npm install stateset-node

yarn add stateset-node

export STATESET_API_KEY=your_api_key_here

import { stateset } from 'stateset-node';

// Initialize with your API key
const client = new stateset(process.env.STATESET_API_KEY);

// Verify connection
async function verifyConnection() {
  try {
    const status = await client.system.healthCheck();
    console.log('Connection status:', status);
  } catch (error) {
    console.error('Failed to connect:', error);
  }
}

verifyConnection();

async function captureOrder(orderData) {
  try {
    let order;
    switch(orderData.type) {
      case 'standard':
        order = await client.order.create({
          source: orderData.channel,
          channel_order_id: orderData.channelOrderId,
          customer: orderData.customer,
          line_items: orderData.lineItems,
          total_price: orderData.totalPrice,
          currency: orderData.currency,
          shipping_address: orderData.shippingAddress,
          status: 'received'
        });
        break;
      case 'pre-order':
        order = await createPreOrder(orderData);
        break;
      case 'backorder':
        order = await createBackOrder(orderData);
        break;
      case 'subscription':
        order = await createSubscriptionOrder(orderData);
        break;
      default:
        throw new Error('Unsupported order type');
    }
    return order;
  } catch (error) {
    console.error("Error capturing order:", error);
    throw error;
  }
}

async function routeOrder(orderId) {
  try {
    const order = await client.order.retrieve(orderId);
    const fulfillmentLocations = await client.location.list({ type: 'fulfillment' });

    if (!order || !fulfillmentLocations.length) {
      throw new Error('Invalid order or no fulfillment locations available');
    }

    const historicalData = await getHistoricalFulfillmentData(order.customer.id);
    const mlPrediction = await mlModel.predict({
      order: order,
      historicalData: historicalData
    });

    const inventoryLevels = await getInventoryLevels(order.line_items.map(item => item.product_id));
    const shippingRates = await getShippingRates(order);

    const optimalLocation = determineOptimalLocation(order, fulfillmentLocations, mlPrediction, shippingRates, inventoryLevels);

    if (!optimalLocation) {
      throw new Error('Unable to determine optimal fulfillment location');
    }

    const updatedOrder = await client.order.update(orderId, { 
      assigned_location: optimalLocation.id,
      status: 'routed',
      routing_metadata: {
        prediction_confidence: mlPrediction.confidence,
        selected_shipping_rate: optimalLocation.selectedRate
      }
    });

    await logRoutingDecision(orderId, optimalLocation, mlPrediction);

    return { 
      optimalLocation, 
      updatedOrder 
    };
  } catch (error) {
    console.error(`Error routing order ${orderId}:`, error);
    await client.order.update(orderId, { status: 'routing_failed' });
    throw error;
  }
}

function determineOptimalLocation(order, locations, mlPrediction, shippingRates, inventoryLevels) {
  const scoredLocations = locations.map(location => {
    const inventoryScore = calculateInventoryScore(location, order, inventoryLevels);
    const shippingScore = calculateShippingScore(location, shippingRates);
    const mlScore = mlPrediction.locationScores[location.id] || 0;
    const fulfillmentCost = estimateFulfillmentCost(location, order);

    const totalScore = (inventoryScore * 0.4) + (shippingScore * 0.3) + (mlScore * 0.2) - (fulfillmentCost * 0.1);

    return {
      ...location,
      score: totalScore,
      selectedRate: shippingRates[location.id].cheapestRate
    };
  });

  return scoredLocations.reduce((best, current) => 
    current.score > best.score ? current : best
  , scoredLocations[0]);
}

function calculateInventoryScore(location, order, inventoryLevels) {
  return order.line_items.reduce((score, item) => {
    const availability = inventoryLevels[location.id]?.[item.product_id] || 0;
    return score + (availability >= item.quantity ? 1 : 0);
  }, 0) / order.line_items.length;
}

function calculateShippingScore(location, shippingRates) {
  const locationRates = shippingRates[location.id];
  const cheapestRate = locationRates.cheapestRate;
  const fastestRate = locationRates.fastestRate;
  return 1 - (cheapestRate.price / fastestRate.price);
}

function estimateFulfillmentCost(location, order) {
  // Simplified cost estimation
  const baseCost = location.fulfillmentCostFactor || 1;
  return baseCost * order.line_items.reduce((total, item) => total + item.quantity, 0);
}

async function getShippingRates(order) {
  try {
    const carriers = await client.carrier.list();
    const fulfillmentLocations = await client.location.list({ type: 'fulfillment' });

    const rates = {};
    for (const location of fulfillmentLocations) {
      const locationRates = await Promise.all(carriers.map(carrier => 
        carrier.getRates({
          origin: location.address,
          destination: order.shipping_address,
          packages: convertOrderToPackages(order)
        })
      ));

