import {
    createVNode,
    defineComponent,
    type Slots,
    type VNode,
    type VNodeChild,
    type VNodeTypes,
} from "vue";
import type { ComponentProps } from "vue-component-type-helpers";
import type { ClassBinding, DynamicComponent } from "@/types";

type SlotComponentProps<C extends VNodeTypes> = {
    /** Component to be get the slot from */
    component: C;
    /** Props to be binded to the injected component. */
    props?: ComponentProps<C>;
    /**
     * Slot name
     * @default "default"
     */
    name?: string;
    /**
     * Tag name of the slot wrapper element
     * @default "div"
     */
    tag?: DynamicComponent;
    /** Class for the slot wrapper element */
    class?: ClassBinding | ClassBinding[];
};

/** This components renders only a specific slot of another component */
export default defineComponent<SlotComponentProps<{ $slots: Slots }>>(
    <C extends { $slots: Slots }>(props: SlotComponentProps<C>, { slots }) => {
        const _props = { tag: "div", name: "default", ...props };

        return (): VNode => {
            let slot: VNodeChild | (() => VNodeChild) = (): VNodeChild =>
                // render the component slot if available
                typeof props.component.$slots[_props.name] === "function"
                    ? props.component.$slots[_props.name]!(props.props)
                    : // render the default if no component slot override is available
                      typeof slots.default === "function"
                      ? slots.default()
                      : undefined;
            if (typeof _props.tag === "string") {
                // Vue prefers components' children to be passed as functions,
                // but native elements' children can't be passed that way.
                slot = slot();
            }

            return createVNode(
                _props.tag as VNode,
                { class: _props.class },
                slot,
            );
        };
    },
    {
        name: "OSlotComponent",
        // manual runtime props declaration is currently still needed.
        props: ["component", "props", "name", "tag"],
    },
);