platform-hooks.js

const React = require('react');

const store = {
  users: [
    {
      id: 'seed-shop-owner',
      username: 'owner',
      password: 'owner123',
      role: 'shop_owner',
      created_at: new Date().toISOString()
    },
    {
      id: 'seed-customer',
      username: 'customer',
      password: 'customer123',
      role: 'customer',
      created_at: new Date().toISOString()
    }
  ],
  customers: [],
  transactions: []
};

const subscribers = new Set();

function notifySubscribers() {
  subscribers.forEach((callback) => callback());
}

function matchesFilter(doc, filter) {
  const entries = Object.entries(filter || {});
  if (entries.length === 0) return true;
  return entries.every(([key, value]) => doc[key] === value);
}

function getCollectionData(collection, filter) {
  const rows = Array.isArray(store[collection]) ? store[collection] : [];
  return rows.filter((row) => matchesFilter(row, filter));
}

function useQuery(collection, filter) {
  const [, forceRender] = React.useState(0);

  React.useEffect(() => {
    const onStoreChange = () => forceRender((prev) => prev + 1);
    subscribers.add(onStoreChange);
    return () => {
      subscribers.delete(onStoreChange);
    };
  }, []);

  const data = React.useMemo(() => {
    return getCollectionData(collection, filter || {});
  }, [collection, JSON.stringify(filter || {}), store[collection]?.length]);

  const refetch = React.useCallback(() => {
    forceRender((prev) => prev + 1);
  }, []);

  return {
    data,
    loading: false,
    error: null,
    refetch
  };
}

function useMutation(collection, operation) {
  const mutate = React.useCallback(
    async (payload) => {
      if (!store[collection]) {
        store[collection] = [];
      }

      if (operation === 'insert') {
        store[collection].push(payload);
        notifySubscribers();
        return payload;
      }

      if (operation === 'update') {
        if (!payload || !payload.id) {
          throw new Error('Update requires payload.id');
        }
        const index = store[collection].findIndex((row) => row.id === payload.id);
        if (index === -1) {
          throw new Error('Record not found');
        }
        store[collection][index] = { ...store[collection][index], ...payload };
        notifySubscribers();
        return store[collection][index];
      }

      if (operation === 'delete') {
        if (!payload || !payload.id) {
          throw new Error('Delete requires payload.id');
        }
        store[collection] = store[collection].filter((row) => row.id !== payload.id);
        notifySubscribers();
        return { id: payload.id };
      }

      throw new Error(`Unsupported mutation operation: ${operation}`);
    },
    [collection, operation]
  );

  return { mutate };
}

module.exports = {
  useQuery,
  useMutation
};