@use 'sass:meta';
@use 'sass:list';
@use 'sass:math';
@use 'sass:string';
@use '../../functions/equals-false' as *;
@use '../../functions/equals-true' as *;
@use '../../functions/is-alias' as *;
@use '../../functions/is-global-value' as *;
@use '../../functions/is-falsey' as *;
@use '../../functions/is-list' as *;
@use '../../functions/is-number' as *;
@use '../../functions/is-string' as *;
@use '../../functions/list-to-string' as *;
@use '../utilities/only-moz' as *;

/// Generates an animation that appears to either slit an element in or out on
/// its axis. It is recommended to use the `animation-stage()` mixin on the
/// parent element.
///
/// @param {String | Bool} $in-or-out ['in'] - Determines if the element will
/// appear to slit `in` or `out`.
/// @param {String} $axis ['horizontal'] - The axis on which the animation turns
/// the element. Must be one of the following values: `horizontal`, `vertical`,
/// `diagonal` or `diagonal2`.
/// @param {Number} $duration [0.5s] - The duration of the animation (`s` or `ms`)
/// @param {Number} $delay [null] - The optional delay time for the animation.
/// @param {Number | String} $iterations [null] - The number of iterations
/// to complete. Sets the value for the `animation-iteration-count` property.
/// Can be `infinite`, any unitless number, or any CSS global value.
/// @param {String} $anim-dir [null] - Sets the value for the
/// `animation-direction` property. Can be `normal`, `reverse`, `alternate`, or
/// `alternate-reverse`. Can also be any CSS global value. Default of `null`
/// assumes the CSS property default of `normal`.
/// @param {Timing-Function} $timing-func [null] - The timing function for
/// the animation. A default of null will apply a timing-function of ease-out
/// on a slit-in animation and ease-in on a slit-out animation.
/// @param {Number | String} $anim-num [null] - If the mixin is used more than
/// once with different values in a stylesheet, you can pass a number or string
/// to the mixin here that gets appeneded to end of the animation name so that
/// the animations do not overwrite each other.
///
/// @group Animations
/// @require {function} equals-false
/// @require {function} equals-true
/// @require {function} is-alias
/// @require {function} is-falsey
/// @require {function} is-global-value
/// @require {function} is-list
/// @require {function} is-number
/// @require {function} is-string
/// @require {function} list-to-string
/// @require {mixin} only-moz
///
/// @throw Invalid $in-or-out value error.
/// @throw Invalid $axis value error.
/// @throw Invalid $duration value error.
/// @throw Invalid $delay value error.
/// @throw Invalid $iterations value error.
/// @throw Invalid $anim-dir value error.
@mixin slit(
  $in-or-out: 'in',
  $axis: 'horizontal',
  $duration: 0.5s,
  $delay: null,
  $iterations: null,
  $anim-dir: null,
  $timing-func: null,
  $anim-num: null
) {
  // Default tranform values for slit in on an $axis of 'horizontal'
  $trans-val-1: translateZ(-800px) rotateX(90deg);
  $trans-val-2: translateZ(-160px) rotateX(87deg);
  $trans-val-3: translateZ(0) rotateX(0);
  $opacity-val-1: 0;
  $opacity-val-2: 1;
  $temp-swap: null;
  $is-diagonal: false;
  $anim-suffix: '';

  @if $in-or-out and is-string($in-or-out) {
    $in-or-out: string.to-lower-case($in-or-out);
  }

  @if $anim-dir {
    @if is-list($anim-dir) {
      $anim-dir: list-to-string($anim-dir);
    }

    @if is-string($anim-dir) {
      $anim-dir: string.to-lower-case($anim-dir);
    }
  }

  @if $delay and is-string($delay) {
    $delay: string.to-lower-case($delay);
  }

  @if $timing-func and is-string($timing-func) {
    $timing-func: string.to-lower-case($timing-func);
  }

  @if equals-true($in-or-out) or $in-or-out == 'in' or $in-or-out == 'i' {
    $in-or-out: true;
    $anim-suffix: '-in';
  } @else if equals-false($in-or-out) or $in-or-out == 'out' {
    $in-or-out: false;
    $anim-suffix: '-out';
  } @else {
    @error 'Invalid $in-or-out value of #{meta.inspect($in-or-out)} for the ' +
        '[ slit() ] mixin.';
  }

  @if $axis {
    @if is-string($axis) {
      $axis: string.to-lower-case($axis);
    }

    @if is-alias('top-to-bottom', $axis) {
      $trans-val-1: translateZ(-800px) rotateY(90deg);
      $trans-val-2: translateZ(-160px) rotateY(87deg);
      $trans-val-3: translateZ(0) rotateY(0);
      $anim-suffix: string.insert(
        $anim-suffix,
        '-vertically',
        string.length($anim-suffix) + 1
      );
    } @else if is-alias('bottom-left-to-top-right', $axis) {
      $trans-val-1: translateZ(-800px) rotate3d(1, 1, 0, 90deg);
      $trans-val-2: translateZ(-160px) rotate3d(1, 1, 0, 87deg);
      $trans-val-3: translateZ(0) rotate3d(1, 1, 0, 0);
      $is-diagonal: true;
      $anim-suffix: string.insert(
        $anim-suffix,
        '-diagonally',
        string.length($anim-suffix) + 1
      );
    } @else if is-alias('bottom-right-to-top-left', $axis) {
      $trans-val-1: translateZ(-800px) rotate3d(-1, 1, 0, -90deg);
      $trans-val-2: translateZ(-160px) rotate3d(-1, 1, 0, -87deg);
      $trans-val-3: translateZ(0) rotate3d(-1, 1, 0, 0);
      $is-diagonal: true;
      $anim-suffix: string.insert(
        $anim-suffix,
        '-diagonally',
        string.length($anim-suffix) + 1
      );
    } @else if is-alias('left-to-right', $axis) {
      $anim-suffix: string.insert(
        $anim-suffix,
        '-horizontally',
        string.length($anim-suffix) + 1
      );
    } @else {
      @error 'Invalid $axis of `#{meta.inspect($axis)}` chosen for the ' +
          '[ slit() ] mixin. The axis must be either, `horizontal`, ' +
          '`vertical`, `diagonal1`, or `diagonal2`.';
    }
  } @else {
    @error 'You must choose an axis for the [ slit() ] mixin.';
  }

