/**
 * Remote OK public feed.
 *
 * https://remoteok.com/api — single JSON endpoint that returns the entire
 * active remote-jobs board in one shot. The first array element is metadata
 * (legal/attribution); jobs follow.
 *
 * No auth, no server-side pagination, no per-term query — we fetch once per
 * pipeline run and apply each `searchTerm` as a case-insensitive filter over
 * `position` + `tags` so the orchestrator's per-term iteration still works.
 *
 * Per Remote OK's TOS we send a descriptive User-Agent so they can identify
 * traffic; we do not strip the legal/attribution element from the response.
 */

import type {
  ExtractorManifest,
  ExtractorRunResult,
} from "@shared/types/extractors";
import type { CreateJobInput } from "@shared/types/jobs";

const API_URL = "https://remoteok.com/api";
const USER_AGENT =
  "Mozilla/5.0 (compatible; JobOps/1.0; +https://github.com/) job-search pipeline";

interface RemoteOkJob {
  id?: string | number;
  slug?: string;
  position?: string;
  company?: string;
  company_logo?: string;
  logo?: string;
  location?: string;
  tags?: string[];
  description?: string;
  url?: string;
  apply_url?: string;
  date?: string;
  epoch?: number;
  salary_min?: number;
  salary_max?: number;
}

interface RemoteOkLegalEntry {
  legal?: string;
  last_updated?: number;
}

type RemoteOkResponseEntry = RemoteOkJob | RemoteOkLegalEntry;

function asString(value: unknown): string | undefined {
  if (typeof value !== "string") return undefined;
  const trimmed = value.trim();
  return trimmed ? trimmed : undefined;
}

function isJobEntry(entry: RemoteOkResponseEntry): entry is RemoteOkJob {
  return (
    "id" in entry || "position" in entry || "url" in entry || "slug" in entry
  );
}

function tagMatchesTerm(job: RemoteOkJob, normalizedTerm: string): boolean {
  if (!normalizedTerm) return true;
  const haystack = [
    job.position ?? "",
    ...(Array.isArray(job.tags) ? job.tags : []),
  ]
    .join(" ")
    .toLowerCase();
  return haystack.includes(normalizedTerm);
}

function mapJob(job: RemoteOkJob): CreateJobInput | null {
  const jobUrl = asString(job.url) ?? asString(job.apply_url);
  if (!jobUrl) return null;

  // Remote OK reports salary as raw numbers; 0 means "not specified".
  const minSalary =
    typeof job.salary_min === "number" && job.salary_min > 0
      ? job.salary_min
      : undefined;
  const maxSalary =
    typeof job.salary_max === "number" && job.salary_max > 0
      ? job.salary_max
      : undefined;

  const tags = Array.isArray(job.tags)
    ? job.tags.filter((tag): tag is string => typeof tag === "string")
    : [];

  return {
    source: "remoteok",
    sourceJobId: job.id != null ? String(job.id) : asString(job.slug),
    title: asString(job.position) ?? "Unknown Title",
    employer: asString(job.company) ?? "Unknown Employer",
    jobUrl,
    applicationLink: asString(job.apply_url) ?? jobUrl,
    location: asString(job.location) ?? "Remote",
    isRemote: true,
    datePosted: asString(job.date),
    jobDescription: asString(job.description),
    companyLogo: asString(job.company_logo) ?? asString(job.logo),
    disciplines: tags.length > 0 ? tags.join(", ") : undefined,
    salaryMinAmount: minSalary,
    salaryMaxAmount: maxSalary,
    salaryCurrency: minSalary || maxSalary ? "USD" : undefined,
    salaryInterval: minSalary || maxSalary ? "yearly" : undefined,
  };
}

async function fetchAll(): Promise<RemoteOkJob[]> {
  const response = await fetch(API_URL, {
    headers: {
      Accept: "application/json",
      "User-Agent": USER_AGENT,
    },
  });
  if (!response.ok) {
    throw new Error(`Remote OK request failed with status ${response.status}`);
  }
  const body = (await response.json()) as RemoteOkResponseEntry[];
  if (!Array.isArray(body)) return [];
  return body.filter(isJobEntry);
}

export const manifest: ExtractorManifest = {
  id: "remoteok",
  displayName: "Remote OK",
  providesSources: ["remoteok"],
  async run(context): Promise<ExtractorRunResult> {
    if (context.shouldCancel?.()) return { success: true, jobs: [] };

    const maxJobsPerTerm = context.settings.remoteokMaxJobsPerTerm
      ? Number.parseInt(context.settings.remoteokMaxJobsPerTerm, 10)
      : 100;

    const terms = context.searchTerms.length > 0 ? context.searchTerms : [""];

    let allJobs: RemoteOkJob[];
    try {
      allJobs = await fetchAll();
    } catch (error) {
      const message = error instanceof Error ? error.message : "Unknown error";
      return { success: false, jobs: [], error: message };
    }

    const seen = new Set<string>();
    const out: CreateJobInput[] = [];

    for (let i = 0; i < terms.length; i += 1) {
      if (context.shouldCancel?.()) break;
      const term = terms[i].trim();
      const normalizedTerm = term.toLowerCase();
      context.onProgress?.({
        phase: "list",
        termsProcessed: i,
        termsTotal: terms.length,
        currentUrl: term || "(all remote)",
        detail: `Remote OK: term ${i + 1}/${terms.length}`,
      });

      let collected = 0;
      for (const job of allJobs) {
        if (collected >= maxJobsPerTerm) break;
        if (!tagMatchesTerm(job, normalizedTerm)) continue;
        const mapped = mapJob(job);
        if (!mapped) continue;
        const key = mapped.sourceJobId || mapped.jobUrl;
        if (seen.has(key)) continue;
        seen.add(key);
        out.push(mapped);
        collected += 1;
      }

      context.onProgress?.({
        phase: "list",
        termsProcessed: i + 1,
        termsTotal: terms.length,
        currentUrl: term || "(all remote)",
        jobPagesProcessed: out.length,
        detail: `Remote OK: completed term ${i + 1}/${terms.length} (${collected} matched)`,
      });
    }

    return { success: true, jobs: out };
  },
};

export default manifest;