/* functions
   ========================================================================== */

// parse int
@function parse-int($number) {
  @if type-of($number) == "number" {
    @return $number / ($number * 0 + 1);
  }

  @warn "Unfortunately, #{$number} is not a valid number";

  @return $number;
}

// units to rem
@function rem($value) {
  @if type-of($value) == "number" {
    $number: parse-int($value);
    $unit: unit($value);

    @if $number == 0 or $unit == "rem" {
      @return $value;
    }

    @return $number / 10 * 1rem;
  }

  @warn "Unfortunately, #{$value} is not a valid number";

  @return $value;
}

// units to em
@function em($value, $context: $font-size-base) {
  @if type-of($value) == "number" and type-of($context) == "number" {
    $number: parse-int($value);
    $unit: unit($value);
    $context: parse-int(rem($context)) * 10;

    @if $number == 0 or $unit == "em" {
      @return $value;
    }

    @if $unit == "rem" {
      $number: $number * 10;
    }

    @return $number / $context * 1em;
  }

  @warn "Unfortunately, #{$value} is not a valid number";

  @return $value;
}

// line height
@function line-height($font-size, $rhythm: $baseline, $minor: false, $custom: false) {
  @if type-of($font-size) == "number" and type-of($rhythm) == "number" and type-of($minor) == "bool" and type-of($custom) == "bool" {
    @if unitless($rhythm) {
      @return $rhythm;
    }
    $font-size: rem($font-size);
    $rhythm: rem($rhythm);
    $line-height: $rhythm / $font-size;
    $scale: 1;

    @if $custom {
      @return $line-height;
    }

    @if $enable-rhythm {
      @while $line-height < 1 {
        $scale: $scale + 1;
        $line-height: $rhythm * $scale / $font-size;
      }

      @if $minor {
        @while $line-height >= 2 {
          $scale: $scale + 1;
          $line-height: $rhythm / $scale / $font-size;
        }
      }

      @return $line-height;
    }
  } @else {
    @warn "Unfortunately, #{$font-size} is not a valid number";
  }

  @return $line-height-base;
}

/* maps
   ========================================================================== */

// color
@function color($color) {
  @if map-has-key($colors, $color) {
    @return map-get($colors, $color);
  }

  @warn "Unfortunately, no value could be retrieved from #{$colors}";
}

// font size
@function font-size($font-size, $key: 1) {
  @if map-has-key($font-sizes, $font-size) {
    $font-size: map-get($font-sizes, $font-size);

    @if type-of($font-size) == "list" {
      @return rem(nth($font-size, $key));
    }

    @if $key == 2 {
      @return null;
    }

    @return rem($font-size);
  }

  @warn "Unfortunately, no value could be retrieved from #{$font-sizes}";
}

// font weight
@function font-weight($font-weight) {
  @if map-has-key($font-weights, $font-weight) {
    @return map-get($font-weights, $font-weight);
  }

  @warn "Unfortunately, no value could be retrieved from #{$font-weights}";
}

// spacer
@function spacer($spacer) {
  @if map-has-key($spacers, $spacer) {
    @return rem(map-get($spacers, $spacer));
  }

  @warn "Unfortunately, no value could be retrieved from #{$spacers}";
}

// breakpoint
$bp-context: 16px;
$bp-plus: ();

@each $bp-name, $bp-value in $breakpoints {
  $breakpoints: map-merge($breakpoints, ($bp-name: em($bp-value, $bp-context)));
  $bp-plus: map-merge($bp-plus, ("#{$bp-name}-plus": em($bp-value, $bp-context) + em(1px, $bp-context)));
}

$bp-plus: map-merge($breakpoints, $bp-plus);

@function bp($bp) {
  @if map-has-key($bp-plus, $bp) {
    @return map-get($bp-plus, $bp);
  }

  @warn "Unfortunately, no value could be retrieved from #{$bp-plus}";
}