/// Responsive font sizing. The size of the font will scale with the viewport
/// based on the information that you provide it. Additional properties may be
/// adding for things like padding.
///
/// @param {Integer} $font-size-min
/// @param {Integer} $font-size-max
/// @param {String} $properties [font-size]
/// @param {Integer} $vw-min [480] - the minimum viewport width
/// @param {Integer} $vw-max [1080px] - the maximum viewport width
///
/// @require {function} strip-unit
///
/// @example scss - Basic usage Sass
///   h1 {
///     @include fluid-type(28px, 52px);
///   }
///
/// @example scss - Basic usage CSS output
///   h1 {
///     font-size: 28px;
///   }
///
///   @media screen and (min-width: 320px) {
///     h1 {
///       font-size: calc(28px + 24 * (100vw - 320px) / 960);
///     }
///   }
///
///   @media screen and (min-width: 1080px) {
///     h1 {
///       font-size: 52px;
///     }
///   }
///
/// Concept of precise control from Mike Riethmuller
/// https://madebymike.com.au/writing/precise-control-responsive-typography/
///
/// Original mixin implementation from Indrek Paas
/// http://www.sassmeister.com/gist/7f22e44ace49b5124eec
@mixin fluid-type(
  $font-size-min,
  $font-size-max,
  $properties: font-size,
  $vw-min: 480px,
  $vw-max: 1080px
) {
  @if (
    unitless($font-size-min) or
      unitless($font-size-max) or
      unitless($vw-min) or
      unitless($vw-max)
  ) {
    @error "All min and max properties must be provided with a unit (e.g.: px)";
  }

  @if (
    unit($font-size-min) ==
      unit($font-size-max) and
      unit($font-size-min) ==
      unit($vw-min) and
      unit($font-size-min) ==
      unit($vw-max)
  ) {
    @each $property in $properties {
      #{$property}: $font-size-min;
    }

    @media screen and (min-width: $vw-min) {
      @each $property in $properties {
        #{$property}: calc(
          #{$font-size-min} +
            #{strip-unit($font-size-max - $font-size-min)} *
            (100vw - #{$vw-min}) /
            #{strip-unit($vw-max - $vw-min)}
        );
      }
    }

    @media screen and (min-width: $vw-max) {
      @each $property in $properties {
        #{$property}: $font-size-max;
      }
    }
  } @else {
    @error "All units must be the same. Incompatible units were passed:#{unit($font-size-min)}, #{unit($font-size-max)}, #{unit($vw-min)},#{unit($vw-max)}";
  }
}

/// Remove the unit of a length
/// @param {Number} $number - Number to remove unit from
/// @return {Number} - Unitless number
///
/// Original implementation by Miriam Suzanne
/// http://stackoverflow.com/a/12335841/1339786
///
/// Update implementation from Hugo Giraudel
/// https://css-tricks.com/snippets/sass/strip-unit-function/
@function strip-unit($number) {
  @if type-of($number) == 'number' and not unitless($number) {
    @return $number / ($number * 0 + 1);
  }

  @return $number;
}