import type { StyleWire } from '@proulr/sdui-contract';

export type BdcElement = {
  type: string;
  props: Record<string, unknown>;
  children: BdcElement[];
};

export type BdcComponent = (props: Record<string, unknown>) => BdcElement;

function flattenChild(child: unknown): BdcElement[] {
  if (child == null || typeof child === 'boolean') return [];
  if (Array.isArray(child)) return child.flatMap(flattenChild);
  if (typeof child === 'object' && 'type' in child) return [child as BdcElement];
  if (typeof child === 'string' || typeof child === 'number') {
    return [{ type: '_text_node', props: { value: String(child) }, children: [] }];
  }
  return [];
}

function createElement(
  type: string | BdcComponent,
  props: Record<string, unknown> | null,
  ...childInputs: unknown[]
): BdcElement {
  const rawProps = props ?? {};
  const { children: propsChildren, ...restProps } = rawProps as Record<string, unknown> & {
    children?: unknown;
  };

  const children = [
    ...flattenChild(propsChildren),
    ...childInputs.flatMap(flattenChild),
  ];

  if (typeof type === 'function') {
    return type({ ...restProps, children });
  }

  return { type, props: restProps, children };
}

export const jsx = createElement;
export const jsxs = createElement;
export const Fragment = '_fragment';

export function styleWire(style: StyleWire): { style: StyleWire } {
  return { style };
}