////
/// @group utils
////

/// 清除浮动
///
/// @example scss
///   .wrapper {
///      @include clearfix;
///   }
///
@mixin clearfix {
    &:after {
        visibility: hidden;
        display: block;
        height: 0;
        font-size: 0;
        content: '\0020';
        clear: both;
    }
}



/// 单行截取文字，添加『...』结尾
///
/// @param {Number | String} $width [100%] - 最大宽度，CSS长度，包括calc方法定义的表达式
///
/// @example scss - 使用
///   .element {
///     @include ellipsis;
///   }
///
/// @example css - 输出
///   .element {
///     display: inline-block;
///     max-width: 100%;
///     overflow: hidden;
///     text-overflow: ellipsis;
///    white-space: nowrap;
///     word-wrap: normal;
///   }
///
@mixin ellipsis($width: 100%) {
    display: inline-block;
    max-width: $width;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    word-wrap: normal;
}

/// 多行截取文字，添加『...』结尾
///
/// @param {Number | String} $line-height [1.2em] - 行高
/// @param {Number} $line-count [2] - 行数, 超出行数开始截取
/// @param {Color} $bg-color [#fff] - 文本背景色
///
/// @example scss - 使用
///   .element {
///     @include multi-line-ellipsis(1.2em, 3, #fff);
///   }
///
/// @example css - 输出
///   .element {
///     overflow: hidden;
///     position: relative;
///     line-height: 1.2em;
///     max-height: 3.6em;
///     text-align: justify;
///     padding-right: 0em;
///   }
///
///   .element:before {
///     content: '...';
///     position: absolute;
///     right: 0;
///     bottom: 0;
///     background: #fff;
///   }
///
///   .element:after {
///     content: '';
///     position: absolute;
///     right: 0;
///     width: 1em;
///     height: 1em;
///     margin-top: 0.2em;
///     background: #fff;
///   }
///
@mixin multi-line-ellipsis(
    $line-height: 1.2em,
    $line-count: 2,
    $bg-color: #fff
) {
    overflow: hidden;
    position: relative;
    line-height: $line-height;
    max-height: $line-height * $line-count;
    text-align: justify;
    padding-right: 0;

    &:before {
        content: '...';
        position: absolute;
        right: 0;
        bottom: 0;
        background: $bg-color;
    }

    &:after {
        content: '';
        position: absolute;
        right: 0;
        width: 1em;
        height: 1em;
        margin-top: .2em;
        background: $bg-color;
    }
}

/// 隐藏文字
///
/// 『text-indent: -9999px』Hack 的替代版本
///
/// @link http://nicolasgallagher.com/another-css-image-replacement-technique
///
/// @example scss
///   .element {
///      @include hide-text;
///      background: url(logo.png);
///   }
///
@mixin hide-text {
    font: 0/0 a;
    text-shadow: none;
    color: transparent;
}

/// 将元素垂直(水平)居中 (transform 版本)
///
/// @param {String} $inner-selector ['.inner'] - 直接子选择器名称
/// @param {Bool} $horizontal [true] - 是否水平居中
///
/// @example scss - 使用
///   .element {
///      @include center-tl;
///   }
///
/// @example css - 输出
///   .element {
///       position: relative;
///   }
///
///   .element > .inner {
///       position: absolute;
///       top: 50%;
///       left: 50%;
///       transform: translate(-50%, -50%);
///   }
///
@mixin center-tl(
    $inner-selector: '.inner',
    $horizontal: true
) {

    position: relative;

    & > #{$inner-selector} {
        position: absolute;
        top: 50%;
        $translate-val: translateY(-50%);

        @if $horizontal {
            left: 50%;
            $translate-val: translate(-50%, -50%);
        }

        transform: $translate-val;
    }
}

/// 将元素垂直(水平)居中 (table 版本)
///
/// @param {String} $inner-selector ['.inner'] - 直接子选择器名称
/// @param {Bool} $horizontal [true] - 是否水平居中
///
/// @example scss - 使用
///   .element {
///     @include center-td;
///   }
///
/// @example css - 输出
///   .element {
///       text-align: center;
///       display: table;
///   }
///
///   .element > .inner {
///       display: table-cell;
///       vertical-align: middle;
///   }
///
@mixin center-td(
    $inner-selector: '.inner',
    $horizontal: true
) {

    @if $horizontal {
        text-align: center;
    }

    display: table;

    & > #{$inner-selector} {
        display: table-cell;
        vertical-align: middle;
    }
}

/// 快捷设置元素width,height的方法
///
/// @param {String | List} $size - CSS尺寸长度
///
/// @example scss - 使用
///   .element {
///     @include size(2em 4em);
///   }
///
/// @example css - 输出
///   .element {
///     width: 2em;
///     height: 4em;
///   }
///
@mixin size($size) {

