// /* SG
//
// # Colors/Blending Modes [[dev]]
//
// @file tools/_t-blend-modes.scss
//
// @priority 1
//
// [Taken from Sass Blend Modes](https://github.com/heygrady/scss-blend-modes/blob/master/stylesheets/_blend-modes.scss)
//
// ##### `blend-normal()`
// ###### function(`$forground, $background, $amount:0`)
//
// ##### `blend-multiply()`
// ###### function(`$forground, $background, $amount:0`)
//
// ##### `blend-lighten()`
// ###### function(`$forground, $background, $amount:0`)
//
// ##### `blend-darken()`
// ###### function(`$forground, $background, $amount:0`)
//
// ##### `blend-lineardodge()`
// ###### function(`$forground, $background, $amount:0`)
//
// ##### `blend-linearburn()`
// ###### function(`$forground, $background, $amount:0`)
//
// ##### `blend-difference`
// ###### function(`$forground, $background, $amount:0`)
//
// ##### `blend-screen()`
// ###### function(`$forground, $background, $amount:0`)
//
// ##### `blend-exclusion()`
// ###### function(`$forground, $background, $amount:0`)
//
// ##### `blend-multiply()`
// ###### function(`$forground, $background, $amount:0`)
//
// */

//Taken from: https://github.com/heygrady/scss-blend-modes/blob/master/stylesheets/_blend-modes.scss

//Mimic blending modes found in photoshop.

@function _color-convert($color-input) {
    $color-input: invert($color-input);
    $color-input: invert($color-input);
    @return $color-input;
}

//--------------------------------
// Normal
//--------------------------------
@function blend-normal($foreground, $background, $amount: 0) {
    $amount: $amount / 100;
    $foreground: transparentize($foreground, $amount);
    $opacity: opacity($foreground);
    $background-opacity: opacity($background);

    // calculate opacity
    $bm-red: red($foreground) * $opacity + red($background) *
        $background-opacity * (1 - $opacity);
    $bm-green: green($foreground) * $opacity + green($background) *
        $background-opacity * (1 - $opacity);
    $bm-blue: blue($foreground) * $opacity + blue($background) *
        $background-opacity * (1 - $opacity);
    @return rgb($bm-red, $bm-green, $bm-blue);
}

//--------------------------------
// Multiply
//--------------------------------
@function blend-multiply($foreground, $background, $amount: 0) {
    $amount: $amount / 100;
    $foreground: transparentize($foreground, $amount);
    $bm-red: red($background) * red($foreground) / 255;
    $bm-green: green($background) * green($foreground) / 255;
    $bm-blue: blue($background) * blue($foreground) / 255;

    @return blend-normal(
        rgba($bm-red, $bm-green, $bm-blue, opacity($foreground)),
        $background
    );
}

//--------------------------------
// Lighten
//--------------------------------
@function blend-lighten($foreground, $background, $amount: 0) {
    $amount: $amount / 100;
    $foreground: transparentize($foreground, $amount);
    $bm-red: blend-lighten-color(red($foreground), red($background));
    $bm-green: blend-lighten-color(green($foreground), green($background));
    $bm-blue: blend-lighten-color(blue($foreground), blue($background));

    @return blend-normal(
        rgba($bm-red, $bm-green, $bm-blue, opacity($foreground)),
        $background
    );
}
@function blend-lighten-color($foreground, $background) {
    @if $background > $foreground {
        $foreground: $background;
    }
    @return $foreground;
}

//--------------------------------
// Darken
//--------------------------------
@function blend-darken($foreground, $background, $amount: 0) {
    $amount: $amount / 100;
    $foreground: transparentize($foreground, $amount);
    $bm-red: blend-darken-color(red($foreground), red($background));
    $bm-green: blend-darken-color(green($foreground), green($background));
    $bm-blue: blend-darken-color(blue($foreground), blue($background));

    @return blend-normal(
        rgba($bm-red, $bm-green, $bm-blue, opacity($foreground)),
        $background
    );
}
@function blend-darken-color($foreground, $background) {
    @if $background < $foreground {
        $foreground: $background;
    }
    @return $foreground;
}

