import type {
  Ticket,
  Queue,
  Dashboard,
  DashboardWidget,
  WidgetData,
  Team,
  User,
  Transaction,
  SavedView,
  Scrip,
  Template,
  TemplatePreview,
  Lifecycle,
  LifecycleDefinition,
  CustomField,
  QueueCustomField,
  PreviewResult,
  UpdateResult,
  Attachment,
  AttachmentUploadResult,
  TicketLink,
  LoginResult,
  Watcher,
  SlaPolicy,
} from "./types";

const BASE_URL = "/api";

async function request<T>(url: string, options?: RequestInit): Promise<{ data: T | null; error: string | null }> {
  try {
    const token = typeof window !== "undefined" ? localStorage.getItem("tessera_token") : null;
    const headers: Record<string, string> = { "Content-Type": "application/json" };
    if (token) {
      headers["Authorization"] = `Bearer ${token}`;
    }
    // Merge with options headers if any
    const opts = { ...options };
    if (opts.headers) {
      Object.assign(headers, opts.headers as Record<string, string>);
      delete opts.headers;
    }
    const res = await fetch(`${BASE_URL}${url}`, {
      headers,
      ...opts,
    });
    if (!res.ok) {
      const body = await res.json().catch(() => ({ error: res.statusText }));
      return { data: null, error: body.error || body.message || `HTTP ${res.status}` };
    }
    const data = await res.json();
    return { data, error: null };
  } catch (err) {
    return { data: null, error: err instanceof Error ? err.message : "Unknown error" };
  }
}

export async function getTickets(params?: {
  queue_id?: string;
  status?: string;
  q?: string;
  owner_id?: string;
  team_id?: string;
  custom_fields?: Record<string, string>;
  subject?: string;
  created?: string;
  updated?: string;
}): Promise<{ data: Ticket[] | null; error: string | null }> {
  const sp = new URLSearchParams();
  if (params?.queue_id) sp.set("queue_id", params.queue_id);
  if (params?.status) sp.set("status", params.status);
  if (params?.q) sp.set("q", params.q);
  if (params?.owner_id) sp.set("owner_id", params.owner_id);
  if (params?.team_id) sp.set("team_id", params.team_id);
  if (params?.subject) sp.set("subject", params.subject);
  if (params?.created) sp.set("created", params.created);
  if (params?.updated) sp.set("updated", params.updated);
  if (params?.custom_fields) {
    for (const [fieldId, value] of Object.entries(params.custom_fields)) {
      if (value) sp.set(`cf.${fieldId}`, value);
    }
  }
  const qs = sp.toString();
  return request<Ticket[]>(`/tickets${qs ? `?${qs}` : ""}`);
}

export async function getTicket(id: number): Promise<{ data: Ticket | null; error: string | null }> {
  return request<Ticket>(`/tickets/${id}`);
}

export async function createTicket(data: {
  subject: string;
  queue_id: string;
  description?: string;
  custom_fields?: Record<string, string>;
}): Promise<{ data: UpdateResult | null; error: string | null }> {
  return request<UpdateResult>("/tickets", { method: "POST", body: JSON.stringify(data) });
}

export async function updateTicket(id: number, data: { subject?: string; status?: string; owner_id?: string | null; team_id?: string | null }): Promise<{ data: UpdateResult | null; error: string | null }> {
  return request<UpdateResult>(`/tickets/${id}`, { method: "PATCH", body: JSON.stringify(data) });
}

export async function previewTicket(id: number, data: { status?: string }): Promise<{ data: PreviewResult | null; error: string | null }> {
  return request<PreviewResult>(`/tickets/${id}/preview`, { method: "POST", body: JSON.stringify(data) });
}

export async function getTicketTransactions(id: number): Promise<{ data: Transaction[] | null; error: string | null }> {
  return request<Transaction[]>(`/tickets/${id}/transactions`);
}

export async function sendComment(id: number, data: { body: string; internal?: boolean; attachment_ids?: string[]; time_worked_minutes?: number }): Promise<{ data: Transaction | null; error: string | null }> {
  return request<Transaction>(`/tickets/${id}/comment`, { method: "POST", body: JSON.stringify(data) });
}

export async function batchUpdateTickets(data: {
  ticket_ids: number[];
  status?: string;
  owner_id?: string | null;
  team_id?: string | null;
}): Promise<{ data: { results: Array<{ id: number; ok: boolean; error?: string }> } | null; error: string | null }> {
  return request<{ results: Array<{ id: number; ok: boolean; error?: string }> }>("/tickets/batch", { method: "POST", body: JSON.stringify(data) });
}

export async function mergeTickets(sourceId: number, targetTicketId: number): Promise<{ data: { ok: boolean; target_id: number } | null; error: string | null }> {
  return request<{ ok: boolean; target_id: number }>(`/tickets/${sourceId}/merge`, { method: "POST", body: JSON.stringify({ target_ticket_id: targetTicketId }) });
}

