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

const GroupOrderContext = createContext(null);

export function GroupOrderProvider({ children }) {
  const [groups, setGroups] = useState(() => {
    const saved = localStorage.getItem('groupOrders');
    return saved ? JSON.parse(saved) : [];
  });

  function createGroup(creatorPhone) {
    const group = {
      id: crypto.randomUUID(),
      creatorPhone,
      orders: [],
      status: 'OPEN',
      createdAt: new Date().toISOString(),
    };
    const updated = [...groups, group];
    setGroups(updated);
    localStorage.setItem('groupOrders', JSON.stringify(updated));
    return group;
  }

  function addOrderToGroup(groupId, phoneNumber, bookId, bookTitle, quantity) {
    const updated = groups.map(g => {
      if (g.id !== groupId) return g;
      const order = {
        orderId: crypto.randomUUID(),
        phoneNumber,
        bookId,
        bookTitle,
        quantity: Number(quantity),
        addedAt: new Date().toISOString(),
      };
      return { ...g, orders: [...g.orders, order] };
    });
    setGroups(updated);
    localStorage.setItem('groupOrders', JSON.stringify(updated));
  }

  function closeGroup(groupId) {
    const updated = groups.map(g =>
      g.id === groupId ? { ...g, status: 'CLOSED' } : g
    );
    setGroups(updated);
    localStorage.setItem('groupOrders', JSON.stringify(updated));
  }

  return (
    <GroupOrderContext.Provider value={{ groups, createGroup, addOrderToGroup, closeGroup }}>
      {children}
    </GroupOrderContext.Provider>
  );
}

export function useGroupOrders() {
  return useContext(GroupOrderContext);
}