//--------------------------------
// Darker Color
//--------------------------------
@function blend-darkercolor($foreground, $background, $amount: 0) {
    $amount: $amount / 100;
    $foreground: transparentize($foreground, $amount);
    $bm-red: red($foreground);
    $bm-green: green($foreground);
    $bm-blue: blue($foreground);
    $background-red: red($background);
    $background-green: green($background);
    $background-blue: blue($background);

    @if $background-red *
        0.3 +
        $background-green *
        0.59 +
        $background-blue *
        0.11 <=
        $bm-red *
        0.3 +
        $bm-green *
        0.59 +
        $bm-blue *
        0.11
    {
        $bm-red: $background-red;
        $bm-green: $background-green;
        $bm-blue: $background-blue;
    }
    @return blend-normal(
        rgba($bm-red, $bm-green, $bm-blue, opacity($foreground)),
        $background
    );
}

//--------------------------------
// Lighter Color
//--------------------------------
@function blend-lightercolor($foreground, $background, $amount: 0) {
    $amount: $amount / 100;
    $foreground: transparentize($foreground, $amount);
    $bm-red: red($foreground);
    $bm-green: green($foreground);
    $bm-blue: blue($foreground);
    $background-red: red($background);
    $background-green: green($background);
    $background-blue: blue($background);

    @if $background-red *
        0.3 +
        $background-green *
        0.59 +
        $background-blue *
        0.11 >
        $bm-red *
        0.3 +
        $bm-green *
        0.59 +
        $bm-blue *
        0.11
    {
        $bm-red: $background-red;
        $bm-green: $background-green;
        $bm-blue: $background-blue;
    }
    @return blend-normal(
        rgba($bm-red, $bm-green, $bm-blue, opacity($foreground)),
        $background
    );
}

//--------------------------------
// Linear Dodge
//--------------------------------
@function blend-lineardodge($foreground, $background, $amount: 0) {
    $amount: $amount / 100;
    $foreground: transparentize($foreground, $amount);
    $bm-red: blend-lineardodge-color(red($foreground), red($background));
    $bm-green: blend-lineardodge-color(green($foreground), green($background));
    $bm-blue: blend-lineardodge-color(blue($foreground), blue($background));

    @return blend-normal(
        rgba($bm-red, $bm-green, $bm-blue, opacity($foreground)),
        $background
    );
}
@function blend-lineardodge-color($foreground, $background) {
    @if $background + $foreground > 255 {
        $foreground: 255;
    } @else {
        $foreground: $background + $foreground;
    }
    @return $foreground;
}

//--------------------------------
// Linear Burn
//--------------------------------
@function blend-linearburn-color($foreground, $background) {
    @if $background + $foreground < 255 {
        $foreground: 0;
    } @else {
        $foreground: $background + $foreground - 255;
    }
    @return $foreground;
}

@function blend-linearburn($foreground, $background, $amount: 0) {
    $amount: $amount / 100;
    $foreground: transparentize($foreground, $amount);
    $bm-red: blend-linearburn-color(red($foreground), red($background));
    $bm-green: blend-linearburn-color(green($foreground), green($background));
    $bm-blue: blend-linearburn-color(blue($foreground), blue($background));

    @return blend-normal(
        rgba($bm-red, $bm-green, $bm-blue, opacity($foreground)),
        $background
    );
}

//--------------------------------
// Difference
//--------------------------------
@function blend-difference($foreground, $background, $amount: 0) {
    $amount: $amount / 100;
    $foreground: transparentize($foreground, $amount);
    $bm-red: abs(red($background) - red($foreground));
    $bm-green: abs(green($background) - green($foreground));
    $bm-blue: abs(blue($background) - blue($foreground));

    @return blend-normal(
        rgba($bm-red, $bm-green, $bm-blue, opacity($foreground)),
        $background
    );
}

//--------------------------------
// Screen
//--------------------------------
@function blend-screen-color($foreground, $background) {
    @return (255 - (((255 - $foreground) * (255 - $background)) / 256));
}