// Notifications

export interface Notification {
  id: string;
  user_id: string;
  ticket_id: number | null;
  type: string;
  title: string;
  body: string | null;
  read: boolean;
  created_at: string;
}

export async function getNotifications(): Promise<{ data: Notification[] | null; error: string | null }> {
  return request<Notification[]>("/notifications");
}

export async function getUnreadCount(): Promise<{ data: { count: number } | null; error: string | null }> {
  return request<{ count: number }>("/notifications/unread-count");
}

export async function markNotificationRead(id: string): Promise<{ data: { ok: boolean } | null; error: string | null }> {
  return request<{ ok: boolean }>(`/notifications/${id}/read`, { method: "PATCH" });
}

export async function markAllNotificationsRead(): Promise<{ data: { ok: boolean } | null; error: string | null }> {
  return request<{ ok: boolean }>("/notifications/read-all", { method: "PATCH" });
}

// API Tokens

export interface ApiToken {
  id: string;
  name: string;
  last_used_at: string | null;
  created_at: string;
}

export interface ApiTokenCreated {
  id: string;
  name: string;
  token: string;
  created_at: string;
}

export async function getApiTokens(): Promise<{ data: ApiToken[] | null; error: string | null }> {
  return request<ApiToken[]>("/auth/tokens");
}

export async function createApiToken(name: string): Promise<{ data: ApiTokenCreated | null; error: string | null }> {
  return request<ApiTokenCreated>("/auth/tokens", { method: "POST", body: JSON.stringify({ name }) });
}

export async function revokeApiToken(id: string): Promise<{ data: { ok: boolean } | null; error: string | null }> {
  return request<{ ok: boolean }>(`/auth/tokens/${id}`, { method: "DELETE" });
}

// Watchers

export async function getWatchers(ticketId: number): Promise<{ data: Watcher[] | null; error: string | null }> {
  return request<Watcher[]>(`/tickets/${ticketId}/watchers`);
}

export async function addWatcher(ticketId: number, userId?: string): Promise<{ data: Watcher | null; error: string | null }> {
  return request<Watcher>(`/tickets/${ticketId}/watchers`, { method: "POST", body: JSON.stringify(userId ? { user_id: userId } : {}) });
}

export async function removeWatcher(ticketId: number, userId: string): Promise<{ data: { ok: boolean } | null; error: string | null }> {
  return request<{ ok: boolean }>(`/tickets/${ticketId}/watchers/${userId}`, { method: "DELETE" });
}

// SLA Policies

export async function getSlaPolicies(): Promise<{ data: SlaPolicy[] | null; error: string | null }> {
  return request<SlaPolicy[]>("/sla-policies");
}

export async function createSlaPolicy(data: {
  name: string;
  queue_id?: string;
  description?: string;
  response_time_minutes?: number;
  resolution_time_minutes?: number;
  disabled?: boolean;
}): Promise<{ data: SlaPolicy | null; error: string | null }> {
  return request<SlaPolicy>("/sla-policies", { method: "POST", body: JSON.stringify(data) });
}

export async function updateSlaPolicy(id: string, data: {
  name?: string;
  queue_id?: string | null;
  description?: string;
  response_time_minutes?: number | null;
  resolution_time_minutes?: number | null;
  disabled?: boolean;
}): Promise<{ data: SlaPolicy | null; error: string | null }> {
  return request<SlaPolicy>(`/sla-policies/${id}`, { method: "PATCH", body: JSON.stringify(data) });
}

export async function deleteSlaPolicy(id: string): Promise<{ data: { ok: boolean } | null; error: string | null }> {
  return request<{ ok: boolean }>(`/sla-policies/${id}`, { method: "DELETE" });
}

export async function getQueues(): Promise<{ data: Queue[] | null; error: string | null }> {
  return request<Queue[]>("/queues");
}

export async function getUsers(): Promise<{ data: User[] | null; error: string | null }> {
  return request<User[]>("/users");
}

