document.addEventListener('DOMContentLoaded', function () {

    // --- Snowflakes Effect ---
    function createSnowflakes() {
        const snowflakeContainer = document.body;
        for (let i = 0; i < 50; i++) {
            const snowflake = document.createElement('div');
            snowflake.className = 'snowflake';
            snowflake.textContent = '❄';
            snowflake.style.left = Math.random() * 100 + 'vw';
            snowflake.style.animationDuration = (Math.random() * 3 + 2) + 's'; // 2-5 seconds
            snowflake.style.animationDelay = Math.random() * 2 + 's';
            snowflake.style.opacity = Math.random();
            snowflake.style.fontSize = Math.random() * 10 + 10 + 'px';
            snowflakeContainer.appendChild(snowflake);
        }
    }

    createSnowflakes();

    // --- Calculator Logic ---
    const ingredientsContainer = document.getElementById('ingredients-container');
    const addIngredientBtn = document.getElementById('add-ingredient');
    const calculateBtn = document.getElementById('calculate-btn');
    const shoppingListContainer = document.getElementById('shopping-list-container');

    let ingredientIndex = 1;

    function addIngredientRow() {
        ingredientIndex++;
        const row = document.createElement('div');
        row.className = 'ingredient-row mb-2';
        row.innerHTML = `
            <input type="text" class="form-control" placeholder="Ingredient Name" aria-label="Ingredient Name">
            <input type="number" class="form-control" placeholder="Qty" aria-label="Quantity" min="0" step="any">
            <input type="text" class="form-control" placeholder="Unit (e.g., grams, ml)" aria-label="Unit">
            <button type="button" class="btn btn-danger btn-sm remove-ingredient">&times;</button>
        `;
        ingredientsContainer.appendChild(row);
    }

    if (addIngredientBtn) {
        addIngredientBtn.addEventListener('click', addIngredientRow);
    }

    if (ingredientsContainer) {
        ingredientsContainer.addEventListener('click', function(e) {
            if (e.target.classList.contains('remove-ingredient')) {
                e.target.closest('.ingredient-row').remove();
            }
        });
    }

    if (calculateBtn) {
        calculateBtn.addEventListener('click', function() {
            const recipeName = document.getElementById('recipeName').value || 'My Festive Recipe';
            const guestCount = parseInt(document.getElementById('guestCount').value, 10);

            if (isNaN(guestCount) || guestCount <= 0) {
                alert('Please enter a valid number of guests.');
                return;
            }

            const ingredients = [];
            const rows = ingredientsContainer.querySelectorAll('.ingredient-row');
            rows.forEach(row => {
                const name = row.children[0].value;
                const qty = parseFloat(row.children[1].value);
                const unit = row.children[2].value;

                if (name && !isNaN(qty) && qty > 0) {
                    ingredients.push({ name, qty, unit });
                }
            });

            if (ingredients.length === 0) {
                alert('Please add at least one ingredient.');
                return;
            }

            // Calculate totals
            const shoppingList = {};
            ingredients.forEach(ing => {
                const totalQty = ing.qty * guestCount;
                const key = ing.name.toLowerCase().trim() + '_' + (ing.unit || '').toLowerCase().trim();

                if (shoppingList[key]) {
                    shoppingList[key].qty += totalQty;
                } else {
                    shoppingList[key] = {
                        name: ing.name,
                        qty: totalQty,
                        unit: ing.unit
                    };
                }
            });

            // Render shopping list
            renderShoppingList(recipeName, guestCount, Object.values(shoppingList));
        });
    }

    function renderShoppingList(recipeName, guestCount, list) {
        let html = `<h3>${recipeName} - Shopping List for ${guestCount} Guests</h3><hr>`;
        
        if (list.length === 0) {
            html += '<p>No ingredients to show. Please fill out the recipe form.</p>';
        } else {
            html += '<ul class="list-group list-group-flush">';
            list.forEach(item => {
                html += `<li class="list-group-item d-flex justify-content-between align-items-center">
                    <span>${item.name}</span>
                    <span class="badge bg-primary rounded-pill">${formatQuantity(item.qty)} ${item.unit}</span>
                </li>`;
            });
            html += '</ul>';
        }

        shoppingListContainer.innerHTML = html;
    }

    function formatQuantity(qty) {
        // Simple formatting, can be expanded for fractions
        return parseFloat(qty.toFixed(2));
    }

    const newRecipeBtn = document.getElementById('new-recipe-btn');

    if (newRecipeBtn) {
        newRecipeBtn.addEventListener('click', function() {
            document.getElementById('recipeName').value = '';
            document.getElementById('guestCount').value = '';
            ingredientsContainer.innerHTML = '';
            addIngredientRow(); // Add a fresh row
            shoppingListContainer.innerHTML = `
                <div class="text-center text-muted p-5">
                    <h3 class="h4">Your Shopping List</h3>
                    <p>Your calculated list will appear here.</p>
                </div>
            `;
        });
    }

    // Add one ingredient row by default
    addIngredientRow();
});