/*
 * ISC License
 *
 * Copyright (c) 2024 idnovate.com
 * idnovate is a Registered Trademark & Property of idnovate.com, innovación y desarrollo SCP
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 *
 * @author    idnovate
 * @copyright 2024 idnovate
 * @license   https://www.isc.org/licenses/ https://opensource.org/licenses/ISC ISC License
 */

(function(mod) {
  if (typeof exports == "object" && typeof module == "object") // CommonJS
    mod(require("../../lib/codemirror"));
  else if (typeof define == "function" && define.amd) // AMD
    define(["../../lib/codemirror"], mod);
  else // Plain browser env
    mod(CodeMirror);
})(function(CodeMirror) {
  "use strict";

  CodeMirror.defineOption("scrollPastEnd", false, function(cm, val, old) {
    if (old && old != CodeMirror.Init) {
      cm.off("change", onChange);
      cm.off("refresh", updateBottomMargin);
      cm.display.lineSpace.parentNode.style.paddingBottom = "";
      cm.state.scrollPastEndPadding = null;
    }
    if (val) {
      cm.on("change", onChange);
      cm.on("refresh", updateBottomMargin);
      updateBottomMargin(cm);
    }
  });

  function onChange(cm, change) {
    if (CodeMirror.changeEnd(change).line == cm.lastLine())
      updateBottomMargin(cm);
  }

  function updateBottomMargin(cm) {
    var padding = "";
    if (cm.lineCount() > 1) {
      var totalH = cm.display.scroller.clientHeight - 30,
          lastLineH = cm.getLineHandle(cm.lastLine()).height;
      padding = (totalH - lastLineH) + "px";
    }
    if (cm.state.scrollPastEndPadding != padding) {
      cm.state.scrollPastEndPadding = padding;
      cm.display.lineSpace.parentNode.style.paddingBottom = padding;
      cm.off("refresh", updateBottomMargin);
      cm.setSize();
      cm.on("refresh", updateBottomMargin);
    }
  }
});