'use strict';

var isSupported = document.queryCommandSupported && document.queryCommandSupported('copy');
export class Clipboard {
  static isSupported():boolean {
    return isSupported;
  }

  static selectElement(element:any):void {
    let range;
    let selection;
    if ((<any>document.body).createTextRange) {
      range = (<any>document.body).createTextRange();
      range.moveToElementText(element);
      range.select();
    } else if (document.createRange && window.getSelection) {
      selection = window.getSelection();
      range = document.createRange();
      range.selectNodeContents(element);
      selection.removeAllRanges();
      selection.addRange(range);
    }
  }

  static deselect():void {
    if ( (<any>document).selection ) {
      (<any>document).selection.empty();
    } else if ( window.getSelection ) {
      window.getSelection().removeAllRanges();
    }
  }

  static copySelected():boolean {
    let result;
    try {
      result = document.execCommand('copy');
    } catch (err) {
      result = false;
    }
    return result;
  }

  static copyElement(element:any):boolean {
    Clipboard.selectElement(element);
    let res = Clipboard.copySelected();
    if (res) Clipboard.deselect();
    return res;
  }

  static copyCustom(text:string):boolean {
    let textArea = document.createElement('textarea');
    textArea.style.position = 'fixed';
    textArea.style.top = '0';
    textArea.style.left = '0';

    // Ensure it has a small width and height. Setting to 1px / 1em
    // doesn't work as this gives a negative w/h on some browsers.
    textArea.style.width = '2em';
    textArea.style.height = '2em';

    // We don't need padding, reducing the size if it does flash render.
    textArea.style.padding = '0';

    // Clean up any borders.
    textArea.style.border = 'none';
    textArea.style.outline = 'none';
    textArea.style.boxShadow = 'none';

    // Avoid flash of white box if rendered for any reason.
    textArea.style.background = 'transparent';


    textArea.value = text;

    document.body.appendChild(textArea);

    textArea.select();

    let res = Clipboard.copySelected();

    document.body.removeChild(textArea);
    return res;
  }
}