const { outputProgress, formatElapsedTime, estimateRemaining, calculateRate, logError } = require('./utils/progress');
const { getConnection } = require('./utils/db');

async function calculateTimeAggregates(startTime, totalProducts, processedCount, isCancelled = false) {
    const connection = await getConnection();
    try {
        if (isCancelled) {
            outputProgress({
                status: 'cancelled',
                operation: 'Time aggregates calculation cancelled',
                current: processedCount,
                total: totalProducts,
                elapsed: formatElapsedTime(startTime),
                remaining: null,
                rate: calculateRate(startTime, processedCount),
                percentage: ((processedCount / totalProducts) * 100).toFixed(1),
                timing: {
                    start_time: new Date(startTime).toISOString(),
                    end_time: new Date().toISOString(),
                    elapsed_seconds: Math.round((Date.now() - startTime) / 1000)
                }
            });
            return processedCount;
        }

        outputProgress({
            status: 'running',
            operation: 'Starting time aggregates calculation',
            current: processedCount,
            total: totalProducts,
            elapsed: formatElapsedTime(startTime),
            remaining: estimateRemaining(startTime, processedCount, totalProducts),
            rate: calculateRate(startTime, processedCount),
            percentage: ((processedCount / totalProducts) * 100).toFixed(1),
            timing: {
                start_time: new Date(startTime).toISOString(),
                end_time: new Date().toISOString(),
                elapsed_seconds: Math.round((Date.now() - startTime) / 1000)
            }
        });

        // Initial insert of time-based aggregates
        await connection.query(`
            INSERT INTO product_time_aggregates (
                pid,
                year,
                month,
                total_quantity_sold,
                total_revenue,
                total_cost,
                order_count,
                stock_received,
                stock_ordered,
                avg_price,
                profit_margin
            )
            WITH sales_data AS (
                SELECT 
                    o.pid,
                    YEAR(o.date) as year,
                    MONTH(o.date) as month,
                    SUM(o.quantity) as total_quantity_sold,
                    SUM((o.price - COALESCE(o.discount, 0)) * o.quantity) as total_revenue,
                    SUM(COALESCE(p.cost_price, 0) * o.quantity) as total_cost,
                    COUNT(DISTINCT o.order_number) as order_count,
                    AVG(o.price - COALESCE(o.discount, 0)) as avg_price,
                    CASE 
                        WHEN SUM((o.price - COALESCE(o.discount, 0)) * o.quantity) = 0 THEN 0
                        ELSE ((SUM((o.price - COALESCE(o.discount, 0)) * o.quantity) - 
                              SUM(COALESCE(p.cost_price, 0) * o.quantity)) / 
                              SUM((o.price - COALESCE(o.discount, 0)) * o.quantity)) * 100
                    END as profit_margin
                FROM orders o
                JOIN products p ON o.pid = p.pid
                WHERE o.canceled = 0
                GROUP BY o.pid, YEAR(o.date), MONTH(o.date)
            ),
            purchase_data AS (
                SELECT 
                    pid,
                    YEAR(date) as year,
                    MONTH(date) as month,
                    SUM(received) as stock_received,
                    SUM(ordered) as stock_ordered,
                    COUNT(DISTINCT CASE WHEN receiving_status = 40 THEN id END) as fulfilled_orders,
                    COUNT(DISTINCT id) as total_orders,
                    AVG(CASE 
                        WHEN receiving_status = 40 
                        THEN DATEDIFF(received_date, date)
                    END) as avg_lead_time,
                    SUM(CASE 
                        WHEN receiving_status = 40 AND received_date > expected_date 
                        THEN 1 ELSE 0 
                    END) as late_deliveries
                FROM purchase_orders
                GROUP BY pid, YEAR(date), MONTH(date)
            ),
            stock_trends AS (
                SELECT 
                    p.pid,
                    YEAR(po.date) as year,
                    MONTH(po.date) as month,
                    AVG(p.stock_quantity) as avg_stock_level,
                    STDDEV(p.stock_quantity) as stock_volatility,
                    SUM(CASE 
                        WHEN p.stock_quantity <= COALESCE(pm.reorder_point, 5) 
                        THEN 1 ELSE 0 
                    END) as days_below_reorder,
                    COUNT(*) as total_days
                FROM products p
                CROSS JOIN (
                    SELECT DISTINCT DATE(date) as date
                    FROM purchase_orders
                    WHERE date >= DATE_SUB(CURRENT_DATE, INTERVAL 12 MONTH)
                ) po
                LEFT JOIN product_metrics pm ON p.pid = pm.pid
                GROUP BY p.pid, YEAR(po.date), MONTH(po.date)
            )
            SELECT 
                s.pid,
                s.year,
                s.month,
                s.total_quantity_sold,
                s.total_revenue,
                s.total_cost,
                s.order_count,
                COALESCE(p.stock_received, 0) as stock_received,
                COALESCE(p.stock_ordered, 0) as stock_ordered,
                s.avg_price,
                s.profit_margin,
                COALESCE(p.fulfilled_orders, 0) as fulfilled_orders,
                COALESCE(p.total_orders, 0) as total_orders,
                COALESCE(p.avg_lead_time, 0) as avg_lead_time,
                COALESCE(p.late_deliveries, 0) as late_deliveries,
                COALESCE(st.avg_stock_level, 0) as avg_stock_level,
                COALESCE(st.stock_volatility, 0) as stock_volatility,
                COALESCE(st.days_below_reorder, 0) as days_below_reorder,
                COALESCE(st.total_days, 0) as total_days
            FROM sales_data s
            LEFT JOIN purchase_data p 
                ON s.pid = p.pid 
                AND s.year = p.year 
                AND s.month = p.month
            LEFT JOIN stock_trends st
                ON s.pid = st.pid
                AND s.year = st.year
                AND s.month = st.month
            UNION
            SELECT 
                p.pid,
                p.year,
                p.month,
                0 as total_quantity_sold,
                0 as total_revenue,
                0 as total_cost,
                0 as order_count,
                p.stock_received,
                p.stock_ordered,
                0 as avg_price,
                0 as profit_margin,
                p.fulfilled_orders,
                p.total_orders,
                p.avg_lead_time,
                p.late_deliveries,
                st.avg_stock_level,
                st.stock_volatility,
                st.days_below_reorder,
                st.total_days
            FROM purchase_data p
            LEFT JOIN sales_data s
                ON p.pid = s.pid 
                AND p.year = s.year 
                AND p.month = s.month
            LEFT JOIN stock_trends st
                ON p.pid = st.pid
                AND p.year = st.year
                AND p.month = st.month
            WHERE s.pid IS NULL
            ON DUPLICATE KEY UPDATE
                total_quantity_sold = VALUES(total_quantity_sold),
                total_revenue = VALUES(total_revenue),
                total_cost = VALUES(total_cost),
                order_count = VALUES(order_count),
                stock_received = VALUES(stock_received),
                stock_ordered = VALUES(stock_ordered),
                avg_price = VALUES(avg_price),
                profit_margin = VALUES(profit_margin),
                last_calculated_at = CURRENT_TIMESTAMP
        `);

