Add minAdaForOutput function

src/index.ts

@@ -1,2 +1,3 @@
 export * from "./address";
 export * from "./generated";
+export * from "./min_ada_calculator";

src/min_ada_calculator.ts

@@ -0,0 +1,61 @@
+/*
+ * This module provides functionality to calculate the minimum amount of ADA (lovelace)
+ * required for a transaction output.
+ *
+ * The primary export is the `minAdaForOutput` function, which computes the minimum ADA needed
+ * for a given `TransactionOutput` and `DataCost`.
+ *
+ * Adapated from https://github.com/Emurgo/cardano-serialization-lib/blob/master/rust/src/utils.rs#L726
+ */
+
+import { BigNum, DataCost, TransactionOutput, Value } from "./generated";
+
+class MinOutputAdaCalculator {
+  output: TransactionOutput;
+  data_cost: DataCost;
+
+  constructor(output: TransactionOutput, data_cost: DataCost) {
+    this.output = output.clone();
+    this.data_cost = data_cost.clone();
+  }
+
+  static new(output: TransactionOutput, data_cost: DataCost): MinOutputAdaCalculator {
+    return new MinOutputAdaCalculator(output, data_cost);
+  }
+
+  calculate_ada(): BigNum {
+    let output = this.output.clone();
+    for (let i = 0; i < 3; i++) {
+      const required_coin = MinOutputAdaCalculator.calc_required_coin(output, this.data_cost);
+      if (output.amount().coin().less_than(required_coin)) {
+        output.set_amount(Value.new(required_coin.clone()));
+      } else {
+        return required_coin;
+      }
+    }
+    output.set_amount(Value.new(BigNum.new(BigNum._maxU64())));
+    return MinOutputAdaCalculator.calc_required_coin(output, this.data_cost);
+  }
+
+  static calc_size_cost(data_cost: DataCost, size: number): BigNum {
+    return new BigNum(BigInt(size))
+      .checked_add(new BigNum(BigInt(160)))
+      .checked_mul(data_cost.coins_per_byte());
+  }
+
+  static calc_required_coin(output: TransactionOutput, data_cost: DataCost): BigNum {
+    return MinOutputAdaCalculator.calc_size_cost(data_cost, output.to_bytes().length);
+  }
+}
+
+/**
+ * Calculates the minimal amount of ada for the output for case when the amount is included to the output
+ *
+ *
+ * @param output - The transaction output for which to calculate the minimum ADA.
+ * @param data_cost - The data cost parameters, including coins per byte.
+ * @returns The minimum ADA required as a `BigNum`.
+ */
+export function minAdaForOutput(output: TransactionOutput, data_cost: DataCost): BigNum {
+  return MinOutputAdaCalculator.new(output, data_cost).calculate_ada();
+}