"use client";

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

export type WishlistItem = {
  productId: string;
  name: string;
  slug: string;
  image: string;
  basePrice: number;
  minOrderQty: number;
};

type WishlistContextValue = {
  items: WishlistItem[];
  toggle: (item: WishlistItem) => void;
  isWishlisted: (productId: string) => boolean;
  remove: (productId: string) => void;
  count: number;
};

const WishlistContext = createContext<WishlistContextValue | null>(null);
const STORAGE_KEY = "ivr_wishlist";

export function WishlistProvider({ children }: { children: React.ReactNode }) {
  const [items, setItems] = useState<WishlistItem[]>([]);
  const [hydrated, setHydrated] = useState(false);

  useEffect(() => {
    try {
      const raw = localStorage.getItem(STORAGE_KEY);
      if (raw) setItems(JSON.parse(raw));
    } catch {
      // ignore corrupt storage
    }
    setHydrated(true);
  }, []);

  useEffect(() => {
    if (!hydrated) return;
    localStorage.setItem(STORAGE_KEY, JSON.stringify(items));
  }, [items, hydrated]);

  const toggle = useCallback((item: WishlistItem) => {
    setItems((prev) => {
      const exists = prev.some((i) => i.productId === item.productId);
      if (exists) return prev.filter((i) => i.productId !== item.productId);
      return [...prev, item];
    });
  }, []);

  const remove = useCallback((productId: string) => {
    setItems((prev) => prev.filter((i) => i.productId !== productId));
  }, []);

  const isWishlisted = useCallback((productId: string) => items.some((i) => i.productId === productId), [items]);

  const count = useMemo(() => items.length, [items]);

  return (
    <WishlistContext.Provider value={{ items, toggle, isWishlisted, remove, count }}>
      {children}
    </WishlistContext.Provider>
  );
}

export function useWishlist() {
  const ctx = useContext(WishlistContext);
  if (!ctx) throw new Error("useWishlist must be used within WishlistProvider");
  return ctx;
}