(function () {

	var exports = this,
	Selection;

	Selection = function (env) {
	this._selection = null;
	this.env = env;

	this._initializeRangeLibrary();
	this._getSelection();
	};

	Selection.prototype = {

	/**
	 * Returns the selection object for the current browser.
	 */
	_getSelection: function () {
		if (this._selection) {
			this._selection.refresh();
		}
		else if (this.env.frame) {
			this._selection = rangy.getIframeSelection(this.env.frame);
		}
		else {
			this._selection = rangy.getSelection();
		}
		return this._selection;
	},

	/**
	 * Creates a range object.
	 */
	createRange: function () {
		return rangy.createRange(this.env.document);
	},

	/**
	 * Returns the range object at the specified position. The current range object
	 * is at position 0. Note - currently only setting single range in `addRange` so
	 * position 0 will be the only allocation filled.
	 */
	getRangeAt: function (pos) {
		this._selection.refresh();
		try {
			return this._selection.getRangeAt(pos);
		}
		catch (e) {
			this._selection = null;
			return this._getSelection().getRangeAt(0);
		}
	},

	/**
	 * Adds the specified range to the current selection. Note - only supporting setting
	 * a single range, so the previous range gets evicted.
	 */
	addRange: function (range) {
		this._selection || (this._selection = this._getSelection());
		this._selection.setSingleRange(range);
		this._selection.ranges = [range];
		return;
	},

	/**
	 * Initialize and extend the `rangy` library with some custom functionality.
	 */
	_initializeRangeLibrary: function () {
		var self = this;

		rangy.init();
		rangy.config.checkSelectionRanges = false;

		var move = function (range, unitType, units, isStart) {
		if (units === 0) {
			throw Error('InvalidArgumentException: units cannot be 0');
		}

		switch (unitType) {
			case ice.dom.CHARACTER_UNIT:
			if (units > 0) {
				range.moveCharRight(isStart, units);
			} else {
				range.moveCharLeft(isStart, units * -1);
			}
			break;

			case ice.dom.WORD_UNIT:
			default:
			// Removed. TODO: possibly refactor or re-implement.
			break;
		}
		};

		/**
		 * Moves the start of the range using the specified `unitType`, by the specified
		 * number of `units`. Defaults to `CHARACTER_UNIT` and units of 1.
		 */
		rangy.rangePrototype.moveStart = function (unitType, units) {
		move(this, unitType, units, true);
		};

		/**
		 * Moves the end of the range using the specified `unitType`, by the specified
		 * number of `units`.
		 */
		rangy.rangePrototype.moveEnd = function (unitType, units) {
		move(this, unitType, units, false);
		};

		/**
		 * Depending on the given `start` boolean, sets the start or end containers
		 * to the given `container` with `offset` units.
		 */
		rangy.rangePrototype.setRange = function (start, container, offset) {
		if (start) {
			this.setStart(container, offset);
		} else {
			this.setEnd(container, offset);
		}
		};

		/**
		 * Depending on the given `moveStart` boolean, moves the start or end containers
		 * to the left by the given number of character `units`. Use the following
		 * example as a demonstration for where the range will fall as it moves in and
		 * out of tag boundaries (where "|" is the marked range):
		 *
		 * test <em>it</em> o|ut
		 * test <em>it</em> |out
		 * test <em>it</em>| out
		 * test <em>i|t</em> out
		 * test <em>|it</em> out
		 * test| <em>it</em> out
		 * tes|t <em>it</em> out
		 *
		 * A range could be mapped in one of two ways:
		 *
		 * (1) If a startContainer is a Node of type Text, Comment, or CDATASection, then startOffset
		 * is the number of characters from the start of startNode. For example, the following
		 * are the range properties for `<p>te|st</p>` (where "|" is the collapsed range):
		 *
		 * startContainer: <TEXT>test<TEXT>
		 * startOffset: 2
		 * endContainer: <TEXT>test<TEXT>
		 * endOffset: 2
		 *
		 * (2) For other Node types, startOffset is the number of child nodes between the start of
		 * the startNode. Take the following html fragment:
		 *
		 * `<p>some <span>test</span> text</p>`
		 *
		 * If we were working with the following range properties:
		 *
		 * startContainer: <p>
		 * startOffset: 2
		 * endContainer: <p>
		 * endOffset: 2
		 *
		 * Since <p> is an Element node, the offsets are based on the offset in child nodes of <p> and
		 * the range is selecting the second child - the <span> tag.
		 *
		 * <p><TEXT>some </TEXT><SPAN>test</SPAN><TEXT> text</TEXT></p>
		 */
		rangy.rangePrototype.moveCharLeft = function (moveStart, units) {
		var container, offset;

		if (moveStart) {
			container = this.startContainer;
			offset = this.startOffset;
		} else {
			container = this.endContainer;
			offset = this.endOffset;
		}

