dynamicStyles

var dynamicStyles = false;
var dynamicStylesCache = [];
var dynamicStylesLastId = 0;


/**
 * 
 * @param ruleName string
 * @param ruleContents array of key value pairs of CSS rules
 * @example
 dynamicStyleWrite('.todo_item', [
 	{
 		property: "border",
 		rule: "3px dashed black"
 	},
 	{
 		property: "background-color",
 		rule: "blue"
 	},
	{
 		property: "color",
 		rule: "" // <-- empty value will unset this property
 	},
 ]);
 * 
 * @returns null
 * @desc highly optimized for minimizing DOM updates. NB! this will not overwrite styles for the same class/id set in CSS files or elsewhere outside dynamic styles
 * @author Allan Laal <allan@permanent.ee>
 */
function dynamicStyleWrite(ruleName, ruleContents)
{
	log('------------------');
	log('DynamicStyles: ' + ruleName + ' ruleContents: ');
	console.log(ruleContents);
	
	if (dynamicStyles === false)
	{ // iniate container:
		var dynamicStylesContainer = document.createElement('style');
		document.head.appendChild(dynamicStylesContainer);
		dynamicStyles = dynamicStylesContainer.sheet;
	}
	
	var ruleCache = [];
	var thisIsEdit = false;
	if (issetAssoc(ruleName, dynamicStylesCache))
	{
		ruleCache = getAssoc(ruleName, dynamicStylesCache);
		thisIsEdit = true;
		log('DynamicStyles: editing existing rule with indexNr: ' + ruleCache.indexNr);
	}
	else
	{
		ruleCache = {
			id: ruleName,
			contents: ruleContents,
			indexNr: dynamicStylesLastId
		};
		dynamicStylesLastId++;
		dynamicStylesCache.push(ruleCache);
		log('DynamicStyles: adding new rule with indexNr: ' + ruleCache.indexNr);
	}
	log('DynamicStyles: ruleCache: ');
	console.log(ruleCache);
	
	// only update DOM if there is something to change:
	var newRules = [];
	if (thisIsEdit)
	{
		log('DynamicStyles: this is edit, checking existing rules');
		$(ruleContents).each(function() {
			log('DynamicStyles: ' + this.property + ' length is ' + this.rule.length);
			if (this.rule.length > 0)
			{
				currentPair = getAssoc(this.property, ruleCache.contents, 'property');
				if (currentPair.length > 0)
				{ // editing existing property:
					console.log(currentPair);
					console.log(currentPair.rule + ' vs ' + this.rule);
					if (currentPair.rule != this.rule) // loose comparison, rules are always strings anyway
					{
						newRules.push(this);
						updateAssoc(this.property, this.rule, ruleCache.contents, 'property'); // update cache
					}
				}
				else
				{	// adding new property to existing rule:
					newRules.push(this);
					ruleCache.contents.push(this);
				}
			}
			else
			{ //  rule is empty, unset! 
				log('DynamicStyles: ' + this.property + ' is empty (' + this.rule + ')! removing');
				removeAssoc(this.property, ruleCache.contents, 'property'); 
			}
		});
	}
	else
	{
		newRules = ruleCache.contents;
	}
	log('DynamicStyles: changes to write ');
	console.log(newRules);
	
	
	replaceAssoc(ruleName, ruleCache, dynamicStylesCache, 'id');
		
	var compiledRule = ruleName + ' {';
	$(newRules).each(function() {
		compiledRule = compiledRule + this.property + ':' + this.rule + ';';
	});
	compiledRule = compiledRule + '}';

	if (thisIsEdit)
	{
		log('DynamicStyles: deleting dynamic rule index:' + ruleCache.indexNr);
		dynamicStyles.deleteRule(ruleCache.indexNr);
	}
	
	log ('DynamicStyles: adding dynamic rule: ' + compiledRule);
	dynamicStyles.insertRule(compiledRule, ruleCache.indexNr);

	return null;
}


/**
 * 
 * @param id string|int
 * @param arr array
 * @returns bool
 * @desc 
 * @example 
 * var arrName = [
 *  {
 *		id: 1337, <- must alway be set!
 *		someOtherLabel: dsfdsf,
 *	},
 *	{},
 *	{},
 * ]
 *	
 *	to check if 1337 is set in arr: issetAssoc(1337, arrName)
 * 
 * @author Allan Laal <allan@permanent.ee>
 */
function issetAssoc(id, arr, keyOverride)
{
	var key = 'id';
	if (typeof keyOverride !== 'undefined')
	{
		key = keyOverride;
	}
	
	var found = false;
	$(arr).each(function () {
		if (this[key] === id)
		{
			found = true;
			return false; // break loop
		}
	});
	
	return found;
}

/**
 * 
 * @param label string
 * @param arr array
 * @param keyOverride string
 * @returns array
 * @desc 
 * @author Allan Laal <allan@permanent.ee>
 */
function getAssoc(label, arr, keyOverride)
{ 
	var key = 'id';
	if (typeof keyOverride !== 'undefined')
	{
		key = keyOverride;
	}
	
	var out = [];
	$(arr).each(function () {
		if (this[key] === label)
		{
			out = this;
			return false; // break loop
		}
	});
	
	return out;
}

/**
 * 
 * @param label string
 * @param arr array
 * @param keyOverride string
 * @returns array
 * @desc replace assoc member with label with value
 * @author Allan Laal <allan@permanent.ee>
 */
function replaceAssoc(label, value, arr, keyOverride)
{ 
	var key = 'id';
	if (typeof keyOverride !== 'undefined')
	{
		key = keyOverride;
	}
	
	var out = [];
	$(arr).each(function () {
		if (this[key] === label)
		{
			out.push(value);
		}
		else
		{
			out.push(this);
		}

	});
	
	return out;
}



/**
 * 
 * @param label string
 * @param arr array
 * @param keyOverride string
 * @returns array
 * @desc remove assoc member by label
 * @author Allan Laal <allan@permanent.ee>
 */
function removeAssoc(label, arr, keyOverride)
{ 
	var key = 'id';
	if (typeof keyOverride !== 'undefined')
	{
		key = keyOverride;
	}
	
	var out = [];
	$(arr).each(function () {
		if (this[key] !== label)
		{
			out.push(this);
		}
	});
	
	return out;
}


/**
 * 
 * @param label string
 * @param arr array
 * @param keyOverride string
 * @returns array
 * @desc changes 1 key value, overwrites if exists
 * @author Allan Laal <allan@permanent.ee>
 */
function updateAssoc(label, value, arr, keyOverride)
{ 
	var key = 'id';
	if (typeof keyOverride !== 'undefined')
	{
		key = keyOverride;
	}
	
	var out = [];
	$(arr).each(function () {
		if (this[key] === label)
		{
			var row = this;
			row[key] = value;
			out.push(row);
		}
		else
		{
			out.push(this);
		}

	});
	
	return out;
}