import { createContext, useContext, useState, useEffect, ReactNode } from "react";
import { User, authApi } from "../api/client";

interface AuthContextType {
  user: User | null;
  token: string | null;
  isLoading: boolean;
  login: (email: string, password: string) => Promise<void>;
  register: (email: string, password: string, name?: string) => Promise<void>;
  logout: () => void;
}

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

export function AuthProvider({ children }: { children: ReactNode }) {
  const [user, setUser] = useState<User | null>(null);
  const [token, setToken] = useState<string | null>(() => localStorage.getItem("token"));
  const [isLoading, setIsLoading] = useState(true);

  useEffect(() => {
    if (token) {
      authApi
        .me()
        .then((res) => setUser(res.data))
        .catch(() => {
          localStorage.removeItem("token");
          setToken(null);
        })
        .finally(() => setIsLoading(false));
    } else {
      setIsLoading(false);
    }
  }, [token]);

  const login = async (email: string, password: string) => {
    const res = await authApi.login({ email, password });
    localStorage.setItem("token", res.data.token);
    setToken(res.data.token);
    setUser(res.data.user);
  };

  const register = async (email: string, password: string, name?: string) => {
    const res = await authApi.register({ email, password, name });
    localStorage.setItem("token", res.data.token);
    setToken(res.data.token);
    setUser(res.data.user);
  };

  const logout = () => {
    localStorage.removeItem("token");
    setToken(null);
    setUser(null);
  };

  return (
    <AuthContext.Provider value={{ user, token, isLoading, login, register, logout }}>
      {children}
    </AuthContext.Provider>
  );
}

export function useAuth() {
  const context = useContext(AuthContext);
  if (!context) {
    throw new Error("useAuth must be used within an AuthProvider");
  }
  return context;
}