    @if length($size) == 1 {
        width: $size;
        height: $size;
    } @else if length($size) == 2 {
        width: nth($size, 1);
        height: nth($size, 2);
    }
}

// 快捷设置元素postion的方法 (传入null参数可略过一个方位)
//
// @param {String} $position [relative]
//   CSS position属性值
//
// @param {List} $coordinates [null null null null]
//   上、右、下、左 四个边值，可以传入1 ~ 4个值
//
// @example scss - 使用
//   .element {
//     @include position(absolute, 0 null null 10px);
//   }
//
// @example css - 输出
//   .element {
//     position: absolute;
//     left: 10px;
//     top: 0;
//   }
//
// @require {function} is-length
// @require {function} unpack
@mixin position($position: relative, $coordinates: null null null null) {

    // 如果参数是数组
    @if type-of($position) == list {
        $coordinates: $position;
        $position: relative;
    }

    $coordinates: unpack($coordinates);

    $offsets: (
        top: nth($coordinates, 1),
        right: nth($coordinates, 2),
        bottom: nth($coordinates, 3),
        left: nth($coordinates, 4)
    );

    position: $position;

    @each $offset, $value in $offsets {

        // 如果是合法长度
        @if is-length($value) {
            #{$offset}: $value;
        }
    }
}

// 三角型生成器(8种形态)
//
// @param {Number | List} $size
//   三角形尺寸
//   传入一个参数，生成等宽高三角形；传入数组且长度为2，第一个设置宽度，第二个设置高度
//
// @param {String | List} $color
//   传入一个参数，设置三角形颜色；传入数组且长度为2，第一个设置三角形颜色，第二个设置背景色
//
// @param {String} $direction
//   三角形朝向，可传参数：up | down | right | left | up-right | up-left | down-right | down-left | inset-up | inset-down | inset-left | inset-right
//
// @example scss - 使用
//   .element {
//     &:before {
//       content: " ";
//       @include triangle(100px 200px, blue, up);
//     }
//   }
//
// @example css - 输出
//   .example:before {
//     content: " ";
//     height: 0;
//     width: 0;
//     border-bottom: 200px solid blue;
//     border-left: 50px solid transparent;
//     border-right: 50px solid transparent;
//   }
//
@mixin triangle($size, $color, $direction) {
    $width: nth($size, 1);
    $height: nth($size, length($size));
    $foreground-color: nth($color, 1);
    $background-color: if(length($color) == 2, nth($color, 2), transparent);
    height: 0;
    width: 0;

    @if ($direction == up) or ($direction == down) or ($direction == right) or ($direction == left) {
        $width: $width / 2;
        $height: if(length($size) > 1, $height, $height/2);

        @if $direction == up {
            border-bottom: $height solid $foreground-color;
            border-left: $width solid $background-color;
            border-right: $width solid $background-color;
        } @else if $direction == right {
            border-bottom: $width solid $background-color;
            border-left: $height solid $foreground-color;
            border-top: $width solid $background-color;
        } @else if $direction == down {
            border-left: $width solid $background-color;
            border-right: $width solid $background-color;
            border-top: $height solid $foreground-color;
        } @else if $direction == left {
            border-bottom: $width solid $background-color;
            border-right: $height solid $foreground-color;
            border-top: $width solid $background-color;
        }
    } @else if ($direction == up-right) or ($direction == up-left) {
        border-top: $height solid $foreground-color;

        @if $direction == up-right {
            border-left: $width solid $background-color;
        } @else if $direction == up-left {
            border-right: $width solid $background-color;
        }
    } @else if ($direction == down-right) or ($direction == down-left) {
        border-bottom: $height solid $foreground-color;

        @if $direction == down-right {
            border-left: $width solid $background-color;
        } @else if $direction == down-left {
            border-right: $width solid $background-color;
        }
    } @else if ($direction == inset-up) {
        border-color: $background-color $background-color $foreground-color;
        border-style: solid;
        border-width: $height $width;
    } @else if ($direction == inset-down) {
        border-color: $foreground-color $background-color $background-color;
        border-style: solid;
        border-width: $height $width;
    } @else if ($direction == inset-right) {
        border-color: $background-color $background-color $background-color $foreground-color;
        border-style: solid;
        border-width: $width $height;
    } @else if ($direction == inset-left) {
        border-color: $background-color $foreground-color $background-color $background-color;
        border-style: solid;
        border-width: $width $height;
    }
}

@mixin box-sizing {
    box-sizing: border-box;
    *,
    *:before,
    *:after {
        box-sizing: border-box;
    }
}

