import {
  createContext,
  useContext,
  useMemo,
  useSyncExternalStore,
  type ReactNode,
} from "react";

import type {
  ApplicationApi,
  SessionState,
} from "../../application/ports/in/application-api.ts";
import { useApplicationSession } from "./application-provider.tsx";

export type SessionContextValue = Readonly<{
  sessionState: SessionState;
  beginSignIn: ApplicationApi["session"]["beginSignIn"];
  signOut: ApplicationApi["session"]["signOut"];
  recover: ApplicationApi["session"]["recover"];
}>;

const SessionContext = createContext<SessionContextValue | null>(null);

export function SessionProvider({
  children,
}: Readonly<{ children: ReactNode }>) {
  const session = useApplicationSession();
  const sessionState = useSyncExternalStore(
    session.subscribe,
    session.getSnapshot,
    session.getSnapshot,
  );
  const value = useMemo<SessionContextValue>(
    () =>
      Object.freeze({
        sessionState,
        beginSignIn: session.beginSignIn,
        signOut: session.signOut,
        recover: session.recover,
      }),
    [session, sessionState],
  );

  return (
    <SessionContext.Provider value={value}>{children}</SessionContext.Provider>
  );
}

export function useSession(): SessionContextValue {
  const session = useContext(SessionContext);
  if (!session) {
    throw new Error("SessionProvider is required");
  }
  return session;
}