"use strict";
let injectorCounter: number = 0;
export function resetInjector(): void {
  injectorCounter = 0;
}

export function injectorReady(): boolean {
  return injectorCounter === 0;
}
export function parseElement(el: HTMLElement, target: HTMLElement): Node[] {
  let arr: Node[] = [];
  if (!el || !el.hasChildNodes()) {
    return;
  }
  let nodes: HTMLCollection = el.children;
  for (let i: number = 0; i < nodes.length; i++) {
    let tempNode: HTMLElement;
    if (nodes.item(i).nodeName.toLowerCase() === "script") {
      tempNode = createScriptNode(nodes.item(i));
    } else {
      tempNode = <HTMLElement>nodes.item(i).cloneNode(true);
    }
    target.appendChild(tempNode);
    arr.push(tempNode);
  }
  return arr;
}

function createScriptNode(refNode: Element): HTMLElement {
  let script: HTMLScriptElement = document.createElement("script");
  let attr: NamedNodeMap = refNode.attributes;
  for (let i: number = 0; i < attr.length; i++) {
    script.setAttribute(attr[i].name, attr[i].textContent);
    if (attr[i].name.toLowerCase() === "src") {
      // waiting only for src to finish loading - async opetation
      injectorCounter++;
      script.onload = () => {
        injectorCounter--;
      };
    }
  }
  
  script.innerHTML = refNode.innerHTML;
  return script;
}

export function runHTMLWidgetRenderer(): void {
  // rendering HTML which was created by HTMLWidgets package
  // wait till all tje script elements are loaded
  let intervalVar: number = window.setInterval(() => {
    if (injectorReady()) {
      window.clearInterval(intervalVar);
      if (window.hasOwnProperty("HTMLWidgets") && window["HTMLWidgets"].staticRender) {
        window["HTMLWidgets"].staticRender();
      }
    }
  }, 100);
}