      const flatRates = locationRates.flatMap(rate => rate);
      rates[location.id] = {
        allRates: flatRates,
        cheapestRate: flatRates.reduce((min, rate) => rate.price < min.price ? rate : min),
        fastestRate: flatRates.reduce((fastest, rate) => rate.deliveryDays < fastest.deliveryDays ? rate : fastest)
      };
    }

    return rates;
  } catch (error) {
    console.error("Error fetching shipping rates:", error);
    throw error;
  }
}

function convertOrderToPackages(order) {
  // Simplified conversion - in reality, this would involve a more complex packing algorithm
  return [{
    weight: order.line_items.reduce((total, item) => total + (item.weight * item.quantity), 0),
    dimensions: {
      length: Math.max(...order.line_items.map(item => item.length)),
      width: Math.max(...order.line_items.map(item => item.width)),
      height: Math.max(...order.line_items.map(item => item.height))
    }
  }];
}

async function getHistoricalFulfillmentData(customerId) {
  // In a real implementation, this would query a data warehouse or analytics service
  return client.analytics.getCustomerFulfillmentHistory(customerId);
}

async function getInventoryLevels(productIds) {
  const inventoryRecords = await client.inventory.list({ product_id: { in: productIds } });
  return inventoryRecords.reduce((acc, record) => {
    acc[record.location_id] = acc[record.location_id] || {};
    acc[record.location_id][record.product_id] = record.available_quantity;
    return acc;
  }, {});
}

async function logRoutingDecision(orderId, optimalLocation, mlPrediction) {
  await client.log.create({
    type: 'order_routing',
    order_id: orderId,
    selected_location: optimalLocation.id,
    ml_confidence: mlPrediction.confidence,
    routing_score: optimalLocation.score
  });
}

async function updateOrderStatus(orderId, newStatus) {
  try {
    const updatedOrder = await client.order.update(orderId, { status: newStatus });
    console.log(`Order ${orderId} status updated to ${newStatus}`);
    return updatedOrder;
  } catch (error) {
    console.error("Error updating order status:", error);
    throw error;
  }
}

async function getGlobalInventory(productId) {
  try {
    const inventoryList = await client.inventory.list({ product_id: productId });
    const globalInventory = inventoryList.reduce((acc, inv) => {
      acc[inv.location_id] = {
        quantity: inv.quantity,
        type: inv.inventory_type, // 'owned', 'dropship', or 'jit'
        safetyStock: inv.safety_stock_level
      };
      return acc;
    }, {});
    return globalInventory;
  } catch (error) {
    console.error("Error fetching global inventory:", error);
    throw error;
  }
}

async function allocateInventory(orderId) {
  let allocatedItems = [];
  try {
    const order = await client.order.retrieve(orderId);
    const allocationResults = await Promise.all(order.line_items.map(async (item) => {
      const allocation = await determineOptimalAllocation(item, order.assigned_location);
      return { item, allocation };
    }));

    for (const { item, allocation } of allocationResults) {
      for (const alloc of allocation) {
        if (alloc.quantity > 0) {
          await client.inventory.allocate({
            product_id: item.product_id,
            location_id: alloc.location_id,
            quantity: alloc.quantity,
            allocation_type: alloc.type,
            order_id: orderId,
            item_id: item.id
          });
          allocatedItems.push({
            item_id: item.id,
            product_id: item.product_id,
            allocated_quantity: alloc.quantity,
            location_id: alloc.location_id,
            allocation_type: alloc.type
          });
        }
      }
    }

    const fullyAllocated = allocatedItems.every(ai => 
      ai.allocated_quantity === order.line_items.find(li => li.id === ai.item_id).quantity
    );

    await client.order.update(orderId, { 
      status: fullyAllocated ? 'fully_allocated' : 'partially_allocated',
      inventory_allocations: allocatedItems
    });

    await logAllocationResult(orderId, allocatedItems, fullyAllocated);

    return { orderId, allocatedItems, fullyAllocated };
  } catch (error) {
    console.error(`Error allocating inventory for order ${orderId}:`, error);
    await client.order.update(orderId, { 
      status: 'allocation_failed',
      allocation_error: error.message
    });
    throw error;
  }
}

async function determineOptimalAllocation(item, preferredLocation) {
  const inventory = await getInventoryLevels(item.product_id);
  const reservations = await getActiveReservations(item.product_id);
  const safetyStockLevels = await getSafetyStockLevels(item.product_id);

  let remainingQuantity = item.quantity;
  let allocations = [];

