////
/// @group settings/colours
////
@use "sass:list";
@use "sass:map";
@use "sass:meta";

@import "../settings/warnings";

/// Default definitions of the functional colours
///
/// @type Map
///
/// @see {variable} $govuk-functional-colours
///
/// @access public
$govuk-default-functional-colours: (
  (
    "brand": (
      name: "blue"
    ),
    "text": (
      name: "black"
    ),
    // The background colour of the template. This is intended to be the same
    // as `surface-background` for the purposes of making the Footer and Cookie
    // banner components merge seamlessly with the template.
    "template-background": (
        name: "blue",
        variant: "tint-95"
      ),
    "body-background": (
      name: "white"
    ),
    // Use 'true black' to avoid printers using colour ink to print body text
    "print-text": #000000,
    // Used in for example 'muted' text and help text.
    "secondary-text": (
        name: "black",
        variant: "tint-25"
      ),
    // Used for outline (and background, where appropriate) when interactive
    // elements (links, form controls) have keyboard focus.
    "focus": (
        name: "yellow"
      ),
    // Ensure that the contrast between the text and background colour passes
    // WCAG Level AA contrast requirements.
    "focus-text": (
        name: "black"
      ),
    // Used to highlight error messages and form controls in an error state
    "error": (
        name: "red"
      ),
    // Used to highlight success messages and banners
    "success": (
        name: "green"
      ),
    // Used in for example borders, separators, rules and keylines.
    "border": (
        name: "black",
        variant: "tint-80"
      ),
    // Used for form inputs and controls
    "input-border": (
        name: "black"
      ),
    // Used for hover states on form controls
    "hover": (
        name: "black",
        variant: "tint-80"
      ),
    // Standard links (on white)
    "link": (
        name: "blue",
        variant: "shade-10"
      ),
    "link-visited": (
      name: "purple"
    ),
    "link-hover": (
      name: "blue",
      variant: "shade-50"
    ),
    "link-active": (
      name: "black"
    ),
    // 'Surfaces' are our name for components that have different colour
    // palettes to typical page content. This is the generic surface.
    "surface-background": (
        name: "blue",
        variant: "tint-95"
      ),
    "surface-text": (
      name: "black"
    ),
    "surface-border": (
      name: "blue",
      variant: "tint-50"
    )
  )
);

/// Validates and merges functional colour overrides with defaults.
///
/// Throws an error if any provided colour name does not exist in the default
/// functional colours map.
///
/// @param {Map} $colours Functional colour overrides.
/// @param {Map} $defaults Default functional colours.
/// @return {Map} Merged functional colours.
/// @access private
@function _govuk-define-functional-colours($colours, $defaults) {
  $existing-colours: map.keys($defaults);

  @each $colour-name, $colour in $colours {
    @if not list.index($existing-colours, $colour-name) {
      @error 'Unknown colour `#{$colour-name}` (available colours: #{$existing-colours})';
    }
  }

  @return map.merge($defaults, $colours);
}

/// Functional colours for the GOV.UK palette.
///
/// Each functional colour is represented by a name (for example `'brand'`) to
/// which the map associates either:
///
///   - a Sass colour (like `#1d70b8`)
///   - a Sass map with a `name` and an optional `variant` properties, referring
///     to one of the colours in the colour palette (like `(name: 'blue',
///     variant: 'primary')`). `variant` defaults to `'primary'` if omitted.
///
/// Use the `govuk-functional-colour` function to access these colours.
///
/// Customise functional colours by defining $govuk-functional-colours with a
/// map of the colours that you want to change before importing GOV.UK Frontend.
/// These will then be merged with the default colours. You can only redefine
/// existing colours.
///
/// @example scss – Redefining functional colours by setting them before import
///
///   // These will be merged with the default functional colours
///   $govuk-functional-colours: (
///     // set the 'brand' colour to the 'primary' variant of 'purple'
///     brand: (name: 'purple'),
///     // set the 'template-background' colour to the 'tint-95' variant of 'purple'
///     template-background: (name: 'purple', variant: 'tint-95'),
///     // set the 'text' colour to an arbitrary colour `#221133`
///     text: #221133
///   );
///
/// @see {function} govuk-functional-colour
///
/// @type Map
///
/// @access public
$govuk-functional-colours: $govuk-default-functional-colours !default;
$govuk-functional-colours: _govuk-define-functional-colours(
  $govuk-functional-colours,
  $defaults: $govuk-default-functional-colours
);

