////
/// (c) hidoo | MIT License
/// @group z-index feature
////

@use "sass:list";
@use "sass:map";
@use "sass:meta";

/// default z-index range
/// @access private
/// @type List
///
$_default-range: (0, 100) !default;

/// content types
/// @access private
/// @type Map
///
$_types: (
  "main": (
    "range": (
      0,
      4999
    ),
    "stack": ()
  ),
  "floating": (
    "range": (
      2000000,
      2999999
    ),
    "stack": ()
  ),
  "popup": (
    "range": (
      3000000,
      3999999
    ),
    "stack": ()
  ),
  "navigation": (
    "range": (
      5000000,
      5999999
    ),
    "stack": ()
  ),
  "fullpage": (
    "range": (
      6000000,
      null
    ),
    "stack": ()
  )
) !default;

/// default options
/// @access private
/// @type Map
///
$_default-options: (
  "debug": false
) !default;

/// reserve z-index value each by types
/// @param {String} $type - content type name
/// @param {Number} $index - index number
/// @param {Map} $options - options
/// @param {Boolean} $options.debug [false] - debug flag
/// @return {Number} z-index value
///
/// @example scss - scss inputs
///   .selector {
///     content: function.z-index-reserve("floating", 100);
///   }
///
/// @example css - css outputs
///   .selector {
///     content: 2000100;
///   }
///
@function reserve($type, $index, $options: ()) {
  @if meta.type-of($type) != "string" or $type == "" {
    @error "@function function.z-index-reserve: Argument $type must be string.";
  }

  @if meta.type-of($index) != "number" or $index < 0 {
    @error "@function function.z-index-reserve: Argument $index must be number and 0 or more.";
  }

  $opts: map.merge($_default-options, $options);

  @if not map.has-key($_types, $type) {
    $_types: map.set(
      $_types,
      $type,
      (
        "range": $_default-range,
        "stack": ()
      )
    ) !global;
  }

  $stack: map.get($_types, $type, "stack");

  @if map.has-key($stack, $index) {
    $reserved-by: map.get($stack, $index);

    @error "@function function.z-index-reserve: $index \"#{$index}\" is already reserved by \"#{$reserved-by}\" in \"#{$type}\".";
  }

  $range: map.get($_types, $type, "range");
  $min: list.nth($range, 1);
  $max: list.nth($range, 2);
  $value: $min + $index;

  @if meta.type-of($max) == "number" and $max < $value {
    @error "@function function.z-index-reserve: Argument $index must be less than or equal to #{$max - $min}.";
  }

  $stack: map.set($stack, $index, &);
  $_types: map.set($_types, $type, "stack", $stack) !global;

  @if map.get($opts, "debug") {
    @each $key, $reserved-by in $stack {
      @debug 'Index #{$key} in "#{$type}" is reserved by "#{$reserved-by}".';
    }
  }

  @return $value;
}