  // Try to allocate from the preferred location first
  if (inventory[preferredLocation]) {
    const preferredAllocation = allocateFromLocation(
      preferredLocation, 
      remainingQuantity, 
      inventory[preferredLocation], 
      reservations[preferredLocation], 
      safetyStockLevels[preferredLocation]
    );
    if (preferredAllocation.quantity > 0) {
      allocations.push(preferredAllocation);
      remainingQuantity -= preferredAllocation.quantity;
    }
  }

  // If we couldn't fully allocate from the preferred location, try others
  if (remainingQuantity > 0) {
    for (const [locationId, quantity] of Object.entries(inventory)) {
      if (locationId === preferredLocation) continue;
      
      const allocation = allocateFromLocation(
        locationId, 
        remainingQuantity, 
        quantity, 
        reservations[locationId], 
        safetyStockLevels[locationId]
      );
      
      if (allocation.quantity > 0) {
        allocations.push(allocation);
        remainingQuantity -= allocation.quantity;
        if (remainingQuantity === 0) break;
      }
    }
  }

  // If we still couldn't allocate everything, create a backorder
  if (remainingQuantity > 0) {
    allocations.push({
      location_id: 'backorder',
      quantity: remainingQuantity,
      type: 'backorder'
    });
  }

  return allocations;
}

function allocateFromLocation(locationId, requiredQuantity, availableQuantity, reservations, safetyStock) {
  const effectiveQuantity = Math.max(availableQuantity - reservations - safetyStock, 0);
  const allocatedQuantity = Math.min(requiredQuantity, effectiveQuantity);
  
  return {
    location_id: locationId,
    quantity: allocatedQuantity,
    type: allocatedQuantity > 0 ? 'standard' : 'none'
  };
}

async function getInventoryLevels(productId) {
  const inventoryRecords = await client.inventory.list({ product_id: productId });
  return inventoryRecords.reduce((acc, record) => {
    acc[record.location_id] = record.available_quantity;
    return acc;
  }, {});
}

async function getActiveReservations(productId) {
  const reservations = await client.reservation.list({ product_id: productId, status: 'active' });
  return reservations.reduce((acc, reservation) => {
    acc[reservation.location_id] = (acc[reservation.location_id] || 0) + reservation.quantity;
    return acc;
  }, {});
}

async function getSafetyStockLevels(productId) {
  const safetyStockRecords = await client.safetyStock.list({ product_id: productId });
  return safetyStockRecords.reduce((acc, record) => {
    acc[record.location_id] = record.quantity;
    return acc;
  }, {});
}

async function logAllocationResult(orderId, allocatedItems, fullyAllocated) {
  await client.log.create({
    type: 'inventory_allocation',
    order_id: orderId,
    allocated_items: allocatedItems,
    fully_allocated: fullyAllocated,
    timestamp: new Date().toISOString()
  });
}

async function rebalanceInventory() {
  const rebalancingLog = [];
  try {
    const inventory = await client.inventory.list();
    const locations = await client.location.list();
    const salesVelocity = await getSalesVelocityByLocation();
    const seasonalTrends = await getSeasonalTrends();
    const shippingCosts = await getShippingCostMatrix();
    const storageCapacity = await getStorageCapacityByLocation();

    const rebalancingPlan = generateRebalancingPlan(
      inventory, 
      locations, 
      salesVelocity, 
      seasonalTrends, 
      shippingCosts, 
      storageCapacity
    );

    for (const transfer of rebalancingPlan) {
      try {
        await client.inventory.transfer(transfer);
        rebalancingLog.push({
          status: 'success',
          transfer: transfer
        });
      } catch (transferError) {
        console.error(`Error executing transfer:`, transferError);
        rebalancingLog.push({
          status: 'failed',
          transfer: transfer,
          error: transferError.message
        });
      }
    }

    const successfulTransfers = rebalancingLog.filter(log => log.status === 'success').length;
    console.log(`Inventory rebalancing completed. ${successfulTransfers}/${rebalancingPlan.length} transfers successful.`);

    await logRebalancingResult(rebalancingLog);

    return {
      totalTransfers: rebalancingPlan.length,
      successfulTransfers: successfulTransfers,
      rebalancingLog: rebalancingLog
    };

  } catch (error) {
    console.error("Error in inventory rebalancing process:", error);
    await logRebalancingError(error);
    throw error;
  }
}

function generateRebalancingPlan(inventory, locations, salesVelocity, seasonalTrends, shippingCosts, storageCapacity) {
  const rebalancingPlan = [];

