import { useEffect, useState } from "react";
import { Failure, Pending, Success, type AsyncOp } from "./async-op.ts";
import { caughtValueToString } from "./caught-value.ts";

/**
 * Checks if the provided value is non-nullish, otherwise calls provided
 * getValue function to obtain the value (presumably from some remote location).
 */
export function useEnsureValue<T>(
  value: T | null | undefined,
  getValue: () => Promise<Success<T> | Failure<string>>,
) {
  const [result, setShareLink] = useState<AsyncOp<T, string>>(
    value != null ? new Success(value) : new Pending(),
  );

  useEffect(() => {
    if (value == null) {
      getValue().then(
        (success) => {
          setShareLink(success);
        },
        (error: unknown) => {
          setShareLink(new Failure(caughtValueToString(error)));
        },
      );
    }
  }, [value, getValue]);

  return result;
}