app.js

document.addEventListener('DOMContentLoaded', () => {
    // --- Element Selectors ---
    const surplusEstimateDisplay = document.querySelector('#surplus-estimate span');
    const calculateSurplusBtn = document.getElementById('calculate-surplus');
    const surplusForm = document.getElementById('surplus-form');
    const marketplaceList = document.getElementById('marketplace-list');
    const downloadReportBtn = document.getElementById('download-report');

    // --- Initial State ---
    let surplusItems = JSON.parse(localStorage.getItem('surplusItems')) || [];

    // --- Functions ---

    /**
     * Renders the surplus items in the marketplace view.
     */
    const renderMarketplace = () => {
        marketplaceList.innerHTML = '';
        if (surplusItems.length === 0) {
            marketplaceList.innerHTML = '<p>No surplus items available at the moment.</p>';
            return;
        }

        surplusItems.forEach(item => {
            const itemElement = document.createElement('div');
            itemElement.classList.add('item');
            itemElement.setAttribute('data-id', item.id);
            itemElement.innerHTML = `
                <div class="info">
                    <p><strong>${item.itemType}</strong></p>
                    <p>Quantity: ${item.quantity}</p>
                    <p>Expires: ${item.expiryDate}</p>
                    <p>Status: <span class="status">${item.status}</span></p>
                </div>
                <div class="actions">
                    ${item.status === 'Available' ? 
                        `<button class="accept-btn" aria-label="Accept ${item.itemType}">Accept</button>
                         <button class="reject-btn" aria-label="Reject ${item.itemType}">Reject</button>` : 
                        ''}
                </div>
            `;
            marketplaceList.appendChild(itemElement);
        });
    };

    /**
     * Updates the status of a surplus item.
     * @param {string} id - The ID of the item to update.
     * @param {string} status - The new status of the item.
     */
    const updateItemStatus = (id, status) => {
        surplusItems = surplusItems.map(item => 
            item.id === id ? { ...item, status } : item
        );
        localStorage.setItem('surplusItems', JSON.stringify(surplusItems));
        renderMarketplace();

        // --- MCP Integration (HubSpot) ---
        // Here, you would make an MCP call to HubSpot to update the CRM with the new item status.
        // console.log(`MCP_CALL: hubspot.update_deal(${id}, { status: '${status}' })`);
    };

    /**
     * Downloads the impact report as a CSV file.
     */
    const downloadImpactReport = () => {
        let csvContent = "data:text/csv;charset=utf-8,Item Type,Quantity,Status,Waste Diverted (kg),Carbon Saved (kgCO2e)\n";
        surplusItems.forEach(item => {
            const wasteDiverted = (item.quantity * 0.5).toFixed(2); // Assuming average weight of 0.5kg per item
            const carbonSaved = (wasteDiverted * 1.5).toFixed(2); // Assuming 1.5 kgCO2e saved per kg of waste
            csvContent += `${item.itemType},${item.quantity},${item.status},${wasteDiverted},${carbonSaved}\n`;
        });

        // --- MCP Integration (Excel) ---
        // Here, an MCP call could be made to generate a more sophisticated Excel report.
        // console.log('MCP_CALL: excel.create_report(data)');
        
        const encodedUri = encodeURI(csvContent);
        const link = document.createElement("a");
        link.setAttribute("href", encodedUri);
        link.setAttribute("download", "impact_report.csv");
        document.body.appendChild(link);
        link.click();
        document.body.removeChild(link);
    };

    // --- Event Listeners ---

    // Calculate Surplus
    calculateSurplusBtn.addEventListener('click', () => {
        const plannedPax = document.getElementById('planned-pax').value;
        const actualAttendance = document.getElementById('actual-attendance').value;
        const surplus = plannedPax - actualAttendance;
        surplusEstimateDisplay.textContent = surplus > 0 ? surplus : 0;
    });

    // List Surplus Item
    surplusForm.addEventListener('submit', (e) => {
        e.preventDefault();
        const newItem = {
            id: `item-${Date.now()}`,
            itemType: document.getElementById('item-type').value,
            quantity: document.getElementById('quantity').value,
            expiryDate: document.getElementById('expiry-date').value,
            pickupAddress: document.getElementById('pickup-address').value,
            status: 'Available'
        };
        surplusItems.push(newItem);
        localStorage.setItem('surplusItems', JSON.stringify(surplusItems));
        renderMarketplace();
        surplusForm.reset();

        // --- MCP Integrations ---
        // 1. HubSpot: Log the new donor and item.
        // console.log(`MCP_CALL: hubspot.create_contact({ email: 'donor@example.com', address: '${newItem.pickupAddress}' })`);
        // console.log(`MCP_CALL: hubspot.create_deal({ title: '${newItem.itemType}', amount: ${newItem.quantity} })`);

        // 2. Google Maps: Geocode the address to get coordinates.
        // console.log(`MCP_CALL: maps.geocode({ address: '${newItem.pickupAddress}' })`);
    });

    // Accept/Reject Buttons
    marketplaceList.addEventListener('click', (e) => {
        const id = e.target.closest('.item').dataset.id;
        if (e.target.classList.contains('accept-btn')) {
            updateItemStatus(id, 'Claimed');
            // --- MCP Integration (Google Calendar) ---
            // Here, you would make an MCP call to Google Calendar to schedule a pickup.
            // console.log('MCP_CALL: calendar.create_event({ title: `Pickup for ${id}`, time: ... })');
        } else if (e.target.classList.contains('reject-btn')) {
            updateItemStatus(id, 'Available'); // Or perhaps 'Rejected' and then remove from view
        }
    });

    // Download Report
    downloadReportBtn.addEventListener('click', downloadImpactReport);

    // --- Initial Render ---
    renderMarketplace();
});