import { format } from "date-fns";
import { redirect } from "next/navigation";
import { DateFormatOptions, DateFormatPattern } from "../_lib/types/date-format.interface";

/**
 * Redirects to a specified path with an encoded message as a query parameter.
 * @param {('error' | 'success')} type - The type of message, either 'error' or 'success'.
 * @param {string} path - The path to redirect to.
 * @param {string} message - The message to be encoded and added as a query parameter.
 * @returns {never} This function doesn't return as it triggers a redirect.
 */
export function encodedRedirect(
  type: "error" | "success",
  path: string,
  message: string,
) {
  return redirect(`${path}?${type}=${encodeURIComponent(message)}`);
}

/**
 * Formats a URL by removing any trailing slashes.
 * @param {string} url - The URL to format.
 * @returns {string} The formatted URL.
 */
// Helper function to ensure URLs are properly formatted
export function formatUrl(url: string): string {
  // If URL starts with a slash, it's already absolute
  if (url.startsWith("/")) {
    return url;
  }

  // Otherwise, ensure it's properly formatted relative to root
  // Remove any potential duplicated '/dashboard' prefixes
  if (url.startsWith("dashboard/")) {
    return "/" + url;
  }

  return "/" + url;
}

/**
 * Creates a FormData object from the FormData object.
 * @returns {FormData} The FormData object.
 */
export function createFormData(): FormData {
  const data = new FormData();
  Object.entries(FormData).forEach(([key, value]) => {
    if (value) {
      data.append(key, value);
    }
  });
  return data;
};


/**
 * Generates a unique username based on the provided email address.
 *
 * The username is created by combining the local part of the email (before the '@' symbol)
 * with a randomly generated alphanumeric suffix.
 *
 * @param email - The email address to generate the username from.
 * @returns A string representing the generated username.
 *
 * @example
 * ```typescript
 * const username = generateUsername("example@gmail.com");
 * console.log(username); // Output: "example.abc123" (random suffix will vary)
 * ```
 */
export function generateUsername(email: string): string {
  const [localPart] = email.split("@");
  const randomSuffix = Math.random().toString(36).substring(2, 8); // Generate a random alphanumeric string
  return `${localPart}.${randomSuffix}`;
}

/**
 * Formats a date string to a human-readable format with type safety.
 * @param date - The date string to format.
 * @param options - Formatting options or a format string.
 * @returns The formatted date string.
 * @example
 * // Using default format
 * formatDate("2025-03-23")
 * 
 * // Using a custom format string
 * formatDate("2025-03-23", "yyyy-MM-dd")
 * 
 * // Using formatting options
 * formatDate("2025-03-23", { format: "MMMM do, yyyy", fallback: "Not available" })
 */
export const formatDate = (
  date: string | Date | undefined | null,
  options: DateFormatOptions | DateFormatPattern = { format: "PPpp" }
): string => {
  if (!date) {
    return typeof options === "string"
      ? "-"
      : (options.fallback || "-");
  }

  const dateObj = date instanceof Date ? date : new Date(date);

  // Handle invalid dates
  if (isNaN(dateObj.getTime())) {
    return typeof options === "string"
      ? "-"
      : (options.fallback || "-");
  }

  if (typeof options === "string") {
    return format(dateObj, options);
  }

  const { format: formatPattern = "PPpp", locale } = options;

  return locale
    ? format(dateObj, formatPattern, { locale })
    : format(dateObj, formatPattern);
};