// CodeMirror, copyright (c) by Marijn Haverbeke and others

// Distributed under an MIT license: https://codemirror.net/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";



  function Bar(cls, orientation, scroll) {

    this.orientation = orientation;

    this.scroll = scroll;

    this.screen = this.total = this.size = 1;

    this.pos = 0;



    this.node = document.createElement("div");

    this.node.className = cls + "-" + orientation;

    this.inner = this.node.appendChild(document.createElement("div"));



    var self = this;

    CodeMirror.on(this.inner, "mousedown", function(e) {

      if (e.which != 1) return;

      CodeMirror.e_preventDefault(e);

      var axis = self.orientation == "horizontal" ? "pageX" : "pageY";

      var start = e[axis], startpos = self.pos;

      function done() {

        CodeMirror.off(document, "mousemove", move);

        CodeMirror.off(document, "mouseup", done);

      }

      function move(e) {

        if (e.which != 1) return done();

        self.moveTo(startpos + (e[axis] - start) * (self.total / self.size));

      }

      CodeMirror.on(document, "mousemove", move);

      CodeMirror.on(document, "mouseup", done);

    });



    CodeMirror.on(this.node, "click", function(e) {

      CodeMirror.e_preventDefault(e);

      var innerBox = self.inner.getBoundingClientRect(), where;

      if (self.orientation == "horizontal")

        where = e.clientX < innerBox.left ? -1 : e.clientX > innerBox.right ? 1 : 0;

      else

        where = e.clientY < innerBox.top ? -1 : e.clientY > innerBox.bottom ? 1 : 0;

      self.moveTo(self.pos + where * self.screen);

    });



    function onWheel(e) {

      var moved = CodeMirror.wheelEventPixels(e)[self.orientation == "horizontal" ? "x" : "y"];

      var oldPos = self.pos;

      self.moveTo(self.pos + moved);

      if (self.pos != oldPos) CodeMirror.e_preventDefault(e);

    }

    CodeMirror.on(this.node, "mousewheel", onWheel);

    CodeMirror.on(this.node, "DOMMouseScroll", onWheel);

  }



  Bar.prototype.setPos = function(pos, force) {

    if (pos < 0) pos = 0;

    if (pos > this.total - this.screen) pos = this.total - this.screen;

    if (!force && pos == this.pos) return false;

    this.pos = pos;

    this.inner.style[this.orientation == "horizontal" ? "left" : "top"] =

      (pos * (this.size / this.total)) + "px";

    return true

  };



  Bar.prototype.moveTo = function(pos) {

    if (this.setPos(pos)) this.scroll(pos, this.orientation);

  }



  var minButtonSize = 10;



  Bar.prototype.update = function(scrollSize, clientSize, barSize) {

    var sizeChanged = this.screen != clientSize || this.total != scrollSize || this.size != barSize

    if (sizeChanged) {

      this.screen = clientSize;

      this.total = scrollSize;

      this.size = barSize;

    }



    var buttonSize = this.screen * (this.size / this.total);

    if (buttonSize < minButtonSize) {

      this.size -= minButtonSize - buttonSize;

      buttonSize = minButtonSize;

    }

    this.inner.style[this.orientation == "horizontal" ? "width" : "height"] =

      buttonSize + "px";

    this.setPos(this.pos, sizeChanged);

  };



  function SimpleScrollbars(cls, place, scroll) {

    this.addClass = cls;

    this.horiz = new Bar(cls, "horizontal", scroll);

    place(this.horiz.node);

    this.vert = new Bar(cls, "vertical", scroll);

    place(this.vert.node);

    this.width = null;

  }



  SimpleScrollbars.prototype.update = function(measure) {

    if (this.width == null) {

      var style = window.getComputedStyle ? window.getComputedStyle(this.horiz.node) : this.horiz.node.currentStyle;

      if (style) this.width = parseInt(style.height);

    }

    var width = this.width || 0;



    var needsH = measure.scrollWidth > measure.clientWidth + 1;

    var needsV = measure.scrollHeight > measure.clientHeight + 1;

    this.vert.node.style.display = needsV ? "block" : "none";

    this.horiz.node.style.display = needsH ? "block" : "none";



    if (needsV) {

      this.vert.update(measure.scrollHeight, measure.clientHeight,

                       measure.viewHeight - (needsH ? width : 0));

      this.vert.node.style.bottom = needsH ? width + "px" : "0";

    }

    if (needsH) {

      this.horiz.update(measure.scrollWidth, measure.clientWidth,

                        measure.viewWidth - (needsV ? width : 0) - measure.barLeft);

      this.horiz.node.style.right = needsV ? width + "px" : "0";

      this.horiz.node.style.left = measure.barLeft + "px";

    }



    return {right: needsV ? width : 0, bottom: needsH ? width : 0};

  };



  SimpleScrollbars.prototype.setScrollTop = function(pos) {

    this.vert.setPos(pos);

  };



  SimpleScrollbars.prototype.setScrollLeft = function(pos) {

    this.horiz.setPos(pos);

  };



  SimpleScrollbars.prototype.clear = function() {

    var parent = this.horiz.node.parentNode;

    parent.removeChild(this.horiz.node);

    parent.removeChild(this.vert.node);

  };



  CodeMirror.scrollbarModel.simple = function(place, scroll) {

    return new SimpleScrollbars("CodeMirror-simplescroll", place, scroll);

  };

  CodeMirror.scrollbarModel.overlay = function(place, scroll) {

    return new SimpleScrollbars("CodeMirror-overlayscroll", place, scroll);

  };

});

