/// COLOUR DEFINITIONS
/// Using a BEM-like syntax for variable names.
///
/// Values used in calculations for hover background and foreground colours are derived from
/// previously hardcoded colours. Those colours are/were:
/// - link colour: ds_colour__blue (#0065bd)
/// - link hover background: ds_colour__blue--light (#d9effc)
/// - link hover colour: ds_colour__blue--darker (#002d64)
///
/// [1] 0.83: the luminance of ds_colour__blue--light
/// [2] 12.5%: the amount that ds_colour__blue--darker is darker than ds_colour__blue

@use 'sass:color';
@use "../../helpers/colours";

// Palette
$ds_colour__white:          #ffffff;
$ds_colour__black:          #000000;

$ds_colour__blue--light:    #d9effc;
$ds_colour__blue:           #0065bd;
$ds_colour__blue--dark:     #00437e;
$ds_colour__blue--darker:   #002d54;

$ds_colour__grey--lighter:  #f8f8f8;
$ds_colour__grey--light:    #ebebeb;
$ds_colour__grey--medium:   #b3b3b3;
$ds_colour__grey:           #5e5e5e;
$ds_colour__grey--dark:     #1a1a1a;

$ds_colour__sg-secondary:   #333e48;


// extended palette
$ds_colour__dark-blue:  $ds_colour__blue--darker;
$ds_colour__teal:       #28a197;
$ds_colour__dark-teal:  #1c5d5d;
$ds_colour__green:      #5eb135;
$ds_colour__dark-green: #1a7032;
$ds_colour__yellow:     #fdd522;
$ds_colour__orange:     #cb4e0b;
$ds_colour__red:        #d32205;
$ds_colour__pink:       #e5007e;
$ds_colour__purple:     #741e6d;
$ds_colour__brown:      #592c20;




// branding
$ds_colour__brand:              $ds_colour__blue !default;
$ds_colour__brand--secondary:   $ds_colour__sg-secondary !default;
$ds_brand-gradient-direction:   right !default;

@if colours.getContrastRatio(#ffffff, $ds_colour__brand) < 4.5 {
    @warn 'Brand colour #{$ds_colour__brand} does not meet 4.5:1 contrast ratio against white.';
}




// general backgrounds
$ds_colour__background--primary:        $ds_colour__white !default;
$ds_colour__background--secondary:      $ds_colour__grey--lighter !default;
$ds_colour__background--tertiary:       $ds_colour__grey--light !default;




// borders
$ds_colour__border:             $ds_colour__grey--medium !default;
$ds_colour__border--strong:     $ds_colour__grey--dark !default;
$ds_colour__border--faint:      $ds_colour__grey--light !default;
$ds_colour__border--highlight:  $ds_colour__brand !default;




// type
$ds_colour__text:               $ds_colour__grey--dark !default;
$ds_colour__text--secondary:    $ds_colour__grey !default;
$ds_colour__text--reversed:     $ds_colour__white !default;
$ds_colour__placeholder:        $ds_colour__text--secondary !default;




// focus
$ds_colour__focus:              $ds_colour__grey--dark !default;
$ds_colour__focus--background:  $ds_colour__yellow !default;




// links
$ds_colour__link:                       $ds_colour__brand !default;
$ds_colour__link--hover__background:    colours.adjustLuminance($ds_colour__link, 0.83) !default; /// [1]
$ds_colour__link--hover:                colours.adjustForContrast(color.adjust($ds_colour__link, $lightness: -12.5%), $ds_colour__link--hover__background, 4.5) !default; /// [2]
$ds_colour__link--focus:                $ds_colour__focus !default;
$ds_colour__link--focus__outline:       $ds_colour__focus--background !default;
$ds_colour__link--focus__background:    $ds_colour__focus--background !default;
$ds_colour__link--focus__shadow:        $ds_colour__focus !default;
$ds_colour__link--current:              $ds_colour__text !default;
$ds_colour__link--current__background:  $ds_colour__background--secondary !default;
$ds_colour__link--disabled:             $ds_colour__text !default;
$ds_colour__link--disabled__background: $ds_colour__background--tertiary !default;
$ds_colour__link--reversed:             currentColor !default;
$ds_colour__link--reversed--hover:      currentColor !default;
$ds_colour__link--reversed--focus:      $ds_colour__link--focus !default;




// block links
$ds_colour__blocklink-bg:               $ds_colour__white !default;
$ds_colour__blocklink-bg--hover:        $ds_colour__link--hover__background !default;
$ds_colour__blocklink-bg--focus:        $ds_colour__link--focus__background !default;




// buttons
$ds_colour__button:                     $ds_colour__white !default;
$ds_colour__button__background:         $ds_colour__brand !default;
$ds_colour__button--hover__background:  colours.adjustForContrast(color.adjust($ds_colour__button__background, $lightness: -12.5%), $ds_colour__button, 4.5) !default; /// [2]
$ds_colour__button--focus:              $ds_colour__link--focus !default;
$ds_colour__button--focus__background:  $ds_colour__link--focus__background !default;


$ds_colour__button--secondary:                      $ds_colour__button__background !default;
$ds_colour__button--secondary__background:          transparent !default;
$ds_colour__button--secondary--hover:               $ds_colour__button--hover__background !default;
$ds_colour__button--secondary--hover__background:   colours.adjustLuminance($ds_colour__button--secondary, 0.83) !default; /// [1]
$ds_colour__button--secondary--focus:               $ds_colour__button--focus !default;
$ds_colour__button--cancel:                         $ds_colour__text !default;
$ds_colour__button--cancel__background:             $ds_colour__button--secondary__background !default;
$ds_colour__button--cancel--hover__background:      colours.adjustLuminance($ds_colour__button--cancel, 0.83) !default; /// [1]
$ds_colour__button--disabled:                       $ds_colour__text !default;
$ds_colour__button--disabled__background:           $ds_colour__grey--medium !default;




// input
$ds_colour__input--border:              $ds_colour__border--strong !default;
$ds_colour__input--hover__border:       $ds_colour__grey--medium !default; // not currently used
$ds_colour__input--focus__background:   $ds_colour__white !default;
$ds_colour__input--focus__outline:      $ds_colour__focus--background !default;
$ds_colour__input--spot:                currentColor !default; // not currently used




// state
$ds_colour__state--info:        $ds_colour__blue;
$ds_colour__state--negative:    $ds_colour__red;
$ds_colour__state--positive:    $ds_colour__dark-green;
$ds_colour__state--warning:     $ds_colour__orange;