import { redirect, type ActionFunctionArgs, type LoaderFunctionArgs } from "react-router";
import { serverOnly$ } from "vite-env-only/macros";
import { buildSelectTenantVM, type SelectTenantData, type TenantRole } from "@toolctrl/view-models";
import type { VMState } from "@toolctrl/view-models";
import { TenantUserType } from "~/application/enums/tenants/TenantUserType";
import { appPath } from "~/utils/app/CanonicalUrlUtils";
import { getMyTenants, getTenantUserType } from "~/utils/db/tenants.db.server";
import { getUser } from "~/utils/db/users.db.server";
import { getUserInfo, validateCSRFToken } from "~/utils/session.server";

// D-D0a — Flow "Login Tenantauswahl (Admin)". Tenant-/Profil-Auswahl nach dem Login.
// Der Loader baut serverseitig das VM (M013) aus getMyTenants + der Rolle des Users je Tenant; die
// Subframe-Karten-UI (select-tenant.component) rendert nur. Klick auf eine Karte postet hierher,
// die Action verifiziert die Mitgliedschaft serverseitig und leitet in den Tenant-Space.
// Route wird per Ordner-Konvention autoregistriert (select-tenant.tsx).

export type SelectTenantVM = VMState<SelectTenantData>;

export type LoaderData = {
  vm: SelectTenantVM;
};

export type ActionData = {
  error?: string;
};

function roleFromType(type: TenantUserType | null | undefined): TenantRole | null {
  switch (type) {
    case TenantUserType.OWNER:
      return "owner";
    case TenantUserType.ADMIN:
      return "admin";
    case TenantUserType.MEMBER:
      return "member";
    default:
      return null;
  }
}

export const loader = serverOnly$(async ({ request }: LoaderFunctionArgs) => {
  const userInfo = await getUserInfo(request);
  if (!userInfo.userId) {
    throw redirect("/login");
  }
  const user = await getUser(userInfo.userId);
  if (!user) {
    throw redirect("/login");
  }
  const tenants = await getMyTenants(userInfo.userId);
  const memberships = await Promise.all(tenants.map((tenant) => getTenantUserType(userInfo.userId, tenant.id)));
  const vm = buildSelectTenantVM({
    tenants: tenants.map((tenant, index) => ({
      id: tenant.id,
      name: tenant.name,
      slug: tenant.slug,
      image: tenant.icon ?? tenant.logo ?? null,
      role: roleFromType(memberships[index]?.type),
      subtitle: user.email,
    })),
    currentTenantId: user.defaultTenantId,
  });
  return Response.json({ vm } satisfies LoaderData);
})!;

export const action = serverOnly$(async ({ request }: ActionFunctionArgs) => {
  const form = await request.formData();
  await validateCSRFToken(request, { formData: form });
  const userInfo = await getUserInfo(request);
  if (!userInfo.userId) {
    throw redirect("/login");
  }
  const tenantId = String(form.get("tenantId") ?? "");
  const slug = String(form.get("slug") ?? "");
  if (!tenantId || !slug) {
    return Response.json({ error: "account.selectTenant.errors.invalidSelection" } satisfies ActionData, { status: 400 });
  }
  // Mitgliedschaft serverseitig verifizieren — der Client-Form nicht vertrauen.
  const membership = await getTenantUserType(userInfo.userId, tenantId);
  if (!membership) {
    return Response.json({ error: "account.selectTenant.errors.notMember" } satisfies ActionData, { status: 403 });
  }
  throw redirect(appPath({ tenantSlug: slug, path: "dashboard", mode: "host-aware" }));
})!;