import { createContext, useContext, useEffect, useMemo, useState, type ReactNode } from "react";
import { api, setPreviewToken, type Me } from "../../api";
import { yandexRedirectUri } from "../../auth/yandexRedirect";

type AuthState = {
  user: Me | null;
  loading: boolean;
  error: string | null;
  refresh: () => Promise<void>;
  logout: () => Promise<void>;
};

const AuthContext = createContext<AuthState | null>(null);

export function AuthProvider({ children }: { children: ReactNode }) {
  const [user, setUser] = useState<Me | null>(null);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);

  const refresh = async () => {
    try {
      setUser(await api.me());
      setError(null);
    } catch {
      setUser(null);
    }
  };

  useEffect(() => {
    const params = new URLSearchParams(window.location.search);
    const code = params.get("code");
    const state = params.get("state");

    const boot = async () => {
      try {
        if (code) {
          const redirectUri =
            sessionStorage.getItem("ts.oauthRedirect") ?? yandexRedirectUri("https://tile-server.ru");
          const auth = await api.loginYandex(code, redirectUri, state);
          sessionStorage.removeItem("ts.oauthState");
          sessionStorage.removeItem("ts.oauthRedirect");
          setUser(auth.user);
          if (auth.cabinetToken) {
            setPreviewToken(auth.cabinetToken);
          }
          window.history.replaceState({}, "", "/");
        } else {
          await refresh();
        }
      } catch (err) {
        setError(err instanceof Error ? err.message : "Ошибка входа");
        setUser(null);
      } finally {
        setLoading(false);
      }
    };

    void boot();
  }, []);

  const logout = async () => {
    await api.logout();
    setUser(null);
  };

  const value = useMemo(
    () => ({ user, loading, error, refresh, logout }),
    [user, loading, error]
  );

  return <AuthContext.Provider value={value}>{children}</AuthContext.Provider>;
}

export function useAuth(): AuthState {
  const ctx = useContext(AuthContext);
  if (!ctx) {
    throw new Error("AuthProvider is required");
  }
  return ctx;
}