"use client";

import { create } from "zustand";
import { LoginForm, RegisterForm, UserData } from "@/types/auth";
import { API_URL } from "@/lib/auth";

// Cookie utilities
const getCookie = (name: string): string | null => {
  if (typeof document === "undefined") return null;

  const value = `; ${document.cookie}`;
  const parts = value.split(`; ${name}=`);
  if (parts.length === 2) {
    return parts.pop()?.split(";").shift() || null;
  }
  return null;
};

const setCookie = (
  name: string,
  value: string | null,
  days: number = 7
): void => {
  if (typeof document === "undefined") return;

  if (value === null) {
    document.cookie = `${name}=; expires=Thu, 01 Jan 1970 00:00:00 UTC; path=/; SameSite=Strict; Secure`;
  } else {
    const expires = new Date();
    expires.setTime(expires.getTime() + days * 24 * 60 * 60 * 1000);
    document.cookie = `${name}=${value}; expires=${expires.toUTCString()}; path=/; SameSite=Strict; Secure`;
  }
};

interface APIError extends Error {
  response?: any;
}

interface AuthState {
  token: string | null;
  isLoading: boolean;
  hydrated: boolean;
  user: UserData | null;
  error: string | null;

  login: (form: LoginForm) => Promise<void>;
  register: (form: RegisterForm) => Promise<void>;
  setToken: (token: string | null) => void;
  logout: () => void;
  initializeAuth: () => Promise<void>;
}

export const useAuthStore = create<AuthState>((set, get) => ({
  token: null,
  isLoading: true,
  hydrated: false,
  error: null,
  user: null,

  setToken: (newToken) => {
    set({ token: newToken });
    setCookie("authToken", newToken);
  },

  login: async (form: LoginForm) => {
    set({ isLoading: true, error: null });
    try {
      const response = await fetch(`${API_URL}/auth/login/`, {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify(form),
      });

      const data = await response.json();

      if (!response.ok) {
        throw new Error(data.message || "Login failed");
      }

      const token = data.token;
      setCookie("authToken", token);
      set({ token });

      // Automatically fetch user info after login
      const userRes = await fetch(`${API_URL}/me/profile/`, {
        headers: { Authorization: `Bearer ${token}` },
      });

      if (!userRes.ok) {
        throw new Error("Failed to fetch user info after login");
      }

      const userData: UserData = await userRes.json();
      set({ user: userData, isLoading: false });
    } catch (err: any) {
      console.error("Login error:", err);
      set({
        error: err?.message || "Login failed",
        isLoading: false,
      });
      throw err;
    }
  },

  register: async (form: RegisterForm) => {
    set({ isLoading: true, error: null });
    try {
      const response = await fetch(`${API_URL}/auth/register/`, {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify(form),
      });

      const data = await response.json();

      if (!response.ok) {
        const error: APIError = new Error(
          data?.detail || "Registration failed"
        );
        error.response = data;
        throw error;
      }

      setCookie("authToken", data.token);
      set({ token: data.token, isLoading: false });
    } catch (err: any) {
      set({
        error: err?.message || "Registration failed",
        isLoading: false,
      });
      throw err;
    }
  },

  logout: () => {
    set({ token: null, user: null });
    setCookie("authToken", null);
  },

  initializeAuth: async () => {
    const storedToken = getCookie("authToken");
    if (storedToken) {
      set({ token: storedToken });
    }
    set({ isLoading: false, hydrated: true });
  },
}));