Fixed the batch computation on money value and money object with string values and builder values and fixed generator for first + next computation concepts with operators

src/main/kotlin/com/cubetiqs/money/MoneyObject.kt

@@ -9,19 +9,11 @@ import java.util.*
  * @author sombochea
  */
 class MoneyObject(
-    val value: Double,
+    var value: Double,
-    val currency: String,
+    var currency: String,
     var operator: MoneyOperator? = null,
     var with: MoneyObject? = null,
 ) : StdMoney {
-    fun appendWith(with: MoneyObject?) {
-        if (this.with == null) {
-            this.with = with
-        } else {
-            this.with!!.appendWith(with)
-        }
-    }
-
     override fun getMoneyCurrency(): StdMoney.Currency {
         return StdMoney.initCurrency(currency)
     }
@@ -30,20 +22,51 @@ class MoneyObject(
         return value
     }
 
-    private fun generate(): StdMoney {
+    fun appendWithNext(with: MoneyObject?) {
-        if (this.with != null) {
+        if (with == null) {
-            val withGenerated = this.with!!.generate()
+            return
-            return when (operator) {
-                MoneyOperator.PLUS -> this plusWith withGenerated
-                MoneyOperator.MINUS -> this minusWith withGenerated
-                MoneyOperator.DIVIDE -> this divideWith withGenerated
-                MoneyOperator.MULTIPLY -> this multiplyWith withGenerated
-                // if operator is null or empty with default Plus operator
-                else -> this plusWith withGenerated
-            }
         }
 
-        return StdMoney.initMoney(value, currency = StdMoney.initCurrency(currency))
+        if (this.with == null) {
+            this.with = with
+        } else {
+            this.with!!.appendWithNext(with)
+        }
+    }
+
+    /**
+     * Internal Generate the value by next compute (First and next)
+     *
+     * Example: we have 3 items => [10, 20, 50]
+     * We want to sum of them => [10 + 20] => [30 + 50] => 80
+     */
+    private fun generate(): StdMoney {
+        // get next record for compute with
+        var next = this.with
+        // get first operator
+        var operatorFirst = this.operator
+        while (next != null) {
+            val temp = when (operatorFirst) {
+                MoneyOperator.PLUS -> this plusWith next
+                MoneyOperator.MINUS -> this minusWith next
+                MoneyOperator.DIVIDE -> this divideWith next
+                MoneyOperator.MULTIPLY -> this multiplyWith next
+                // if operator is null or empty with default Plus operator
+                else -> this plusWith next
+            }
+            // move the temp value that computed
+            this.value = temp.getMoneyValue()
+            // move the currency into parent, if changed
+            this.currency = temp.getMoneyCurrency().getCurrency()
+            // move the first operator to previous next operator
+            // example: first ops = +, then next ops = -, then inside next ops = *, n
+            // return next: first ops = -, then next ops = *, then n
+            operatorFirst = next.operator
+            // move next element
+            next = next.with
+        }
+
+        return this
     }
 
     fun compute(): StdMoney {
@@ -68,32 +91,46 @@ class MoneyObject(
         MULTIPLY;
 
         companion object {
-            fun operator(value: Char?): MoneyOperator {
+            fun operator(value: Any?, defaultOperator: MoneyOperator? = null): MoneyOperator {
                 return try {
-                    when (value!!) {
+                    when (val temp = value!!) {
-                        '+' -> PLUS
+                        is String -> {
-                        '-' -> MINUS
+                            if (temp.length == 1) {
-                        '/' -> DIVIDE
+                                operator(temp[0])
-                        '*' -> MULTIPLY
+                            } else {
-                        else -> throw IllegalArgumentException("operator not found with value: $value!")
+                                valueOf(temp.toUpperCase().trim())
+                            }
+                        }
+                        is Char -> {
+                            when (temp) {
+                                '+' -> PLUS
+                                '-' -> MINUS
+                                '/' -> DIVIDE
+                                '*' -> MULTIPLY
+                                else -> throw IllegalArgumentException("operator not found with value: $temp!")
+                            }
+                        }
+                        else -> throw IllegalArgumentException("operator not found by value: $value!")
                     }
                 } catch (ex: Exception) {
-                    throw IllegalArgumentException("operator not found!")
+                    defaultOperator ?: throw IllegalArgumentException("operator not found!")
                 }
             }
         }
     }
 
-    class MoneyGeneratorBuilder {
+    class MoneyObjectBuilder {
+        private val defaultCurrency = MoneyCurrency.USD.getCurrency()
+
         private var currency: String? = null
-        private val withs: MutableCollection<MoneyObject> = LinkedList()
+        private val withs: Deque<MoneyObject> = ArrayDeque()
 
         fun withCurrency(currency: String) = apply {
             this.currency = currency
         }
 
