"use client";

import { SweepButton } from "@/components/Buttons";
import { HexAvatar } from "@/components/HexAvatar";
import { useEffect, useRef, useState } from "react";
import type { DiscoverCategory } from "@/lib/discover";
import { fetchDiscover } from "@/lib/discover-client";
import type { ExpertResult } from "@/lib/experts-search";
import { fetchExperts } from "@/lib/experts-search-client";

export type SearchStatus = "idle" | "loading" | "ready" | "error";

export interface ExpertSearchViewProps {
  query: string;
  onQuery: (q: string) => void;
  categories: DiscoverCategory[];
  activeCategory: string | null;
  onCategory: (name: string | null) => void;
  status: SearchStatus;
  results: ExpertResult[];
}

export function ExpertSearchView(p: ExpertSearchViewProps) {
  return (
    <section className="tile panel expert-search" aria-labelledby="h-find">
      <div className="panel-head">
        <h2 id="h-find" className="type-title type-title-strong">Find experts</h2>
      </div>
      <form role="search" className="search-form" onSubmit={(e) => e.preventDefault()}>
        <label htmlFor="expert-q">Search experts</label>
        <div className="search-field">
          <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" aria-hidden="true">
            <circle cx="11" cy="11" r="7" /><path d="m20 20-3.5-3.5" />
          </svg>
          <input
            id="expert-q"
            type="search"
            value={p.query}
            placeholder="Name or topic"
            autoComplete="off"
            maxLength={80}
            onChange={(e) => p.onQuery(e.target.value)}
          />
        </div>
      </form>
      {p.categories.length > 0 ? (
        <div role="group" aria-label="Browse experts by category" className="chips">
          {p.categories.map((c) => (
            <SweepButton
              key={String(c.id)}
              label={c.name}
              selected={p.activeCategory === c.name}
              onClick={() => p.onCategory(p.activeCategory === c.name ? null : c.name)}
            />
          ))}
        </div>
      ) : null}
      <div aria-live="polite" className="search-results panel-scroll fade-edges">
        {p.status === "loading" ? <p className="search-note">Searching...</p> : null}
        {p.status === "error" ? <p className="search-note" role="alert">Search is unavailable. Try again.</p> : null}
        {p.status === "ready" && p.results.length === 0 ? (
          <p className="search-note">No experts found.</p>
        ) : null}
        {p.status === "ready" && p.results.length > 0 ? (
          <ul className="rail-list search-rows">
            {p.results.map((e) => (
              <li key={String(e.id)} className="expert-row" data-testid="search-result">
                <HexAvatar name={e.displayName} pictureUrl={e.pictureUrl} size="md" />
                <div className="expert-text">
                  <strong>{e.displayName || "Expert"}</strong>
                  {e.byline ? <span>{e.byline}</span> : null}
                </div>
                {e.rating !== null ? (
                  <span className="expert-rate" aria-label={`Rating ${e.rating.toFixed(1)}`}>
                    <svg viewBox="0 0 24 24" fill="currentColor" aria-hidden="true"><path d="m12 2.8 2.9 5.9 6.5.9-4.7 4.6 1.1 6.5L12 17.6l-5.8 3.1 1.1-6.5L2.6 9.6l6.5-.9L12 2.8Z" /></svg>
                    {e.rating.toFixed(1)}
                  </span>
                ) : null}
              </li>
            ))}
          </ul>
        ) : null}
      </div>
    </section>
  );
}

const DEBOUNCE_MS = 300;

export function ExpertSearch() {
  const [query, setQuery] = useState("");
  const [category, setCategory] = useState<string | null>(null);
  const [categories, setCategories] = useState<DiscoverCategory[]>([]);
  const [status, setStatus] = useState<SearchStatus>("idle");
  const [results, setResults] = useState<ExpertResult[]>([]);
  const seq = useRef(0);

  useEffect(() => {
    let live = true;
    fetchDiscover().then(
      (d) => { if (live) setCategories(d.categories); },
      () => {},
    );
    return () => { live = false; };
  }, []);

  useEffect(() => {
    const q = query.trim();
    const mine = ++seq.current;
    if (!q && !category) {
      setStatus("idle");
      setResults([]);
      return;
    }
    setStatus("loading");
    const t = setTimeout(() => {
      fetchExperts(q ? { q } : { category: category ?? undefined }).then(
        (r) => { if (seq.current === mine) { setResults(r); setStatus("ready"); } },
        () => { if (seq.current === mine) { setResults([]); setStatus("error"); } },
      );
    }, q ? DEBOUNCE_MS : 0);
    return () => clearTimeout(t);
  }, [query, category]);

  return (
    <ExpertSearchView
      query={query}
      onQuery={setQuery}
      categories={categories}
      activeCategory={category}
      onCategory={setCategory}
      status={status}
      results={results}
    />
  );
}