const { outputProgress } = require('./utils/progress');
const { getConnection } = require('./utils/db');

async function calculateVendorMetrics(startTime, totalProducts, processedCount) {
    const connection = await getConnection();
    try {
        outputProgress({
            status: 'running',
            operation: 'Ensuring vendors exist in vendor_details',
            current: Math.floor(totalProducts * 0.7),
            total: totalProducts,
            elapsed: formatElapsedTime(startTime),
            remaining: estimateRemaining(startTime, Math.floor(totalProducts * 0.7), totalProducts),
            rate: calculateRate(startTime, Math.floor(totalProducts * 0.7)),
            percentage: '70'
        });

        // First ensure all vendors exist in vendor_details
        await connection.query(`
            INSERT IGNORE INTO vendor_details (vendor, status, created_at, updated_at)
            SELECT DISTINCT 
                vendor,
                'active' as status,
                NOW() as created_at,
                NOW() as updated_at
            FROM products
            WHERE vendor IS NOT NULL
        `);

        outputProgress({
            status: 'running',
            operation: 'Calculating vendor metrics',
            current: Math.floor(totalProducts * 0.8),
            total: totalProducts,
            elapsed: formatElapsedTime(startTime),
            remaining: estimateRemaining(startTime, Math.floor(totalProducts * 0.8), totalProducts),
            rate: calculateRate(startTime, Math.floor(totalProducts * 0.8)),
            percentage: '80'
        });

        // Now calculate vendor metrics
        await connection.query(`
            INSERT INTO vendor_metrics (
                vendor,
                total_revenue,
                total_orders,
                total_late_orders,
                avg_lead_time_days,
                on_time_delivery_rate,
                order_fill_rate,
                avg_order_value,
                active_products,
                total_products,
                status,
                last_calculated_at
            )
            WITH vendor_sales AS (
                SELECT 
                    p.vendor,
                    SUM(o.quantity * o.price) as total_revenue,
                    COUNT(DISTINCT o.id) as total_orders,
                    COUNT(DISTINCT p.pid) as active_products
                FROM products p
                JOIN orders o ON p.pid = o.pid
                WHERE o.canceled = false
                    AND o.date >= DATE_SUB(CURRENT_DATE, INTERVAL 12 MONTH)
                GROUP BY p.vendor
            ),
            vendor_po AS (
                SELECT 
                    p.vendor,
                    COUNT(DISTINCT CASE WHEN po.receiving_status = 40 THEN po.id END) as received_orders,
                    COUNT(DISTINCT po.id) as total_orders,
                    AVG(CASE 
                        WHEN po.receiving_status = 40 
                        THEN DATEDIFF(po.received_date, po.date) 
                    END) as avg_lead_time_days
                FROM products p
                JOIN purchase_orders po ON p.pid = po.pid
                WHERE po.date >= DATE_SUB(CURRENT_DATE, INTERVAL 12 MONTH)
                GROUP BY p.vendor
            ),
            vendor_products AS (
                SELECT 
                    vendor,
                    COUNT(DISTINCT pid) as total_products
                FROM products
                GROUP BY vendor
            )
            SELECT 
                vs.vendor,
                COALESCE(vs.total_revenue, 0) as total_revenue,
                COALESCE(vp.total_orders, 0) as total_orders,
                COALESCE(vp.total_orders - vp.received_orders, 0) as total_late_orders,
                COALESCE(vp.avg_lead_time_days, 0) as avg_lead_time_days,
                CASE 
                    WHEN vp.total_orders > 0 
                    THEN (vp.received_orders / vp.total_orders) * 100 
                    ELSE 0 
                END as on_time_delivery_rate,
                CASE 
                    WHEN vp.total_orders > 0 
                    THEN (vp.received_orders / vp.total_orders) * 100 
                    ELSE 0 
                END as order_fill_rate,
                CASE 
                    WHEN vs.total_orders > 0 
                    THEN vs.total_revenue / vs.total_orders 
                    ELSE 0 
                END as avg_order_value,
                COALESCE(vs.active_products, 0) as active_products,
                COALESCE(vpr.total_products, 0) as total_products,
                'active' as status,
                NOW() as last_calculated_at
            FROM vendor_sales vs
            LEFT JOIN vendor_po vp ON vs.vendor = vp.vendor
            LEFT JOIN vendor_products vpr ON vs.vendor = vpr.vendor
            WHERE vs.vendor IS NOT NULL
            ON DUPLICATE KEY UPDATE
                total_revenue = VALUES(total_revenue),
                total_orders = VALUES(total_orders),
                total_late_orders = VALUES(total_late_orders),
                avg_lead_time_days = VALUES(avg_lead_time_days),
                on_time_delivery_rate = VALUES(on_time_delivery_rate),
                order_fill_rate = VALUES(order_fill_rate),
                avg_order_value = VALUES(avg_order_value),
                active_products = VALUES(active_products),
                total_products = VALUES(total_products),
                status = VALUES(status),
                last_calculated_at = VALUES(last_calculated_at)
        `);

        return Math.floor(totalProducts * 0.9);
    } finally {
        connection.release();
    }
}

module.exports = calculateVendorMetrics;