// -----------------------------------------------------------------------------
// Rent-Ka — Rental listings aggregator (Canada, outside Québec)
// Author: Simon-Pierre Boucher — contact@spboucher.ai
// components/ImmeubleBloc.tsx: "Building passport" block (detail page)
//   Everything is computed from what Rent-Ka actually observes (active AND
//   historical listings of the same building): units, median rents, turnover,
//   rent pressure. An indicator without a sufficient sample is shown as
//   "insufficient data" — never invented.
// -----------------------------------------------------------------------------
import { Immeuble, fmtPrice } from "../api";

const NBSP = " ";

const fmtTs = (ts: number | null | undefined): string =>
  ts
    ? new Date(ts * 1000).toLocaleDateString("en-CA", { month: "long", year: "numeric" })
    : "—";

const ROTATION_CLS: Record<string, string> = {
  // backend classes (bilingual for migration safety)
  "low": "zi-ok", "normal": "zi-nc", "high": "zi-modere", "very high": "zi-eleve",
  "faible": "zi-ok", "normale": "zi-nc", "élevée": "zi-modere", "très élevée": "zi-eleve",
};

export default function ImmeubleBloc({ im }: { im: Immeuble }) {
  // at least 2 grouped listings, otherwise the "passport" adds nothing
  if (!im || im.annonces_total < 2) return null;
  const rot = im.rotation;
  const pres = im.pression_loyers;
  const parCc = im.loyer_median_par_cc;

  return (
    <section className="f-bloc f-immeuble" id="immeuble">
      <h2>Building passport</h2>
      <div className="kv">
        <div className="cell">
          <div className="k">Listings observed</div>
          <div className="v">{im.annonces_total} <small>incl. {im.annonces_actives} active</small></div>
        </div>
        <div className="cell">
          <div className="k">Estimated units</div>
          <div className="v">≥{NBSP}{im.unites_estimees}</div>
        </div>
        {im.loyer_median != null && (
          <div className="cell">
            <div className="k">Median rent (active)</div>
            <div className="v">{fmtPrice(im.loyer_median)}</div>
          </div>
        )}
        {im.pi2_median != null && (
          <div className="cell">
            <div className="k">Median $/sq ft</div>
            <div className="v">${im.pi2_median.toFixed(2)}</div>
          </div>
        )}
      </div>

      {parCc && Object.keys(parCc).length > 0 && (
        <p className="im-parcc">
          By bedroom count:{" "}
          {Object.entries(parCc)
            .map(([cc, v]) => `${cc}${NBSP}bd ${fmtPrice(v)}`)
            .join(" · ")}
        </p>
      )}

      <div className="im-indicateurs">
        <div className="im-indic">
          <span className="k">Unit turnover</span>{" "}
          {rot.statut === "calculated" ? (
            <>
              <span className={`zi-badge ${ROTATION_CLS[rot.classe ?? ""] ?? "zi-nc"}`}>
                {rot.classe}
              </span>{" "}
              <span className="im-detail">
                {rot.annonces_12m} listing{(rot.annonces_12m ?? 0) > 1 ? "s" : ""} over
                12 months for ≥{NBSP}{rot.unites_estimees} units
              </span>
            </>
          ) : (
            <span className="zi-badge zi-nc">insufficient data</span>
          )}
        </div>
        <div className="im-indic">
          <span className="k">Rent pressure</span>{" "}
          {pres ? (
            <>
              <span className={`zi-badge ${pres.variation_12m > 0.05 ? "zi-modere" : pres.variation_12m < -0.02 ? "zi-ok" : "zi-nc"}`}>
                {pres.variation_12m > 0 ? "+" : "−"}
                {Math.abs(Math.round(pres.variation_12m * 100))}{NBSP}% over 12 months
              </span>{" "}
              <span className="im-detail">
                median asking price: {fmtPrice(pres.mediane_12_24m)} →{" "}
                {fmtPrice(pres.mediane_12m)} ({pres.n_12_24m} vs {pres.n_12m} listings)
              </span>
            </>
          ) : (
            <span className="zi-badge zi-nc">insufficient sample</span>
          )}
        </div>
      </div>

      <p className="fine">
        Building tracked by Rent-Ka since {fmtTs(im.premiere_observation)}
        {rot.statut === "calculated" && rot.methode ? ` — ${rot.methode}` : (
          " — indicators computed only from listings observed by Rent-Ka " +
          "syncs (not a census of the building)."
        )}
      </p>
    </section>
  );
}