import React, { createContext, useContext, useState, useMemo, useEffect } from "react";
import PropTypes from "prop-types";
import { apiFetch } from "../lib/api";

const AuthContext = createContext();

const AuthProvider = ({ children }) => {
  const [user, setUser] = useState(null);
  const [loading, setLoading] = useState(true);

  const refresh = async () => {
    try {
      const data = await apiFetch("/auth/me");
      setUser(data);
    } catch {
      setUser(null);
    }
  };

  useEffect(() => {
    refresh().finally(() => setLoading(false));
  }, []);

  useEffect(() => {
    const onExpired = () => setUser(null);
    window.addEventListener("auth:expired", onExpired);
    return () => window.removeEventListener("auth:expired", onExpired);
  }, []);

  const logout = async () => {
    try {
      await apiFetch("/auth/logout", { method: "POST" });
    } catch {
      // ignore
    }
    setUser(null);
  };

  const editUser = async (updatedFields) => {
    const data = await apiFetch(`/users/${user.id}`, {
      method: "PUT",
      body: JSON.stringify(updatedFields),
    });
    setUser((prev) => ({ ...prev, ...data.user }));
    return "User updated successfully";
  };

  const authContextValue = useMemo(
    () => ({
      user,
      loading,
      logout,
      refresh,
      editUser,
      setUser: (newUser) => setUser(newUser),
    }),
    [user, loading]
  );

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

AuthProvider.propTypes = {
  children: PropTypes.node.isRequired,
};

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

export { AuthProvider, useAuth };