// P4 Tasks (AK-P4b) §5 — shared loader/action guard for Tasks routes.
//
// Resolves the authenticated tenant context and the user's permission set once,
// so routes can gate consistently. Module-not-active handling differs by intent
// (§ "404 vs locked" decision):
//   - GET loaders pass `requireModule: false` and render a locked/empty VM when
//     `hasModule` is false.
//   - Write actions pass `requireModule: true` → 404 (CatalogError.notFound) when
//     the module is off, and additionally require an explicit permission.

import { CatalogError, foundationErrors, requirePermission } from "@toolctrl/foundation";
import { requireAuth } from "~/utils/loaders.middleware";
import { getTenantIdFromUrl } from "~/utils/services/.server/urlService";
import { getUserInfo } from "~/utils/session.server";
import { tenantHasModule } from "~/utils/connector/tenantConnector.server";
import { getPermissionsByUser } from "~/utils/db/permissions/userRoles.db.server";
import { TaskServiceError, type TaskVisibilityContext } from "./taskService.server";

export const TASKS_MODULE_KEY = "tasks";

export type TasksRouteContext = TaskVisibilityContext & {
  tenantId: string;
  hasModule: boolean;
};

export async function loadTasksContext({
  request,
  params,
  requireModule = false,
}: {
  request: Request;
  params: Record<string, string | undefined>;
  requireModule?: boolean;
}): Promise<TasksRouteContext> {
  await requireAuth({ request, params });
  const [tenantId, userInfo] = await Promise.all([getTenantIdFromUrl(params), getUserInfo(request)]);
  if (!tenantId || !userInfo.userId) {
    throw new CatalogError(foundationErrors.notFound);
  }
  const [hasModule, permissions] = await Promise.all([
    tenantHasModule({ tenantId, userId: userInfo.userId, moduleKey: TASKS_MODULE_KEY }),
    getPermissionsByUser(userInfo.userId, tenantId),
  ]);
  if (requireModule && !hasModule) {
    // Mutations on a disabled module look "not found" (Bauprinzip A.5.3).
    throw new CatalogError(foundationErrors.notFound, { module: TASKS_MODULE_KEY });
  }
  return { tenantId, userId: userInfo.userId, permissions, hasModule };
}

/** Require a tasks.* permission; throws 404 (CatalogError.notFound) if missing. */
export function requireTasksPermission(ctx: TasksRouteContext, permission: string): TasksRouteContext {
  requirePermission({ tenantId: ctx.tenantId, userId: ctx.userId, permissions: ctx.permissions }, permission);
  return ctx;
}

/**
 * Bare 404 Response for throwing from Tasks loaders/actions. The body text is
 * never shown to users (the route ErrorBoundary renders ServerError); we keep a
 * `return new Response` helper so call sites can `throw notFoundResponse()`
 * without inlining a hardcoded user-facing literal.
 */
export function notFoundResponse(): Response {
  return new Response("Not Found", { status: 404 });
}

/** Bare 400 Response for invalid action input (same rationale as notFoundResponse). */
export function badRequestResponse(): Response {
  return new Response("Bad Request", { status: 400 });
}

/**
 * Map a Tasks action error to a JSON Response for resource routes. CatalogError
 * keeps its status + i18nKey; TaskServiceError is a 400 with its Klartext
 * message key. Unknown errors are rethrown (→ 500).
 */
export function taskActionErrorResponse(error: unknown): Response {
  if (error instanceof CatalogError) {
    return Response.json({ error: error.i18nKey, code: error.code }, { status: error.status });
  }
  if (error instanceof TaskServiceError) {
    return Response.json({ error: error.messageKey }, { status: 400 });
  }
  throw error;
}