"use strict";

// const {asBuffer, asDownload, asZipDownload, atScale, options} = require('./io')
import io from "./io";
const { asBuffer, asDownload, asZipDownload, atScale, options } = io;
//
// Browser equivalents of the skia-canvas convenience initializers and polyfills for
// the Canvas object’s newPage & export methods
//

const _toURL_ = Symbol.for("toDataURL");

const loadImage = src =>
  new Promise((onload, onerror) =>
    Object.assign(new Image(), {
      crossOrigin: "Anonymous",
      onload,
      onerror,
      src
    })
  );

class Canvas {
  constructor(width, height) {
    // alert(1)
    let elt = document.createElement("canvas"),
      pages = [];

    Object.defineProperty(elt, "async", {
      value: true,
      writable: false,
      enumerable: true
    });

    for (var [prop, get] of Object.entries({
      png: () => asBuffer(elt, "image/png"),
      jpg: () => asBuffer(elt, "image/jpeg"),
      pages: () => pages.concat(elt).map(c => c.getContext("2d"))
    }))
      Object.defineProperty(elt, prop, { get });

    return Object.assign(elt, {
      width,
      height,

      newPage(...size) {
        var { width, height } = elt,
          page = Object.assign(document.createElement("canvas"), {
            width,
            height
          });
        page.getContext("2d").drawImage(elt, 0, 0);
        pages.push(page);

        var [width, height] = size.length ? size : [width, height];
        return Object.assign(elt, { width, height }).getContext("2d");
      },

      saveAs(filename, args) {
        args = typeof args == "number" ? { quality: args } : args;
        let opts = options(this.pages, { filename, ...args }),
          { pattern, padding, mime, quality, matte, density, archive } = opts,
          pages = atScale(opts.pages, density);
        return padding == undefined
          ? asDownload(pages[0], mime, quality, matte, filename)
          : asZipDownload(
              pages,
              mime,
              quality,
              matte,
              archive,
              pattern,
              padding
            );
      },

      toBuffer(extension = "png", args = {}) {
        args = typeof args == "number" ? { quality: args } : args;
        let opts = options(this.pages, { extension, ...args }),
          { mime, quality, matte, pages, density } = opts,
          canvas = atScale(pages, density, matte)[0];
        return asBuffer(canvas, mime, quality, matte);
      },

      [_toURL_]: elt.toDataURL.bind(elt),
      toDataURL(extension = "png", args = {}) {
        args = typeof args == "number" ? { quality: args } : args;
        let opts = options(this.pages, { extension, ...args }),
          { mime, quality, matte, pages, density } = opts,
          canvas = atScale(pages, density, matte)[0],
          url = canvas[canvas === elt ? _toURL_ : "toDataURL"](mime, quality);
        return Promise.resolve(url);
      }
    });
  }
}

const {
  CanvasRenderingContext2D,
  CanvasGradient,
  CanvasPattern,
  Image,
  ImageData,
  Path2D,
  DOMMatrix,
  DOMRect,
  DOMPoint
} = window;

// module.exports = {
//   Canvas,
//   loadImage,
//   CanvasRenderingContext2D,
//   CanvasGradient,
//   CanvasPattern,
//   Image,
//   ImageData,
//   Path2D,
//   DOMMatrix,
//   DOMRect,
//   DOMPoint
// };

const obj = {
  Canvas,
  loadImage,
  CanvasRenderingContext2D,
  CanvasGradient,
  CanvasPattern,
  Image,
  ImageData,
  Path2D,
  DOMMatrix,
  DOMRect,
  DOMPoint
};
export default obj;