/**
 * The AI actions of the editor spend the site's credits: what one costs
 * against what is left, and the question asked before one runs a second
 * time on the same page the same day.
 */

/** The actions the server notes against a post when they went through. */
export type AiAction = 'fix' | 'rewrite' | 'links' | 'faq' | 'catalog';

const NAMES: Record<AiAction, string> = {
  fix: 'Fix with AI',
  rewrite: 'the content rewrite',
  links: 'the internal link suggestions',
  faq: 'the FAQ',
  catalog: 'Fix title & description',
};

/**
 * The question to answer before running an action again, or null when it
 * has not run on this page today.
 *
 * @param action   - What is about to run.
 * @param ranToday - The actions that already spent credits on the page today.
 * @param credits  - What this run costs.
 * @param kind     - The page's type, as the panel names it: "post", "product".
 * @return The question, or null.
 */
export const repeatQuestion = (
  action: AiAction,
  ranToday: readonly string[],
  credits: number,
  kind: string
): string | null =>
  ranToday.includes(action)
    ? `You ran ${NAMES[action]} on this ${kind.toLowerCase()} today. Running it again costs ${credits} credits more. Run it again?`
    : null;

/**
 * What is left, said after the price: nothing while the balance is unknown.
 *
 * @param balance - Credits left, when Recomaze said.
 * @param cost    - What the run costs.
 * @return " You have 245 credits.", or a warning when they do not cover it.
 */
export const balanceNote = (
  balance: number | null | undefined,
  cost: number
): string => {
  if (balance === null || balance === undefined) {
    return '';
  }
  return balance < cost
    ? ` You have ${balance}, not enough for this run.`
    : ` You have ${balance} credits.`;
};