/*!
 * VisualEditor plugin for QUnit.
 *
 * @copyright 2011-2013 VisualEditor Team and others; see AUTHORS.txt
 * @license The MIT License (MIT); see LICENSE.txt
 */

/*global difflib,diffview */

( function ( QUnit ) {

QUnit.config.requireExpects = true;

/**
 * Plugin for QUnit.
 *
 * @class ve.QUnit
 * @extends QUnit
 */

/**
 * Builds a summary of a node tree.
 *
 * Generated summaries contain node types, lengths, outer lengths, attributes and summaries for
 * each child recursively. It's simple and fast to use deepEqual on this.
 *
 * @method
 * @private
 * @param {ve.Node} node Node tree to summarize
 * @param {boolean} [shallow] Do not summarize each child recursively
 * @returns {Object} Summary of node tree
 */
function getNodeTreeSummary( node, shallow ) {
	var i,
		summary = {
			'getType': node.getType(),
			'getLength': node.getLength(),
			'getOuterLength': node.getOuterLength(),
			'element': node.element
		},
		numChildren;

	if ( node.children !== undefined ) {
		numChildren = node.children.length;
		if ( !shallow ) {
			summary.children = [];
			for ( i = 0; i < numChildren; i++ ) {
				summary.children.push( getNodeTreeSummary( node.children[i] ) );
			}
		}
	}
	return summary;
}

/**
 * Builds a summary of a node selection.
 *
 * Generated summaries contain length of results as well as node summaries, ranges, indexes, indexes
 * within parent and node ranges for each result. It's simple and fast to use deepEqual on this.
 *
 * @method
 * @private
 * @param {Object[]} selection Selection to summarize
 * @returns {Object} Summary of selection
 */
function getNodeSelectionSummary( selection ) {
	var i,
		summary = {
			'length': selection.length
		};

	if ( selection.length ) {
		summary.results = [];
		for ( i = 0; i < selection.length; i++ ) {
			summary.results.push( {
				'node': getNodeTreeSummary( selection[i].node, true ),
				'range': selection[i].range,
				'index': selection[i].index,
				'indexInNode': selection[i].indexInNode,
				'nodeRange': selection[i].nodeRange,
				'nodeOuterRange': selection[i].nodeOuterRange,
				'parentOuterRange': selection[i].parentOuterRange
			} );
		}
	}
	return summary;
}

/**
 * Callback for ve#copy to convert nodes to a comparable summary.
 *
 * @private
 * @param {ve.dm.Node|Object} value Value in the object/array
 * @returns {Object} Node summary if value is a node, otherwise just the value
 */
function convertNodes( value ) {
	return value instanceof ve.dm.Node || value instanceof ve.ce.Node ?
		getNodeTreeSummary( value ) :
		value;
}

/**
 * Undo what QUnit's escapeText does.
 *
 * @ignore
 * @param {string} s
 * @returns {string}
 */
function unescapeText( s ) {
	return s.replace( /&(#039|quot|lt|gt|amp);/g, function ( match, seq ) {
		switch ( seq )  {
		case '#039':
			return '\'';
		case 'quot':
			return '"';
		case 'lt':
			return '<';
		case 'gt':
			return '>';
		case 'amp':
			return '&';
		}
	} );
}

/**
 * Assertion helpers for VisualEditor test suite.
 * @class ve.QUnit.assert
 */

/**
 * Assert that summaries of two node trees are equal.
 * @method
 * @static
 */
QUnit.assert.equalNodeTree = function ( actual, expected, shallow, message ) {
	if ( typeof shallow === 'string' && arguments.length === 3 ) {
		message = shallow;
		shallow = undefined;
	}
	var actualSummary = getNodeTreeSummary( actual, shallow ),
		expectedSummary = getNodeTreeSummary( expected, shallow );
	QUnit.push(
		QUnit.equiv( actualSummary, expectedSummary ), actualSummary, expectedSummary, message
	);
};

/**
 * @method
 * @static
 */
QUnit.assert.equalNodeSelection = function ( actual, expected, message ) {
	var i,
		actualSummary = getNodeSelectionSummary( actual ),
		expectedSummary = getNodeSelectionSummary( expected );

	for ( i = 0; i < actual.length; i++ ) {
		if ( expected[i] && expected[i].node !== actual[i].node ) {
			QUnit.push( false, actualSummary, expectedSummary,
				message + ' (reference equality for selection[' + i + '].node)'
			);
			return;
		}
	}
	QUnit.push(
		QUnit.equiv( actualSummary, expectedSummary ), actualSummary, expectedSummary, message
	);
};

/**
 * @method
 * @static
 */
QUnit.assert.equalDomElement = function ( actual, expected, message ) {
	var actualSummary = ve.getDomElementSummary( actual ),
		expectedSummary = ve.getDomElementSummary( expected ),
		actualSummaryHtml = ve.getDomElementSummary( actual, true ),
		expectedSummaryHtml = ve.getDomElementSummary( expected, true );

	QUnit.push(
		QUnit.equiv( actualSummary, expectedSummary ), actualSummaryHtml, expectedSummaryHtml, message
	);
};

/**
 * Assert that two objects which may contain dom elements are equal.
 * @method
 * @static
 */
QUnit.assert.deepEqualWithDomElements = function ( actual, expected, message ) {
	// Recursively copy objects or arrays, converting any dom elements found to comparable summaries
	actual = ve.copy( actual, ve.convertDomElements );
	expected = ve.copy( expected, ve.convertDomElements );

	QUnit.push( QUnit.equiv(actual, expected), actual, expected, message );
};

/**
 * Assert that two objects which may contain dom elements are equal.
 * @method
 * @static
 */
QUnit.assert.deepEqualWithNodeTree = function ( actual, expected, message ) {
	// Recursively copy objects or arrays, converting any dom elements found to comparable summaries
	actual = ve.copy( actual, convertNodes );
	expected = ve.copy( expected, convertNodes );

	QUnit.push( QUnit.equiv(actual, expected), actual, expected, message );
};

QUnit.assert.equalRange = function ( actual, expected, message ) {
	actual = {
		start: actual.start,
		end: actual.end,
		from: actual.from,
		to: actual.to
	};
	expected = {
		start: expected.start,
		end: expected.end,
		from: expected.from,
		to: expected.to
	};
	QUnit.push( QUnit.equiv(actual, expected), actual, expected, message );
};

QUnit.diff = function ( o, n ) {
	// o and n are partially HTML escaped by QUnit. As difflib does
	// its own escaping we should unescape them first.
	var oLines = difflib.stringAsLines( unescapeText( o ) ),
		nLines = difflib.stringAsLines( unescapeText( n ) ),
		sm = new difflib.SequenceMatcher( oLines, nLines ),
		/*jshint camelcase:false */
		opcodes = sm.get_opcodes(),
		$div = $( '<div>' );

	$div.append( diffview.buildView( {
		baseTextLines: oLines,
		newTextLines: nLines,
		opcodes: opcodes,
		baseTextName: 'Expected',
		newTextName: 'Result',
		contextSize: 10,
		viewType: 0
	} ) );

	return $div.html();
};

}( QUnit ) );