/**
 * KTUI - Free & Open-Source Tailwind UI Components by Keenthemes
 * Copyright 2025 by Keenthemes Inc
 */

import KTData from '../../helpers/data';
import KTDom from '../../helpers/dom';
import KTComponent from '../component';
import { KTScrolltoInterface, KTScrolltoConfigInterface } from './types';

declare global {
	interface Window {
		KT_SCROLLTO_INITIALIZED: boolean;
		KTScrollto: typeof KTScrollto;
	}
}

export class KTScrollto extends KTComponent implements KTScrolltoInterface {
	protected override _name: string = 'scrollto';
	protected override _defaultConfig: KTScrolltoConfigInterface = {
		smooth: true,
		parent: 'body',
		target: '',
		offset: 0,
	};
	protected override _config: KTScrolltoConfigInterface = this._defaultConfig;
	protected _targetElement: HTMLElement;

	constructor(element: HTMLElement, config?: KTScrolltoConfigInterface) {
		super();

		if (KTData.has(element as HTMLElement, this._name)) return;

		this._init(element);
		this._buildConfig(config);

		if (!this._element) return;

		this._targetElement = this._getTargetElement();

		if (!this._targetElement) {
			return;
		}

		this._handlers();
	}

	private _getTargetElement(): HTMLElement | null {
		return (
			KTDom.getElement(
				this._element.getAttribute('data-kt-scrollto') as string,
			) || KTDom.getElement(this._getOption('target') as string)
		);
	}

	protected _handlers(): void {
		if (!this._element) return;

		this._element.addEventListener('click', (event: Event) => {
			event.preventDefault();
			this._scroll();
		});
	}

	protected _scroll(): void {
		const pos =
			this._targetElement.offsetTop +
			parseInt(this._getOption('offset') as string);

		let parent: HTMLElement | Window = KTDom.getElement(
			this._getOption('parent') as string,
		);

		if (!parent || parent === document.body) {
			parent = window;
		}

		parent.scrollTo({
			top: pos,
			behavior: (this._getOption('smooth') as boolean) ? 'smooth' : 'instant',
		});
	}

	public scroll(): void {
		this._scroll();
	}

	public static getInstance(element: HTMLElement): KTScrollto {
		if (!element) return null;

		if (KTData.has(element, 'scrollto')) {
			return KTData.get(element, 'scrollto') as KTScrollto;
		}

		if (element.getAttribute('data-kt-scrollto')) {
			return new KTScrollto(element);
		}

		return null;
	}

	public static getOrCreateInstance(
		element: HTMLElement,
		config?: KTScrolltoConfigInterface,
	): KTScrollto {
		return this.getInstance(element) || new KTScrollto(element, config);
	}

	public static createInstances(): void {
		const elements = document.querySelectorAll('[data-kt-scrollto]');

		elements.forEach((element) => {
			new KTScrollto(element as HTMLElement);
		});
	}

	public static init(): void {
		KTScrollto.createInstances();
	}
}

if (typeof window !== 'undefined') {
	window.KTScrollto = KTScrollto;
}