import { createContext, useContext, useState } from 'react';

const ReviewContext = createContext(null);

export function ReviewProvider({ children }) {
  const [reviews, setReviews] = useState(() => {
    const saved = localStorage.getItem('reviews');
    return saved ? JSON.parse(saved) : [];
  });

  function addReview(bookId, bookTitle, username, rating, comment) {
    const review = {
      reviewId: crypto.randomUUID(),
      bookId,
      bookTitle,
      username,
      rating,
      comment,
      createdAt: new Date().toISOString(),
    };
    const updated = [...reviews, review];
    setReviews(updated);
    localStorage.setItem('reviews', JSON.stringify(updated));
    return review;
  }

  function getReviewsByBook(bookId) {
    return reviews.filter(r => String(r.bookId) === String(bookId));
  }

  return (
    <ReviewContext.Provider value={{ reviews, addReview, getReviewsByBook }}>
      {children}
    </ReviewContext.Provider>
  );
}

export function useReviews() {
  return useContext(ReviewContext);
}