// Note: Symbols starting with _ are private.

// Current sort problem size.
var _problem_size = 20;

// Root directory for animations.
var _root = '/animation';

// Resolution ultiplier for animations.
var _resolution = 1;

// Map problem size to native image size.
var _image_sizes = {40: 166, 50: 206, 20: 86, 30: 126};

// List of algorithms.
var _algorithms = ['insertion-sort', 'selection-sort', 'bubble-sort', 'shell-sort', 'merge-sort', 'heap-sort', 'quick-sort', 'quick-sort-3-way'];

// List of initialization conditions.
var _conditions = ['random-initial-order', 'nearly-sorted-initial-order', 'reversed-initial-order', 'few-unique-keys'];

// Set static poster images for all animations.
function _sortInit() {
	for (var i = 0; i < _algorithms.length; i++) {
		for (var j = 0; j < _conditions.length; j++) {
			var id = _conditions[j] + '_' + _algorithms[i];
			var el = document.getElementById(id);
			if (!el) { continue; } 
			el.src = _root + '/' + _problem_size + '/' + _conditions[j] + '/' + _algorithms[0] + '-0.gif';
		}
	}
}

// Set size for all animations.
function _sortResize() {
	for (var i = 0; i < _algorithms.length; i++) {
		for (var j = 0; j < _conditions.length; j++) {
			var id = _conditions[j] + '_' + _algorithms[i];
			var el = document.getElementById(id);
			if (!el) { continue; } 
			var sz = _image_sizes[_problem_size] * _resolution;
			el.width = sz;
			el.height = sz;
		}
	}
}

// Change problem size.
function selectSize(n) {
	_problem_size = n;
	_sortInit();
	_sortResize();
}

// Change image resolution.
function selectResolution(x) {
	_resolution = x;
	_sortResize();
}

// Restart a specified list of animations.
function sortRestart(init,alg) {
	for (var i = 0; i < _algorithms.length; i++) {
		for (var j = 0; j < _conditions.length; j++) {
			if ((alg == '*' || alg == _algorithms[i]) && 
			(init == '*' || init == _conditions[j])) {
				var id = _conditions[j] + '_' + _algorithms[i];
				var el = document.getElementById(id);
				if (!el) { continue; } 
				el.src = _root + '/' + _problem_size + '/' + _conditions[j] + '/' + _algorithms[i] + '.gif';
			}
		}
	}
}