@function blend-screen($foreground, $background, $amount: 0) {
    $amount: $amount / 100;
    $foreground: transparentize($foreground, $amount);
    $bm-red: blend-screen-color(red($foreground), red($background));
    $bm-green: blend-screen-color(green($foreground), green($background));
    $bm-blue: blend-screen-color(blue($foreground), blue($background));

    @return blend-normal(
        rgba($bm-red, $bm-green, $bm-blue, opacity($foreground)),
        $background
    );
}

//--------------------------------
// Exclusion
//--------------------------------
@function blend-exclusion($foreground, $background, $amount: 0) {
    $amount: $amount / 100;
    $foreground: transparentize($foreground, $amount);
    $bm-red: blend-exclusion-color(red($foreground), red($background));
    $bm-green: blend-exclusion-color(green($foreground), green($background));
    $bm-blue: blend-exclusion-color(blue($foreground), blue($background));

    @return blend-normal(
        rgba($bm-red, $bm-green, $bm-blue, opacity($foreground)),
        $background
    );
}

@function blend-exclusion-color($foreground, $background) {
    @return $background - ($background * (2 / 255) - 1) * $foreground;
}

//--------------------------------
// Overlay
//--------------------------------
@function blend-overlay-color($foreground, $background) {
    $comparison: 255 / 2;
    @if $background <= $comparison {
        $foreground: (2 * $background * $foreground) / 255;
    } @else {
        $foreground: 255 -
            (255 - 2 * ($background - (255 / 2))) *
            (255 - $foreground) /
            255;
    }
    @return $foreground;
}

@function blend-overlay($foreground, $background, $amount: 0) {
    $amount: $amount / 100;
    $foreground: transparentize($foreground, $amount);

    $bm-red: blend-overlay-color(red($foreground), red($background));
    $bm-green: blend-overlay-color(green($foreground), green($background));
    $bm-blue: blend-overlay-color(blue($foreground), blue($background));

    @return blend-normal(
        rgba($bm-red, $bm-green, $bm-blue, opacity($foreground)),
        $background
    );
}

//--------------------------------
// Soft Light
//--------------------------------
@function blend-softlight-color($foreground, $background) {
    @if $background < 128 {
        $foreground: (($foreground / 2) + 64) * $background * (2 / 255);
    } @else {
        $foreground: 255 -
            (191 - ($foreground / 2)) *
            (255 - $background) *
            (2 / 255);
    }
    @return $foreground;
}

@function blend-softlight($foreground, $background, $amount: 0) {
    $amount: $amount / 100;
    $foreground: transparentize($foreground, $amount);
    $bm-red: blend-softlight-color(red($foreground), red($background));
    $bm-green: blend-softlight-color(green($foreground), green($background));
    $bm-blue: blend-softlight-color(blue($foreground), blue($background));

    @return blend-normal(
        rgba($bm-red, $bm-green, $bm-blue, opacity($foreground)),
        $background
    );
}

//--------------------------------
// Hard Light
//--------------------------------
@function blend-hardlight-color($foreground, $background) {
    $tmp-blend: $foreground;
    @if $tmp-blend < 128 {
        $foreground: $background * $tmp-blend * (2 / 255);
    } @else {
        $foreground: 255 - (255 - $background) * (255 - $tmp-blend) * (2 / 255);
    }
    @return $foreground;
}

@function blend-hardlight($foreground, $background, $amount: 0) {
    $amount: $amount / 100;
    $foreground: transparentize($foreground, $amount);
    $bm-red: blend-hardlight-color(red($foreground), red($background));
    $bm-green: blend-hardlight-color(green($foreground), green($background));
    $bm-blue: blend-hardlight-color(blue($foreground), blue($background));

    @return blend-normal(
        rgba($bm-red, $bm-green, $bm-blue, opacity($foreground)),
        $background
    );
}

//--------------------------------
// Color Dodge
//--------------------------------
@function blend-colordodge-color($foreground, $background) {
    $comparison: 256 / (255 - $foreground);
    @if $comparison == Infinity {
        $comparison: 255;
    }
    $tmp: $background * $comparison;
    @if $tmp > 255 or $foreground == 255 {
        $foreground: 255;
    } @else {
        $foreground: $tmp;
    }
    @return $foreground;
}

