import utif, { TiffTag } from "utif2";
import { Bitmap, Format } from "@jimp/types";

function getDimensionValue(dimension: number | Uint8Array | TiffTag) {
  if (typeof dimension === "number") {
    return dimension;
  }

  if (dimension instanceof Uint8Array) {
    return dimension[0];
  }

  if (typeof dimension[0] === "string") {
    return parseInt(dimension[0]);
  }

  return dimension[0];
}

export default function tiff() {
  return {
    mime: "image/tiff",
    encode: (bitmap) => {
      const tiff = utif.encodeImage(bitmap.data, bitmap.width, bitmap.height);
      return Buffer.from(tiff);
    },
    decode: (data) => {
      const ifds = utif.decode(data);
      const page = ifds[0];

      if (!page) {
        throw new Error("No page found in TIFF");
      }

      if (!page.t256) {
        throw new Error("No image width found in TIFF");
      }

      if (!page.t257) {
        throw new Error("No image height found in TIFF");
      }

      ifds.forEach((ifd) => {
        utif.decodeImage(data, ifd);
      });

      const rgba = utif.toRGBA8(page);

      return {
        data: Buffer.from(rgba),
        width: getDimensionValue(page.t256),
        height: getDimensionValue(page.t257),
      } as Bitmap;
    },
  } satisfies Format<"image/tiff">;
}