export async function createUser(data: {
  username: string;
  email?: string | null;
  role?: string;
  password?: string | null;
}): Promise<{ data: User | null; error: string | null }> {
  return request<User>("/users", { method: "POST", body: JSON.stringify(data) });
}

export async function updateUser(id: string, data: {
  username?: string;
  email?: string | null;
  role?: string;
  password?: string | null;
}): Promise<{ data: User | null; error: string | null }> {
  return request<User>(`/users/${id}`, { method: "PATCH", body: JSON.stringify(data) });
}

export async function deleteUser(id: string): Promise<{ data: { ok: boolean } | null; error: string | null }> {
  return request<{ ok: boolean }>(`/users/${id}`, { method: "DELETE" });
}

export async function createQueue(data: { name: string; description?: string | null; lifecycle_id?: string | null; team_id?: string | null }): Promise<{ data: Queue | null; error: string | null }> {
  return request<Queue>("/queues", { method: "POST", body: JSON.stringify(data) });
}

export async function updateQueue(id: string, data: { name?: string; description?: string | null; lifecycle_id?: string | null; team_id?: string | null }): Promise<{ data: Queue | null; error: string | null }> {
  return request<Queue>(`/queues/${id}`, { method: "PATCH", body: JSON.stringify(data) });
}

export async function getScrips(): Promise<{ data: Scrip[] | null; error: string | null }> {
  return request<Scrip[]>("/scrips");
}

export async function createScrip(data: {
  name: string;
  description?: string | null;
  queue_id?: string | null;
  condition_type: string;
  condition_config?: Record<string, unknown>;
  action_type: string;
  action_config?: Record<string, unknown>;
  template_id?: string | null;
  stage?: string;
  sort_order?: number;
  disabled?: boolean;
}): Promise<{ data: Scrip | null; error: string | null }> {
  return request<Scrip>("/scrips", { method: "POST", body: JSON.stringify(data) });
}

export async function updateScrip(id: string, data: {
  name?: string;
  description?: string | null;
  queue_id?: string | null;
  condition_type?: string;
  condition_config?: Record<string, unknown>;
  action_type?: string;
  action_config?: Record<string, unknown>;
  template_id?: string | null;
  stage?: string;
  sort_order?: number;
  disabled?: boolean;
}): Promise<{ data: Scrip | null; error: string | null }> {
  return request<Scrip>(`/scrips/${id}`, { method: "PATCH", body: JSON.stringify(data) });
}

export async function getTemplates(): Promise<{ data: Template[] | null; error: string | null }> {
  return request<Template[]>("/templates");
}

export async function createTemplate(data: {
  name: string;
  queue_id?: string | null;
  subject_template: string;
  body_template: string;
}): Promise<{ data: Template | null; error: string | null }> {
  return request<Template>("/templates", { method: "POST", body: JSON.stringify(data) });
}

export async function updateTemplate(id: string, data: {
  name?: string;
  queue_id?: string | null;
  subject_template?: string;
  body_template?: string;
}): Promise<{ data: Template | null; error: string | null }> {
  return request<Template>(`/templates/${id}`, { method: "PATCH", body: JSON.stringify(data) });
}

export async function previewTemplate(data: {
  subject_template: string;
  body_template: string;
  ticket_id?: number | null;
}): Promise<{ data: TemplatePreview | null; error: string | null }> {
  return request<TemplatePreview>("/templates/preview", { method: "POST", body: JSON.stringify(data) });
}

export async function deleteTemplate(id: string): Promise<{ data: { ok: boolean } | null; error: string | null }> {
  return request<{ ok: boolean }>(`/templates/${id}`, { method: "DELETE" });
}

export async function getLifecycles(): Promise<{ data: Lifecycle[] | null; error: string | null }> {
  return request<Lifecycle[]>("/lifecycles");
}

export async function createLifecycle(data: {
  name: string;
  definition: Record<string, unknown> | LifecycleDefinition;
}): Promise<{ data: Lifecycle | null; error: string | null }> {
  return request<Lifecycle>("/lifecycles", { method: "POST", body: JSON.stringify(data) });
}

export async function updateLifecycle(id: string, data: {
  name?: string;
  definition?: Record<string, unknown> | LifecycleDefinition;
}): Promise<{ data: Lifecycle | null; error: string | null }> {
  return request<Lifecycle>(`/lifecycles/${id}`, { method: "PATCH", body: JSON.stringify(data) });
}

export async function getCustomFields(): Promise<{ data: CustomField[] | null; error: string | null }> {
  return request<CustomField[]>("/custom-fields");
}

