/**
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at

 * http://www.apache.org/licenses/LICENSE-2.0

 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import { isValid } from './typeChecks';

let measureCtx: CanvasRenderingContext2D;

/**
 * Get pixel ratio
 * @param canvas
 * @returns {number}
 */
export function getPixelRatio(canvas: HTMLCanvasElement): number {
  return canvas.ownerDocument?.defaultView?.devicePixelRatio ?? 1;
}

export function createFont(
  size?: number,
  weight?: string | number,
  family?: string,
): string {
  return `${weight ?? 'normal'} ${size ?? 12}px ${family ?? '"Roboto", sans-serif'}`;
}

/**
 * Measure the width of text
 * @param text
 * @returns {number}
 */
export function calcTextWidth(
  text: string,
  size?: number,
  weight?: string | number,
  family?: string,
): number {
  if (!isValid(measureCtx)) {
    const canvas = document.createElement('canvas');
    const pixelRatio = getPixelRatio(canvas);
    measureCtx = canvas.getContext('2d')!;
    measureCtx.scale(pixelRatio, pixelRatio);
  }
  measureCtx.font = createFont(size, weight, family);
  return Math.round(measureCtx.measureText(text).width);
}