// =============================================================================
// Legacy variables
//
// To help migrate to `govuk-functional-colour`, we're keeping the variables
// which were previously storing the functional colours. This should reduce
// breakage as teams upgrade
// =============================================================================

// Because the file may be imported multiple times, subsequent imports will see
// the legacy variable and warn when they shouldn't so we need to track those
$_govuk-deprecated-applied-colour-variables: () !default;

/// Warn if a given legacy applied colour variable is set
///
/// @param {String} Name of variable to check
/// @access private
@mixin _warn-if-applied-colour-variable-set($functional-colour-name) {
  @if not list.index($_govuk-deprecated-applied-colour-variables, $functional-colour-name) {
    @if meta.variable-exists("govuk-#{$functional-colour-name}-colour") {
      $deprecation-message: "Setting \`$govuk-#{$functional-colour-name}-colour\` no longer has any effect. Use \`$govuk-functional-colours: (#{$functional-colour-name}: <NEW_COLOUR_VALUE>);\` instead.";

      @include _warning("applied-colour-variables", $deprecation-message);
    }

    $_govuk-deprecated-applied-colour-variables: list.append(
      $_govuk-deprecated-applied-colour-variables,
      $functional-colour-name
    ) !global;
  }
}

@include _warn-if-applied-colour-variable-set(brand);
/// Brand colour
///
/// @type Colour
/// @access public
/// @deprecated
///   Variables for applied colours are deprecated. Please use the `govuk-functional-colour`
///   function instead: `govuk-functional-colour(brand)`.
$govuk-brand-colour: govuk-functional-colour(brand);

@include _warn-if-applied-colour-variable-set(text);
/// Text colour
///
/// @type Colour
/// @access public
/// @deprecated
///   Variables for applied colours are deprecated. Please use the `govuk-functional-colour`
///   function instead: `govuk-functional-colour(text)`.
$govuk-text-colour: govuk-functional-colour(text);

@include _warn-if-applied-colour-variable-set(template-background);
/// Template background colour
///
/// Used by components that want to give the illusion of extending
/// the template background (such as the footer and cookie banner).
///
/// @type Colour
/// @access public
/// @deprecated
///   Variables for applied colours are deprecated. Please use the `govuk-functional-colour`
///   function instead: `govuk-functional-colour(template-background)`.
$govuk-template-background-colour: govuk-functional-colour(template-background);

@include _warn-if-applied-colour-variable-set(body-background);
/// Body background colour
///
/// @type Colour
/// @access public
/// @deprecated
///   Variables for applied colours are deprecated. Please use the `govuk-functional-colour`
///   function instead: `govuk-functional-colour(body-background)`.
$govuk-body-background-colour: govuk-functional-colour(body-background);

@include _warn-if-applied-colour-variable-set(print-text);
/// Text colour for print media
///
/// Use 'true black' to avoid printers using colour ink to print body text
///
/// @type Colour
/// @access public
/// @deprecated
///   Variables for applied colours are deprecated. Please use the `govuk-functional-colour`
///   function instead: `govuk-functional-colour(print-text)`.
$govuk-print-text-colour: govuk-functional-colour(print-text);

@include _warn-if-applied-colour-variable-set(secondary-text);
/// Secondary text colour
///
/// Used in for example 'muted' text and help text.
///
/// @type Colour
/// @access public
/// @deprecated
///   Variables for applied colours are deprecated. Please use the `govuk-functional-colour`
///   function instead: `govuk-functional-colour(secondary-text)`.
$govuk-secondary-text-colour: govuk-functional-colour(secondary-text);

