improve IPAddress constructor and make isAddressV4 and isAddressV6 private

1 files changed, 33 insertions, 12 deletions

diff --git a/src/main/kotlin/IPAddress.kt b/src/main/kotlin/IPAddress.kt
index 5707ced..58d0aae 100644
--- a/src/main/kotlin/IPAddress.kt
+++ b/src/main/kotlin/IPAddress.kt
@@ -9,9 +9,6 @@ class IPAddress {
      * @throws NumberFormatException if the IP address follows neither the IPv4 syntax, nor the IPv6 syntax.
      */
     constructor(address: String) {
-        val split4 = address.split('.')
-        val split6 = address.split(':')
-
         if (isAddressV4(address)) {
             this.is4 = true
         } else if (isAddressV6(address)) {
@@ -20,24 +17,48 @@ class IPAddress {
             throw NumberFormatException()
         }
 
-        var bytes: List<Byte> = if (this.is4) {
-            split4.map { it.toByte(10) }
+        val split4 = address.split('.')
+        val split6 = address.split(':')
+        val bytes: List<Byte>
+        if (this.is4) {
+            bytes = split4.map { it.toByte(10) }
         } else {
-            split6.map { it.toByte(16) }
+            val shorts = split6.map { it.toShort(16) }
+            bytes = shorts.flatMap {
+                listOf(
+                    it.toInt().shr(8).toByte(),
+                    it.toInt().and(0x00FF).toByte()
+                )
+            }
         }
         this.address = bytes.toTypedArray()
     }
 
-    fun isAddressV4(address: String): Boolean {
+    private fun isAddressV4(address: String): Boolean {
         val split4 = address.split('.')
-        return split4.size == 4 &&
-                split4.size == split4.filter { it.matches(Regex("^[0-9]+$")) }.size
+        var isOK = split4.size == 4
+        isOK = isOK && split4.size == split4.filter { it.matches(Regex("^[0-9]+$")) }.size
+        return isOK
     }
 
-    fun isAddressV6(address: String): Boolean {
+    private fun isAddressV6(address: String): Boolean {
         val split6 = address.split(':')
-        return split6.size == 16 &&
-                split6.size == split6.filter { it.contains(Regex("^[0-9][a-f]+$")) }.size
+        var isOK = split6.size == 8
+        isOK = isOK && split6.size == split6.filter { it.contains(Regex("^[0-9][a-f]+$")) }.size
+        if (isOK) {
+            return true
+        }
+
+        // try with "::"
+        val split6Double = address.split("::")
+        if (split6Double.size != 2) {
+            return false
+        }
+        val omitted = 8 - split6Double[0].split(':').size - split6Double[1].split(':').size
+        if (omitted < 0) {
+            return false
+        }
+        return true
     }
 
     override fun toString(): String {