/**
 * Parser for the "goauction" UK auction-house platform (Sworders, Chiswick Auctions, Dominic Winter …):
 *  - results calendar: `.auction-calendar-item` blocks with title, "Tuesday 21 April 2026" (or a range), sale number
 *    and a link carrying `au=<auctionId>`;
 *  - lot grid: `.auction-grid-lot` / `.auction-lot` cards with "Lot 12 - Title", optional `.sub-title`, image,
 *    "Sold for £1,800" (only sold lots carry a price; unsold lots show nothing), 48–96 per page, `<link rel="next">`.
 * Prices are what the house publishes as "Sold for" — the pages do not say hammer vs premium, so the basis is
 * left to each connector (null = unknown unless the house's terms say otherwise).
 */
import type { CurrencyCode } from '@rareindex/shared';
import { parseEuMoney } from './index.js';
import { absolute, chunksBetween, pick, textOf, type ParsedLot, type ParsedSalePage, type SaleRef } from './sale-results.js';

export interface GoauctionHouse {
  base: string;
  currency: CurrencyCode;
  /** path of the lot-list page: 'details' → /auction/details/<slug>/?au=ID ; 'search' → /Auction/Search?au=ID&sd=2 */
  listStyle: 'details' | 'search';
}

/**
 * "Tuesday 21 April 2026" | "Tuesday 1 September - Monday 7 September 2026" | "20th August 2026" | "4th Sep, 2026 12:00"
 * → first day ISO (UTC midnight).
 */
export function parseUkDate(text: string | null | undefined): string | null {
  if (!text) return null;
  const t = text.replace(/\s+/g, ' ').trim();
  const range = t.match(/(\d{1,2})(?:st|nd|rd|th)?\s+([A-Za-z]{3,9})?,?\s*-\s*[A-Za-z]*,?\s*(\d{1,2})(?:st|nd|rd|th)?\s+([A-Za-z]{3,9}),?\s+(\d{4})/);
  const m = range ? { d: range[1]!, mon: range[2] ?? range[4]!, y: range[5]! } : (() => {
    const s = t.match(/(\d{1,2})(?:st|nd|rd|th)?\s+([A-Za-z]{3,9})\.?,?\s+(\d{4})/);
    return s ? { d: s[1]!, mon: s[2]!, y: s[3]! } : null;
  })();
  if (!m) return null;
  const months = ['jan', 'feb', 'mar', 'apr', 'may', 'jun', 'jul', 'aug', 'sep', 'oct', 'nov', 'dec'];
  const mo = months.indexOf(m.mon.slice(0, 3).toLowerCase());
  if (mo < 0) return null;
  const d = new Date(Date.UTC(Number(m.y), mo, Number(m.d)));
  return Number.isNaN(d.getTime()) ? null : d.toISOString();
}

export function parseGoauctionCalendar(htmlText: string, house: GoauctionHouse): SaleRef[] {
  const out: SaleRef[] = [];
  const seen = new Set<string>();
  for (const chunk of chunksBetween(htmlText, /<div class="auction-calendar-item[^"]*"/)) {
    const au = chunk.match(/[?&](?:amp;)?au=(\d+)/)?.[1];
    if (!au || seen.has(au)) continue;
    const href = chunk.match(/href=['"]([^'"]*[?&](?:amp;)?au=\d+[^'"]*)['"]/)?.[1] ?? null;
    if (!href) continue;
    seen.add(au);
    const title = pick(chunk, /<H[3-6]>([\s\S]*?)<\/H[3-6]>/i) ?? pick(chunk, /alt="([^"]*)"/) ?? `Auction ${au}`;
    // Sworders: <h5>Tuesday 21 April 2026</h5>; Chiswick (timed): "Starts: 24th Aug, 2026 17:00 … Ends: 4th Sep, 2026 12:00";
    // Dominic Winter (sessions): "Lot: 1 to 410 - 2nd Sep, 2026 10:00" → first session day.
    const text = textOf(chunk.replace(/<a[^>]*>|<\/a>/g, ' '));
    const startsText = text.match(/Starts:\s*(\d{1,2}(?:st|nd|rd|th)?\s+[A-Za-z]{3,9},?\s+\d{4})/i)?.[1] ?? null;
    const endsText = text.match(/Ends:\s*(\d{1,2}(?:st|nd|rd|th)?\s+[A-Za-z]{3,9},?\s+\d{4})/i)?.[1] ?? null;
    const dateText = pick(chunk, /<h5>([\s\S]*?)<\/h5>/) ?? pick(chunk, /<p class="auction-calendar-date">([\s\S]*?)<\/p>/) ?? startsText ?? text.match(/((?:\d{1,2}(?:st|nd|rd|th)?\s+[A-Za-z]+,?\s*-\s*)?\d{1,2}(?:st|nd|rd|th)?\s+[A-Za-z]{3,9},?\s+\d{4})/)?.[1] ?? null;
    const saleNo = pick(chunk, /Sale number:\s*([A-Z0-9]+)/i);
    const timed = /timed online|Starts:/i.test(chunk);
    const resultsPublished = /View Results|Download PDF results/i.test(chunk);
    out.push({ id: au, title, url: absolute(house.base, href.replace(/&amp;/g, '&')) ?? `${house.base}/auction/details/?au=${au}`, date: parseUkDate(dateText), location: null, extra: { sale_number: saleNo, timed, date_text: dateText, end_date: parseUkDate(endsText), results_published: resultsPublished } });
  }
  return out;
}