@include _warn-if-applied-colour-variable-set(focus);
/// Focus colour
///
/// Used for outline (and background, where appropriate) when interactive
/// elements (links, form controls) have keyboard focus.
///
/// @type Colour
/// @access public
/// @deprecated
///   Variables for applied colours are deprecated. Please use the `govuk-functional-colour`
///   function instead: `govuk-functional-colour(focus)`.
$govuk-focus-colour: govuk-functional-colour(focus);

@include _warn-if-applied-colour-variable-set(focus-text);
/// Focused text colour
///
/// Ensure that the contrast between the text and background colour passes
/// WCAG Level AA contrast requirements.
///
/// @type Colour
/// @access public
/// @deprecated
///   Variables for applied colours are deprecated. Please use the `govuk-functional-colour`
///   function instead: `govuk-functional-colour(focus-text)`.
$govuk-focus-text-colour: govuk-functional-colour(focus-text);

@include _warn-if-applied-colour-variable-set(error);
/// Error colour
///
/// Used to highlight error messages and form controls in an error state
///
/// @type Colour
/// @access public
/// @deprecated
///   Variables for applied colours are deprecated. Please use the `govuk-functional-colour`
///   function instead: `govuk-functional-colour(error)`.
$govuk-error-colour: govuk-functional-colour(error);

@include _warn-if-applied-colour-variable-set(success);
/// Success colour
///
/// Used to highlight success messages and banners
///
/// @type Colour
/// @access public
/// @deprecated
///   Variables for applied colours are deprecated. Please use the `govuk-functional-colour`
///   function instead: `govuk-functional-colour(error)`.
$govuk-success-colour: govuk-functional-colour(success);

@include _warn-if-applied-colour-variable-set(border);
/// Border colour
///
/// Used in for example borders, separators, rules and keylines.
///
/// @type Colour
/// @access public
/// @deprecated
///   Variables for applied colours are deprecated. Please use the `govuk-functional-colour`
///   function instead: `govuk-functional-colour(border)`.
$govuk-border-colour: govuk-functional-colour(border);

@include _warn-if-applied-colour-variable-set(input-border);
/// Input border colour
///
/// Used for form inputs and controls
///
/// @type Colour
/// @access public
/// @deprecated
///   Variables for applied colours are deprecated. Please use the `govuk-functional-colour`
///   function instead: `govuk-functional-colour(input-border)`.
$govuk-input-border-colour: govuk-functional-colour(input-border);

@include _warn-if-applied-colour-variable-set(hover);
/// Input hover colour
///
/// Used for hover states on form controls
///
/// @type Colour
/// @access public
/// @deprecated
///   Variables for applied colours are deprecated. Please use the `govuk-functional-colour`
///   function instead: `govuk-functional-colour(hover)`.
$govuk-hover-colour: govuk-functional-colour(hover);

@include _warn-if-applied-colour-variable-set(link);
/// Link colour
///
/// @type Colour
/// @access public
/// @deprecated
///   Variables for applied colours are deprecated. Please use the `govuk-functional-colour`
///   function instead: `govuk-functional-colour(link)`.
$govuk-link-colour: govuk-functional-colour(link);

@include _warn-if-applied-colour-variable-set(link-visited);
/// Visited link colour
///
/// @type Colour
/// @access public
/// @deprecated
///   Variables for applied colours are deprecated. Please use the `govuk-functional-colour`
///   function instead: `govuk-functional-colour(link-visited)`.
$govuk-link-visited-colour: govuk-functional-colour(link-visited);

@include _warn-if-applied-colour-variable-set(link-hover);
/// Link hover colour
///
/// @type Colour
/// @access public
/// @deprecated
///   Variables for applied colours are deprecated. Please use the `govuk-functional-colour`
///   function instead: `govuk-functional-colour(link-hover)`.
$govuk-link-hover-colour: govuk-functional-colour(link-hover);

@include _warn-if-applied-colour-variable-set(link-active);
/// Active link colour
///
/// @type Colour
/// @access public
/// @deprecated
///   Variables for applied colours are deprecated. Please use the `govuk-functional-colour`
///   function instead: `govuk-functional-colour(link-active)`.
$govuk-link-active-colour: govuk-functional-colour(link-active);

/*# sourceMappingURL=_colours-functional.scss.map */