@function blend-colordodge($foreground, $background, $amount: 0) {
    $amount: $amount / 100;
    $foreground: transparentize($foreground, $amount);
    $bm-red: blend-colordodge-color(red($foreground), red($background));
    $bm-green: blend-colordodge-color(green($foreground), green($background));
    $bm-blue: blend-colordodge-color(blue($foreground), blue($background));

    @return blend-normal(
        rgba($bm-red, $bm-green, $bm-blue, opacity($foreground)),
        $background
    );
}

//--------------------------------
// Color Burn
//--------------------------------
@function blend-colorburn-color($foreground, $background) {
    $tmp: (255 - ((255 - $background) * 255) / $foreground);

    @if $foreground == 0 {
        $foreground: 255;
    }
    @else if $tmp < 0 {
        $foreground: 0;
    } @else {
        $foreground: $tmp;
    }
    @return $foreground;
}

@function blend-colorburn($foreground, $background, $amount: 0) {
    $amount: $amount / 100;
    $foreground: transparentize($foreground, $amount);
    $bm-red: blend-colorburn-color(red($foreground), red($background));
    $bm-green: blend-colorburn-color(green($foreground), green($background));
    $bm-blue: blend-colorburn-color(blue($foreground), blue($background));

    @return blend-normal(
        rgba($bm-red, $bm-green, $bm-blue, opacity($foreground)),
        $background
    );
}

//--------------------------------
// Linear Light
//--------------------------------
@function blend-linearlight($foreground, $background, $amount: 0) {
    $amount: $amount / 100;
    $foreground: transparentize($foreground, $amount);
    $bm-red: blend-linearlight-color(red($foreground), red($background));
    $bm-green: blend-linearlight-color(green($foreground), green($background));
    $bm-blue: blend-linearlight-color(blue($foreground), blue($background));

    @return blend-normal(
        rgba($bm-red, $bm-green, $bm-blue, opacity($foreground)),
        $background
    );
}
@function blend-linearlight-color($foreground, $background) {
    @if $foreground < 128 {
        $foreground: blend-linearburn-color($background, 2 * $foreground);
    } @else {
        $foreground: blend-lineardodge-color(
            $background,
            2 * ($foreground - 128)
        );
    }
    @return $foreground;
}

//--------------------------------
// Vivid Light
//--------------------------------
@function blend-vividlight($foreground, $background, $amount: 0) {
    $amount: $amount / 100;
    $foreground: transparentize($foreground, $amount);
    $bm-red: blend-vividlight-color(red($foreground), red($background));
    $bm-green: blend-vividlight-color(green($foreground), green($background));
    $bm-blue: blend-vividlight-color(blue($foreground), blue($background));

    @return blend-normal(
        rgba($bm-red, $bm-green, $bm-blue, opacity($foreground)),
        $background
    );
}

@function blend-vividlight-color($foreground, $background) {
    @if $foreground < 128 {
        $foreground: blend-colorburn-color(2 * $foreground, $background);
    } @else {
        $foreground: blend-colordodge-color(
            2 * ($foreground - 128),
            $background
        );
    }
    @return $foreground;
}

//--------------------------------
// Pin Light
//--------------------------------
@function blend-pinlight($foreground, $background, $amount: 0) {
    $amount: $amount / 100;
    $foreground: transparentize($foreground, $amount);
    $bm-red: blend-pinlight-color(red($foreground), red($background));
    $bm-green: blend-pinlight-color(green($foreground), green($background));
    $bm-blue: blend-pinlight-color(blue($foreground), blue($background));

    @return blend-normal(
        rgba($bm-red, $bm-green, $bm-blue, opacity($foreground)),
        $background
    );
}

@function blend-pinlight-color($foreground, $background) {
    @if $foreground < 128 {
        $foreground: blend-darken-color($background, 2 * $foreground);
    } @else {
        $foreground: blend-lighten-color($background, 2 * ($foreground - 128));
    }
    @return $foreground;
}