        processedCount = Math.floor(totalProducts * 0.60);
        outputProgress({
            status: 'running',
            operation: 'Base time aggregates calculated, updating financial metrics',
            current: processedCount,
            total: totalProducts,
            elapsed: formatElapsedTime(startTime),
            remaining: estimateRemaining(startTime, processedCount, totalProducts),
            rate: calculateRate(startTime, processedCount),
            percentage: ((processedCount / totalProducts) * 100).toFixed(1),
            timing: {
                start_time: new Date(startTime).toISOString(),
                end_time: new Date().toISOString(),
                elapsed_seconds: Math.round((Date.now() - startTime) / 1000)
            }
        });

        if (isCancelled) return processedCount;

        // Update with financial metrics
        await connection.query(`
            UPDATE product_time_aggregates pta
            JOIN (
                SELECT 
                    p.pid,
                    YEAR(o.date) as year,
                    MONTH(o.date) as month,
                    p.cost_price * p.stock_quantity as inventory_value,
                    SUM(o.quantity * (o.price - p.cost_price)) as gross_profit,
                    COUNT(DISTINCT DATE(o.date)) as days_in_period
                FROM products p
                LEFT JOIN orders o ON p.pid = o.pid
                WHERE o.canceled = false
                GROUP BY p.pid, YEAR(o.date), MONTH(o.date)
            ) fin ON pta.pid = fin.pid 
                AND pta.year = fin.year 
                AND pta.month = fin.month
            SET 
                pta.inventory_value = COALESCE(fin.inventory_value, 0),
                pta.gmroi = CASE 
                    WHEN COALESCE(fin.inventory_value, 0) > 0 AND fin.days_in_period > 0 THEN 
                        (COALESCE(fin.gross_profit, 0) * (365.0 / fin.days_in_period)) / COALESCE(fin.inventory_value, 0)
                    ELSE 0 
                END,
                pta.last_calculated_at = CURRENT_TIMESTAMP
        `);

        processedCount = Math.floor(totalProducts * 0.65);
        outputProgress({
            status: 'running',
            operation: 'Financial metrics updated',
            current: processedCount,
            total: totalProducts,
            elapsed: formatElapsedTime(startTime),
            remaining: estimateRemaining(startTime, processedCount, totalProducts),
            rate: calculateRate(startTime, processedCount),
            percentage: ((processedCount / totalProducts) * 100).toFixed(1),
            timing: {
                start_time: new Date(startTime).toISOString(),
                end_time: new Date().toISOString(),
                elapsed_seconds: Math.round((Date.now() - startTime) / 1000)
            }
        });

        return processedCount;
    } catch (error) {
        logError(error, 'Error calculating time aggregates');
        throw error;
    } finally {
        if (connection) {
            connection.release();
        }
    }
}

module.exports = calculateTimeAggregates;