//////////////////////////////
// Compass Extension Imports
//////////////////////////////

//////////////////////////////
// Tint and Shade
//////////////////////////////
@function tint($color, $amount) {
  @return mix(toolkit-get('tint color'), $color, $amount);
}

@function shade($color, $amount) {
  @return mix(toolkit-get('shade color'), $color, $amount);
}

//////////////////////////////
// Luma
//////////////////////////////
@function luma($color) {
  @return (red($color) * .299) + (green($color) * .587) + (blue($color) * .114);
}

@function luma-gte($color1, $color2) {
  @if luma($color1) >= luma($color2) {
    @return true;
  }
  @else {
    @return false;
  }
}

@function luma-lte($color1, $color2) {
  @if luma($color1) <= luma($color2) {
    @return true;
  }
  @else {
    @return false;
  }
}

@function luma-diff($color1, $color2) {
  @return luma($color1) - luma($color2);
}

//////////////////////////////
// Color Stacks
//////////////////////////////
@function color-stack($main, $secondary, $amounts...) {
  @if length($amounts) == 0 {
    $amounts: toolkit-get('color stack amounts');
  }
  @else if length($amounts) == 1 {
    $amounts: nth($amounts, 1);
  }

  $stack: $main;

  @each $amount in $amounts {
    $stack: join($stack, mix($secondary, nth($stack, 1), $amount));
  }

  @return $stack;
}

// Tint Stack
@function tint-stack($color, $amounts...) {
  @if length($amounts) > 0 {
    @return color-stack($color, toolkit-get('tint color'), $amounts);
  }
  @else {
    @return color-stack($color, toolkit-get('tint color'));
  }
}

// Shade Stack
@function shade-stack($color, $amounts...) {
  @if length($amounts) > 0 {
    @return color-stack($color, toolkit-get('shade color'), $amounts);
  }
  @else {
    @return color-stack($color, toolkit-get('shade color'));
  }
}

// Tint/Shade Stack
@function tint-shade-stack($color, $amounts...) {
  $colors: ();
  @if length($amounts) == 0 {
    $amounts: toolkit-get('tint shade amounts');
  }
  $length: length($amounts);

  // Shades
  @for $i from 1 through $length {
    $colors: append($colors, shade($color, nth($amounts, $i)));
  }

  // Base
  $colors: append($colors, $color);

  // Tints
  @for $i from 0 through $length - 1 {
    $colors: append($colors, tint($color, nth($amounts, $length - $i)));
  }

  @return $colors;
}

//////////////////////////////
// Color Scales
//////////////////////////////
@function color-scale($main, $secondary, $steps: null) {
  $steps: if($steps != null, $steps, toolkit-get('color scale steps'));

  $list: $main;

  $red1: red($main);
  $red2: red($secondary);
  $red-diff: (($red1 - $red2) / (($steps - 1)));

  $hue1: hue($main);
  $hue2: hue($secondary);
  @if ($hue2 + 359 - $hue1) < abs($hue1 - $hue2) {
    $hue2: $hue2 + 359;
  }
  $hue-diff: ($hue2 - $hue1) / ($steps - 1);

  $sat1: saturation($main);
  $sat2: saturation($secondary);
  $sat-diff: 0;
  @if $sat1 > $sat2 {
    $sat-diff: ($sat2 - $sat1) / ($steps - 1);
  }
  @else {
    $sat-diff: ($sat1 - $sat2) / ($steps - 1);
  }

  $lte1: lightness($main);
  $lte2: lightness($secondary);
  $lte-diff: 0;
  @if $lte1 > $lte2 {
    $lte-diff: ($lte2 - $lte1) / ($steps - 1);
  }
  @else {
    $lte-diff: ($lte1 - $lte2) / ($steps - 1);
  }

  $alp1: alpha($main);
  $alp2: alpha($secondary);
  $alp-diff: 0;
  @if $alp1 > $alp2 {
    $alp-diff: ($alp2 - $alp1) / ($steps - 1);
  }
  @else {
    $alp-diff: ($alp1 - $alp2) / ($steps - 1);
  }

  $hue-hold: $hue1;
  $sat-hold: $sat1;
  $lte-hold: $lte1;
  $alp-hold: $alp1;
  $color-hold: 0;

  @for $i from 2 through $steps {
    $hue-hold: $hue-hold + $hue-diff;
    $sat-hold: $sat-hold + $sat-diff;
    $lte-hold: $lte-hold + $lte-diff;
    $alp-hold: $alp-hold + $alp-diff;

    $color-hold: hsla($hue-hold, $sat-hold, $lte-hold, $alp-hold);
    $list: append($list, $color-hold);
  }

  @return $list;
}