  // Group inventory by product
  const productInventory = groupInventoryByProduct(inventory);

  for (const [productId, productLocations] of Object.entries(productInventory)) {
    const totalInventory = sum(Object.values(productLocations));
    const totalSalesVelocity = sum(Object.values(salesVelocity[productId] || {}));
    
    if (totalSalesVelocity === 0) continue; // Skip products with no sales

    const idealDistribution = calculateIdealDistribution(
      productId,
      totalInventory,
      locations,
      salesVelocity,
      seasonalTrends,
      storageCapacity
    );

    for (const [fromLocation, fromQuantity] of Object.entries(productLocations)) {
      const idealQuantity = idealDistribution[fromLocation] || 0;
      const difference = fromQuantity - idealQuantity;

      if (difference > 0) { // This location has excess inventory
        for (const [toLocation, toIdealQuantity] of Object.entries(idealDistribution)) {
          if (productLocations[toLocation] < toIdealQuantity) {
            const transferQuantity = Math.min(difference, toIdealQuantity - productLocations[toLocation]);
            if (transferQuantity > 0 && isTransferCostEffective(productId, fromLocation, toLocation, transferQuantity, shippingCosts)) {
              rebalancingPlan.push({
                product_id: productId,
                from_location: fromLocation,
                to_location: toLocation,
                quantity: transferQuantity
              });
              productLocations[fromLocation] -= transferQuantity;
              productLocations[toLocation] = (productLocations[toLocation] || 0) + transferQuantity;
            }
          }
        }
      }
    }
  }

  return rebalancingPlan;
}

function calculateIdealDistribution(productId, totalInventory, locations, salesVelocity, seasonalTrends, storageCapacity) {
  const distribution = {};
  const totalSalesVelocity = sum(Object.values(salesVelocity[productId] || {}));

  for (const location of locations) {
    const locationSalesVelocity = salesVelocity[productId]?.[location.id] || 0;
    const seasonalFactor = seasonalTrends[productId]?.[location.id] || 1;
    const adjustedSalesVelocity = locationSalesVelocity * seasonalFactor;

    let idealQuantity = Math.round((adjustedSalesVelocity / totalSalesVelocity) * totalInventory);
    idealQuantity = Math.min(idealQuantity, storageCapacity[location.id]); // Respect storage capacity

    distribution[location.id] = idealQuantity;
  }

  return distribution;
}

function isTransferCostEffective(productId, fromLocation, toLocation, quantity, shippingCosts) {
  const transferCost = shippingCosts[fromLocation]?.[toLocation] * quantity;
  const productValue = getProductValue(productId);
  const transferValueRatio = transferCost / (productValue * quantity);

  // Consider transfer cost-effective if it's less than 10% of the inventory value
  return transferValueRatio < 0.1;
}

function groupInventoryByProduct(inventory) {
  return inventory.reduce((acc, item) => {
    acc[item.product_id] = acc[item.product_id] || {};
    acc[item.product_id][item.location_id] = item.quantity;
    return acc;
  }, {});
}

async function getSalesVelocityByLocation() {
  const cacheKey = 'sales_velocity';
  let salesVelocity = cache.get(cacheKey);

  if (salesVelocity) {
    return salesVelocity;
  }

  try {
    // Assume we're fetching data for the last 90 days
    const endDate = new Date();
    const startDate = new Date(endDate.getTime() - (90 * 24 * 60 * 60 * 1000));

    const salesData = await client.analytics.getSales({
      start_date: startDate.toISOString(),
      end_date: endDate.toISOString(),
      group_by: ['product_id', 'location_id']
    });

    salesVelocity = salesData.reduce((acc, sale) => {
      acc[sale.product_id] = acc[sale.product_id] || {};
      acc[sale.product_id][sale.location_id] = sale.quantity / 90; // Daily sales velocity
      return acc;
    }, {});

    cache.set(cacheKey, salesVelocity);
    return salesVelocity;
  } catch (error) {
    console.error('Error fetching sales velocity:', error);
    throw new Error('Failed to fetch sales velocity data');
  }
}

async function getSeasonalTrends() {
  const cacheKey = 'seasonal_trends';
  let seasonalTrends = cache.get(cacheKey);

  if (seasonalTrends) {
    return seasonalTrends;
  }

  try {
    // Assume we're fetching seasonal data for the next 90 days
    const startDate = new Date();
    const endDate = new Date(startDate.getTime() + (90 * 24 * 60 * 60 * 1000));

    const trendsData = await client.analytics.getSeasonalTrends({
      start_date: startDate.toISOString(),
      end_date: endDate.toISOString(),
      group_by: ['product_id', 'location_id']
    });

    seasonalTrends = trendsData.reduce((acc, trend) => {
      acc[trend.product_id] = acc[trend.product_id] || {};
      acc[trend.product_id][trend.location_id] = trend.seasonal_factor;
      return acc;
    }, {});