@mixin icon-size($size, $marginLeft: false, $marginRight: false, $transform: false) {
    @if ($transform) {
        transform: $transform;
    }
    @if ($marginLeft) {
        margin-left: $marginLeft;
    }
    @if ($marginRight) {
        margin-right: $marginRight;
    }

    &:before {
        width: $size;
        font-size: $size;
        line-height: inherit;
    }

    // Chrome不支持小于12px的字体，故采用缩放的方式缩小字体
    @if (type-of($size) == 'number') {
        @if ($size < 12) {
            @media all and (-webkit-min-device-pixel-ratio: 0) and (min-resolution: .001dpcm) {
                @if ($transform) {
                    transform: scale($size / $icon-s) $transform;
                } @else {
                    transform: scale($size / $icon-s);
                }
                @if ($marginLeft) {
                    margin-left: $marginLeft - ($icon-s - $size) / 2;
                } @else {
                    margin-left: -($icon-s - $size) / 2;
                }
                @if ($marginRight) {
                    margin-right: $marginRight - ($icon-s - $size) / 2;
                } @else {
                    margin-right: -($icon-s - $size) / 2;
                }

                &:before {
                    width: $icon-s;
                    font-size: $icon-s;
                }
            }
        }
    }
}

@mixin icon-square-size($size, $marginTop: false, $marginRight: false, $marginBottom: false, $marginLeft: false, $transform: false) {
    @if ($transform) {
        transform: $transform;
    }
    @if ($marginTop) {
        margin-top: $marginTop;
    }
    @if ($marginRight) {
        margin-right: $marginRight;
    }
    @if ($marginBottom) {
        margin-bottom: $marginBottom;
    }
    @if ($marginLeft) {
        margin-left: $marginLeft;
    }

    width: $size;
    height: $size;
    line-height: $size;

    &:before {
        width: $size;
        height: $size;
        font-size: $size;
        line-height: $size;
    }

    // Chrome不支持小于12px的字体，故采用缩放的方式缩小字体
    @if ($size < 12) {
        @media all and (-webkit-min-device-pixel-ratio: 0) and (min-resolution: .001dpcm) {
            @if ($transform) {
                transform: scale($size / $icon-s) $transform;
            } @else {
                transform: scale($size / $icon-s);
            }
            @if ($marginTop) {
                margin-top: $marginTop - ($icon-s - $size) / 2;
            } @else {
                margin-top: -($icon-s - $size) / 2;
            }
            @if ($marginRight) {
                margin-right: $marginRight - ($icon-s - $size) / 2;
            } @else {
                margin-right: -($icon-s - $size) / 2;
            }
            @if ($marginBottom) {
                margin-bottom: $marginBottom - ($icon-s - $size) / 2;
            } @else {
                margin-bottom: -($icon-s - $size) / 2;
            }
            @if ($marginLeft) {
                margin-left: $marginLeft - ($icon-s - $size) / 2;
            } @else {
                margin-left: -($icon-s - $size) / 2;
            }

            width: $icon-s;
            height: $icon-s;
            line-height: $icon-s;

            &:before {
                width: $icon-s;
                height: $icon-s;
                font-size: $icon-s;
                line-height: $icon-s;
            }
        }
    }
}

@mixin font-face-handler($name, $url) {
    @if ($name != Roboto) {
        @font-face {
            font-family: "#{$name}";
            src: url("#{$url}");
        }
    }
}

/// 设置 button 外观颜色
///
/// @param {String} $color 字体色
/// @param {String} $color-hover 鼠标悬浮时的字体色
/// @param {String} $bg-color 背景色
/// @param {String} $bg-color-hover 鼠标悬浮时的背景色
/// @param {String} $border-color 边框色
/// @param {String} $border-color-hover 鼠标悬浮时的边框色
@mixin button-color($color, $color-hover, $bg-color: transparent, $bg-color-hover: transparent, $border-color: transparent, $border-color-hover: transparent) {
    background-color: $bg-color;
    border-color: $border-color;

    &,
    &:link,
    &:visited,
    &.visited {
        color: $color;
    }

    &:focus,
    &:hover,
    &.hover,
    &:active,
    &.active {
        color: $color-hover;
        background-color: $bg-color-hover;
        border-color: $border-color-hover;
        text-decoration: none;
    }
}

/// 设置 button 大小
///
/// @param {Number} $padding 内边距
/// @param {Number} $height 高度
/// @param {Number} $font-size 字体大小
/// @param {Number} $border-width 边框宽度
@mixin button-size($padding, $height, $font-size, $border-width) {
    padding: 0 $padding;
    height: $height;
    line-height: $height - 2 * $border-width;
    font-size: $font-size;
    border-width: $border-width;
}