routes.js

const assert = require('assert');
const { basename, dirname } = require('path');
const fg = require('fast-glob');

const getRoutes = async (opts) => {
  // e.g. ['a/a.route.jsx', 'b/b.route.jsx', 'a.c/b.route.jsx']
  const files = await fg(['*/*.route.jsx'], {
    cwd: opts.baseDir,
  });
  return getRoutesByFiles({
    ...opts,
    files,
  });
};

const getRoutesByFiles = async (opts) => {
  const routes = {};
  opts.files.forEach((file) => {
    const id = basename(dirname(file));
    assert(!routes[id], `Duplicate route id: ${id}`);
    routes[id] = {
      id,
      file,
      path: getPath(id),
    };
  });

  // ['a.c', 'a', 'b']
  const ids = Object.keys(routes).sort(byLongestFirst);
  const layoutIds = ids.filter((id) => {
    return id.endsWith('.');
  });
  layoutIds.forEach((layoutId) => {
    const childIds = findChildRoutes(ids, routes, layoutId);
    childIds.forEach((id) => {
      routes[id].parentId = layoutId;
    });
  });

  return routes;
};

function byLongestFirst(a, b) {
  return b.length - a.length;
}

function findChildRoutes(ids, routes, layoutId) {
  const compareId = layoutId.replace(/index\.$/, '');
  return ids.filter((id) => {
    return id !== layoutId && !routes[id].parentId && id.startsWith(compareId);
  });
}

function getPath(id) {
  let path = id;
  // layout id is ends with .
  if (path.endsWith('.')) path = path.slice(0, -1);
  if (path.endsWith('index')) path = path.slice(0, -5);
  path = path
    .split('.')
    .map((part) => {
      // ignore _ prefixed path
      if (part.startsWith('_')) return '';
      // splat
      if (part.endsWith('$')) return '*';
      // dynamic import
      if (part.startsWith('$')) return `:${part.slice(1)}`;
      return part;
    })
    .join('/');
  return `/${path}`;
}

exports.getRoutes = getRoutes;