    cache.set(cacheKey, seasonalTrends);
    return seasonalTrends;
  } catch (error) {
    console.error('Error fetching seasonal trends:', error);
    throw new Error('Failed to fetch seasonal trend data');
  }
}

async function getShippingCostMatrix() {
  const cacheKey = 'shipping_cost_matrix';
  let shippingCostMatrix = cache.get(cacheKey);

  if (shippingCostMatrix) {
    return shippingCostMatrix;
  }

  try {
    const locations = await client.location.list();
    shippingCostMatrix = {};

    for (const fromLocation of locations) {
      shippingCostMatrix[fromLocation.id] = {};
      for (const toLocation of locations) {
        if (fromLocation.id !== toLocation.id) {
          const shippingRate = await client.shipping.getRate({
            from: fromLocation.id,
            to: toLocation.id,
            weight: 1, // Assume 1 kg as a base weight
            volume: 1 // Assume 1 cubic meter as a base volume
          });
          shippingCostMatrix[fromLocation.id][toLocation.id] = shippingRate.cost;
        }
      }
    }

    cache.set(cacheKey, shippingCostMatrix);
    return shippingCostMatrix;
  } catch (error) {
    console.error('Error fetching shipping cost matrix:', error);
    throw new Error('Failed to fetch shipping cost data');
  }
}

async function getStorageCapacityByLocation() {
  const cacheKey = 'storage_capacity';
  let storageCapacity = cache.get(cacheKey);

  if (storageCapacity) {
    return storageCapacity;
  }

  try {
    const locations = await client.location.list();
    storageCapacity = {};

    for (const location of locations) {
      const capacityData = await client.warehouse.getCapacity(location.id);
      storageCapacity[location.id] = capacityData.available_capacity;
    }

    cache.set(cacheKey, storageCapacity);
    return storageCapacity;
  } catch (error) {
    console.error('Error fetching storage capacity:', error);
    throw new Error('Failed to fetch storage capacity data');
  }
}

function getProductValue(productId) {
  return new Promise((resolve, reject) => {
    const cacheKey = `product_value_${productId}`;
    const cachedValue = cache.get(cacheKey);

    if (cachedValue) {
      resolve(cachedValue);
    } else {
      client.product.get(productId)
        .then(product => {
          const value = product.cost || product.price || 0;
          cache.set(cacheKey, value);
          resolve(value);
        })
        .catch(error => {
          console.error(`Error fetching product value for ${productId}:`, error);
          reject(new Error(`Failed to fetch product value for ${productId}`));
        });
    }
  });
}

function sum(numbers) {
  return numbers.reduce((a, b) => a + b, 0);
}

async function logRebalancingResult(rebalancingLog) {
  await client.log.create({
    type: 'inventory_rebalancing',
    result: rebalancingLog,
    timestamp: new Date().toISOString()
  });
}

async function logRebalancingError(error) {
  await client.log.create({
    type: 'inventory_rebalancing_error',
    error: error.message,
    stack: error.stack,
    timestamp: new Date().toISOString()
  });
}

async function createFulfillmentOrder(orderId) {
  try {
    const order = await client.order.retrieve(orderId);
    const fulfillmentCenter = await selectFulfillmentCenter(order);
    
    const fulfillmentOrder = await client.fulfillmentOrder.create({
      order_id: orderId,
      location_id: fulfillmentCenter.id,
      line_items: order.line_items,
      picking_method: determineOptimalPickingMethod(order, fulfillmentCenter)
    });
    
    await client.order.update(orderId, { status: 'in_fulfillment' });
    
    return fulfillmentOrder;
  } catch (error) {
    console.error("Error creating fulfillment order:", error);
    throw error;
  }
}

function determineOptimalPickingMethod(order, fulfillmentCenter) {

  const orderSize = order.line_items.length;
  const orderVolume = order.line_items.reduce((total, item) => total + item.quantity, 0);
  const uniqueProducts = new Set(order.line_items.map(item => item.product_id)).size;

  if (fulfillmentCenter.capabilities.includes('wave_picking') && orderSize > 50) {
    return 'wave_picking';
  } else if (fulfillmentCenter.capabilities.includes('zone_picking') && uniqueProducts > 20) {
    return 'zone_picking';
  } else if (fulfillmentCenter.capabilities.includes('batch_picking') && orderVolume > 100) {
    return 'batch_picking';
  } else if (fulfillmentCenter.capabilities.includes('cluster_picking') && orderSize > 10 && orderSize <= 50) {
    return 'cluster_picking';
  } else {
    return 'discrete_order_picking'; // Default to single-order picking for smaller, simpler orders
  }
}

async function selectFulfillmentCenter(order) {
  // Implement logic to select the best fulfillment center based on various factors
  const fulfillmentCenters = await client.location.list({ type: 'fulfillment' });
  
