import {
  getHitElementByPoint,
  getSelectedElements,
  PlaitBoard,
  Point,
} from '@plait/core';
import { DataURL } from '../types';
import { getDataURL } from './blob';
import { MindElement, MindTransforms } from '@plait/mind';
import { DrawTransforms } from '@plait/draw';
import { getElementOfFocusedImage } from '@plait/common';

export const loadHTMLImageElement = (dataURL: DataURL) => {
  return new Promise<HTMLImageElement>((resolve, reject) => {
    const image = new Image();
    image.onload = () => {
      resolve(image);
    };
    image.onerror = (error) => {
      reject(error);
    };
    image.src = dataURL;
  });
};

export const buildImage = (
  image: HTMLImageElement,
  dataURL: DataURL,
  maxWidth: number
) => {
  const width = image.width > maxWidth ? maxWidth : image.width;
  const height = (width / image.width) * image.height;
  return {
    url: dataURL,
    width,
    height,
  };
};

export const insertImage = async (
  board: PlaitBoard,
  imageFile: File,
  startPoint?: Point,
  isDrop?: boolean
) => {
  const selectedElement =
    getSelectedElements(board)[0] || getElementOfFocusedImage(board);
  const defaultImageWidth = selectedElement ? 240 : 400;
  const dataURL = await getDataURL(imageFile);
  const image = await loadHTMLImageElement(dataURL);
  const imageItem = buildImage(image, dataURL, defaultImageWidth);
  const element = startPoint && getHitElementByPoint(board, startPoint);
  if (isDrop && element && MindElement.isMindElement(board, element)) {
    MindTransforms.setImage(board, element as MindElement, imageItem);
    return;
  }
  if (
    selectedElement &&
    MindElement.isMindElement(board, selectedElement) &&
    !isDrop
  ) {
    MindTransforms.setImage(board, selectedElement as MindElement, imageItem);
  } else {
    DrawTransforms.insertImage(board, imageItem, startPoint);
  }
};