// @category   ui
@import "hacks";
@import "compass/layout/stretching";

// computes the border position to use
// @function  _getTriangleBorderDirection
// @private
// @param     $direction {String} the direction the arrow is pointing (top, left, top left, etc)
// @return    {List} the computed border position (e.g. top, left, bottom)
@function _getTriangleBorderDirection($direction) {
  @if(length($direction) == 1) {
    @return opposite-position($direction);
  }
  @return if(index($direction, top), bottom, top);
}

// computes the border width for the triangle
// @function  _getTriangleBorderWidth
// @private
// @param     $width {Number} the width of the arrow
// @param     $height {Number} the height of the arrow
// @param     $direction {String} the direction the arrow is pointing (top, left, top left, etc)
// @return    {List} the computed border widths
@function _getTriangleBorderWidth($width, $height, $direction) {
  @if(length($direction) == 1) {
    // TOP
    @if($direction == top) {
      @return 0 ($width/2) $height;
    }
    // BOTTOM
    @else if($direction == bottom) {
      @return $height ($width/2) 0;
    }
    // LEFT
    @else if($direction == left) {
      @return ($height/2) $width ($height/2) 0;
    }
    // RIGHT
    @else if($direction == right) {
      @return ($height/2) 0 ($height/2) $width;
    }
  }
  @else if(index($direction, top)) {
    // TOP LEFT
    @if(index($direction, left)) {
      @return 0 $width $height 0;
    }
    // TOP RIGHT
    @else {
      @return 0 0 $height $width;
    }
  }
  @else if(index($direction, bottom)) {
    // BOTTOM LEFT
    @if(index($direction, left)) {
      @return $height $width 0 0;
    }
    // BOTTOM RIGHT
    @else {
      @return $height 0 0 $width;
    }
  }
  @return 0;
}

// generates a cross-browser triangle using borders
// @mixin     triangle
// @param     $direction {String} the direction the arrow is pointing (top, left, top left, etc)
// @param     $width {Number} the width of the arrow
// @param     $height {Number} the height of the arrow
// @param     $color {Color} the color of the arrow
@mixin triangle($direction: bottom, $width: 1em, $height: false, $color: #aaa) {
  $direction: rtl($direction);
  // if no height was specified, assume it's identitcal to width
  @if(not $height) {
    $height: $width;
  }
  // zero out it's content
  height: 0;
  width : 0;
  // IE6 needs some extra love
  @include target-browser(ie 6, font-size, 0);
  @include target-browser(ie 6, line-height, 0);
  border: {
    // for IE6, transparent borders are simulated using `dashed` styles instead of a chroma filter
    // IE won't render a `dashed` border-style unless (width * 5) >= border-width
    // since width is always 0, dashed borders aren't rendered
    // @link http://hedgerwow.appspot.com/demo/arrows
    style: dashed;
    // transparent for all other browsers
    color: transparent;
    width: _getTriangleBorderWidth($width, $height, $direction);
    #{_getTriangleBorderDirection($direction)}: {
      color: $color;
      style: solid;
    }
  }
}

// makes your element centered vertically and horizontally in a parent element
// @mixin   centered-box
@mixin centered-box() {
  @include stretch();
  margin: auto;
}

// hide element visibly but preserve screen-reader support
// @mixin     hide-element
// @credit    Jonathan Snook
// @link      http://snook.ca/archives/html_and_css/hiding-content-for-accessibility
@mixin hide-element() {
  position: absolute !important;
  height: 1px;
  width: 1px;
  overflow: hidden;
  @include target-browser(ie lte 7, clip, rect(1px 1px 1px 1px));
  clip: rect(1px, 1px, 1px, 1px);
}

