import { type ClassValue, clsx } from "clsx";
import { ReadonlyURLSearchParams } from 'next/navigation';
import { twMerge } from "tailwind-merge";

export const createUrl = (pathname: string, params: URLSearchParams | ReadonlyURLSearchParams) => {
  const paramsString = params.toString();
  const queryString = `${paramsString.length ? '?' : ''}${paramsString}`;

  return `${pathname}${queryString}`;
};

export const ensureStartsWith = (stringToCheck: string, startsWith: string) => {
  if (typeof stringToCheck !== 'string') {
    return stringToCheck;
  }

  if (startsWith.length === 0) {
    return stringToCheck;
  }

  if (stringToCheck.startsWith(startsWith)) {
    return stringToCheck;
  }

  return `${startsWith}${stringToCheck}`;
};

export const validateEnvironmentVariables = () => {
  const requiredEnvironmentVariables = ['SHOPIFY_STORE_DOMAIN', 'SHOPIFY_STOREFRONT_ACCESS_TOKEN'];
  const missingEnvironmentVariables = [] as string[];

  requiredEnvironmentVariables.forEach((envVar) => {
    if (!process.env[envVar]) {
      missingEnvironmentVariables.push(envVar);
    }
  });

  if (missingEnvironmentVariables.length) {
    throw new Error(
      `The following environment variables are missing. Your site will not work without them. Read more: https://vercel.com/docs/integrations/shopify#configure-environment-variables\n\n${missingEnvironmentVariables.join(
        '\n'
      )}\n`
    );
  }

  if (
    process.env.SHOPIFY_STORE_DOMAIN?.includes('[') ||
    process.env.SHOPIFY_STORE_DOMAIN?.includes(']')
  ) {
    throw new Error(
      'Your `SHOPIFY_STORE_DOMAIN` environment variable includes brackets (ie. `[` and / or `]`). Your site will not work with them there. Please remove them.'
    );
  }
};

export function cn(...inputs: ClassValue[]) {
  return twMerge(clsx(inputs))
}

export const container = 'container mx-auto max-w-[1400px] px-4 sm:px-6 lg:px-4';