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/**
 * @license
 * Copyright (c) 2021 - 2024 Vaadin Ltd.
 * This program is available under Apache License Version 2.0, available at https://vaadin.com/license/
 */
import { dedupingMixin } from '@polymer/polymer/lib/utils/mixin.js';

/**
 * A mixin to delegate properties and attributes to a target element.
 *
 * @polymerMixin
 */
export const DelegateStateMixin = dedupingMixin(
  (superclass) =>
    class DelegateStateMixinClass extends superclass {
      static get properties() {
        return {
          /**
           * A target element to which attributes and properties are delegated.
           * @protected
           */
          stateTarget: {
            type: Object,
            observer: '_stateTargetChanged',
          },
        };
      }

      /**
       * An array of the host attributes to delegate to the target element.
       */
      static get delegateAttrs() {
        return [];
      }

      /**
       * An array of the host properties to delegate to the target element.
       */
      static get delegateProps() {
        return [];
      }

      /** @protected */
      ready() {
        super.ready();

        this._createDelegateAttrsObserver();
        this._createDelegatePropsObserver();
      }

      /** @protected */
      _stateTargetChanged(target) {
        if (target) {
          this._ensureAttrsDelegated();
          this._ensurePropsDelegated();
        }
      }

      /** @protected */
      _createDelegateAttrsObserver() {
        this._createMethodObserver(`_delegateAttrsChanged(${this.constructor.delegateAttrs.join(', ')})`);
      }

      /** @protected */
      _createDelegatePropsObserver() {
        this._createMethodObserver(`_delegatePropsChanged(${this.constructor.delegateProps.join(', ')})`);
      }

      /** @protected */
      _ensureAttrsDelegated() {
        this.constructor.delegateAttrs.forEach((name) => {
          this._delegateAttribute(name, this[name]);
        });
      }

      /** @protected */
      _ensurePropsDelegated() {
        this.constructor.delegateProps.forEach((name) => {
          this._delegateProperty(name, this[name]);
        });
      }

      /** @protected */
      _delegateAttrsChanged(...values) {
        this.constructor.delegateAttrs.forEach((name, index) => {
          this._delegateAttribute(name, values[index]);
        });
      }

      /** @protected */
      _delegatePropsChanged(...values) {
        this.constructor.delegateProps.forEach((name, index) => {
          this._delegateProperty(name, values[index]);
        });
      }

      /** @protected */
      _delegateAttribute(name, value) {
        if (!this.stateTarget) {
          return;
        }

        if (name === 'invalid') {
          this._delegateAttribute('aria-invalid', value ? 'true' : false);
        }

        if (typeof value === 'boolean') {
          this.stateTarget.toggleAttribute(name, value);
        } else if (value) {
          this.stateTarget.setAttribute(name, value);
        } else {
          this.stateTarget.removeAttribute(name);
        }
      }

      /** @protected */
      _delegateProperty(name, value) {
        if (!this.stateTarget) {
          return;
        }

        this.stateTarget[name] = value;
      }
    },
);