// app/api/options/lens/route.ts
import { NextResponse } from "next/server";
import { directusFetch } from "@/lib/directus";

type Target =
| "settings_fiber"
| "settings_uv"
| "settings_co2gal"
| "settings_co2gan";

/** Map target -> Directus collection */
function collectionForTarget(t?: string) {
  switch ((t ?? "") as Target) {
    case "settings_fiber":
    case "settings_uv":
    case "settings_co2gal":
      return "laser_scan_lens" as const;   // has field_size + focal_length
    case "settings_co2gan":
      return "laser_focus_lens" as const;  // has name (no focal_length)
    default:
      return null;
  }
}

/** Parse "110x110", "110×110", "110 x 110", or single "110" => {w,h} */
function parseFieldSize(raw: unknown): { w: number; h: number } | null {
  if (raw == null) return null;
  const s = String(raw).trim();
  const m = s.match(/(\d+(?:\.\d+)?)(?:\s*[x×]\s*(\d+(?:\.\d+)?))?/i);
  if (!m) return null;
  const w = Number(m[1]);
  const h = m[2] ? Number(m[2]) : w;
  if (!Number.isFinite(w) || !Number.isFinite(h)) return null;
  return { w, h };
}

const fmtNum = (n: number) =>
Number.isInteger(n) ? String(n) : String(n).replace(/\.0+$/, "");
const dimsText = (d: { w: number; h: number }) => `${fmtNum(d.w)}x${fmtNum(d.h)}`;

export async function GET(req: Request) {
  try {
    const { searchParams } = new URL(req.url);
    const target = searchParams.get("target") || undefined;
    const q = (searchParams.get("q") || "").toLowerCase().trim();
    const limit = Number(searchParams.get("limit") || "500");

    const coll = collectionForTarget(target);
    if (!coll) return NextResponse.json({ data: [] });

    if (coll === "laser_scan_lens") {
      // fiber / uv / co2gal → scan lenses have field_size + focal_length
      const { data } = await directusFetch<{ data: any[] }>(
        `/items/${coll}?fields=id,field_size,focal_length&limit=${encodeURIComponent(
          String(limit)
        )}`
      );

      const rows = (data ?? []).map((r) => {
        const dim = parseFieldSize(r.field_size);
        const fnumRaw = r.focal_length;
        const label =
        dim && fnumRaw != null && fnumRaw !== ""
        ? `${dimsText(dim)} (F${fmtNum(Number(fnumRaw))})`
        : dim
        ? dimsText(dim)
        : String(r.field_size ?? r.id);

        const area =
        dim && Number.isFinite(dim.w) && Number.isFinite(dim.h)
        ? dim.w * dim.h
        : Number.POSITIVE_INFINITY;

        return {
          id: String(r.id),
                                    label,
                                    _sort: { area, w: dim?.w ?? Number.POSITIVE_INFINITY, h: dim?.h ?? Number.POSITIVE_INFINITY },
                                    _search: `${r.field_size ?? ""} ${r.focal_length ?? ""} ${label}`.toLowerCase(),
        };
      });

      const filtered = q ? rows.filter((r) => r._search.includes(q)) : rows;

      filtered.sort((a, b) => {
        if (a._sort.area !== b._sort.area) return a._sort.area - b._sort.area;
        if (a._sort.w !== b._sort.w) return a._sort.w - b._sort.w;
        if (a._sort.h !== b._sort.h) return a._sort.h - b._sort.h;
        return a.label.localeCompare(b.label);
      });

      return NextResponse.json({
        data: filtered.map(({ id, label }) => ({ id, label })),
      });
    }

    // CO2 Gantry → focus lenses only have "name"
    const { data } = await directusFetch<{ data: any[] }>(
      `/items/${coll}?fields=id,name&limit=${encodeURIComponent(String(limit))}`
    );

    const rows = (data ?? []).map((r) => ({
      id: String(r.id),
                                          label: String(r.name ?? r.id),
                                          _search: String(r.name ?? r.id).toLowerCase(),
    }));

    const filtered = q ? rows.filter((r) => r._search.includes(q)) : rows;
    filtered.sort((a, b) => a.label.localeCompare(b.label));

    return NextResponse.json({
      data: filtered.map(({ id, label }) => ({ id, label })),
    });
  } catch (err: any) {
    console.error("[options/lens] error:", err?.message || err);
    return NextResponse.json({ data: [] }, { status: 200 });
  }
}