/**
 * Pages Function: GET|POST /api/mobile-demand
 *
 * Best-effort edge counter for "please add mobile support" demand.
 * Stored via the Cache API (no KV / wrangler binding), same pattern as
 * live-status. Counts may undercount under concurrent colo races and can
 * reset if the edge entry is evicted; good enough as a demand signal.
 *
 * GET  -> { count }
 * POST -> increment once, return { count, voted: true }
 */

const CACHE_KEY = "https://mobile-demand.internal/v1";
// Long store TTL so eviction is rare; freshness is not time-gated.
const CACHE_STORE_MAX_AGE_S = 365 * 24 * 60 * 60;

function jsonResponse(body, status = 200) {
  return new Response(JSON.stringify(body), {
    status,
    headers: {
      "Content-Type": "application/json; charset=utf-8",
      "Cache-Control": "no-store",
    },
  });
}

async function readCount() {
  try {
    const cached = await caches.default.match(CACHE_KEY);
    if (!cached) return 0;
    const data = await cached.json();
    const n = Number(data && data.count);
    return Number.isFinite(n) && n >= 0 ? Math.floor(n) : 0;
  } catch {
    return 0;
  }
}

async function writeCount(count) {
  const body = {
    count,
    updated_at: new Date().toISOString(),
  };
  const cached = new Response(JSON.stringify(body), {
    headers: {
      "Content-Type": "application/json; charset=utf-8",
      "Cache-Control": `max-age=${CACHE_STORE_MAX_AGE_S}`,
    },
  });
  await caches.default.put(CACHE_KEY, cached);
}

export async function onRequestGet() {
  try {
    const count = await readCount();
    return jsonResponse({ count });
  } catch {
    return jsonResponse({ count: 0 });
  }
}

export async function onRequestPost() {
  try {
    const next = (await readCount()) + 1;
    await writeCount(next);
    return jsonResponse({ count: next, voted: true });
  } catch {
    return jsonResponse({ error: "increment_failed" }, 503);
  }
}