
"paperEnd",
"paperNearEnd",
"offline",
];
const missing = expected.filter((k) => flags[k] === undefined);
if (missing.length > 0) {
return {
status: "degraded",
detail: `unexpected status page (missing: ${missing.join(", ")})`,
checkedAt,
};
}
const faults = expected.filter((k) => flags[k] === true);
const labels: Record<StatusFlag, string> = {
paperEnd: "paper out",
coverOpen: "cover open",
cutterError: "cutter error",
offline: "printer off-line",
paperNearEnd: "paper low",
};
return {
status: faults.length > 0 ? "degraded" : "ready",
...flags,
detail:
faults.length > 0 ? faults.map((f) => labels[f]).join(", ") : undefined,
checkedAt,
};
}
}
/** Type guard: does this device carry a printer role (entry vs. booth)? */
export type PrinterRole = "entry-dispenser" | "booth-receipt";
const roleField: ConfigField = {
key: "role",
label: "Role",
type: "select",
required: true,
default: "entry-dispenser",
options: [
{
value: "entry-dispenser",
label: "Entry dispenser (outside / at the lane)",
},
{ value: "booth-receipt", label: "Booth printer (receipts + backup)" },
],
help: "Entry tickets print on the entry dispenser, falling back to the booth printer if it is offline.",
};
const rankField: ConfigField = {
key: "failoverRank",
label: "Failover rank",
type: "number",
required: false,
default: 0,
help: "Higher = tried first within the same role. The booth printer also backs up the entry dispenser.",
};
export const rongtaDriver: PrinterDriver = {
id: "rongta",
category: "printer",
label: "Rongta 80mm thermal printer",
description:
"Rongta RP-series 80mm thermal printer (and ESC/POS-compatible clones that serve the /prn_stat.htm status page) over raw TCP (port 9100), OR local USB /dev/usb/lp0. The decoded status page is a network feature — a USB Rongta is monitored by reachability only. No auth on the print socket — isolate the VLAN.",
transports: ["tcp-ip", "usb"],
configFields: [
transportField,
devicePathField,
// host/port/status-page are TCP-only; not required for a USB printer.
{ ...hostField, required: false, help: `${hostField.help} Leave blank for a USB printer.` },
{
...portField(9100),
required: false,
help: "Raw print socket (ESC/POS over JetDirect/RAW, default 9100). TCP only.",
},
{
key: "httpPort",
label: "Status web port",
type: "port",
required: false,
default: 80,
help: "Device status page (/prn_stat.htm) port for live monitoring (default 80). TCP only.",
},
roleField,
rankField,
{
key: "timeoutMs",
label: "Timeout (ms)",
type: "number",
required: false,
default: 3000,
},
],
create: (c) => new RongtaPrinter(c),
};
/** Type guard exposed for callers that need to read a device's printer role. */
export function isPrinter(device: Device): device is PrinterDevice {
return typeof (device as Partial<PrinterDevice>).printTicket === "function";
}