export async function getQueueCustomFields(queueId: string): Promise<{ data: QueueCustomField[] | null; error: string | null }> {
  return request<QueueCustomField[]>(`/custom-fields/queues/${queueId}`);
}

export async function assignQueueCustomField(queueId: string, customFieldId: string): Promise<{ data: QueueCustomField | null; error: string | null }> {
  return request<QueueCustomField>(`/custom-fields/queues/${queueId}`, {
    method: "POST",
    body: JSON.stringify({ custom_field_id: customFieldId }),
  });
}

export async function unassignQueueCustomField(queueId: string, customFieldId: string): Promise<{ data: { ok: boolean } | null; error: string | null }> {
  return request<{ ok: boolean }>(`/custom-fields/queues/${queueId}/${customFieldId}`, { method: "DELETE" });
}

export async function updateTicketCustomField(ticketId: number, customFieldId: string, value: string): Promise<{ data: Transaction | null; error: string | null }> {
  return request<Transaction>(`/tickets/${ticketId}/custom-fields/${customFieldId}`, {
    method: "PATCH",
    body: JSON.stringify({ value }),
  });
}

export async function createCustomField(data: {
  key?: string;
  name: string;
  field_type: string;
  values?: unknown | null;
  max_values?: number;
  pattern?: string | null;
  validation_config?: Record<string, unknown> | null;
  default_value?: string | null;
}): Promise<{ data: CustomField | null; error: string | null }> {
  return request<CustomField>("/custom-fields", { method: "POST", body: JSON.stringify(data) });
}

export async function updateCustomField(id: string, data: {
  key?: string;
  name?: string;
  field_type?: string;
  values?: unknown | null;
  max_values?: number;
  pattern?: string | null;
  validation_config?: Record<string, unknown> | null;
  default_value?: string | null;
}): Promise<{ data: CustomField | null; error: string | null }> {
  return request<CustomField>(`/custom-fields/${id}`, { method: "PATCH", body: JSON.stringify(data) });
}

export async function getViews(): Promise<{ data: SavedView[] | null; error: string | null }> {
  return request<SavedView[]>("/views");
}

export async function createView(data: {
  name: string;
  filters: { field: string; operator: string; value: string }[];
  sort_key?: string;
  columns?: { key: string; label: string; width: number; display: string }[];
  is_public?: boolean;
}): Promise<{ data: SavedView | null; error: string | null }> {
  return request<SavedView>("/views", { method: "POST", body: JSON.stringify(data) });
}

export async function updateView(id: string, data: {
  name?: string;
  filters?: { field: string; operator: string; value: string }[];
  sort_key?: string;
  columns?: unknown[];
  is_public?: boolean;
}): Promise<{ data: SavedView | null; error: string | null }> {
  return request<SavedView>(`/views/${id}`, { method: "PATCH", body: JSON.stringify(data) });
}

export async function deleteView(id: string): Promise<{ data: { ok: boolean } | null; error: string | null }> {
  return request<{ ok: boolean }>(`/views/${id}`, { method: "DELETE" });
}

export async function getDashboards(): Promise<{ data: Dashboard[] | null; error: string | null }> {
  return request<Dashboard[]>("/dashboards");
}

export async function getDashboard(id: string): Promise<{ data: Dashboard | null; error: string | null }> {
  return request<Dashboard>(`/dashboards/${id}`);
}

export async function createDashboard(data: {
  name: string;
  description?: string;
  team_id?: string | null;
  is_default?: boolean;
}): Promise<{ data: Dashboard | null; error: string | null }> {
  return request<Dashboard>("/dashboards", { method: "POST", body: JSON.stringify(data) });
}

export async function updateDashboard(id: string, data: {
  name?: string;
  description?: string | null;
  team_id?: string | null;
  is_default?: boolean;
  layout?: unknown[];
}): Promise<{ data: Dashboard | null; error: string | null }> {
  return request<Dashboard>(`/dashboards/${id}`, { method: "PATCH", body: JSON.stringify(data) });
}

export async function deleteDashboard(id: string): Promise<{ data: { ok: boolean } | null; error: string | null }> {
  return request<{ ok: boolean }>(`/dashboards/${id}`, { method: "DELETE" });
}

export async function getDashboardWidgets(dashboardId: string): Promise<{ data: DashboardWidget[] | null; error: string | null }> {
  return request<DashboardWidget[]>(`/dashboards/${dashboardId}/widgets`);
}

