@use 'sass:list';
@use 'sass:map';
@use 'sass:math';
@use 'sass:meta';
@use 'sass:string';
@use '../style/private';


// Utility for fetching a nested value from a typography config.
@function _mat-get-type-value($config, $level, $name) {
  @return map.get(map.get($config, $level), $name);
}

/// Gets the font size for a level inside a typography config.
/// @param {Map} $config A typography config.
/// @param {Map} $level A typography level.
@function font-size($config, $level) {
  @return _mat-get-type-value($config, $level, font-size);
}

/// Gets the line height for a level inside a typography config.
/// @param {Map} $config A typography config.
/// @param {Map} $level A typography level.
@function line-height($config, $level) {
  @return _mat-get-type-value($config, $level, line-height);
}

/// Gets the font weight for a level inside a typography config.
/// @param {Map} $config A typography config.
/// @param {Map} $level A typography level.
@function font-weight($config, $level) {
  @return _mat-get-type-value($config, $level, font-weight);
}

/// Gets the letter spacing for a level inside a typography config.
/// @param {Map} $config A typography config.
/// @param {Map} $level A typography level.
@function letter-spacing($config, $level) {
  @return _mat-get-type-value($config, $level, letter-spacing);
}

/// Gets the font-family from a typography config and removes the quotes around it.
/// @param {Map} $config A typography config.
/// @param {Map} $level A typography level.
@function font-family($config, $level: null) {
  $font-family: map.get($config, font-family);

  @if $level != null {
    $font-family: _mat-get-type-value($config, $level, font-family);
  }

  // Guard against unquoting non-string values, because it's deprecated.
  @return if(meta.type-of($font-family) == string, string.unquote($font-family), $font-family);
}

/// Outputs the shorthand `font` CSS property, based on a set of typography values. Falls back to
/// the individual properties if a value that isn't allowed in the shorthand is passed in.
/// @param {String} $font-size The font-size value.
/// @param {String | Number} $font-weight The font-weight value.
/// @param {String | Number} $line-height The line-height value.
/// @param {String} $font-family The font-family value.
/// @returns {String} The `font` shorthand value combining the given parts.
@mixin font-shorthand($font-size, $font-weight, $line-height, $font-family) {
  // If any of the values are set to `inherit`, we can't use the shorthand
  // so we fall back to passing in the individual properties.
  @if ($font-size == inherit or
       $font-weight == inherit or
       $line-height == inherit or
       $font-family == inherit or
       $font-size == null or
       $font-weight == null or
       $line-height == null or
       $font-family == null) {

    font-size: $font-size;
    font-weight: $font-weight;
    line-height: $line-height;
    font-family: $font-family;
  }
  @else {
    // Otherwise use the shorthand `font`, because it's the least amount of bytes. Note
    // that we need to use `list.slash` for `font-size/line-height` in order to prevent
    // Sass from dividing the two values.
    font: $font-weight private.private-slash($font-size, $line-height) $font-family;
  }
}

/// Emits CSS styles for the given typography level.
/// @param {Map} $config A typography config.
/// @param {Map} $level A typography level.
@mixin typography-level($config, $level) {
  $font-size: font-size($config, $level);
  $font-weight: font-weight($config, $level);
  $line-height: line-height($config, $level);
  $font-family: font-family($config, $level);

  @include font-shorthand($font-size, $font-weight, $line-height, $font-family);
  letter-spacing: letter-spacing($config, $level);
}

/// Coerce a value to `em` if it is a unitless number, otherwise returns
/// the value provided.
@function private-coerce-unitless-to-em($value) {
  @return if(math.is-unitless($value), 1em * $value, $value);
}