import invariant from 'tiny-invariant';

var getRect = function getRect(_ref) {
  var top = _ref.top,
      right = _ref.right,
      bottom = _ref.bottom,
      left = _ref.left;
  var width = right - left;
  var height = bottom - top;
  var rect = {
    top: top,
    right: right,
    bottom: bottom,
    left: left,
    width: width,
    height: height,
    x: left,
    y: top,
    center: {
      x: (right + left) / 2,
      y: (bottom + top) / 2
    }
  };
  return rect;
};
var expand = function expand(target, expandBy) {
  return {
    top: target.top - expandBy.top,
    left: target.left - expandBy.left,
    bottom: target.bottom + expandBy.bottom,
    right: target.right + expandBy.right
  };
};
var shrink = function shrink(target, shrinkBy) {
  return {
    top: target.top + shrinkBy.top,
    left: target.left + shrinkBy.left,
    bottom: target.bottom - shrinkBy.bottom,
    right: target.right - shrinkBy.right
  };
};

var shift = function shift(target, shiftBy) {
  return {
    top: target.top + shiftBy.y,
    left: target.left + shiftBy.x,
    bottom: target.bottom + shiftBy.y,
    right: target.right + shiftBy.x
  };
};

var noSpacing = {
  top: 0,
  right: 0,
  bottom: 0,
  left: 0
};
var createBox = function createBox(_ref2) {
  var borderBox = _ref2.borderBox,
      _ref2$margin = _ref2.margin,
      margin = _ref2$margin === void 0 ? noSpacing : _ref2$margin,
      _ref2$border = _ref2.border,
      border = _ref2$border === void 0 ? noSpacing : _ref2$border,
      _ref2$padding = _ref2.padding,
      padding = _ref2$padding === void 0 ? noSpacing : _ref2$padding;
  var marginBox = getRect(expand(borderBox, margin));
  var paddingBox = getRect(shrink(borderBox, border));
  var contentBox = getRect(shrink(paddingBox, padding));
  return {
    marginBox: marginBox,
    borderBox: getRect(borderBox),
    paddingBox: paddingBox,
    contentBox: contentBox,
    margin: margin,
    border: border,
    padding: padding
  };
};

var parse = function parse(raw) {
  var value = raw.slice(0, -2);
  var suffix = raw.slice(-2);

  if (suffix !== 'px') {
    return 0;
  }

  var result = Number(value);
  !!isNaN(result) ? process.env.NODE_ENV !== "production" ? invariant(false, "Could not parse value [raw: " + raw + ", without suffix: " + value + "]") : invariant(false) : void 0;
  return result;
};

var getWindowScroll = function getWindowScroll() {
  return {
    x: window.pageXOffset,
    y: window.pageYOffset
  };
};

var offset = function offset(original, change) {
  var borderBox = original.borderBox,
      border = original.border,
      margin = original.margin,
      padding = original.padding;
  var shifted = shift(borderBox, change);
  return createBox({
    borderBox: shifted,
    border: border,
    margin: margin,
    padding: padding
  });
};
var withScroll = function withScroll(original, scroll) {
  if (scroll === void 0) {
    scroll = getWindowScroll();
  }

  return offset(original, scroll);
};
var calculateBox = function calculateBox(borderBox, styles) {
  var margin = {
    top: parse(styles.marginTop),
    right: parse(styles.marginRight),
    bottom: parse(styles.marginBottom),
    left: parse(styles.marginLeft)
  };
  var padding = {
    top: parse(styles.paddingTop),
    right: parse(styles.paddingRight),
    bottom: parse(styles.paddingBottom),
    left: parse(styles.paddingLeft)
  };
  var border = {
    top: parse(styles.borderTopWidth),
    right: parse(styles.borderRightWidth),
    bottom: parse(styles.borderBottomWidth),
    left: parse(styles.borderLeftWidth)
  };
  return createBox({
    borderBox: borderBox,
    margin: margin,
    padding: padding,
    border: border
  });
};
var getBox = function getBox(el) {
  var borderBox = el.getBoundingClientRect();
  var styles = window.getComputedStyle(el);
  return calculateBox(borderBox, styles);
};

export { calculateBox, createBox, expand, getBox, getRect, offset, shrink, withScroll };