/* ============================================================================
   ROUTE CONFIG
   ----------------------------------------------------------------------------
   URL shape - an explicit locale prefix on BOTH languages, never a ?lang=:

     /                                 -> 302 to /en or /ar (Accept-Language)
     /:lang                            -> home
     /:lang/<section>                  -> one of the ten top-level sections
     /:lang/<section>/<slug>           -> one entry of a CMS-backed section
     /:lang/events-calendar/<slug>.ics -> that event as an RFC 5545 file
     anything else                     -> 404

   ONE set of route modules serves both languages: the ":lang" layout wraps
   every page, so a page module is written once and rendered for /en/about and
   /ar/about alike. An unknown ":lang" is rejected by that layout's loader, and
   any other unmatched URL falls through to the catch-all, which renders the
   root ErrorBoundary's localised 404.

   LISTING AND DETAIL ARE SIBLINGS, NOT PARENT AND CHILD
   -----------------------------------------------------
   A detail route is registered as a SIBLING of its listing route - both are
   children of the ":lang" layout - and deliberately not as a child of the
   listing. React Router only renders a child where its parent renders an
   <Outlet/>, and a listing module renders a page, not an outlet: nesting would
   either hide the detail page entirely or paint it underneath the whole index
   (its filters, its cards, its pagination). "locale-layout.tsx" is the only
   module in this tree that renders an <Outlet/>, so it is the only legitimate
   parent. The shared URL prefix is expressed in the path string
   ("events-calendar/:slug"), which costs nothing and keeps each page's route a
   leaf that owns its whole screen.

   ":slug.ics" DOES NOT SHADOW ":slug"
   -----------------------------------
   Both patterns match /en/events-calendar/kickoff.ics, so ranking - not array
   order - has to decide. React Router scores a partial dynamic segment
   (":slug.ics") above a whole-segment one (":slug"), so the resource route
   wins the .ics URL and the page route keeps every other slug. The .ics module
   exports only a `loader`, which is what makes it a resource route: its
   Response is handed to the browser verbatim and no parent loader - not even
   the ":lang" layout's - runs, which is why that module validates the locale
   segment itself.

   ROUTE IDS
   ---------
   "root" | "routes/locale-redirect" | "locale" | "routes/not-found", one per
   section named after its key: "home", "about", "whatWeDo", "activities",
   "events", "applications", "news", "contact", "resources", "knowledgeHub" -
   and one per detail route, the section key plus "Detail" ("newsDetail",
   "eventsDetail", ...), plus "eventsIcs". So `useRouteLoaderData("locale")`
   reads the ":lang" layout's data anywhere.

   ADDING A SECTION PAGE
   ---------------------
   Add the section to `ROUTE_SLUGS`, name its module in `SECTION_MODULES` (and
   in `DETAIL_MODULES` if entries can be drilled into), and write the file. The
   tables below are declared, not discovered: every module named here is
   registered unconditionally, so a path that does not resolve fails the build
   instead of quietly falling through to the 404 route. Vite does not
   re-evaluate this file when a route module appears, so restart `pnpm dev`
   after adding one.
   ========================================================================= */

import {
  index,
  route,
  type RouteConfig,
  type RouteConfigEntry,
} from "@react-router/dev/routes";

import { ROUTE_SLUGS, type RouteSlugKey } from "./lib/route-slugs";

/**
 * Section -> route module. The file name is always the slug, so the URL and
 * the module that serves it can be read off each other.
 */
const SECTION_MODULES = {
  home: "routes/home.tsx",
  about: "routes/about.tsx",
  whatWeDo: "routes/what-we-do.tsx",
  activities: "routes/activities-and-initiatives.tsx",
  events: "routes/events-calendar.tsx",
  applications: "routes/applications-and-opportunities.tsx",
  news: "routes/news-and-updates.tsx",
  contact: "routes/contact.tsx",
  resources: "routes/resources-and-publications.tsx",
  knowledgeHub: "routes/knowledge-hub.tsx",
} as const satisfies Record<RouteSlugKey, string>;

/**
 * Section -> the module that renders ONE entry of it, at
 * `<section slug>/:slug`. Only the six CMS-backed sections have one; "about",
 * "what-we-do", "contact" and the home page are single pages with nothing to
 * drill into.
 */
const DETAIL_MODULES = {
  activities: "routes/activities-and-initiatives.$slug.tsx",
  events: "routes/events-calendar.$slug.tsx",
  applications: "routes/applications-and-opportunities.$slug.tsx",
  news: "routes/news-and-updates.$slug.tsx",
  resources: "routes/resources-and-publications.$slug.tsx",
  knowledgeHub: "routes/knowledge-hub.$slug.tsx",
} as const satisfies Partial<Record<RouteSlugKey, string>>;

/**
 * Resource routes: a module with a `loader` and no component, whose Response
 * is served as-is. `path` is relative to the ":lang" layout, like every other
 * entry here.
 */
const RESOURCE_ROUTES = [
  {
    id: "eventsIcs",
    path: `${ROUTE_SLUGS.events}/:slug.ics`,
    file: "routes/events-calendar.$slug.ics.ts",
  },
] as const;

const detailKeys = Object.keys(DETAIL_MODULES) as (keyof typeof DETAIL_MODULES)[];

/**
 * Every page under ":lang": the ten sections, then the six detail routes, then
 * the .ics resource route. Flat on purpose - see "LISTING AND DETAIL ARE
 * SIBLINGS" above.
 */
const localeChildRoutes: RouteConfigEntry[] = [
  ...(Object.keys(SECTION_MODULES) as RouteSlugKey[]).map((key) =>
    key === "home"
      ? index(SECTION_MODULES.home, { id: "home" })
      : route(ROUTE_SLUGS[key], SECTION_MODULES[key], { id: key }),
  ),

  ...detailKeys.map((key) =>
    route(`${ROUTE_SLUGS[key]}/:slug`, DETAIL_MODULES[key], {
      id: `${key}Detail`,
    }),
  ),

  ...RESOURCE_ROUTES.map((entry) =>
    route(entry.path, entry.file, { id: entry.id }),
  ),
];

export default [
  // Bare "/" is not a page: it negotiates and redirects.
  index("routes/locale-redirect.tsx"),

  // Every page, in both languages, through one shared route module.
  route(
    ":lang",
    "routes/locale-layout.tsx",
    { id: "locale" },
    localeChildRoutes,
  ),

  // Unknown locale segments are handled by the layout's loader; every other
  // unmatched URL lands here.
  route("*", "routes/not-found.tsx"),
] satisfies RouteConfig;