export async function createWidget(dashboardId: string, data: {
  view_id: string;
  title: string;
  widget_type: string;
  position?: { x: number; y: number; w: number; h: number };
  config?: Record<string, unknown>;
}): Promise<{ data: DashboardWidget | null; error: string | null }> {
  return request<DashboardWidget>(`/dashboards/${dashboardId}/widgets`, { method: "POST", body: JSON.stringify(data) });
}

export async function updateWidget(dashboardId: string, widgetId: string, data: {
  title?: string;
  widget_type?: string;
  position?: { x: number; y: number; w: number; h: number };
  config?: Record<string, unknown>;
}): Promise<{ data: DashboardWidget | null; error: string | null }> {
  return request<DashboardWidget>(`/dashboards/${dashboardId}/widgets/${widgetId}`, { method: "PATCH", body: JSON.stringify(data) });
}

export async function deleteWidget(dashboardId: string, widgetId: string): Promise<{ data: { ok: boolean } | null; error: string | null }> {
  return request<{ ok: boolean }>(`/dashboards/${dashboardId}/widgets/${widgetId}`, { method: "DELETE" });
}

export async function getWidgetData(dashboardId: string, widgetId: string): Promise<{ data: WidgetData | null; error: string | null }> {
  return request<WidgetData>(`/dashboards/${dashboardId}/widgets/${widgetId}/data`);
}

export async function getTeams(): Promise<{ data: Team[] | null; error: string | null }> {
  return request<Team[]>("/teams");
}

export async function createTeam(data: { name: string; description?: string | null }): Promise<{ data: Team | null; error: string | null }> {
  return request<Team>("/teams", { method: "POST", body: JSON.stringify(data) });
}

export async function updateTeam(id: string, data: { name?: string; description?: string | null }): Promise<{ data: Team | null; error: string | null }> {
  return request<Team>(`/teams/${id}`, { method: "PATCH", body: JSON.stringify(data) });
}

export async function deleteTeam(id: string): Promise<{ data: { ok: boolean } | null; error: string | null }> {
  return request<{ ok: boolean }>(`/teams/${id}`, { method: "DELETE" });
}

export async function addTeamMember(teamId: string, userId: string): Promise<{ data: unknown | null; error: string | null }> {
  return request<unknown>(`/teams/${teamId}/members`, { method: "POST", body: JSON.stringify({ user_id: userId }) });
}

export async function removeTeamMember(teamId: string, userId: string): Promise<{ data: { ok: boolean } | null; error: string | null }> {
  return request<{ ok: boolean }>(`/teams/${teamId}/members/${userId}`, { method: "DELETE" });
}

export async function uploadAttachments(
  ticketId: number,
  files: File[],
): Promise<{ data: { attachments: AttachmentUploadResult[] } | null; error: string | null }> {
  try {
    const formData = new FormData();
    for (const file of files) {
      formData.append("files", file);
    }

    const token = typeof window !== "undefined" ? localStorage.getItem("tessera_token") : null;
    const headers: Record<string, string> = {};
    if (token) headers["Authorization"] = `Bearer ${token}`;

    const res = await fetch(`/api/tickets/${ticketId}/attachments`, {
      method: "POST",
      headers,
      body: formData,
    });

    if (!res.ok) {
      const body = await res.json().catch(() => ({ error: res.statusText }));
      return { data: null, error: body.error || body.message || `HTTP ${res.status}` };
    }

    const data = await res.json();
    return { data, error: null };
  } catch (err) {
    return { data: null, error: err instanceof Error ? err.message : "Unknown error" };
  }
}

export function getAttachmentUrl(attachmentId: string): string {
  return `/api/attachments/${attachmentId}`;
}

export async function getTicketAttachments(
  ticketId: number,
): Promise<{ data: Attachment[] | null; error: string | null }> {
  return request<Attachment[]>(`/tickets/${ticketId}/attachments`);
}

export async function getTicketLinks(
  ticketId: number,
): Promise<{ data: TicketLink[] | null; error: string | null }> {
  return request<TicketLink[]>(`/tickets/${ticketId}/links`);
}

export async function createTicketLink(
  ticketId: number,
  data: { target_ticket_id: number; link_type: string },
): Promise<{ data: TicketLink | null; error: string | null }> {
  return request<TicketLink>(`/tickets/${ticketId}/links`, { method: "POST", body: JSON.stringify(data) });
}

export async function deleteTicketLink(
  ticketId: number,
  linkId: string,
): Promise<{ data: { ok: boolean } | null; error: string | null }> {
  return request<{ ok: boolean }>(`/tickets/${ticketId}/links/${linkId}`, { method: "DELETE" });
}