export function parseGoauctionLots(htmlText: string, sale: SaleRef, house: GoauctionHouse): ParsedSalePage | null {
  if (!/class="auction-lot"|class='auction-grid-lot|class="auction-lot-title"/.test(htmlText)) return null;
  const lots: ParsedLot[] = [];
  for (const chunk of chunksBetween(htmlText, /<div class="auction-lot">/, /<nav class="pagination">|<footer|id="footer"/)) {
    const href = chunk.match(/href="([^"]*\/auction\/lot\/[^"]+)"/i)?.[1] ?? null;
    const titleBlock = chunk.match(/<span class='lot-title[^']*'>([\s\S]*?)<\/span>\s*<\/a>/)?.[1] ?? chunk.match(/<p class="auction-lot-title">([\s\S]*?)<\/p>/)?.[1] ?? null;
    if (!titleBlock) continue;
    const sub = pick(titleBlock, /<span class='sub-title[^']*'>([\s\S]*?)<\/span>/);
    const main = textOf(titleBlock.replace(/<span class='sub-title[^']*'>[\s\S]*?<\/span>/, ''));
    const lm = main.match(/^Lot\s+(\S+?)\s*(?:-|–|\s)\s*([\s\S]*)$/i);
    const lotNo = lm?.[1]?.replace(/[,:]$/, '') ?? chunk.match(/alt="(?:Lot\s+)?(\d+[A-Za-z]?)\s*-/)?.[1] ?? null;
    const title = (lm?.[2] ?? main).trim();
    if (!lotNo || !title) continue;
    const soldText = pick(chunk, /<strong[^>]*>\s*(Sold for[^<]*)<\/strong>/i);
    const price = soldText ? parseEuMoney(soldText.replace(/^Sold for\s*/i, ''), house.currency, 'en') : null;
    const image = chunk.match(/<img (?:src|data-lazy)="([^"]+)"/)?.[1] ?? null;
    const lotId = href?.match(/[?&](?:amp;)?lot=(\d+)/)?.[1] ?? null;
    lots.push({
      lotNo,
      title,
      subtitle: sub || null,
      description: null,
      url: absolute(house.base, href?.replace(/&amp;/g, '&')) ?? sale.url,
      image: image ? image.replace(/&amp;/g, '&') : null,
      price: price?.amount ?? null,
      currency: price?.currency ?? house.currency,
      premiumIncluded: null,
      estimateLow: null,
      estimateHigh: null,
      date: null,
      sold: price !== null,
      extra: { platform_lot_id: lotId, sold_text: soldText },
    });
  }
  const next = /<link rel="next" href="[^"]+"/.test(htmlText) || /class="next"[^>]*href=|rel="next"/.test(htmlText);
  const header = pick(htmlText, /<h1[^>]*>([\s\S]*?)<\/h1>/);
  const dateText = pick(htmlText, /((?:\d{1,2}(?:st|nd|rd|th)?\s+[A-Za-z]+\s*-\s*)?\d{1,2}(?:st|nd|rd|th)?\s+[A-Za-z]{3,9}\s+\d{4})\s*\|/);
  return { lots, hasMore: next, totalLots: null, sale: { title: header && header.length < 160 ? header : undefined, date: parseUkDate(dateText) ?? undefined } };
}

export function goauctionPageUrl(sale: SaleRef, page: number, house: GoauctionHouse): string {
  const u = new URL(sale.url);
  if (house.listStyle === 'search') {
    const au = u.searchParams.get('au') ?? sale.id;
    return `${house.base}/Auction/Search?au=${au}&sd=2${page > 1 ? `&pn=${page}` : ''}&g=1`;
  }
  u.searchParams.set('g', '1');
  if (page > 1) u.searchParams.set('pn', String(page));
  return u.toString();
}