find-image

import {
  drawthingsLimits,
  encodeJpegPreviewFromBuffer,
  getDefaultPreviewOptions,
  getSize,
} from "../core-bundle.mjs";

export async function shouldUsePreviewPayload(
  originalBytes: Uint8Array,
  usePreviews: boolean,
): Promise<boolean> {
  if (!usePreviews) return false;
  const { width, height } = await getSize(Buffer.from(originalBytes));
  return width > 0 && height > 0 && width + height > drawthingsLimits.previewMaxSum;
}

export async function previewPayloadBytes(
  originalBytes: Uint8Array,
  usePreviews: boolean,
): Promise<Uint8Array> {
  if (!(await shouldUsePreviewPayload(originalBytes, usePreviews))) return originalBytes;
  const { data } = await encodeJpegPreviewFromBuffer(Buffer.from(originalBytes), getDefaultPreviewOptions());
  return new Uint8Array(data);
}

export interface GeneratedPreviewPayload {
  bytes: Uint8Array;
  sourceWidth: number;
  sourceHeight: number;
  payloadWidth: number;
  payloadHeight: number;
}

export async function generatePreviewPayload(
  originalBytes: Uint8Array,
): Promise<GeneratedPreviewPayload> {
  const { width: sourceWidth, height: sourceHeight } = await getSize(Buffer.from(originalBytes));
  const { data, width: payloadWidth, height: payloadHeight } = await encodeJpegPreviewFromBuffer(
    Buffer.from(originalBytes),
    getDefaultPreviewOptions(),
  );
  return {
    bytes: new Uint8Array(data),
    sourceWidth,
    sourceHeight,
    payloadWidth,
    payloadHeight,
  };
}