// Queue Permissions (admin)

export interface QueuePermission {
  id: string;
  queue_id: string;
  team_id: string;
  right_name: string;
  team_name?: string;
  queue_name?: string;
}

export async function getQueuePermissions(): Promise<{ data: QueuePermission[] | null; error: string | null }> {
  return request<QueuePermission[]>("/queue-permissions");
}

export async function getTeamsAndQueues(): Promise<{ data: { teams: Team[]; queues: Queue[] } | null; error: string | null }> {
  return request<{ teams: Team[]; queues: Queue[] }>("/queue-permissions/teams-and-queues");
}

export async function grantQueuePermission(
  queue_id: string,
  team_id: string,
  right_name: string,
): Promise<{ data: QueuePermission | null; error: string | null }> {
  return request<QueuePermission>("/queue-permissions", {
    method: "POST",
    body: JSON.stringify({ queue_id, team_id, right_name }),
  });
}

export async function revokeQueuePermission(id: string): Promise<{ data: { ok: boolean } | null; error: string | null }> {
  return request<{ ok: boolean }>(`/queue-permissions/${id}`, { method: "DELETE" });
}

// User Permissions (admin)

export interface UserPermission {
  id: string;
  queue_id: string;
  user_id: string;
  right_name: string;
  username?: string;
  queue_name?: string;
}

export async function getUserPermissions(): Promise<{ data: UserPermission[] | null; error: string | null }> {
  return request<UserPermission[]>("/user-permissions");
}

export async function grantUserPermission(
  queue_id: string,
  user_id: string,
  right_name: string,
): Promise<{ data: UserPermission | null; error: string | null }> {
  return request<UserPermission>("/user-permissions", {
    method: "POST",
    body: JSON.stringify({ queue_id, user_id, right_name }),
  });
}

export async function revokeUserPermission(id: string): Promise<{ data: { ok: boolean } | null; error: string | null }> {
  return request<{ ok: boolean }>(`/user-permissions/${id}`, { method: "DELETE" });
}

// Auth

function getStoredToken(): string | null {
  if (typeof window === "undefined") return null;
  return localStorage.getItem("tessera_token");
}

export function setStoredToken(token: string | null) {
  if (typeof window === "undefined") return;
  if (token) {
    localStorage.setItem("tessera_token", token);
  } else {
    localStorage.removeItem("tessera_token");
  }
}

export async function login(
  username: string,
  password: string,
): Promise<{ data: LoginResult | null; error: string | null }> {
  const result = await request<LoginResult>("/auth/login", {
    method: "POST",
    body: JSON.stringify({ username, password }),
  });
  if (result.data?.token) {
    setStoredToken(result.data.token);
  }
  return result;
}

export function logout() {
  setStoredToken(null);
}

export async function getMe(): Promise<{ data: User | null; error: string | null }> {
  const token = getStoredToken();
  if (!token) return { data: null, error: "Not authenticated" };

  try {
    const res = await fetch(`/api/auth/me`, {
      headers: { Authorization: `Bearer ${token}` },
    });
    if (!res.ok) {
      setStoredToken(null);
      return { data: null, error: "Session expired" };
    }
    const data = await res.json();
    return { data, error: null };
  } catch (err) {
    return { data: null, error: err instanceof Error ? err.message : "Unknown error" };
  }
}

/**
 * Fetch wrapper that includes the auth token.
 */
async function authRequest<T>(url: string, options?: RequestInit): Promise<{ data: T | null; error: string | null }> {
  const token = getStoredToken();
  const headers: Record<string, string> = { "Content-Type": "application/json" };
  if (token) {
    headers["Authorization"] = `Bearer ${token}`;
  }
  try {
    const res = await fetch(`/api${url}`, { ...options, headers: { ...headers, ...(options?.headers as Record<string, string> ?? {}) } });
    if (!res.ok) {
      if (res.status === 401 || res.status === 403) {
        setStoredToken(null);
      }
      const body = await res.json().catch(() => ({ error: res.statusText }));
      return { data: null, error: body.error || body.message || `HTTP ${res.status}` };
    }
    const data = await res.json();
    return { data, error: null };
  } catch (err) {
    return { data: null, error: err instanceof Error ? err.message : "Unknown error" };
  }
}