  // Calculate scores for each fulfillment center
  const scoredCenters = await Promise.all(fulfillmentCenters.map(async (center) => {
    const inventoryAvailability = await checkInventoryAvailability(center.id, order.line_items);
    const shippingCost = await estimateShippingCost(center.id, order.shipping_address);
    const processingTime = estimateProcessingTime(center, order);
    
    const score = calculateScore(inventoryAvailability, shippingCost, processingTime);
    
    return { center, score };
  }));
  
  // Sort centers by score (descending) and return the best one
  const bestCenter = scoredCenters.sort((a, b) => b.score - a.score)[0].center;
  
  return bestCenter;
}

async function updateFulfillmentStatus(fulfillmentOrderId, status, trackingInfo = null) {
  try {
    const updatedFulfillment = await client.fulfillmentOrder.update(fulfillmentOrderId, { 
      status: status,
      tracking_number: trackingInfo?.trackingNumber,
      tracking_url: trackingInfo?.trackingUrl
    });
    
    if (status === 'completed') {
      const order = await client.order.retrieve(updatedFulfillment.order_id);
      await client.order.update(order.id, { status: 'fulfilled' });
      await updateInventoryPostFulfillment(order);
    }
    
    await syncFulfillmentStatusWithWMS(fulfillmentOrderId, status);
    
    return updatedFulfillment;
  } catch (error) {
    console.error("Error updating fulfillment status:", error);
    throw error;
  }
}

async function syncFulfillmentStatusWithWMS(fulfillmentOrderId, status) {
  // Implement WMS integration logic
  try {
    const wmsClient = await getWMSClient();
    const wmsStatus = mapStatesetToWMSStatus(status);
    
    await wmsClient.updateFulfillmentStatus({
      externalOrderId: fulfillmentOrderId,
      status: wmsStatus
    });

    console.log(`Successfully synced fulfillment status ${status} for order ${fulfillmentOrderId} with WMS`);
  } catch (error) {
    console.error(`Error syncing fulfillment status with WMS for order ${fulfillmentOrderId}:`, error);
    // Consider implementing retry logic or alerting mechanism here
  }
}

async function updateInventoryPostFulfillment(order) {
  for (const item of order.line_items) {
    const fulfillment = await client.fulfillmentOrder.retrieve(item.fulfillment_order_id);
    if (fulfillment.status === 'completed') {
      await client.inventory.update({
        product_id: item.product_id,
        location_id: fulfillment.location_id,
        quantity: -item.quantity,
        reason: 'fulfillment'
      });
    }
  }

  // Update any reserved inventory
  const reservations = await client.reservation.list({ order_id: order.id });
  for (const reservation of reservations) {
    await client.reservation.delete(reservation.id);
  }

  console.log(`Inventory updated for order ${order.id} after successful fulfillment`);
}

async function createSplitFulfillment(orderId) {
  try {
    const order = await client.order.retrieve(orderId);
    const splitFulfillments = [];
    
    for (const item of order.line_items) {
      const availableLocations = await findAvailableLocations(item.product_id, item.quantity);
      
      for (const location of availableLocations) {
        const fulfillmentOrder = await client.fulfillmentOrder.create({
          order_id: orderId,
          location_id: location.id,
          line_items: [{ ...item, quantity: location.availableQuantity }]
        });
        splitFulfillments.push(fulfillmentOrder);
      }
    }
    
    await client.order.update(orderId, { status: 'split_fulfillment' });
    
    return splitFulfillments;
  } catch (error) {
    console.error("Error creating split fulfillment:", error);
    throw error;
  }
}

async function findAvailableLocations(productId, requiredQuantity) {
  // Implement logic to find locations with available inventory
  const locations = await client.location.list({ type: 'fulfillment' });
  const availableLocations = [];

  for (const location of locations) {
    const inventory = await client.inventory.get({ product_id: productId, location_id: location.id });
    if (inventory.available_quantity >= requiredQuantity) {
      availableLocations.push({ id: location.id, availableQuantity: inventory.available_quantity });
    }
  }

  return availableLocations;
}

async function syncInventoryAcrossChannels() {
  try {
    const inventory = await client.inventory.list();
    const channels = await client.channel.list();
    
    for (const item of inventory) {
      for (const channel of channels) {
        await updateChannelInventory(channel.id, item.product_id, item.quantity);
      }
    }
    
    console.log("Inventory sync completed successfully");
  } catch (error) {
    console.error("Error during inventory sync:", error);
  }
}

