// The floor the whole pipeline is budgeted against: the cheapest Android that
// clears this app's minimum. What sets the minimum: minSdk 26 (below it
// vision-camera's NativeBufferHelper throws "HardwareBuffers require minSdk 26
// or higher!" on every frame), a 32-bit armeabi-v7a build (the shipped APK
// carries both ABIs), Camera2 with EXIF, and Skia's GL backend, which links
// -lGLESv2 (see node_modules/@shopify/react-native-skia/android/CMakeLists.txt).
// Every API 26 phone clears the GL bar, so the floor is the Android Go, 1 GB
// class: Redmi Go (Snapdragon 425, Adreno 308, 5.8-7.2 GFLOPS / 5.3 GB/s,
// 8 MP), Nokia 1 (MT6737M, Mali-T720, 5 MP) and Galaxy J2 Core (Exynos 7570,
// 8 MP) — 4x Cortex-A53 at 1.1-1.4 GHz, 1 GB RAM, 8 GB storage, 480p-720p
// screen. Nothing weaker can install.
//
// What that floor affords, at 4 bytes per RGBA8888 pixel:
//   8 MP raster         32 MB  -> the export's live surfaces alone = 96 MB
//   one full-frame pass 64 MB of traffic @ 5.3 GB/s ~ 12 ms
//   4 slow A53 cores    ~1/6 of a current flagship core
// Hence, here: one resample at the door instead of a full-resolution surface
// chain, and no 3-frame burst (six 8 MP decodes plus a CPU alignment on four
// slow cores is seconds of shutter lag on the device class least able to afford
// it). The live preview needs no cap — Viewfinder already forces the frame
// stream to the 4:3 size nearest 1280x960.
//
// No state and no native import: the RAM reading comes from
// photoMeta.devicePerf() and is passed in, so this module also runs under plain
// node (see deviceFloor.check.ts).
export const FLOOR_RAM_MB = 2048;
export const FLOOR_EXPORT_PIXELS = 4_000_000;

// ramMb 0 = the platform would not say. Unknown is never a floor device: the app
// must not downgrade a phone it could not measure.
export const isFloorDevice = (ramMb: number): boolean => ramMb > 0 && ramMb <= FLOOR_RAM_MB;

// Most pixels the export may paint. 4 MP (2336x1752) still prints 10x15 cm at
// 300 dpi and halves every surface behind it — the 12S Ultra's 12 MP capture is
// untouched, since it is not a floor device.
// ponytail: downscale rather than tile — tile the render the day a floor user
// needs the full 8 MP file.
export const maxExportPixels = (ramMb: number): number =>
  isFloorDevice(ramMb) ? FLOOR_EXPORT_PIXELS : Infinity;

// ponytail: one capability, all or nothing — add a 2-frame CPU-lite merge if a
// floor device ever reports it can afford one.
export const canBurst = (ramMb: number): boolean => !isFloorDevice(ramMb);

// Scale a raster down to at most `cap` pixels, keeping its aspect. Whole pixels
// only: the surface allocator and the EXIF stamp both read these back.
export function floorRaster(
  w: number,
  h: number,
  cap: number
): { width: number; height: number } {
  if (!(w > 0 && h > 0) || !(w * h > cap)) return { width: w, height: h };
  const s = Math.sqrt(cap / (w * h));
  return { width: Math.max(1, Math.round(w * s)), height: Math.max(1, Math.round(h * s)) };
}