/**
 * Comms Express Scraper — comms-express.com
 *
 * UK-based reseller with excellent coverage of:
 * CFP, CFP2, CFP4, CFP2-DCO, CSFP, SFP-DD, QSFP112, OSFP, legacy GBIC/XENPAK/CXP
 * Good pricing transparency, cheerio-friendly.
 *
 * Schedule: every 8h
 */
import * as cheerio from "cheerio";
import { ensureVendor, upsertPriceObservation, findOrCreateScrapedTransceiver, pool } from "../utils/db";
import { contentHash, parsePrice, parseStockLevel } from "../utils/hash";
import { logger } from "../utils/logger";

const BASE = "https://www.comms-express.com";

// Categories mapped to form_factor
const CATEGORIES: Array<{ url: string; form_factor: string; speed_hint?: string }> = [
  { url: "/transceivers/sfp-modules/",                  form_factor: "SFP" },
  { url: "/transceivers/sfp-plus-modules/",             form_factor: "SFP+" },
  { url: "/transceivers/sfp28-modules/",                form_factor: "SFP28" },
  { url: "/transceivers/sfp56-modules/",                form_factor: "SFP56" },
  { url: "/transceivers/sfp-dd-modules/",               form_factor: "SFP-DD" },
  { url: "/transceivers/qsfp-modules/",                 form_factor: "QSFP+" },
  { url: "/transceivers/qsfp28-modules/",               form_factor: "QSFP28" },
  { url: "/transceivers/qsfp56-modules/",               form_factor: "QSFP56" },
  { url: "/transceivers/qsfp-dd-modules/",              form_factor: "QSFP-DD" },
  { url: "/transceivers/qsfp-dd-800-modules/",          form_factor: "QSFP-DD800" },
  { url: "/transceivers/qsfp112-modules/",              form_factor: "QSFP112" },
  { url: "/transceivers/osfp-modules/",                 form_factor: "OSFP" },
  { url: "/transceivers/osfp112-modules/",              form_factor: "OSFP112" },
  { url: "/transceivers/cfp-modules/",                  form_factor: "CFP" },
  { url: "/transceivers/cfp2-modules/",                 form_factor: "CFP2" },
  { url: "/transceivers/cfp2-dco-modules/",             form_factor: "CFP2-DCO" },
  { url: "/transceivers/cfp4-modules/",                 form_factor: "CFP4" },
  { url: "/transceivers/csfp-modules/",                 form_factor: "CSFP" },
  { url: "/transceivers/xfp-modules/",                  form_factor: "XFP" },
  { url: "/transceivers/cxp-modules/",                  form_factor: "CXP" },
  { url: "/transceivers/gbic-modules/",                 form_factor: "GBIC" },
  { url: "/transceivers/xenpak-modules/",               form_factor: "XENPAK" },
];

interface Product {
  partNumber: string;
  name: string;
  price: number;
  currency: string;
  stock: string;
  url: string;
  formFactor: string;
}

async function fetchCategory(cat: typeof CATEGORIES[0], vendorId: string, page = 1): Promise<Product[]> {
  const url = `${BASE}${cat.url}?page=${page}`;
  const resp = await fetch(url, {
    headers: { "User-Agent": "Mozilla/5.0 (compatible; TIPBot/1.0; +https://tip.context-x.org)" },
    signal: AbortSignal.timeout(30_000),
  });
  if (!resp.ok) return [];
  const html = await resp.text();
  const $ = cheerio.load(html);
  const products: Product[] = [];

  $(".product-item, .product-list-item, [data-product-id]").each((_, el) => {
    const $el = $(el);
    const name = $el.find(".product-name, .product-title, h3, h4").first().text().trim();
    const priceText = $el.find(".price, .product-price, [class*=price]").first().text().trim();
    const href = $el.find("a[href*='/transceivers/']").first().attr("href") || "";
    const partMatch = name.match(/[A-Z0-9]{2,4}-[A-Z0-9][A-Z0-9\-\.]+/) ||
                      href.match(/\/([A-Z0-9\-]{6,30})\/?$/i);
    const partNumber = partMatch ? partMatch[1] || partMatch[0] : name.substring(0, 40);
    const { price, currency } = parsePrice(priceText);
    const stockText = $el.find(".stock, .availability, [class*=stock]").first().text().trim();

    if (!partNumber || price <= 0) return;
    products.push({
      partNumber: partNumber.toUpperCase(),
      name,
      price,
      currency: currency || "GBP",
      stock: parseStockLevel(stockText),
      url: href.startsWith("http") ? href : `${BASE}${href}`,
      formFactor: cat.form_factor,
    });
  });

  // Check for next page
  const hasNext = $(".pagination .next, a[rel=next]").length > 0;
  if (hasNext && products.length > 0 && page < 20) {
    const next = await fetchCategory(cat, vendorId, page + 1);
    products.push(...next);
  }
  return products;
}

export async function scrapeCommsExpress(): Promise<void> {
  logger.info("Comms Express scraper starting");
  const vendorId = await ensureVendor("Comms Express", "https://www.comms-express.com");
  let total = 0;
  let newItems = 0;

  for (const cat of CATEGORIES) {
    try {
      const products = await fetchCategory(cat, vendorId);
      for (const p of products) {
        const transceiverResult = await findOrCreateScrapedTransceiver({
          partNumber: p.partNumber,
          vendorId,
          formFactor: p.formFactor,
          name: p.name,
          url: p.url,
        });
        const hash = contentHash(`${p.partNumber}:${p.price}:${p.currency}`);
        const isNew = await upsertPriceObservation({
          transceiverId: transceiverResult.id,
          sourceVendorId: vendorId,
          price: p.price,
          currency: p.currency,
          stockLevel: p.stock,
          url: p.url,
          contentHash: hash,
        });
        if (isNew) newItems++;
        total++;
      }
      if (products.length > 0) {
        logger.info(`Comms Express ${cat.form_factor}: ${products.length} products`);
      }
    } catch (e) {
      logger.warn(`Comms Express ${cat.form_factor} failed`, { err: e });
    }
  }
  logger.info(`Comms Express done — ${total} total, ${newItems} new`);
}