import { connect as netConnect } from "node:net";
import type {
  DeviceHealth,
  MonitorableDevice,
  PrinterDevice,
  PrinterStatus,
  PrintReport,
  ReceiptData,
  SubscriptionCardData,
  TicketData,
  WindowChargeNoticeData,
} from "../interfaces.js";
import type { ConfigField, DeviceConfig, PrinterDriver } from "../registry.js";
import { stubLog } from "./common.js";
import { transportFromConfig } from "./printer-escpos.js";
import { escposDriver } from "./printer-generic.js";

// K200L 80mm ESC/POS thermal printer (Xprinter / ICS "XP-K200L" family; label:
// "THERMAL RECEIPT PRINTER Model:K200L, Interface: USB+LAN, Command Support: ESC/POS").
// Its LAN board is the "J-Speed Ethernet Interface Module" (web UI "Ethernet WebConfig
// 1.02") and calls the printer "POS-80" — over USB it enumerates as 1fc9:2016
// "Printer POS-80". Identified on the lab bench 2026-09-09: it is the park-buzi unit.
// See wiki/entities/k200l-printer.md.
//
// PRINTING is the shared ESC/POS path (delegated to the generic driver — same bytes,
// same TCP-9100 / usblp transports). What this driver ADDS is live status: the board
// serves a status page, /prt_status.htm, with the same five decoded Yes/No rows the
// Rongta board serves under /prn_stat.htm (cover open, cutter error, paper end, paper
// near end, off-line). So over TCP the operator gets a real paper/cover verdict —
// the generic driver deliberately can't (reachability only), and the Rongta driver
// can't read THIS board either: its reply carries NO status line and NO headers
// (HTTP/0.9 style — the body starts at byte 0), which Node's http client rejects
// ("Parse Error: Expected HTTP/"). Hence the raw-socket fetch below, tolerant of both
// shapes. Over USB there is no page; status degrades to the reachability floor.
//
// Board facts worth knowing (all verified on the bench): factory address
// 192.168.123.100, DHCP off; web configurator on port 80 (Information / Configuration
// / Printer Status / Printer Test); the frameset reloads its frames every 1–3 s and
// the status page every 5 s, and the embedded HTTP server is tiny — leave the browser
// closed while the monitor polls, or connects will intermittently time out.

/** 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 (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",
};
const EXPECTED: readonly StatusFlag[] = ["coverOpen", "cutterError", "paperEnd", "paperNearEnd", "offline"];
const LABELS: Record<StatusFlag, string> = {
  paperEnd: "paper out",
  coverOpen: "cover open",
  cutterError: "cutter error",
  offline: "printer off-line",
  paperNearEnd: "paper low",
};

/** The board's status page. */
export const K200L_STATUS_PATH = "/prt_status.htm";

/**
 * GET `path` over a raw TCP socket and return whatever the board sent, verbatim,
 * once it closes the connection (HTTP/1.0 semantics — the board closes after the
 * reply). No HTTP parsing here: this board answers without a status line, which
 * node:http refuses to parse.
 */
export function fetchRaw(host: string, port: number, path: string, timeoutMs: number): Promise<string> {
  return new Promise((resolve, reject) => {
    const chunks: Buffer[] = [];
    let settled = false;
    const sock = netConnect({ host, port });
    const timer = setTimeout(() => {
      finish(() => reject(new Error("status page timeout")));
      sock.destroy();
    }, timeoutMs);
    const finish = (fn: () => void) => {
      if (settled) return;
      settled = true;
      clearTimeout(timer);
      fn();
    };
    sock.setNoDelay(true);
    sock.on("connect", () => {
      sock.write(`GET ${path} HTTP/1.0\r\nHost: ${host}\r\nConnection: close\r\n\r\n`);
    });
    sock.on("data", (c: Buffer) => chunks.push(c));
    sock.on("error", (err) => finish(() => reject(err)));
    sock.on("close", () => finish(() => resolve(Buffer.concat(chunks).toString("latin1"))));
  });
}

/**
 * Split a raw reply into its HTTP status and body. A reply that starts with a status
 * line is real HTTP (status + headers, body after the blank line); anything else is
 * the HTTP/0.9-style reply this board sends — the whole thing IS the body, status 200.
 */
export function parseRawReply(raw: string): { status: number; body: string } {
  const m = /^HTTP\/\d\.\d\s+(\d{3})[^\r\n]*\r?\n/.exec(raw);
  if (!m) return { status: 200, body: raw };
  const sep = raw.search(/\r?\n\r?\n/);
  const body = sep === -1 ? "" : raw.slice(sep).replace(/^\r?\n\r?\n/, "");
  return { status: Number(m[1]), body };
}

/** A cell's visible text: inner tags stripped (the board wraps a "Yes" in markup the
 *  "No" cells don't carry), entities and padding normalised, lowercased. */
function cellText(inner: string): string {
  return inner
    .replace(/<[^>]*>/g, "")
    .replace(/&nbsp;/gi, " ")
    .replace(/\s+/g, " ")
    .trim()
    .toLowerCase();
}

