import { filterEmpty } from './props-util';
import type { Slots, VNode, VNodeArrayChildren, VNodeProps } from 'vue';
import { cloneVNode, isVNode, Comment, Fragment, render as VueRender } from 'vue';
import warning from './warning';
import type { RefObject } from './createRef';
type NodeProps = Record<string, any> &
  Omit<VNodeProps, 'ref'> & { ref?: VNodeProps['ref'] | RefObject };

export function cloneElement<T, U>(
  vnode: VNode<T, U> | VNode<T, U>[],
  nodeProps: NodeProps = {},
  override = true,
  mergeRef = false,
): VNode<T, U> {
  let ele = vnode;
  if (Array.isArray(vnode)) {
    ele = filterEmpty(vnode)[0];
  }
  if (!ele) {
    return null;
  }
  const node = cloneVNode(ele as VNode<T, U>, nodeProps as any, mergeRef);

  // cloneVNode内部是合并属性，这里改成覆盖属性
  node.props = (override ? { ...node.props, ...nodeProps } : node.props) as any;
  warning(typeof node.props.class !== 'object', 'class must be string');
  return node;
}

export function cloneVNodes(vnodes, nodeProps = {}, override = true) {
  return vnodes.map(vnode => cloneElement(vnode, nodeProps, override));
}

export function deepCloneElement<T, U>(
  vnode: VNode<T, U> | VNode<T, U>[],
  nodeProps: NodeProps = {},
  override = true,
  mergeRef = false,
) {
  if (Array.isArray(vnode)) {
    return vnode.map(item => deepCloneElement(item, nodeProps, override, mergeRef));
  } else {
    // 需要判断是否为vnode方可进行clone操作
    if (!isVNode(vnode)) {
      return vnode;
    }
    const cloned = cloneElement(vnode, nodeProps, override, mergeRef);
    if (Array.isArray(cloned.children)) {
      cloned.children = deepCloneElement(cloned.children as VNode<T, U>[]);
    }
    return cloned;
  }
}

export function triggerVNodeUpdate(vm: VNode, attrs: Record<string, any>, dom: any) {
  VueRender(cloneVNode(vm, { ...attrs }), dom);
}

const ensureValidVNode = (slot: VNodeArrayChildren | null) => {
  return (slot || []).some(child => {
    if (!isVNode(child)) return true;
    if (child.type === Comment) return false;
    if (child.type === Fragment && !ensureValidVNode(child.children as VNodeArrayChildren))
      return false;
    return true;
  })
    ? slot
    : null;
};

export function customRenderSlot(
  slots: Slots,
  name: string,
  props: Record<string, unknown>,
  fallback?: () => VNodeArrayChildren,
) {
  const slot = slots[name]?.(props);
  if (ensureValidVNode(slot)) {
    return slot;
  }
  return fallback?.();
}