import { timingSafeEqual } from "node:crypto";
import { toBool, toNumber } from "./fields.js";

/** Constant-time string compare for shared webhook secrets. */
export function safeEqual(a: string, b: string): boolean {
  const ba = Buffer.from(a || "");
  const bb = Buffer.from(b || "");
  if (ba.length !== bb.length) return false;
  return timingSafeEqual(ba, bb);
}

/** Read a FluentForms compound name field, given as a nested object
 * (`names: {first_name,...}`) or flattened bracket keys (`names[first_name]`). */
export function nameGroup(body: Record<string, any>, base: string): string {
  const obj = body[base];
  let first: any, middle: any, last: any;
  if (obj && typeof obj === "object") {
    ({ first_name: first, middle_name: middle, last_name: last } = obj);
  } else {
    first = body[`${base}[first_name]`];
    middle = body[`${base}[middle_name]`];
    last = body[`${base}[last_name]`];
  }
  return [first, middle, last]
    .map((x) => (x == null ? "" : String(x).trim()))
    .filter(Boolean)
    .join(" ");
}

/** Read an item_quantity / payment field's numeric value (handles nested
 * objects like {quantity} / {value} and money strings like "$40.00"). */
export function qty(v: any): number {
  if (v == null || v === "") return 0;
  if (typeof v === "object") return toNumber(v.quantity ?? v.value ?? v.item_quantity ?? v.amount ?? 0);
  if (typeof v === "string") return toNumber(v.replace(/[^0-9.\-]/g, ""));
  return toNumber(v);
}

/** A payment/extra field counts as "selected" if it has a meaningful value.
 * Donor (free) items can be $0, so a non-empty, non-"no"/"0" value also counts. */
export function selected(v: any): boolean {
  if (v == null || v === "") return false;
  if (typeof v === "object") {
    if ("selected" in v) return toBool((v as any).selected);
    return qty(v) > 0 || Object.keys(v).length > 0;
  }
  const s = String(v).trim().toLowerCase();
  if (!s || s === "no" || s === "0" || s === "$0" || s === "$0.00" || s === "false" || s === "none") return false;
  return true;
}

/** Flatten a FluentForms compound address (`address_1`) to a single line. */
export function addressLine(v: any): string | undefined {
  if (v && typeof v === "object") return Object.values(v).filter(Boolean).join(", ");
  if (v !== undefined) return String(v);
  return undefined;
}

const NUMBER_WORDS: Record<string, number> = { one: 1, two: 2, three: 3, four: 4, five: 5, six: 6 };

/**
 * Total bags of ice from the `payment_ice` field. The form sends a descriptive
 * option label, e.g. "One Ice ticket good for one bag per day (3 total bags)",
 * so the reliable signal is the "(N total bags)" the label states. Falls back to
 * a worded ticket count ("Two Ice tickets" → 2 × bagsPerTicket), then to a
 * numeric dollar-total/ticket-count for forward compatibility.
 */
export function iceBagsFromPayment(
  value: unknown,
  opts: { bagsPerTicket: number; ticketPrice: number },
): number {
  const { bagsPerTicket, ticketPrice } = opts;
  const s = typeof value === "string" ? value : "";
  // Preferred: the label states the total bags directly.
  const bagsMatch = s.match(/(\d+)\s*total\s*bags/i);
  if (bagsMatch) return Math.max(0, parseInt(bagsMatch[1], 10));
  // Worded ticket count: "One Ice ticket", "Two Ice tickets".
  const wordMatch = s.match(/\b(one|two|three|four|five|six)\b\s+ice/i);
  if (wordMatch) return NUMBER_WORDS[wordMatch[1].toLowerCase()] * bagsPerTicket;
  // Numeric fallback: a dollar total (>= price) → tickets; else a small count.
  const n = qty(value);
  if (n <= 0) return 0;
  const tickets = n >= ticketPrice ? Math.round(n / ticketPrice) : Math.round(n);
  return Math.max(0, tickets) * bagsPerTicket;
}

/** Donor status from the hidden lookup fields + the "are you a donor?" radio. */
export function readDonor(body: Record<string, any>): { isDonor: boolean; donorTier: string } {
  const donorTier = String(body.donor_tier ?? "").trim();
  const isDonor =
    donorTier === "member" ||
    donorTier === "donor" ||
    toBool(body.donor_eligible) ||
    selected(body.input_radio); // "Are you a campground donor?"
  return { isDonor, donorTier };
}