// mixin for generating a fade box which fades from transparent to white
// @mixin     fade-box
// @param     $width {String} the width of the overlay
// @param     $height {String} the height of the overlay
// @param     $direction {String} top=vertical left=horizontal
@mixin fade-box($width: 100%, $height: 100%, $direction: top) {
  $direction: rtl($direction);
  // TODO - update this when Compass supports IE alpha channels
  @if $direction == left {
    @include ie-filter(gradient(startColorstr='#00ffffff', endColorstr='#ffffff', GradientType=1));
  }
  @else {
    @include ie-filter(gradient(startColorstr='#00ffffff', endColorstr='#ffffff'));
  }
  @include background-image(linear-gradient($direction, rgba(255,255,255,0.4), rgba(255,255,255,1)) );
  @include pseudo-element($width: $width, $height: $height, $position: absolute);
  text-align: center;
  bottom: 0;
  #{if($direction == left, right, left)}: 0;
}

// create a stroke line around text (or font icon)
// @mixin     stroke
// @param     $width {Number} the width of the stroke
// @param     $color {Color} the color of the stroke
// @param     $shadow {List} an additional drop shadow to attach
@mixin glyph-stroke($width: 1px, $color: black, $shadow: false) {
  @include box-shadow(compact(0 $width 0 $color, 0 -1*$width 0 $color, $width 0 0 $color, -1*$width 0 0 $color, $shadow));
}

// create a glyph icon
// @mixin     glyph-icon
// @param     $icon {String} the icon name
// @param     $size {Number} the size of the icon
// @param     $color {Color} the color of the font
// @param     $placement {String} where to place the icon [before|after|inline]
// @param     $ie-styles {String} styles to apply to IE6/7 (this is needed because the faux :before isn't extensible)
@mixin glyph-icon($icon, $size: default, $color: inherit, $placement: before, $ie-styles: false) {
  $char-mapping: nil;
  $char-code: nil;
  @if $icon {
    $char-mapping: -compass-list(associative($CONFIG_GLYPHS_MAPPINGS, $icon, $strict: true));
    $char-code: nth($char-mapping, 1);
  }
  @if $char-code == nil and $icon != false {
    @warn "could not find character mapping for `#{icon}`";
  }
  @else {
    @if $size == default {
      $default-size: nil;
      @if $icon {
        $default-size: nth-cyclic($char-mapping, 2);
      }
      $size: if(type-of($default-size) == number, $default-size, 100%);
    }
    // if the size is under a given threshold, use a halfling, if available
    @if $icon {
      $char-code: nth-cyclic(-compass-list($char-code), if(comparable($CONFIG_GLYPHS_THRESHOLD, $size) and $size <= $CONFIG_GLYPHS_THRESHOLD, 2, 1));
    }
    $selector: if(index(before after, $placement), '&:#{$placement}', '&');
    #{$selector} {
      font-family: $CONFIG_GLYPHS_NAME;
      font-weight: $CONFIG_GLYPHS_WEIGHT;
      font-style: $CONFIG_GLYPHS_STYLE;
      text-decoration: inherit;
      speak: none;
      @include if-set(font-size, $size);
      @include if-set(color, $color);
      @if $icon {
        content: $char-code;
      }
    }
    @if($selector != '&' and $ie-styles != nil) {
      // support for IE6/7
      $styles: "font-family:'#{$CONFIG_GLYPHS_NAME}';font-weight:#{$CONFIG_GLYPHS_WEIGHT};font-style:#{$CONFIG_GLYPHS_STYLE};text-decoration:inherit;";
      @if($size != nil) {
        $styles: $styles + "font-size:#{$size};"
      }
      @if($color != nil) {
        $styles: $styles + "color:#{$color};"
      }
      @if($ie-styles) {
        $styles: $styles + $ie-styles;
      }
      @include ie-pseudo($styles: $styles, $content: $char-code, $placement: $placement, $name: glyph);
    }
  }
}

