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

// Decide which collection to read based on target
function lensCollectionForTarget(target?: string) {
  if (target === "settings_co2gan") return "laser_focus_lens"; // gantry
  // fiber, uv, co2gal → scan lenses
  return "laser_scan_lens";
}

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

    const coll = lensCollectionForTarget(target);

    // Request both possible PK fields, plus name & focal_length for labels
    const url = `/items/${coll}?fields=submission_id,id,name,focal_length&limit=${limit}`;
    const { data } = await directusFetch<{ data: any[] }>(url);
    const list = Array.isArray(data) ? data : [];

    const mapped = list.map((x) => {
      const id = String(x.submission_id ?? x.id);
      const label =
      (x.name && String(x.name)) ||
      (x.focal_length != null ? `F${x.focal_length} mm` : id);
      const key =
      (x.focal_length != null ? String(x.focal_length).padStart(6, "0") : "") +
      " " +
      label.toLowerCase();
      return { id, label, key, focal: Number(x.focal_length ?? NaN) };
    });

    // Optional text filter
    const filtered = q
    ? mapped.filter((m) => m.label.toLowerCase().includes(q))
    : mapped;

    // Prefer numeric focal_length ordering, fallback to label
    filtered.sort((a, b) => {
      const aNum = Number.isFinite(a.focal);
      const bNum = Number.isFinite(b.focal);
      if (aNum && bNum) return a.focal - b.focal;
      if (aNum) return -1;
      if (bNum) return 1;
      return a.key.localeCompare(b.key);
    });

    return NextResponse.json({ data: filtered.map(({ id, label }) => ({ id, label })) });
  } catch (e: any) {
    return NextResponse.json({ error: e?.message || "Failed to load lens options" }, { status: 500 });
  }
}