From da5049627131aa24d6b922c64cb9dd68bef37821 Mon Sep 17 00:00:00 2001
From: Oscar Mira <valldrac@molly.im>
Date: Sun, 3 Mar 2024 12:43:47 +0100
Subject: [PATCH] lib: improve amount parsing and formating

---
 .../kotlin/im/molly/monero/MoneroAmount.kt    |  4 ++++
 .../kotlin/im/molly/monero/MoneroCurrency.kt  | 24 +++++++++++++++----
 2 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/lib/android/src/main/kotlin/im/molly/monero/MoneroAmount.kt b/lib/android/src/main/kotlin/im/molly/monero/MoneroAmount.kt
index 4d6267b..445a805 100644
--- a/lib/android/src/main/kotlin/im/molly/monero/MoneroAmount.kt
+++ b/lib/android/src/main/kotlin/im/molly/monero/MoneroAmount.kt
@@ -18,6 +18,8 @@ value class MoneroAmount(val atomicUnits: Long) : Parcelable {
     val xmr: BigDecimal
         get() = BigDecimal.valueOf(atomicUnits, ATOMIC_UNIT_SCALE)
 
+    val isZero: Boolean get() = atomicUnits == 0L
+
     override fun toString() = atomicUnits.toString()
 
     operator fun plus(other: MoneroAmount) =
@@ -39,6 +41,8 @@ inline val BigDecimal.xmr: MoneroAmount
         return MoneroAmount(atomicUnits)
     }
 
+inline val Number.xmr: MoneroAmount get() = (this as BigDecimal).xmr
+
 inline val Double.xmr: MoneroAmount get() = BigDecimal(this).xmr
 
 inline val Long.xmr: MoneroAmount get() = BigDecimal(this).xmr
diff --git a/lib/android/src/main/kotlin/im/molly/monero/MoneroCurrency.kt b/lib/android/src/main/kotlin/im/molly/monero/MoneroCurrency.kt
index 442bfac..eacdd36 100644
--- a/lib/android/src/main/kotlin/im/molly/monero/MoneroCurrency.kt
+++ b/lib/android/src/main/kotlin/im/molly/monero/MoneroCurrency.kt
@@ -1,5 +1,6 @@
 package im.molly.monero
 
+import java.text.DecimalFormat
 import java.text.NumberFormat
 import java.util.Locale
 import kotlin.math.absoluteValue
@@ -19,16 +20,20 @@ object MoneroCurrency {
             }
         }
 
-        private val numberFormat = NumberFormat.getInstance(locale).apply {
+        private val numberFormat = (DecimalFormat.getInstance(locale) as DecimalFormat).apply {
             minimumFractionDigits = precision
+            isParseBigDecimal = true
         }
 
         open fun format(amount: MoneroAmount): String {
             return numberFormat.format(amount.xmr)
         }
 
+        /**
+         * @throw ParseException
+         */
         open fun parse(source: String): MoneroAmount {
-            TODO()
+            return numberFormat.parse(source)?.xmr ?: MoneroAmount.ZERO
         }
     }
 
@@ -59,7 +64,18 @@ object MoneroCurrency {
         return outputFormat.format(amount)
     }
 
-    fun format(amount: MoneroAmount, precision: Int): String {
-        return Format(precision = precision).format(amount)
+    fun format(amount: MoneroAmount, precision: Int, appendSymbol: Boolean = false): String {
+        val formatted = Format(precision = precision).format(amount)
+        return if (appendSymbol) "$formatted $SYMBOL" else formatted
+    }
+
+    /**
+     * @throw ParseException
+     */
+    fun parse(source: String, outputFormat: Format = ExactFormat): MoneroAmount {
+        return outputFormat.parse(source)
     }
 }
+
+fun MoneroAmount.toFormattedString(precision: Int = 5, appendSymbol: Boolean = false): String =
+    MoneroCurrency.format(amount = this, precision = precision, appendSymbol = appendSymbol)