import { base64 } from "./archive.ts";
import { uid, type Asset } from "./schema.ts";
import { sliceImage } from "./two-d.ts";
/** Read image dimensions without DOM, so browser and MCP import share validation. */
export function imageInfo(bytes: Uint8Array) {
  if (bytes.length > 25 * 1024 * 1024)
    throw Error("Изображение превышает 25 МБ");
  const d = new DataView(bytes.buffer, bytes.byteOffset, bytes.byteLength);
  let width = 0,
    height = 0,
    mime = "",
    ext = "";
  if (
    bytes.length >= 24 &&
    d.getUint32(0) === 0x89504e47 &&
    d.getUint32(4) === 0x0d0a1a0a
  ) {
    width = d.getUint32(16);
    height = d.getUint32(20);
    mime = "image/png";
    ext = "png";
  } else if (
    bytes.length >= 30 &&
    d.getUint32(0) === 0x52494646 &&
    d.getUint32(8) === 0x57454250
  ) {
    const kind = d.getUint32(12);
    if (kind === 0x56503858) {
      width = 1 + bytes[24] + bytes[25] * 256 + bytes[26] * 65536;
      height = 1 + bytes[27] + bytes[28] * 256 + bytes[29] * 65536;
    } else if (kind === 0x5650384c && bytes[20] === 0x2f) {
      const bits = d.getUint32(21, true);
      width = (bits & 0x3fff) + 1;
      height = ((bits >>> 14) & 0x3fff) + 1;
    } else if (
      kind === 0x56503820 &&
      bytes[23] === 0x9d &&
      bytes[24] === 1 &&
      bytes[25] === 0x2a
    ) {
      width = d.getUint16(26, true) & 0x3fff;
      height = d.getUint16(28, true) & 0x3fff;
    }
    mime = "image/webp";
    ext = "webp";
  } else if (bytes.length > 4 && d.getUint16(0) === 0xffd8) {
    let offset = 2;
    while (offset + 4 <= bytes.length) {
      if (bytes[offset++] !== 255) break;
      while (bytes[offset] === 255) offset++;
      const marker = bytes[offset++];
      if (marker === 0xda || marker === 0xd9) break;
      const length = d.getUint16(offset);
      if (length < 2 || offset + length > bytes.length) break;
      if ([0xc0, 0xc1, 0xc2].includes(marker) && length >= 7) {
        height = d.getUint16(offset + 3);
        width = d.getUint16(offset + 5);
        break;
      }
      offset += length;
    }
    mime = "image/jpeg";
    ext = "jpg";
  }
  if (!width || !height || width > 16384 || height > 16384)
    throw Error("Ожидалось PNG, JPEG или WebP размером до 16384×16384");
  return { width, height, mime, ext };
}
export function imageAsset(bytes: Uint8Array, name: string): Asset {
  const info = imageInfo(bytes);
  return {
    id: uid("image"),
    name: name.replace(/\.[^.]+$/, "") + "." + info.ext,
    kind: "image",
    uri: `data:${info.mime};base64,${base64(bytes)}`,
    image: {
      width: info.width,
      height: info.height,
      pixelsPerUnit: 100,
      filter: "nearest",
      frames: sliceImage(info.width, info.height, info.width, info.height),
    },
  };
}