import {ReactElement, useRef} from "react";
import Draggable from "react-draggable";

export interface RackProps<E extends {key: string | number}> {
    id: string,
    objects: E[],
    onChange: (objects: E[]) => void,
    canDetach: (ref: HTMLDivElement) => boolean,
    onElementDetached: (ref: HTMLDivElement, el: E) => void,
    render: (e: E) => ReactElement,
}

interface RackItemProps<E extends {key: string | number}> {
    item: E,
    onTryDetach: (ref: HTMLDivElement, el: E) => void,
    render: (e: E) => ReactElement,
}

/**
 * A container of draggable objects
 * */
export function Rack<E extends {key: string | number}>({id, objects, onChange, canDetach, onElementDetached, render}: RackProps<E>) {
    return (
        <div id={id} style={{
            display: "flex"
        }}>
            {objects.map(element => (
                <RackItem key={element.key}
                          item={element}
                          render={render}
                          onTryDetach={(ref, element) => {
                              if (!canDetach(ref))
                                  return

                              const index = objects.findIndex(o => o.key === element.key)
                              onChange(objects.toSpliced(index, 1))

                              onElementDetached(ref, element)
                          }}/>
            ))}
        </div>
    )
}

function RackItem<E extends {key: string | number}>({item, onTryDetach, render}: RackItemProps<E>) {
    const divRef = useRef<HTMLDivElement>(null);

    return (
        <Draggable
            position={{x: 0, y: 0}}
            nodeRef={divRef}
            onStop={() => onTryDetach(divRef.current!, item)}>
            <div ref={divRef}>
                {render(item)}
            </div>
        </Draggable>
    )
}