// 由于 Vue 没有直接的 DependencyObject 概念，这里使用 HTMLElement 代替
// 同时由于没有 VisualTreeHelper 等，需要手动实现一些查找逻辑

// 模拟 Predicate 类型
type Predicate<T> = (item: T) => boolean;

// 视觉树查找子元素
function findVisualTreeChildren(target: HTMLElement, predicate?: Predicate<HTMLElement>): HTMLElement[] {
    const result: HTMLElement[] = [];
    if (target) {
        const children = target.children;
        for (let i = 0; i < children.length; i++) {
            const element = children[i] as HTMLElement;
            if (element) {
                if (!predicate || predicate(element)) {
                    result.push(element);
                }
                result.push(...findVisualTreeChildren(element, predicate));
            }
        }
    }
    return result;
}

// 视觉树查找第一个子元素
function firstVisualTreeChild(target: HTMLElement, predicate?: Predicate<HTMLElement>): HTMLElement | null {
    if (target) {
        const children = target.children;
        for (let i = 0; i < children.length; i++) {
            const element = children[i] as HTMLElement;
            if (element) {
                if (!predicate || predicate(element)) {
                    return element;
                }
                const childResult = firstVisualTreeChild(element, predicate);
                if (childResult) {
                    return childResult;
                }
            }
        }
    }
    return null;
}

// 视觉树查找父元素
function findVisualTreeAncestor(target: HTMLElement, predicate?: Predicate<HTMLElement>): HTMLElement | null {
    if (target) {
        const parent = target.parentElement;
        if (!predicate) {
            return parent;
        } else if (parent) {
            return predicate(parent) ? parent : findVisualTreeAncestor(parent, predicate);
        }
    }
    return null;
}

// 模拟路由事件触发（在 Vue 中可以使用自定义事件）
function raiseEvent(target: HTMLElement, event: Event) {
    target.dispatchEvent(event);
}

// 模拟添加路由事件处理程序
function addHandler(target: HTMLElement, eventType: string, handler: EventListenerOrEventListenerObject) {
    target.addEventListener(eventType, handler);
}

// 模拟移除路由事件处理程序
function removeHandler(target: HTMLElement, eventType: string, handler: EventListenerOrEventListenerObject) {
    target.removeEventListener(eventType, handler);
}

// 在逻辑树中查找父窗口（这里简单返回 document.body）
function getOwnerWindow(target: HTMLElement): HTMLElement | null {
    return document.body;
}

// 查找视觉父元素
function findVisualParent<T extends HTMLElement>(element: HTMLElement): T | null {
    let parent: HTMLElement | null = element;
    while (parent) {
        if (parent instanceof HTMLElement) {
            return parent as T;
        }
        parent = null;//parent.parentElement;TODO VUE上有视觉树的概念吗？
    }
    return null;
}

// 获取鼠标悬停的元素
function getElementUnderMouse<T extends HTMLElement>(): T | null {
    const element = document.elementFromPoint(window.innerWidth / 2, window.innerHeight / 2);
    if (element instanceof HTMLElement) {
        return findVisualParent<T>(element);
    }
    return null;
}

export {
    findVisualTreeChildren,
    firstVisualTreeChild,
    findVisualTreeAncestor,
    raiseEvent,
    addHandler,
    removeHandler,
    getOwnerWindow,
    findVisualParent,
    getElementUnderMouse
};
