////
/// @group BEM
///
/// @access public
////

@use '../functions';
@use '../contexts';
@use './block';
@use './element';
@use './modifier';
@use './state';
@use './suffix';
@use './theme';
@use './vars';

/// 
/// Generate multiple entities (BEM or not) at once.
///
/// NOTE: This mixin does not generate perfectly optimized selectors in order to keep track of contexts.
///
/// @param {string | list} $first  - First selector. Either a string for a manual selector, or a list with the first items standing for a BEM selector function (optionally suffixed by a colon) and other items being passed as arguments to said function.
/// @param {string | list} $others - Other selectors. Either a string for a manual selector, or a list with the first items standing for a BEM selector function (optionally suffixed by a colon) and other items being passed as arguments to said function.
///
/// @content
///
/// @example scss - Creating multiple elements, a modifier and an anchor
///   @include object('buttonstrip') {
///     display: none;
///     
///     @include multi('modifier' 'mod', 'elem' 'button' 'separator', '> a') {
///       display: block;
///     }
///   }
///   
///   // Generates:
///   
///   .o-buttonstrip {
///     display: none;
///   }
///   
///   .o-buttonstrip--mod {
///     display: block;
///   }
///   
///   .o-buttonstrip__button, {
///   .o-buttonstrip__separator {
///     display: block;
///   }
///   
///   .o-buttonstrip > a {
///     display: block;
///   }
///
/// @example scss - Creating multiple elements, a modifier and an anchor - optional colons included
///   @include object('buttonstrip') {
///     display: none;
///     
///     @include multi('modifier:' 'mod', 'elem:' 'button' 'separator', '> a') {
///       display: block;
///     }
///   }
///   
///   // Generates:
///   
///   .o-buttonstrip {
///     display: none;
///   }
///   
///   .o-buttonstrip--mod {
///     display: block;
///   }
///   
///   .o-buttonstrip__button, {
///   .o-buttonstrip__separator {
///     display: block;
///   }
///   
///   .o-buttonstrip > a {
///     display: block;
///   }
///
@mixin multi($first, $others...) {
    @include contexts.assert-stack-count(vars.$context-id, vars.$max-depth);

    @each $entity in functions.list-prepend($others, $first) {
        $is-manual-selector: false;

        @if type-of($entity) == string {
            @if find-bem-function($entity) == null {
                $is-manual-selector: true;
            }
        }

        @if $is-manual-selector {
            $sel: if(&, selector-nest(&, $entity), selector-parse($entity));

            @at-root #{$sel} {
                @content;
            }
        } @else {
            $entity-func-id: null;

            @if type-of($entity) == list {
                $entity-func-id: nth($entity, 1);
                $entity:         functions.list-slice($entity, 2);
            } @else {
                $entity-func-id: $entity;
                $entity:         ();
            }

            @if str-slice($entity-func-id, str-length($entity-func-id)) == ':' {
                $entity-func-id: unquote(str-slice($entity-func-id, 1, str-length($entity-func-id) - 1));
            }

            $sel-func: find-bem-function($entity-func-id);

            @if $sel-func == null {
                @error 'Function "#{inspect($entity-func-id)}" was not found.';
            }

            $entity-result:          call($sel-func, $entity...);
            $entity-result-selector: nth($entity-result, 1);
            $entity-result-context:  nth($entity-result, 2);

            @if $entity-result-context != null {
                @include contexts.push(vars.$context-id, $entity-result-context...);
            }
            @at-root #{$entity-result-selector} {
                @content;
            }
            @if $entity-result-context != null {
                @include contexts.pop(vars.$context-id);
            }
        }
    }
}

@function find-bem-function($name) {
    @each $module in (block element modifier state suffix theme) {
        @if function-exists($name, $module) {
            @return get-function($name, $module: $module);
        }
    }

    @return null;
}