		// Handle the case where the range conforms to (2) (noted in the comment above).
		if (container.nodeType === ice.dom.ELEMENT_NODE) {
			if (container.hasChildNodes()) {
			container = container.childNodes[offset];

			container = this.getPreviousTextNode(container);

			// Get the previous text container that is not an empty text node.
			while (container && container.nodeType == ice.dom.TEXT_NODE && container.nodeValue === "") {
				container = this.getPreviousTextNode(container);
			}

			offset = container.data.length - units;
			} else {
			offset = units * -1;
			}
		} else {
			offset -= units;
		}

		if (offset < 0) {
			// We need to move to a previous selectable container.
			while (offset < 0) {
			var skippedBlockElem = [];

			container = this.getPreviousTextNode(container, skippedBlockElem);

			// We are at the beginning/out of the editable - break.
			if (!container) {
				return;
			}

			if (container.nodeType === ice.dom.ELEMENT_NODE) {
				continue;
			}

			offset += container.data.length;
			}
		}

		this.setRange(moveStart, container, offset);
		};

		/**
		 * Depending on the given `moveStart` boolean, moves the start or end containers
		 * to the right by the given number of character `units`. Use the following
		 * example as a demonstration for where the range will fall as it moves in and
		 * out of tag boundaries (where "|" is the marked range):
		 *
		 * tes|t <em>it</em> out
		 * test| <em>it</em> out
		 * test |<em>it</em> out
		 * test <em>i|t</em> out
		 * test <em>it|</em> out
		 * test <em>it</em> |out
		 *
		 * A range could be mapped in one of two ways:
		 *
		 * (1) If a startContainer is a Node of type Text, Comment, or CDATASection, then startOffset
		 * is the number of characters from the start of startNode. For example, the following
		 * are the range properties for `<p>te|st</p>` (where "|" is the collapsed range):
		 *
		 * startContainer: <TEXT>test<TEXT>
		 * startOffset: 2
		 * endContainer: <TEXT>test<TEXT>
		 * endOffset: 2
		 *
		 * (2) For other Node types, startOffset is the number of child nodes between the start of
		 * the startNode. Take the following html fragment:
		 *
		 * `<p>some <span>test</span> text</p>`
		 *
		 * If we were working with the following range properties:
		 *
		 * startContainer: <p>
		 * startOffset: 2
		 * endContainer: <p>
		 * endOffset: 2
		 *
		 * Since <p> is an Element node, the offsets are based on the offset in child nodes of <p> and
		 * the range is selecting the second child - the <span> tag.
		 *
		 * <p><TEXT>some </TEXT><SPAN>test</SPAN><TEXT> text</TEXT></p>
		 */
		rangy.rangePrototype.moveCharRight = function (moveStart, units) {
		var container, offset;

		if (moveStart) {
			container = this.startContainer;
			offset = this.startOffset;
		} else {
			container = this.endContainer;
			offset = this.endOffset;
		}

		if (container.nodeType === ice.dom.ELEMENT_NODE) {
			container = container.childNodes[offset];
			if (container.nodeType !== ice.dom.TEXT_NODE) {
			container = this.getNextTextNode(container);
			}

			offset = units;
		} else {
			offset += units;
		}

		var diff = (offset - container.data.length);
		if (diff > 0) {
			var skippedBlockElem = [];
			// We need to move to the next selectable container.
			while (diff > 0) {
			container = this.getNextContainer(container, skippedBlockElem);

			if (container.nodeType === ice.dom.ELEMENT_NODE) {
				continue;
			}

			if (container.data.length >= diff) {
				// We found a container with enough content to select.
				break;
			} else if (container.data.length > 0) {
				// Container does not have enough content,
				// find the next one.
				diff -= container.data.length;
			}
			}

			offset = diff;
		}

		this.setRange(moveStart, container, offset);
		};

		/**
		 * Returns the deepest next container that the range can be extended to.
		 * For example, if the next container is an element that contains text nodes,
		 * the the container's firstChild is returned.
		 */
		rangy.rangePrototype.getNextContainer = function (container, skippedBlockElem) {
		if (!container) {
			return null;
		}

		while (container.nextSibling) {
			container = container.nextSibling;
			if (container.nodeType !== ice.dom.TEXT_NODE) {
			var child = this.getFirstSelectableChild(container);
			if (child !== null) {
				return child;
			}
			} else if (this.isSelectable(container) === true) {
			return container;
			}
		}