async function updateChannelInventory(channelId, productId, quantity) {
  // Implement channel-specific inventory update logic
  // Example: Send HTTP POST requests to channel's inventory API
  try {
    await fetch(`https://api.${channelId}.com/inventory/update`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json', 'Authorization': `Bearer ${channelId}_API_KEY` },
      body: JSON.stringify({
        product_id: productId,
        quantity: quantity
      })
    });
    console.log(`Channel ${channelId} inventory updated for Product ${productId}`);
  } catch (error) {
    console.error(`Error updating channel ${channelId} inventory for Product ${productId}:`, error);
  }
}

async function syncOrderStatus(orderId) {
  try {
    const order = await client.order.retrieve(orderId);
    await updateChannelOrderStatus(order.channel, order.channel_order_id, order.status);
    console.log(`Order status for Order ${orderId} synchronized across channels.`);
  } catch (error) {
    console.error("Error syncing order status:", error);
    throw error;
  }
}

async function updateChannelOrderStatus(channelId, channelOrderId, status) {
  // Implement channel-specific order status update logic
  // Example: Send HTTP PUT requests to channel's order API
  try {
    await fetch(`https://api.${channelId}.com/orders/${channelOrderId}/status`, {
      method: 'PUT',
      headers: { 'Content-Type': 'application/json', 'Authorization': `Bearer ${channelId}_API_KEY` },
      body: JSON.stringify({ status: status })
    });
    console.log(`Channel ${channelId} order ${channelOrderId} status updated to ${status}`);
  } catch (error) {
    console.error(`Error updating channel ${channelId} order ${channelOrderId} status:`, error);
  }
}

async function generateFulfillmentPerformanceReport(startDate, endDate) {
  try {
    const orders = await client.order.list({
      created_at: { gte: startDate, lte: endDate },
      status: 'fulfilled'
    });

    const performance = orders.reduce((acc, order) => {
      const fulfillmentTime = calculateFulfillmentTime(order);
      const pickingEfficiency = calculatePickingEfficiency(order);
      acc.totalOrders++;
      acc.totalFulfillmentTime += fulfillmentTime;
      acc.totalPickingEfficiency += pickingEfficiency;
      acc.locations[order.assigned_location] = (acc.locations[order.assigned_location] || 0) + 1;
      return acc;
    }, { totalOrders: 0, totalFulfillmentTime: 0, totalPickingEfficiency: 0, locations: {} });

    performance.averageFulfillmentTime = performance.totalFulfillmentTime / performance.totalOrders;
    performance.averagePickingEfficiency = performance.totalPickingEfficiency / performance.totalOrders;

    return performance;
  } catch (error) {
    console.error("Error generating fulfillment performance report:", error);
    throw error;
  }
}

function calculateFulfillmentTime(order) {
  const receivedDate = new Date(order.created_at);
  const fulfilledDate = new Date(order.fulfilled_at);
  const fulfillmentTime = (fulfilledDate - receivedDate) / (1000 * 60 * 60); // Convert to hours
  return fulfillmentTime;
}

function calculatePickingEfficiency(order) {
  // Implement logic to calculate picking efficiency based on chosen picking method
  const pickingMethod = order.picking_method || 'single';
  let efficiency = 0;

  switch (pickingMethod) {
    case 'single':
      efficiency = calculateSingleOrderPickingEfficiency(order);
      break;
    case 'batch':
      efficiency = calculateBatchPickingEfficiency(order);
      break;
    case 'zone':
      efficiency = calculateZonePickingEfficiency(order);
      break;
    case 'wave':
      efficiency = calculateWavePickingEfficiency(order);
      break;
    default:
      console.warn(`Unknown picking method: ${pickingMethod}. Using default efficiency calculation.`);
      efficiency = calculateDefaultPickingEfficiency(order);
  }

  return efficiency;
}

function calculateSingleOrderPickingEfficiency(order) {
  // Placeholder for single order picking efficiency calculation
  return 1; // Assume perfect efficiency
}

function calculateBatchPickingEfficiency(order) {
  // Placeholder for batch picking efficiency calculation
  return 0.9; // Example efficiency
}

function calculateZonePickingEfficiency(order) {
  // Placeholder for zone picking efficiency calculation
  return 0.95; // Example efficiency
}

function calculateWavePickingEfficiency(order) {
  // Placeholder for wave picking efficiency calculation
  return 0.92; // Example efficiency
}

function calculateDefaultPickingEfficiency(order) {
  // Placeholder for default picking efficiency calculation
  return 0.85; // Example efficiency
}

async function generateInventoryReport(startDate, endDate) {
  try {
    const sales = await client.order.list({
      created_at: { gte: startDate, lte: endDate },
      status: 'fulfilled'
    });
    const currentInventory = await client.inventory.list();
    const historicalData = await getHistoricalInventoryData();

