1 files changed, 34 insertions, 0 deletions
diff --git a/packages/asset-buyer/src/utils/calculate_liquidity.ts b/packages/asset-buyer/src/utils/calculate_liquidity.ts
new file mode 100644
index 000000000..910c756ac
--- /dev/null
+++ b/packages/asset-buyer/src/utils/calculate_liquidity.ts
@@ -0,0 +1,34 @@
+import { BigNumber } from '@0x/utils';
+
+import { LiquidityForAssetData, OrdersAndFillableAmounts } from '../types';
+
+import { orderUtils } from './order_utils';
+
+export const calculateLiquidity = (ordersAndFillableAmounts: OrdersAndFillableAmounts): LiquidityForAssetData => {
+    const { orders, remainingFillableMakerAssetAmounts } = ordersAndFillableAmounts;
+    const liquidityInBigNumbers = orders.reduce(
+        (acc, order, curIndex) => {
+            const availableMakerAssetAmount = remainingFillableMakerAssetAmounts[curIndex];
+            if (availableMakerAssetAmount === undefined) {
+                throw new Error(`No corresponding fillableMakerAssetAmounts at index ${curIndex}`);
+            }
+
+            const tokensAvailableForCurrentOrder = availableMakerAssetAmount;
+            const ethValueAvailableForCurrentOrder = orderUtils.getTakerFillAmount(order, availableMakerAssetAmount);
+            return {
+                tokensAvailableInBaseUnits: acc.tokensAvailableInBaseUnits.plus(tokensAvailableForCurrentOrder),
+                ethValueAvailableInWei: acc.ethValueAvailableInWei.plus(ethValueAvailableForCurrentOrder),
+            };
+        },
+        {
+            tokensAvailableInBaseUnits: new BigNumber(0),
+            ethValueAvailableInWei: new BigNumber(0),
+        },
+    );
+
+    // Turn into regular numbers
+    return {
+        tokensAvailableInBaseUnits: liquidityInBigNumbers.tokensAvailableInBaseUnits.toNumber(),
+        ethValueAvailableInWei: liquidityInBigNumbers.ethValueAvailableInWei.toNumber(),
+    };
+};