// BookMyShow (in.bookmyshow.com) provider.
//
// BMS sits behind Cloudflare bot management that rejects Node's fetch and curl with 403
// regardless of headers or cookies: the block is on the TLS/HTTP2 fingerprint. `impit`
// performs the request with a real Chrome fingerprint, which is why it is a dependency.
//
// Unlike District there is no 204. A date that is not on sale yet answers 200 with a
// short body that simply has no `showtimeWidgets` key, so "closed" is inferred from the
// payload rather than the status code.
import { CheckError } from "../lib.js";

export const key = "bookmyshow";
export const label = "BookMyShow";

let Impit = null;
let client = null;

async function getClient(cfg) {
  if (client) return client;
  if (!Impit) ({ Impit } = await import("impit"));
  // With socks5:// impit resolves DNS locally and asks the proxy for that address,
  // which fails outright on an IPv6-only exit that cannot reach the IPv4 we picked.
  // socks5h:// leaves resolution to the proxy, so normalize to it.
  const proxyUrl = cfg.proxyUrl ? cfg.proxyUrl.replace(/^socks5:\/\//i, "socks5h://") : "";
  client = new Impit({
    browser: "chrome",
    ...(proxyUrl ? { proxyUrl } : {}),
  });
  return client;
}

/** BMS dates are YYYYMMDD; the rest of the app speaks YYYY-MM-DD. */
export const toDateCode = (isoDate) => isoDate.replaceAll("-", "");

function apiUrl(p, date) {
  const q = new URLSearchParams({
    etCodes: p.eventCode,
    dateCode: toDateCode(date),
    isDesktop: "true",
    regionCode: p.regionCode,
    xLocationShared: "false",
    memberId: "", lsId: "", subCode: "",
    appCode: "WEB",
    refEventCode: p.refEventCode || p.eventCode,
    ...(p.language ? { language: p.language } : {}),
  });
  return `https://in.bookmyshow.com/api/movies-data/v5/showtimes-by-event/primary-dynamic?${q}`;
}

/** Generated by the BMS web client itself, not issued by the server. */
const bmsId = () => `1.${Math.floor(Math.random() * 9e8 + 1e8)}.${Date.now()}`;

export async function check(cfg, p, date) {
  const impit = await getClient(cfg);
  let res, text;
  try {
    res = await impit.fetch(apiUrl(p, date), {
      headers: {
        accept: "application/json, text/plain, */*",
        "x-region-code": p.regionCode,
        "x-region-slug": p.regionSlug,
        "x-latitude": p.lat,
        "x-longitude": p.lng,
        "x-bms-id": bmsId(),
        "x-app-code": "WEB",
        "x-platform-code": "WEB",
        "x-platform": "WEB",
      },
    });
    text = await res.text();
  } catch (err) {
    throw new CheckError(`fetch failed: ${err.message}`);
  }
  if (res.status !== 200) throw new CheckError(`HTTP ${res.status}`);
  let data;
  try {
    data = JSON.parse(text);
  } catch (err) {
    throw new CheckError(`unparseable body: ${err.message}`);
  }
  // No showtime widgets at all means the date has not gone on sale.
  if (!data?.data?.showtimeWidgets) return { kind: "closed" };
  return { kind: "open", data };
}

/** Venue cards sit several widget layers deep, so walk rather than index blindly. */
function collectVenueCards(node, out = []) {
  if (Array.isArray(node)) {
    for (const n of node) collectVenueCards(n, out);
  } else if (node && typeof node === "object") {
    if (node.type === "venue-card") out.push(node);
    for (const v of Object.values(node)) collectVenueCards(v, out);
  }
  return out;
}

/** Seat tiers live in the double-tap bottom sheet: type, price and an availability word. */
function tiersOf(showtime, cfg) {
  const widgets = showtime?.customGestureCTA?.additionalData?.bottomSheetData?.widgets ?? [];
  return widgets
    .filter((w) => w?.variableData?.seatType)
    .map((w) => {
      const v = w.variableData;
      const cost = String(v.seatCost || "").replace(/[^\d.]/g, "");
      const price = cost ? `${cfg.currency}${Math.round(Number(cost))}` : "";
      return `${v.seatType} ${price} (${v.seatAvalibility || ""})`.replace(/\s+/g, " ").trim();
    })
    .join(" · ");
}

function formatOf(showtime) {
  return String(showtime.screenAttr || showtime?.additionalData?.attributes || "");
}

function isMatch(showtime, p) {
  if (!p.formatMatch) return true;
  return formatOf(showtime).toUpperCase().includes(p.formatMatch.toUpperCase());
}

export function extract(data, cfg, p) {
  const cards = collectVenueCards(data?.data?.showtimeWidgets ?? []);
  const out = { matched: [], other: [], cinemaCount: cards.length, sessionCount: 0, showDates: [] };
  for (const card of cards) {
    const info = card.additionalData ?? {};
    const name = info.venueName || info.venueCode || "unknown venue";
    for (const section of card.showtimesSections ?? []) {
      for (const st of section.showtimes ?? []) {
        out.sessionCount++;
        if (!isMatch(st, p)) continue;
        const ad = st.additionalData ?? {};
        const session = {
          sid: String(ad.sessionId || `${info.venueCode}-${ad.showTimeCode || st.title}`),
          cinema: name,
          // BMS already returns local wall-clock time, so no timezone shift is applied.
          time: ad.showTime || st.title || "",
          audi: "",
          format: formatOf(st),
          // BMS exposes availability words per tier, never exact seat counts.
          avail: null,
          total: null,
          tiers: tiersOf(st, cfg),
        };
        const wanted = !p.venueId || String(info.venueCode) === String(p.venueId);
        (wanted ? out.matched : out.other).push(session);
      }
    }
  }
  return out;
}