document.addEventListener('DOMContentLoaded', function() {
    const categorySelect = document.getElementById('category_id');
    const headSelect = document.getElementById('head_id');
    
    categorySelect.addEventListener('change', function() {
        const categoryId = this.value;
        headSelect.innerHTML = '<option value="">Loading...</option>';
        
        fetch(`get_expense_heads.php?category_id=${categoryId}`)
            .then(response => {
                if (!response.ok) {
                    throw new Error('Network response was not ok');
                }
                return response.json();
            })
            .then(data => {
                headSelect.innerHTML = '<option value="">Select an expense head</option>';
                if (data.error) {
                    throw new Error(data.error);
                }
                if (data.length === 0) {
                    headSelect.innerHTML = '<option value="">No expense heads found</option>';
                } else {
                    data.forEach(head => {
                        const option = document.createElement('option');
                        option.value = head.id;
                        option.textContent = head.name;
                        headSelect.appendChild(option);
                    });
                }
            })
            .catch(error => {
                console.error('Error:', error);
                headSelect.innerHTML = `<option value="">Error: ${error.message}</option>`;
            });
    });

    const editLinks = document.querySelectorAll('.edit-expense');
    editLinks.forEach(link => {
        link.addEventListener('click', function(e) {
            e.preventDefault();
            const expenseId = this.getAttribute('href').split('=')[1];
            window.location.href = `edit_expense.php?id=${expenseId}`;
        });
    });

    const deleteLinks = document.querySelectorAll('.delete-confirm');
    deleteLinks.forEach(link => {
        link.addEventListener('click', function(e) {
            if (!confirm('Are you sure you want to delete this expense?')) {
                e.preventDefault();
            }
        });
    });
});