// ------------------------------
// Default settings
// ------------------------------

// A map of (name: screen width),
// if screen width <= 0, CSS rules are output outside @media blocks
$wm-breakpoints: (
  all: 0,
  sm: 576px,
  md: 768px,
  lg: 992px,
  xl: 1200px
) !default;

// Placeholder to include in the selector,
// replaced by the breakpoint name
$wm-breakpoint-placeholder: 'BR' !default;

// Placeholder to include in the selector,
// replaced by the value name
$wm-val-placeholder: 'VAL' !default;

// For minimum screen width, the number of strings to be removed
// from the selector with `$wm-breakpoint-placeholder`
//  0: .foo-BR-bar => .foo--bar
//  1: .foo-BR-bar => .foo-bar
// -1: .foo-BR-bar => .foo-bar
$wm-min-breakpoint-addition: 1 !default;

// If you want output error messages into CSS files
// instead of the terminal, set `true`
$wm-error-to-css: false !default;

// If you want to display error messages in the your site, set `true`
$wm-show-error: false !default;

// ------------------------------
// Main mixin
// ------------------------------

$wm-error-messages: () !default;

@mixin windmill(
  $style: (),
  $selector: null,
  $breakpoints: $wm-breakpoints
) {
  // Set `false` and disable output when an exception is thrown
  $is-output: true;

  // Resolve type of `$style`
  @if type-of($style) != map {
    $style: ();
  }

  // Throw if `$selector` doesn't exists
  @if (& == null) and (not $selector or ($selector == '')) {
    @include wm-warn('Something wrong with your selector', $selector);
    $is-output: false;
  }

  // Cast the selector to string
  @if not $selector or ($selector == '') {
    $selector: wm-to-selector(&);
  } @else {
    $selector: wm-to-selector($selector);
  }

  // Resolve type of `$breakpoints`
  @if type-of($breakpoints) != map {
    $breakpoints: ();
  }

  // Throw if `$selector` includes `$wm-breakpoint-placeholder`,
  // but `$breakpoints` is empty
  @if $is-output and wm-include($selector, $wm-breakpoint-placeholder) and wm-is-empty($breakpoints) {
    @include wm-warn('If you include `#{$wm-breakpoint-placeholder}` in your selector, set the breakpoints. Target selector: `#{$selector}`', $selector);
    $is-output: false;
  }

  // Throw if `$selector` doesn't include `$wm-val-placeholder`,
  // but the value of `$style` includes `map`
  $style-values: wm-flatten-deep(map-values($style));
  @if $is-output and not wm-include($selector, $wm-val-placeholder) and wm-include-type($style-values, map) {
    @include wm-warn('If you include `map` in the value of `$style` argument, include `#{$wm-val-placeholder}` in your selector. Target selector: `#{$selector}`', $selector);
    $is-output: false;
  }

  // If `$selector` doesn't contain `$wm-breakpoint-placeholder`,
  // empty `$breakpoints` and disable output to @media blocks
  @if not wm-include($selector, $wm-breakpoint-placeholder) {
    $breakpoints: ();
  }

  // If `$breakpoints` is empty,
  // set the temporary breakpoints to execute Each-statement only once
  @if wm-is-empty($breakpoints) {
    $breakpoints: (null: 0);
  }

  // Outputs CSS rule
  @if $is-output {
    @at-root {
      @each $breakpoint-name, $breakpoint in $breakpoints {
        @include wm-override-mq($breakpoint) {
          $breakpoint-values: map-values($breakpoints);
          $is-min-breakpoint: $breakpoint == min($breakpoint-values...);

          $style-values: wm-flatten-deep(map-values($style));
          $style-val-names: null;
          @if wm-include-type($style-values, map) {
            $style-val-names: wm-filter($style-values, wm-is-type-of, map);
            $style-val-names: wm-reduce($style-val-names, map-merge);
            $style-val-names: map-keys($style-val-names);
          }

          // Groups selectors,
          // outputs CSS rule based on normal declarations and @content block
          $selectors: ();
          @each $style-val-name in $style-val-names {
            $selectors: append($selectors, wm-resolve-placeholder($selector, $breakpoint-name, $style-val-name, $is-min-breakpoint));
          }
          #{wm-join($selectors, ', ')} {
            @each $prop, $val in wm-remove-keys-including-map($style) {
              $output-val: wm-style-val-to-str($val);
              $output-val: wm-fix-style-val($output-val);
              @include wm-output-declaration($prop, $output-val);
            }
            @content;
          }

          // Outputs CSS rule based on declarations including `map`
          @each $style-val-name in $style-val-names {
            #{wm-resolve-placeholder($selector, $breakpoint-name, $style-val-name, $is-min-breakpoint)} {
              @each $prop, $val in wm-remove-keys-not-including-map($style) {
                $output-val: wm-style-val-to-str($val, $style-val-name);
                $output-val: wm-fix-style-val($output-val);
                @include wm-output-declaration($prop, $output-val);
              }
            }
          }
        }
      }
    }
  }
}