"use client";

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

const API_URL = process.env.NEXT_PUBLIC_API_URL || "http://localhost:8000";

interface User {
  id: number;
  email: string;
}

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

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

export function AuthProvider({ children }: { children: ReactNode }) {
  const [user, setUser] = useState<User | null>(null);
  const [isLoading, setIsLoading] = useState(true);

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

  const checkAuth = async () => {
    try {
      const res = await fetch(`${API_URL}/api/auth/me`, {
        credentials: "include",
      });
      if (res.ok) {
        const userData = await res.json();
        setUser(userData);
      }
    } catch {
      // Not authenticated
    } finally {
      setIsLoading(false);
    }
  };

  const login = async (email: string, password: string) => {
    const res = await fetch(`${API_URL}/api/auth/login`, {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      credentials: "include",
      body: JSON.stringify({ email, password }),
    });

    if (!res.ok) {
      const error = await res.json();
      throw new Error(error.detail || "Login failed");
    }

    const userData = await res.json();
    setUser(userData);
  };

  const register = async (email: string, password: string) => {
    const res = await fetch(`${API_URL}/api/auth/register`, {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      credentials: "include",
      body: JSON.stringify({ email, password }),
    });

    if (!res.ok) {
      const error = await res.json();
      throw new Error(error.detail || "Registration failed");
    }

    const userData = await res.json();
    setUser(userData);
  };

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

  return (
    <AuthContext.Provider value={{ user, 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;
}