		// Look at parents next sibling.
		while (container && !container.nextSibling) {
			container = container.parentNode;
		}

		if (!container) {
			return null;
		}

		container = container.nextSibling;
		if (this.isSelectable(container) === true) {
			return container;
		} else if (skippedBlockElem && ice.dom.isBlockElement(container) === true) {
			skippedBlockElem.push(container);
		}

		var selChild = this.getFirstSelectableChild(container);
		if (selChild !== null) {
			return selChild;
		}

		return this.getNextContainer(container, skippedBlockElem);
		};

		/**
		 * Returns the deepest previous container that the range can be extended to.
		 * For example, if the previous container is an element that contains text nodes,
		 * then the container's lastChild is returned.
		 */
		rangy.rangePrototype.getPreviousContainer = function (container, skippedBlockElem) {
		if (!container) {
			return null;
		}

		while (container.previousSibling) {
			container = container.previousSibling;
			if (container.nodeType !== ice.dom.TEXT_NODE) {
			if (ice.dom.isStubElement(container) === true) {
				return container;
			} else {
				var child = this.getLastSelectableChild(container);
				if (child !== null) {
				return child;
				}
			}
			} else if (this.isSelectable(container) === true) {
			return container;
			}
		}

		// Look at parents next sibling.
		while (container && !container.previousSibling) {
			container = container.parentNode;
		}

		if (!container) {
			return null;
		}

		container = container.previousSibling;
		if (this.isSelectable(container) === true) {
			return container;
		} else if (skippedBlockElem && ice.dom.isBlockElement(container) === true) {
			skippedBlockElem.push(container);
		}

		var selChild = this.getLastSelectableChild(container);
		if (selChild !== null) {
			return selChild;
		}
		return this.getPreviousContainer(container, skippedBlockElem);
		};

		rangy.rangePrototype.getNextTextNode = function (container) {
		if (container.nodeType === ice.dom.ELEMENT_NODE) {
			if (container.childNodes.length !== 0) {
			return this.getFirstSelectableChild(container);
			}
		}

		container = this.getNextContainer(container);
		if (container.nodeType === ice.dom.TEXT_NODE) {
			return container;
		}

		return this.getNextTextNode(container);
		};

		rangy.rangePrototype.getPreviousTextNode = function (container, skippedBlockEl) {
		container = this.getPreviousContainer(container, skippedBlockEl);
		if (container.nodeType === ice.dom.TEXT_NODE) {
			return container;
		}

		return this.getPreviousTextNode(container, skippedBlockEl);
		};

		rangy.rangePrototype.getFirstSelectableChild = function (element) {
		if (element) {
			if (element.nodeType !== ice.dom.TEXT_NODE) {
			var child = element.firstChild;
			while (child) {
				if (this.isSelectable(child) === true) {
				return child;
				} else if (child.firstChild) {
				// This node does have child nodes.
				var res = this.getFirstSelectableChild(child);
				if (res !== null) {
					return res;
				} else {
					child = child.nextSibling;
				}
				} else {
				child = child.nextSibling;
				}
			}
			} else {
			// Given element is a text node so return it.
			return element;
			}
		}
		return null;
		};

		rangy.rangePrototype.getLastSelectableChild = function (element) {
		if (element) {
			if (element.nodeType !== ice.dom.TEXT_NODE) {
			var child = element.lastChild;
			while (child) {
				if (this.isSelectable(child) === true) {
				return child;
				} else if (child.lastChild) {
				// This node does have child nodes.
				var res = this.getLastSelectableChild(child);
				if (res !== null) {
					return res;
				} else {
					child = child.previousSibling;
				}
				} else {
				child = child.previousSibling;
				}
			}
			} else {
			// Given element is a text node so return it.
			return element;
			}
		}
		return null;
		};

		rangy.rangePrototype.isSelectable = function (container) {
		if (container && container.nodeType === ice.dom.TEXT_NODE && container.data.length !== 0) {
			return true;
		}
		return false;
		};

		rangy.rangePrototype.getHTMLContents = function (clonedSelection) {
		if (!clonedSelection) {
			clonedSelection = this.cloneContents();
		}
		var div = self.env.document.createElement('div');
		div.appendChild(clonedSelection.cloneNode(true));
		return div.innerHTML;
		};

		rangy.rangePrototype.getHTMLContentsObj = function () {
		return this.cloneContents();
		};
	}
	};

	exports.Selection = Selection;

}).call(this.ice);