// generate rotational and position keyframes for loading spinners
// @mixin     generate-loader-keyframes
@mixin generate-loader-keyframes() {
  @if not $CONFIG_DISABLE_STYLEGUIDE_SPRITES {
    // generate rotating keyframes
    @include -generate-loader-keyframes-360();
    // generate specific keyframes
    @each $size in $CONFIG_LOADERS {
      @if $size != nil {
        $values: nth($size, 2);
        $size: nth($size, 1);
        @each $context in (1 2) {
          $name: unquote('#{$size}-#{$context}');
          $icon: nth-cyclic(associative($values, default), $context);
          $position: styleguide-sprite-position($CONFIG_SPRITE_LOADERS, $icon);
          $sprite-file: styleguide-sprite-file($CONFIG_SPRITE_LOADERS, $icon);
          $width: styleguide-image-width($sprite-file);
          $height: styleguide-image-height($sprite-file);
          @include -generate-loader-keyframes-position($name, $position, $width, $height);
        }
      }
    }
  }
}

// generate rotational keyframes for loading spinners
// @mixin     -generate-loader-keyframes-360
// @private
@mixin -generate-loader-keyframes-360() {
  @if do-once("archetype/ui/generate-keyframe/#{$CONFIG_KEYFRAME_LOADERS}") {
    @if archetype-version('compass >= 0.13') {
      @include keyframes($CONFIG_KEYFRAME_LOADERS) {
        from { @include rotate(0deg); }
        to { @include rotate(360deg); }
      }
    }
    @else {
      @-webkit-keyframes #{$CONFIG_KEYFRAME_LOADERS} {
        from { -webkit-transform: rotate(0deg); }
        to { -webkit-transform: rotate(360deg); }
      }
      @-moz-keyframes #{$CONFIG_KEYFRAME_LOADERS} {
        from { -moz-transform: rotate(0deg); }
        to { -moz-transform: rotate(360deg); }
      }
      @-ms-keyframes #{$CONFIG_KEYFRAME_LOADERS} {
        from { -ms-transform: rotate(0deg); }
        to { -ms-transform: rotate(360deg); }
      }
      @-o-keyframes #{$CONFIG_KEYFRAME_LOADERS} {
        from { -o-transform: rotate(0deg); }
        to { -o-transform: rotate(360deg); }
      }
      @keyframes #{$CONFIG_KEYFRAME_LOADERS} {
        from { transform: rotate(0deg); }
        to { transform: rotate(360deg); }
      }
    }
  }
}

// generate position keyframes for loading spinners
// @mixin     -generate-loader-keyframes-position
// @private
// @param     $name {String} the name for this keyframe
// @param     $position {List} the background-position of the spinner image
// @param     $width {Number} the width of the spinner image
// @param     $height {Number} the height of the spinner image
@mixin -generate-loader-keyframes-position($name, $position, $width, $height) {
  $name: unquote('#{$CONFIG_KEYFRAME_LOADERS}-position-#{$name}');
  @if do-once("archetype/ui/generate-keyframe/#{$name}") {
    @if archetype-version('compass >= 0.13') {
      @include keyframes($name) {
        from, to { @include -generate-loader-keyframes-position-css($position, $width, $height); }
      }
    }
    @else {
      @-webkit-keyframes #{$name} {
        from, to { @include -generate-loader-keyframes-position-css($position, $width, $height); }
      }
      @-moz-keyframes #{$name} {
        from, to { @include -generate-loader-keyframes-position-css($position, $width, $height); }
      }
      @-ms-keyframes #{$name} {
        from, to { @include -generate-loader-keyframes-position-css($position, $width, $height); }
      }
      @-o-keyframes #{$name} {
        from, to { @include -generate-loader-keyframes-position-css($position, $width, $height); }
      }
      @keyframes #{$name} {
        from, to { @include -generate-loader-keyframes-position-css($position, $width, $height); }
      }
    }
  }
}

// a helper to generate the required CSS for the position keyframe
// @mixin     -generate-loader-keyframes-position-css
// @private
// @param     $position {List} the background-position of the spinner image
// @param     $width {Number} the width of the spinner image
// @param     $height {Number} the height of the spinner image
@mixin -generate-loader-keyframes-position-css($position, $width, $height) {
  background-position: $position;
  width: $width;
  height: $height;
  margin-left: $width / -2;
  margin-top: $height / -2;
}

// a method for removing default styling from a button
// @mixin     unstyled-button
@mixin unstyled-button() {
  background: none;
  border: none;
  padding: 0;
  @include appearance(none);
}