//--------------------------------
// Hard Mix
//--------------------------------
@function blend-hardmix($foreground, $background, $amount: 0) {
    $amount: $amount / 100;
    $foreground: transparentize($foreground, $amount);
    $bm-red: blend-hardmix-color(red($foreground), red($background));
    $bm-green: blend-hardmix-color(green($foreground), green($background));
    $bm-blue: blend-hardmix-color(blue($foreground), blue($background));

    @return blend-normal(
        rgba($bm-red, $bm-green, $bm-blue, opacity($foreground)),
        $background
    );
}

@function blend-hardmix-color($foreground, $background) {
    $tmp: blend-vividlight-color($foreground, $background);
    @if $tmp < 128 {
        $foreground: 0;
    } @else {
        $foreground: 255;
    }
    @return $foreground;
}

// Unique to Photoshop

//--------------------------------
// Color Blend
//--------------------------------
@function blend-colorblend($foreground, $background, $amount: 0) {
    $amount: $amount / 100;
    $foreground: transparentize($foreground, $amount);
    $foreground-hsv: color-to-hsv($foreground);
    $background-hsv: color-to-hsv($background);

    $bm-hsv: nth($foreground-hsv, 1), nth($foreground-hsv, 2),
        nth($background-hsv, 3);
    $bm-color: hsv-to-color($bm-hsv);

    @return blend-normal(
        rgba(
            red($bm-color),
            green($bm-color),
            blue($bm-color),
            opacity($foreground)
        ),
        $background
    );
}

//--------------------------------
// Dissolve
//--------------------------------
@function blend-dissolve($foreground, $background, $amount: 0) {
    // The Dissolve blend mode acts on transparent and partially transparent pixels
    // it treats transparency as a pixel pattern and applies a diffusion dither pattern.
    // @see http://photoblogstop.com/photoshop/photoshop-blend-modes-explained
    @return $foreground;
}

//--------------------------------
// Divide
//--------------------------------
@function blend-divide($foreground, $background, $amount: 0) {
    $amount: $amount / 100;
    $foreground: transparentize($foreground, $amount);
    $bm-red: blend-divide-colors(red($foreground), red($background));
    $bm-green: blend-divide-colors(green($foreground), green($background));
    $bm-blue: blend-divide-colors(blue($foreground), blue($background));

    @return blend-normal(
        rgba($bm-red, $bm-green, $bm-blue, opacity($foreground)),
        $background
    );
}
@function blend-divide-colors($foreground, $background) {
    @return min((($background / 255) / ($foreground / 255)) * 255, 255);
}

//--------------------------------
// Hue
//--------------------------------
@function blend-hue($foreground, $background, $amount: 0) {
    $amount: $amount / 100;
    $foreground: transparentize($foreground, $amount);
    $foreground-hsv: color-to-hsv($foreground);
    $background-hsv: color-to-hsv($background);

    $bm-hsv: nth($foreground-hsv, 1), nth($background-hsv, 2),
        nth($background-hsv, 3);
    $bm-color: hsv-to-color($bm-hsv);

    @return blend-normal(
        rgba(
            red($bm-color),
            green($bm-color),
            blue($bm-color),
            opacity($foreground)
        ),
        $background
    );
}

//--------------------------------
// Luminosity
//--------------------------------
@function blend-luminosity($foreground, $background, $amount: 0) {
    $amount: $amount / 100;
    $foreground: transparentize($foreground, $amount);
    $foreground-hsv: color-to-hsv($foreground);
    $background-hsv: color-to-hsv($background);

    $bm-hsv: nth($background-hsv, 1), nth($background-hsv, 2),
        nth($foreground-hsv, 3);
    $bm-color: hsv-to-color($bm-hsv);

    @return blend-normal(
        rgba(
            red($bm-color),
            green($bm-color),
            blue($bm-color),
            opacity($foreground)
        ),
        $background
    );
}

//--------------------------------
// Saturation
//--------------------------------
@function blend-saturation($foreground, $background, $amount: 0) {
    $amount: $amount / 100;
    $foreground: transparentize($foreground, $amount);
    $foreground-hsv: color-to-hsv($foreground);
    $background-hsv: color-to-hsv($background);