    const report = currentInventory.reduce((acc, inv) => {
      const sold = calculateTotalSold(sales, inv.product_id, inv.location_id);
      const turnoverRate = sold / ((inv.quantity + sold) / 2);
      const predictedDemand = predictFutureDemand(inv.product_id, historicalData);
      
      acc[inv.location_id] = acc[inv.location_id] || {};
      acc[inv.location_id][inv.product_id] = {
        currentStock: inv.quantity,
        soldQuantity: sold,
        turnoverRate: turnoverRate,
        predictedDemand: predictedDemand
      };
      return acc;
    }, {});

    return report;
  } catch (error) {
    console.error("Error generating inventory report:", error);
    throw error;
  }
}

function calculateTotalSold(sales, productId, locationId) {
  return sales.reduce((total, order) => {
    const relevantLineItems = order.line_items.filter(item => 
      item.product_id === productId && item.fulfillment_location_id === locationId
    );
    const quantitySold = relevantLineItems.reduce((sum, item) => sum + item.quantity, 0);
    return total + quantitySold;
  }, 0);
}

function predictFutureDemand(productId, historicalData) {
  // Implement demand forecasting logic using historical data
  const historicalSales = historicalData.filter(data => data.product_id === productId);
  
  if (historicalSales.length === 0) {
    return 0; // No historical data available
  }

  // Calculate average daily sales for the last 90 days
  const last90Days = historicalSales.slice(-90);
  const totalSales = last90Days.reduce((sum, day) => sum + day.quantity_sold, 0);
  const averageDailySales = totalSales / 90;

  // Apply simple exponential smoothing for short-term forecast
  const alpha = 0.3; // Smoothing factor
  let forecast = averageDailySales;
  for (let i = last90Days.length - 1; i >= 0; i--) {
    forecast = alpha * last90Days[i].quantity_sold + (1 - alpha) * forecast;
  }

  // Apply seasonal adjustment if applicable
  const seasonalIndex = calculateSeasonalIndex(historicalSales);
  forecast *= seasonalIndex;

  // Round to nearest integer and ensure non-negative
  return Math.max(Math.round(forecast), 0);
}

function calculateSeasonalIndex(historicalSales) {
  // Placeholder for seasonal index calculation
  // In reality, this would involve more sophisticated analysis
  return 1; // No seasonal adjustment
}

async function getHistoricalInventoryData() {
  // Implement logic to fetch historical inventory data
  // This might involve querying a data warehouse or analytics service
  return client.analytics.getHistoricalInventory();
}

async function syncWithERP() {
  try {
    const fulfilledOrders = await client.order.list({ status: 'fulfilled' });
    await updateERPWithFulfilledOrders(fulfilledOrders.items);
    console.log('Synchronized fulfilled orders with ERP.');
  } catch (error) {
    console.error("Error syncing with ERP:", error);
  }
}

async function updateERPWithFulfilledOrders(orders) {
  for (const order of orders) {
    // Implement ERP-specific order update logic
    try {
      await fetch('https://erp.example.com/api/orders/update', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json', 'Authorization': `Bearer ERP_API_KEY` },
        body: JSON.stringify({
          order_id: order.channel_order_id,
          status: order.status,
          fulfillment_details: order.fulfillment_metadata
        })
      });
      console.log(`ERP updated for Order ${order.channel_order_id}`);
    } catch (error) {
      console.error(`Error updating ERP for Order ${order.channel_order_id}:`, error);
    }
  }
}

syncWithERP();

async function syncWithWMS() {
  try {
    const fulfillmentOrders = await client.fulfillmentOrder.list({ status: 'in_progress' });
    await updateWMSWithFulfillmentOrders(fulfillmentOrders.items);
    console.log('Synchronized fulfillment orders with WMS.');
  } catch (error) {
    console.error("Error syncing with WMS:", error);
  }
}

async function updateWMSWithFulfillmentOrders(fulfillmentOrders) {
  for (const fulfillment of fulfillmentOrders) {
    // Implement WMS-specific fulfillment order update logic
    try {
      await fetch('https://wms.example.com/api/fulfillment/update', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json', 'Authorization': `Bearer WMS_API_KEY` },
        body: JSON.stringify({
          fulfillment_order_id: fulfillment.id,
          status: fulfillment.status,
          tracking_number: fulfillment.tracking_number
        })
      });
      console.log(`WMS updated for Fulfillment Order ${fulfillment.id}`);
    } catch (error) {
      console.error(`Error updating WMS for Fulfillment Order ${fulfillment.id}:`, error);
    }
  }
}

syncWithWMS();