-        fun with(`object`: MoneyObject) = apply {
+        fun with(value: MoneyObject) = apply {
-            this.withs.add(`object`)
+            this.withs.add(value)
         }
 
         fun with(value: Double, currency: String, operator: MoneyOperator = MoneyOperator.PLUS) = apply {
@@ -112,21 +149,36 @@ class MoneyObject(
             )
         }
 
+        /**
+         * Example: String format => usd:1:+,khr:4000.0:-,usd:1 => 1 + (4000 eh) - 1 = 1USD
+         */
+        fun parseFromString(valuesString: String) = apply {
+            val valueGroups = valuesString.split(",")
+            valueGroups.forEach { value ->
+                val tempValue = value.trim().split(":")
+                if (tempValue.isNotEmpty() && !tempValue.firstOrNull().isNullOrEmpty()) {
+                    this.with(
+                        tempValue.getOrNull(1)?.toDoubleOrNull() ?: 0.0,
+                        tempValue.firstOrNull() ?: defaultCurrency,
+                        MoneyOperator.operator(tempValue.getOrNull(2), MoneyOperator.PLUS),
+                    )
+                }
+            }
+        }
+
         fun build(): MoneyObject {
-            val first: MoneyObject
+            val first: MoneyObject = if (this.currency.isNullOrEmpty() && withs.isNotEmpty()) {
-            if (this.currency.isNullOrEmpty() && withs.isNotEmpty()) {
+                withs.removeFirst()
-                first = withs.first()
-                withs.remove(first)
             } else {
-                first = MoneyObject(
+                MoneyObject(
                     value = 0.0,
+                    currency = this.currency ?: defaultCurrency,
                     operator = MoneyOperator.PLUS,
-                    currency = this.currency ?: MoneyCurrency.USD.getCurrency()
                 )
             }
 
-            withs.forEach { with ->
+            while (withs.isNotEmpty()) {
-                first.appendWith(with)
+                first.appendWithNext(withs.pop())
             }
 
             return first
@@ -138,6 +190,6 @@ class MoneyObject(
     }
 
     companion object {
-        fun builder() = MoneyGeneratorBuilder()
+        fun builder() = MoneyObjectBuilder()
     }
 }

src/test/kotlin/MoneyTests.kt

@@ -14,6 +14,14 @@ class MoneyTests {
         }
     }
 
+    object MyBatchRates {
+        fun getJsonRates(): String {
+            return """
+                {"USD": 1.0,"KHR": 4000.0, "eur": 0.5}
+            """.trimIndent()
+        }
+    }
+
     @Test
     fun exchange_2usd_to_khr_test() {
         initMoneyConfig()
@@ -47,14 +55,6 @@ class MoneyTests {
         Assert.assertEquals(156000.0, sum.getMoneyValue(), 0.0)
     }
 
-    object MyBatchRates {
-        fun getJsonRates(): String {
-            return """
-                {"USD": 1.0,"KHR": 4000.0, "eur": 0.5}
-            """.trimIndent()
-        }
-    }
-
     @Test
     fun moneyGenerator() {
         initMoneyConfig()
@@ -102,4 +102,37 @@ class MoneyTests {
 
         Assert.assertEquals(expected, result.getMoneyValue(), 0.0)
     }
+
+    @Test
+    fun moneyGeneratorBuilderWithStringValues() {
+        initMoneyConfig()
+
+        val values = "usd:1:+,khr:4000:-,usd:1:+,eur:1:+" // result = 3
+        val expected1 = 3.0
+        val expected2 = 3.5
+
+        val builder = MoneyObject.builder()
+            .withCurrency("usd")
+            .with(1.0, "usd", '-')
+            .with(4000.0, "khr")
+            .with(1.0, "usd")
+            .with(1.0, "usd")
+            .with(1.0, "usd")
+            .with(1.0, "usd")
+            .with(1.0, "eur", '-') // 2 usd
+            .with(1.0, "usd")
+            .with(2.0, "usd", '/')
+            .with(2.0, "usd")
+            .build() // 3.5
+
+        val result1 = MoneyObject.builder()
+            .parseFromString(values)
+            .withCurrency("usd")
+            .build()
+            .compute()
+        val result2 = builder.compute()
+
+        Assert.assertEquals(expected1, result1.getMoneyValue(), 0.0)
+        Assert.assertEquals(expected2, result2.getMoneyValue(), 0.0)
+    }
 }