    $bm-hsv: nth($background-hsv, 1), nth($foreground-hsv, 2),
        nth($background-hsv, 3);
    $bm-color: hsv-to-color($bm-hsv);

    @return blend-normal(
        rgba(
            red($bm-color),
            green($bm-color),
            blue($bm-color),
            opacity($foreground)
        ),
        $background
    );
}

//--------------------------------
// Subtract
//--------------------------------
@function blend-subtract($foreground, $background, $amount: 0) {
    $amount: $amount / 100;
    $foreground: transparentize($foreground, $amount);
    $bm-red: max(red($background) - red($foreground), 0);
    $bm-green: max(green($background) - green($foreground), 0);
    $bm-blue: max(blue($background) - blue($foreground), 0);

    @return blend-normal(
        rgba($bm-red, $bm-green, $bm-blue, opacity($foreground)),
        $background
    );
}

//--------------------------------
// Tints and Shades (adding black or white to a color)
//--------------------------------
// Adapted from: https://gist.github.com/benfrain/7545629

// Add percentage of white to a color
@function blend-tint($color, $percent) {
    @return mix(white, $color, $percent);
}
@function tint($color, $percent) {
    @return mix(white, $color, $percent);
}

// Add percentage of black to a color
@function shade($color, $percent) {
    @return mix(black, $color, $percent);
}
@function blend-shade($color, $percent) {
    @return mix(black, $color, $percent);
}

//Shortcut function for blendmodes
@function blend($mode, $foreground, $background, $amount: 0) {
    $mode: unquote($mode);
    $blended-color: null;

    $blended-color: call(
        safe-get-function(blend-#{$mode}),
        $foreground,
        $background,
        $amount
    );

    @return $blended-color;
}

//--------------------------------
// HSL and HSV
//--------------------------------
// @see https://gist.github.com/1069204
@function hsv-to-hsl($h, $s: 0, $v: 0) {
    @if type-of($h) == 'list' {
        $v: nth($h, 3);
        $s: nth($h, 2);
        $h: nth($h, 1);
    }

    @if unit($h) == 'deg' {
        $h: 3.1415 * 2 * ($h / 360deg);
    }
    @if unit($s) == '%' {
        $s: 0 + ($s / 100%);
    }
    @if unit($v) == '%' {
        $v: 0 + ($v / 100%);
    }

    $ss: $s * $v;
    $ll: (2 - $s) * $v;

    @if $ll <= 1 {
        $ss: $ss / $ll;
    } @else if ($ll == 2) {
        $ss: 0;
    } @else {
        $ss: $ss / (2 - $ll);
    }

    $ll: $ll / 2;

    @return 360deg * $h / (3.1415 * 2), percentage(max(0, min(1, $ss))),
        percentage(max(0, min(1, $ll)));
}

@function hsl-to-hsv($h, $ss: 0, $ll: 0) {
    @if type-of($h) == 'list' {
        $ll: nth($h, 3);
        $ss: nth($h, 2);
        $h: nth($h, 1);
    } @else if type-of($h) == 'color' {
        $ll: lightness($h);
        $ss: saturation($h);
        $h: hue($h);
    }

    @if unit($h) == 'deg' {
        $h: 3.1415 * 2 * ($h / 360deg);
    }
    @if unit($ss) == '%' {
        $ss: 0 + ($ss / 100%);
    }
    @if unit($ll) == '%' {
        $ll: 0 + ($ll / 100%);
    }

    $ll: $ll * 2;

    @if $ll <= 1 {
        $ss: $ss * $ll;
    } @else {
        $ss: $ss * (2 - $ll);
    }

    $v: ($ll + $ss) / 2;
    $s: (2 * $ss) / ($ll + $ss);

    @return 360deg * $h / (3.1415 * 2), percentage(max(0, min(1, $s))),
        percentage(max(0, min(1, $v)));
}

@function color-to-hsv($color) {
    @return hsl-to-hsv($color);
}

@function hsv-to-color($h, $s: 0, $v: 0) {
    $hsl: hsv-to-hsl($h, $s, $v);
    @return hsl(nth($hsl, 1), nth($hsl, 2), nth($hsl, 3));
}