import type { ReactNode } from "react";
import { remove as stripAccents } from 'diacritics';

function getSafeRegexpString(input: string): string {
  return input
    .split("")
    .map((char) => `\\${char}`)
    .join("");
}

/**
 * Format a string by removing spaces, non-alphabetical caracters and by
 * adding delimiter
 */
function format(
  input: string,
  delimiter: string,
  ignoreInvalid = false
): string {
  const harmonized = stripAccents(input).trim().toLowerCase();
  const safeDelimiter = getSafeRegexpString(delimiter);

  if (ignoreInvalid) {
    return harmonized.replace(/\s+/g, delimiter);
  }

  return harmonized
    .replace(new RegExp(`[^a-z0-9${safeDelimiter}]+`, "g"), delimiter) // Replace all non-valid caracters by delimiter
    .replace(new RegExp(`${safeDelimiter}+`, "g"), delimiter) // Remove multiple delimiters repetition
    .replace(new RegExp(`^${safeDelimiter}`, "g"), "") // remove delimiter at the beginning
    .replace(new RegExp(`${safeDelimiter}$`, "g"), ""); // remove delimiter at the end
};

interface SlugifyOptions {
  delimiter?: string;
  prefix?: string;
}

/**
 * Slugify a React node
 */
export default function slugify(
  node: ReactNode,
  options: SlugifyOptions = { delimiter: "-", prefix: "" }
): string {
  if (!options.delimiter) options.delimiter = "-";
  if (!options.prefix) options.prefix = "";

  // null, undefined, falsy
  if (!node || typeof node === "boolean") {
    return "";
  }

  const { delimiter, prefix } = options;

  // boolean
  if (typeof node === "boolean") {
    return ""; // not much we can do here
  }

  // string, number
  if (typeof node === "string" || typeof node === "number" || typeof node === "bigint") {
    const harmonizedPrefix = format(prefix, delimiter, true);
    const harmonizedNode = format(String(node), delimiter);

    if (harmonizedPrefix) {
      return `${harmonizedPrefix}${delimiter}${harmonizedNode}`;
    }

    return harmonizedNode;
  }

  // ReactPortal
  if ("children" in node) {
    return slugify(node.children);
  }

  // ReactElement
  if ("props" in node) {
    if (typeof node.props !== "object" || !node.props) {
      return "";
    }

    if ("children" in node.props)

      return slugify(node.props.children as ReactNode, options);
  }

  // ReactFragment (including array of nodes)
  if (Symbol.iterator in node) {
    return slugify(
      Array.from(node)
        .map((subNode) => slugify(subNode, { delimiter }))
        .join(delimiter),
      options
    );
  }

  if (node instanceof Promise) {
    throw new Error("react-slugify does not support Promises");
  }

  // unhandled case
  return "";
};