import { slugify, USER_AGENT } from "./http";
import type { ScrapedJob, Scraper } from "./types";

// Adecco has no public API, but its job search page loads results from this internal JSON endpoint
// (a Solr-style query passed as `queryString`). Unknown filter fields are silently ignored by the
// API, so results are checked against the requested category.
const API_URL = "https://www.adecco.com/api/data/jobs/summarized";
const JOB_PAGE = "https://www.adecco.com/sl-si/prosta-delovna-mesta";
const MAX_PAGES = 50; // 10 jobs per page

interface AdeccoJob {
  jobId: string;
  jobTitle: string;
  jobLocation: string | null;
  cityName: string | null;
  postedDate: string | null;
  jobCategoryId: string | null;
  jobSubCategoryId: string | null;
  contractTypeTitle: string | null;
  employmentTypeTitle: string | null;
  industryTypeTitle: string | null;
}

interface AdeccoResponse {
  jobs?: AdeccoJob[];
  pagination?: { total: number; nextRange: number };
}

/** The site builds "<title>-<location>/<jobid>" URLs; only the job ID matters, the slug is cosmetic. */
function jobUrl(j: AdeccoJob): string {
  const slug = slugify(`${j.jobTitle}-${j.jobLocation ?? ""}`);
  return `${JOB_PAGE}/${slug}/${j.jobId.toLowerCase()}`;
}

/**
 * Scraper for adecco.com (Slovenia), filtered by job category.
 * `category` is the CategoryFilter value from the site's URL, e.g. "ADCSICAT014" (IT).
 */
export function adecco(category: string, label: string): Scraper {
  return {
    id: `adecco-si-${category.toLowerCase()}`,
    name: `Adecco (${label})`,
    async scrape() {
      const raw: AdeccoJob[] = [];
      for (let page = 0, range = 0; page < MAX_PAGES; page++) {
        const res = await fetch(API_URL, {
          method: "POST",
          headers: { "User-Agent": USER_AGENT, "content-type": "text/plain;charset=UTF-8" },
          body: JSON.stringify({
            queryString: `&fq=JobCategoryId:${category}`,
            range,
            siteName: "adecco",
            brand: "adecco",
            countryCode: "SI",
            languageCode: "sl-SI",
          }),
        });
        if (!res.ok) throw new Error(`POST ${API_URL} -> HTTP ${res.status}`);
        const data = (await res.json()) as AdeccoResponse;
        if (!Array.isArray(data.jobs)) throw new Error("unexpected API response (no `jobs` array)");
        raw.push(...data.jobs);
        const total = data.pagination?.total ?? 0;
        if (data.jobs.length === 0 || raw.length >= total || !data.pagination?.nextRange) break;
        range = data.pagination.nextRange;
      }

      const jobs = raw.filter((j) => j.jobCategoryId === category || j.jobSubCategoryId === category);
      if (raw.length > 0 && jobs.length === 0) {
        throw new Error(`category filter ${category} was ignored by the API (query format changed?)`);
      }

      return jobs.map((j) => ({
        externalId: j.jobId,
        title: j.jobTitle.trim(),
        url: jobUrl(j),
        location: j.cityName || j.jobLocation || undefined,
        tags: [j.contractTypeTitle, j.employmentTypeTitle, j.industryTypeTitle].filter(
          (t): t is string => !!t?.trim(),
        ),
        postedAt: j.postedDate ?? undefined,
      }));
    },
  };
}