/* eslint-disable @typescript-eslint/no-explicit-any */
import {
  definesRenderSuspension,
  withRenderSuspension,
} from "./renderSuspension.js";
import { ElementProps, WebJSXManagedElement } from "./types.js";

/**
 * Updates an event listener on an element.
 * @param el Target element
 * @param eventName Name of the event (without 'on' prefix)
 * @param newHandler New event handler function
 * @param oldHandler Previous event handler function
 */
function updateEventListener(
  el: Element,
  eventName: string,
  newHandler?: EventListenerOrEventListenerObject,
  oldHandler?: EventListenerOrEventListenerObject
): void {
  if (oldHandler && oldHandler !== newHandler) {
    el.removeEventListener(eventName, oldHandler);
  }
  if (newHandler && oldHandler !== newHandler) {
    el.addEventListener(eventName, newHandler);
    (el as WebJSXManagedElement).__webjsx_listeners =
      (el as WebJSXManagedElement).__webjsx_listeners ?? {};
    (el as WebJSXManagedElement).__webjsx_listeners[eventName] = newHandler;
  }
}

/**
 * Updates a single property or attribute on an element.
 * @param el Target element
 * @param key Property or attribute name
 * @param value New value to set
 */
function updatePropOrAttr(el: Element, key: string, value: unknown): void {
  if (el instanceof HTMLElement) {
    if (key in el) {
      // Fast path: property exists on HTMLElement
      (el as any)[key] = value;
      return;
    }
    if (typeof value === "string") {
      el.setAttribute(key, value);
      return;
    }
    // Fallback for non-string values on HTMLElement
    (el as any)[key] = value;
    return;
  }

  // SVG/Other namespace elements
  const isSVG = el.namespaceURI === "http://www.w3.org/2000/svg";
  if (isSVG) {
    if (value !== undefined && value !== null) {
      el.setAttribute(key, `${value}`);
    } else {
      el.removeAttribute(key);
    }
    return;
  }

  // Fallback for other element types
  if (typeof value === "string") {
    el.setAttribute(key, value);
  } else {
    (el as any)[key] = value;
  }
}

/**
 * Updates all attributes and properties on a DOM element.
 * @param el Target element
 * @param newProps New properties to apply
 * @param oldProps Previous properties for comparison (default empty object)
 */
function updateAttributesCore(
  el: Element,
  newProps: ElementProps,
  oldProps: ElementProps = {}
): void {
  // Handle new/updated props
  for (const key of Object.keys(newProps)) {
    const value = newProps[key];

    if (
      key === "children" ||
      key === "key" ||
      key === "dangerouslySetInnerHTML" ||
      key === "nodes"
    )
      continue;

    if (key.startsWith("on") && typeof value === "function") {
      const eventName = key.substring(2).toLowerCase();
      updateEventListener(
        el,
        eventName,
        value as EventListenerOrEventListenerObject,
        (el as WebJSXManagedElement).__webjsx_listeners?.[eventName]
      );
    } else if (value !== oldProps[key]) {
      updatePropOrAttr(el, key, value);
    }
  }

  // Handle dangerouslySetInnerHTML
  if (newProps.dangerouslySetInnerHTML) {
    if (
      !oldProps.dangerouslySetInnerHTML ||
      newProps.dangerouslySetInnerHTML.__html !==
        oldProps.dangerouslySetInnerHTML.__html
    ) {
      const html = newProps.dangerouslySetInnerHTML?.__html || "";
      el.innerHTML = html;
    }
  } else {
    if (oldProps.dangerouslySetInnerHTML) {
      el.innerHTML = "";
    }
  }

  // Remove old props/attributes
  for (const key of Object.keys(oldProps)) {
    if (
      !(key in newProps) &&
      key !== "children" &&
      key !== "key" &&
      key !== "dangerouslySetInnerHTML" &&
      key !== "nodes"
    ) {
      if (key.startsWith("on")) {
        const eventName = key.substring(2).toLowerCase();
        const existingListener = (el as WebJSXManagedElement)
          .__webjsx_listeners?.[eventName];
        if (existingListener) {
          el.removeEventListener(eventName, existingListener);
          delete (el as WebJSXManagedElement).__webjsx_listeners[eventName];
        }
      } else if (key in el) {
        (el as any)[key] = undefined;
      } else {
        el.removeAttribute(key);
      }
    }
  }
}

/**
 * Sets initial attributes and properties on a DOM element.
 * @param el Target element
 * @param props Properties to apply
 */
export function setAttributes(
  el: Element,
  props: { [key: string]: unknown }
): void {
  if (definesRenderSuspension(el)) {
    withRenderSuspension(el, () => {
      updateAttributesCore(el, props);
    });
  } else {
    updateAttributesCore(el, props);
  }
}

/**
 * Updates existing attributes and properties on a DOM element.
 * @param el Target element
 * @param newProps New properties to apply
 * @param oldProps Previous properties for comparison
 */
export function updateAttributes(
  el: Element,
  newProps: { [key: string]: unknown },
  oldProps: { [key: string]: unknown }
): void {
  if (definesRenderSuspension(el)) {
    withRenderSuspension(el, () => {
      updateAttributesCore(el, newProps, oldProps);
    });
  } else {
    updateAttributesCore(el, newProps, oldProps);
  }
}