import type { QuestionType } from "@/db/schema/form";

export type FormAnswerValue = string | string[];

export function decodeCheckboxAnswer(value: FormAnswerValue | undefined): string[] {
  if (Array.isArray(value)) {
    return value.filter((item): item is string => typeof item === "string");
  }

  if (!value) {
    return [];
  }

  try {
    const parsed: unknown = JSON.parse(value);
    if (Array.isArray(parsed) && parsed.every((item) => typeof item === "string")) {
      return parsed;
    }
  } catch {
    // Older checkbox answers were stored as comma-separated text.
  }

  return value.split(", ").filter(Boolean);
}

export function encodeAnswerValue(value: FormAnswerValue): string {
  return Array.isArray(value) ? JSON.stringify(value) : value;
}

export function formatStoredAnswer(
  value: string | undefined,
  questionType: QuestionType | string
): string {
  if (!value) {
    return "";
  }

  return questionType === "checkbox"
    ? decodeCheckboxAnswer(value).join(", ")
    : value;
}