  // If animation slits out rather than in, reverse the necessary values
  @if not $in-or-out {
    $temp-swap: $trans-val-1;
    $trans-val-1: $trans-val-3;
    $trans-val-3: $temp-swap;
    $opacity-val-1: 1;
    $opacity-val-2: 0;
  }

  @if not is-number($duration) {
    @error 'Invalid $duration value of `#{$duration}` for the [ slit() ] ' +
        'mixin. The duration property must be a number.';
  } @else if math.is-unitless($duration) {
    // If no there is no unit for $duration, unless $duration > 60, assume seconds
    $duration: if($duration > 60, $duration * 1ms, $duration * 1s);
  } @else if not list.index('s' 'ms', math.unit($duration)) {
    @error 'Invalid $duration value of `#{$duration}` for the [ slit() ] ' +
        'mixin. The duration property must be in either s or ms units.';
  } @else if $duration % 10 == 0ms {
    // If time in ms would be shorter as seconds, convert it
    $duration: math.div($duration, 1000ms) * 1s;

    // Get rid of possible leading zero in front of decimal place
    @if string.slice($duration + '', 1, 2) == '0.' {
      $duration: #{string.slice($duration + '', 2)};
    }
  }

  @if is-falsey($delay) or
      is-alias('none', $delay)
      $delay == 0s or $delay == 0ms
  {
    $delay: null;
  }

  @if $delay {
    @if not is-number($delay) {
      @error 'Invalid delay value of `#{meta.inspect($delay)}` for the [ slit() ]' +
          ' mixin. The delay property must be a number.';
    } @else if math.is-unitless($delay) {
      // If no there is no unit for $delay, unless $delay > 60, assume seconds
      $delay: if($delay > 60, $delay * 1ms, $delay * 1s);
    } @else if not list.index('s' 'ms', math.unit($delay)) {
      @error 'Invalid delay value of `#{meta.inspect($delay)}` for the [ slit() ]' +
          ' mixin. The delay property must be in either s or ms units.';
    } @else if $delay % 10 == 0ms {
      $delay: math.div($delay, 1000ms) * 1s;

      @if string.slice($delay + '', 1, 2) == '0.' {
        $delay: #{string.slice($delay + '', 2)};
      }
    }
  }

  @if $iterations {
    @if is-string($iterations) {
      $iterations: string.to-lower-case($iterations);
    }

    @if is-alias('infinite', $iterations) {
      $iterations: infinite;
    } @else if not (is-number($iterations) and math.is-unitless($iterations)) and
        not is-global-value($iterations)
    {
      @error 'Invalid $iterations value of `#{meta.inspect($iterations)}`' +
          ' for the [ slit() ] mixin.';
    }
  } @else {
    $iteratons: null;
  }

  @if is-falsey($anim-dir) or
      is-alias('none', $anim-dir) or
      is-alias('normal', $anim-dir)
  {
    $anim-dir: null;
  } @else if is-alias('reverse', $anim-dir) {
    $anim-dir: reverse;
  } @else if is-alias('alternate', $anim-dir) {
    $anim-dir: alternate;
  } @else if is-alias('alternate-reverse', $anim-dir) {
    $anim-dir: alternate-reverse;
  } @else if not is-global-value($anim-dir) {
    @error 'Invalid animation-direction value of `#{$anim-dir}`' +
        ' for the [ slit() ] mixin.';
  }

  @if equals-false($timing-func) or is-alias('normal', $timing-func) {
    $timing-func: if(($in-or-out), ease-out, ease-in);
  }

  @if equals-false($anim-num) or $anim-num == '' {
    $anim-num: null;
  } @else {
    $anim-suffix: string.insert(
      $anim-suffix,
      '--#{$anim-num}',
      string.length($anim-suffix) + 1
    );
  }

  transform: translate3d(0, 0, 0);
  transform-style: preserve-3d;
  animation: slit#{$anim-suffix} #{$duration} #{$timing-func} #{$delay}
    #{$iterations} #{$anim-dir} both;

  @include only-moz {
    backface-visibility: hidden;
  }

  @at-root {
    @keyframes slit#{$anim-suffix} {
      0% {
        @if $in-or-out and $is-diagonal {
          animation-timing-function: ease-in;
        }

        opacity: $opacity-val-1;
        transform: $trans-val-1;
      }

      54% {
        @if $in-or-out and $is-diagonal {
          animation-timing-function: ease-in-out;
        }

        opacity: $opacity-val-2;
        transform: $trans-val-2;
      }

      100% {
        @if $in-or-out and $is-diagonal {
          animation-timing-function: ease-out;
        }
        @if not $in-or-out {
          opacity: 0;
        }

        transform: $trans-val-3;
      }
    }
  }
}