import { createContext, useContext, useState, useEffect, useCallback, type ReactNode } from "react";

export interface AuthUser {
  id: number;
  email: string;
  displayName?: string | null;
  isAdmin: boolean;
}

interface AuthContextValue {
  user: AuthUser | null;
  isLoaded: boolean;
  isSignedIn: boolean;
  isAdmin: boolean;
  signIn: (email: string, password: string) => Promise<void>;
  signUp: (email: string, password: string, displayName?: string) => Promise<void>;
  signOut: () => Promise<void>;
  refetch: () => Promise<void>;
}

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

const BASE = import.meta.env.BASE_URL.replace(/\/$/, "");
const API_BASE = `${BASE}/api`;

export function AuthProvider({ children }: { children: ReactNode }) {
  const [user, setUser] = useState<AuthUser | null>(null);
  const [isLoaded, setIsLoaded] = useState(false);

  const fetchMe = useCallback(async () => {
    try {
      const res = await fetch(`${API_BASE}/auth/me`, { credentials: "include" });
      if (res.ok) {
        const data = await res.json();
        setUser(data);
      } else {
        setUser(null);
      }
    } catch {
      setUser(null);
    } finally {
      setIsLoaded(true);
    }
  }, []);

  useEffect(() => { fetchMe(); }, [fetchMe]);

  const signIn = async (email: string, password: string) => {
    const res = await fetch(`${API_BASE}/auth/login`, {
      method: "POST",
      credentials: "include",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({ email, password }),
    });
    const data = await res.json();
    if (!res.ok) throw new Error(data.error || "Login failed");
    setUser(data);
  };

  const signUp = async (email: string, password: string, displayName?: string) => {
    const res = await fetch(`${API_BASE}/auth/signup`, {
      method: "POST",
      credentials: "include",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({ email, password, displayName }),
    });
    const data = await res.json();
    if (!res.ok) throw new Error(data.error || "Registration failed");
    setUser(data);
  };

  const signOut = async () => {
    await fetch(`${API_BASE}/auth/logout`, { method: "POST", credentials: "include" });
    setUser(null);
  };

  return (
    <AuthContext.Provider value={{
      user,
      isLoaded,
      isSignedIn: !!user,
      isAdmin: !!user?.isAdmin,
      signIn,
      signUp,
      signOut,
      refetch: fetchMe,
    }}>
      {children}
    </AuthContext.Provider>
  );
}

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