/**
 * Parse the status table into boolean flags. Each fault is a `<TD>label</TD>
 * <TD>Yes|No</TD>` pair (the board pads the value with spaces, and may wrap a fault's
 * "Yes" in its own tags — 2026-09-09, seen live as "missing coverOpen, paperEnd,
 * offline" with the cover open, i.e. exactly the Yes cells). Returns only the
 * recognised fields; a missing field stays undefined so the caller can detect an
 * unexpected page (fail safe, not a false "ok").
 */
export function parseStatusPage(html: string): StatusFlags {
  const out: StatusFlags = {};
  const rowRe = /<TR[^>]*>\s*<TD[^>]*>([\s\S]*?)<\/TD>\s*<TD[^>]*>([\s\S]*?)<\/TD>/gi;
  let m: RegExpExecArray | null;
  while ((m = rowRe.exec(html))) {
    if (m[1] === undefined || m[2] === undefined) continue;
    const key = STATUS_FIELDS[cellText(m[1])];
    const value = cellText(m[2]);
    if (key && (value === "yes" || value === "no")) out[key] = value === "yes";
  }
  return out;
}

class K200lPrinter implements PrinterDevice, MonitorableDevice {
  readonly driverId = "k200l";
  /** The print path — the generic ESC/POS device built from the SAME config. */
  readonly #print: PrinterDevice;
  readonly #tcp: boolean;
  readonly #host: string;
  readonly #httpPort: number;
  readonly #timeout: number;

  constructor(config: DeviceConfig) {
    this.#print = escposDriver.create(config) as PrinterDevice;
    this.#tcp = transportFromConfig(config).kind === "tcp";
    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.#print.connect();
  }

  async disconnect(): Promise<void> {
    await this.#print.disconnect();
    stubLog(this.driverId, "disconnect");
  }

  healthCheck(): Promise<DeviceHealth> {
    return this.#print.healthCheck();
  }

  printTicket(data: TicketData): Promise<void> {
    return this.#print.printTicket(data);
  }

  printReport(report: PrintReport): Promise<void> {
    return this.#print.printReport(report);
  }

  printSubscriptionCard(data: SubscriptionCardData): Promise<void> {
    return this.#print.printSubscriptionCard(data);
  }

  printReceipt(data: ReceiptData): Promise<void> {
    return this.#print.printReceipt(data);
  }

  printWindowChargeNotice(data: WindowChargeNoticeData): Promise<void> {
    return this.#print.printWindowChargeNotice(data);
  }

  /**
   * Live operator-actionable status from the board's own page.
   * - USB: no page — reachability floor only (ready/offline, never a guessed state);
   * - board unreachable / timeout → offline (the same signal as a dead printer);
   * - page reachable but not the status table (wrong path, index served, non-200) →
   *   degraded ("unexpected status page") — never "ready" off a page we didn't read;
   * - any fault flag true → degraded, with the faults named; otherwise → ready.
   */
  async readStatus(): Promise<PrinterStatus> {
    const checkedAt = new Date().toISOString();
    if (!this.#tcp) {
      const h = await this.#print.healthCheck();
      return { status: h.status === "ready" ? "ready" : "offline", detail: h.detail, checkedAt };
    }
    let raw: string;
    try {
      raw = await fetchRaw(this.#host, this.#httpPort, K200L_STATUS_PATH, this.#timeout);
    } catch (err) {
      return { status: "offline", detail: (err as Error).message, checkedAt };
    }
    const { status, body } = parseRawReply(raw);
    if (status !== 200) {
      return { status: "degraded", detail: `unexpected status page (${K200L_STATUS_PATH}: HTTP ${status})`, checkedAt };
    }
    const flags = parseStatusPage(body);
    const missing = EXPECTED.filter((k) => flags[k] === undefined);
    if (missing.length > 0) {
      return {
        status: "degraded",
        detail: `unexpected status page (${K200L_STATUS_PATH}: missing ${missing.join(", ")})`,
        checkedAt,
      };
    }
    const faults = EXPECTED.filter((k) => flags[k] === true);
    return {
      status: faults.length > 0 ? "degraded" : "ready",
      ...flags,
      detail: faults.length > 0 ? faults.map((f) => LABELS[f]).join(", ") : undefined,
      checkedAt,
    };
  }
}

const httpPortField: ConfigField = {
  key: "httpPort",
  label: "Status web port",
  type: "port",
  required: false,
  default: 80,
  help: "The board's web configurator port; the status page /prt_status.htm is read from it for live monitoring (default 80). TCP only.",
};

/** The generic driver's fields (transport, device path, host, port, role, rank,
 *  timeout) plus the status-page port, placed right after the print port. */
function k200lFields(): ConfigField[] {
  const out = [...escposDriver.configFields];
  const i = out.findIndex((f) => f.key === "port");
  out.splice(i === -1 ? out.length : i + 1, 0, httpPortField);
  return out;
}

export const k200lDriver: PrinterDriver = {
  id: "k200l",
  category: "printer",
  label: "K200L 80mm thermal printer (Xprinter / ICS, USB+LAN)",
  description:
    "Xprinter / ICS K200L (XP-K200L) 80mm ESC/POS printer; its LAN board reports itself as 'POS-80' (web configurator at 192.168.123.100:80 from the factory, DHCP off). Prints over raw TCP (port 9100) OR local USB /dev/usb/lp0 — the same bytes as the generic ESC/POS driver. Over TCP the board's /prt_status.htm page gives live paper / cover / cutter / off-line status; over USB there is no page, so it is monitored by reachability only. No auth on the print socket or the web UI — isolate the VLAN.",
  transports: ["tcp-ip", "usb"],
  configFields: k200lFields(),
  create: (c) => new K200lPrinter(c),
};