/*
Functions

Styleguide 1.1
*/


/*
Image-Url($imagePath)

Returns the path of an Image asset.

<!= type: css || isPureCode !>

Markup:
.selector {
	background-image: image-url("logo.png");
}

Styleguide 1.1.1
*/
@function image-url($imagePath) {
	@if(type-of($imagePath) != "string") {
		@warn 'Argument $imagePath of image-url() must be a string';
	}

	@return url(#{"../Images/" + $imagePath});
}



/*
Relative Size($target-size, $context, $unit)

Calculates em's based on pixel values.

<!= type: css || isPureCode !>

Markup:
.selector {
	font-size: rs(19, 16);
}

Styleguide 1.1.2
*/
@function rs($target-size, $context: $base-font-size, $unit: em) {
	@if(type-of($target-size) != "number") {
		@warn 'Argument $target-size of rs() must be a number';
	}
	@if(type-of($context) != "number") {
		@warn 'Argument $context of rs() must be a number';
	}
	@if(type-of($unit) != "string") {
		@warn 'Argument $unit of rs() must be a string';
	}
	@if(not ($unit == "em" or $unit == "rem")) {
		@warn 'Argument $unit of rs() must be either "em" or "rem"';
	}

	@return #{$target-size/$context}$unit;
}


//
// Text direction check
//
// Checks the reading-direction of the site based on the '$direction' variable and sets the correct $start and $end variables
//
$direction: ltr !default;
$start: left !default;
$end: right !default;
@if $direction == rtl {
	$start: right;
	$end: left;
}


/*
Color-Adjust($color, $contrast)

Adjusts a color based on the lightness which is passed as a second parameter, this function was written by @necolas(https://github.com/necolas/).

<!= type: css || isPureCode !>

Markup:
.selector {
	background: color-adjust(#0097d7, 100%);
}

// Styleguide 1.1.3
*/
@function color-adjust($color, $contrast: 100%) {
	@if(type-of($color) != "color") {
		@warn 'Argument $color of color-adjust() must be a color';
	}
	@if(type-of($contrast) != "number") {
		@warn 'Argument $contrast of color-adjust() must be a number';
	}

	@if (lightness($color) > 50) {
		@return darken($color, $contrast)
	}
	@else {
		@return lighten($color, $contrast)
	}
}


/*
Map-Fetch($map, $keys)

Navigates through nested Sass maps, this function was written by @jlong(https://github.com/jlong/)

<!= type: css || isPureCode !>

Markup:
@each $key, $value in map-get($headings, elements) {
	.selector {
	 	font-size: map-fetch($headings, elements $key font-size) +px;
	}
}

Styleguide 1.1.4
*/
@function map-fetch($map, $keys) {
	@if(type-of($map) != "map") {
		@warn 'Argument $map of map-fetch() must be a Sass map';
	}
	@if(type-of($keys) != "list") {
		@warn 'Argument $keys of map-fetch() must be a Sass list';
	}

	$key: nth($keys, 1);
	$length: length($keys);
	$value: map-get($map, $key);
	@if ($length > 1) {
		$rest: ();
		@for $i from 2 through $length {
			$rest: append($rest, nth($keys, $i))
		}
		@return map-fetch($value, $rest)
	} @else {
		@return $value;
	}
}


/*
Map-RemoveKeys($map, $keys)

Removes multiple keys in a Sass map.

<!= type: css || isPureCode !>

Markup:
$newDecalarationsMap: map-removeKeys($declarations, font-size margin-bottom);

Styleguide 1.1.5
*/
@function map-removeKeys($map, $keys) {
	@if(type-of($map) != "map") {
		@warn 'Argument $map of map-removeKeys() must be a Sass map';
	}
	@if(not (type-of($keys) == "list") and not (type-of($keys) == "string")) {
		@warn 'Argument $keys of map-removeKeys() must be a Sass list or string';
	}

	$length: length($keys);
	@if ($length > 1) {
		$restMap: $map;
		@each $key in $keys {
			$restMap: map-remove($restMap, $key);
		}
		@return $restMap;
	} @else {
		@return map-remove($map, $keys);
	}
}


/*
generateModifierComments($map, $keys)

Generate the modifier class comments for kss-node from a Sass map.

Markup:
generateModifierComments($brand-colors, " brand color.")
*/
@function generateModifierComments($map, $modifierClassPrefix , $additionalDescriptionText) {
	@if(type-of($map) != "map") {
		@warn 'Argument $map of generateModifierComments() must be a Sass map';
	}
	@if(type-of($modifierClassPrefix) != "string") {
		@warn 'Argument $modifierClassPrefix of generateModifierComments() must be a string';
	}

	$text: "";
	$description: "";
	$class: "";

	@if($additionalDescriptionText) {
		$description: $additionalDescriptionText;
	}

	// Generate an modifier class for each key.
	@each $key, $value in $map {
		@if($modifierClassPrefix) {
			$class: $modifierClassPrefix + $key;
		} @else {
			$class: $key;
		}

		$text: #{$text + "
." +  $class + " - " + $key + $additionalDescriptionText}
	}

	@return $text
}