1 files changed, 43 insertions, 2 deletions
diff --git a/src/scalevalapokalypsi/utils/utils.scala b/src/scalevalapokalypsi/utils/utils.scala
index ab262ad..54d407b 100644
--- a/src/scalevalapokalypsi/utils/utils.scala
+++ b/src/scalevalapokalypsi/utils/utils.scala
@@ -2,6 +2,9 @@ package scalevalapokalypsi.utils
 
 import java.io.InputStream
 import java.nio.charset.StandardCharsets
+import scala.util.Try
+import scalevalapokalypsi.constants.*
+import scala.io.StdIn.readLine
 
 /** Converts this string to an array of bytes (probably for transmission).
   *
@@ -11,6 +14,16 @@ import java.nio.charset.StandardCharsets
 def stringToByteArray(str: String): Array[Byte] =
 	str.getBytes(StandardCharsets.UTF_8)
 
+/** Converts the given byte array to a string if possible*.
+  * (* Doesn't convert strings with control sequences in them)
+  *
+  * @param bytes the byte array to convert
+  * @return      the matching string, if possible*.
+  */
+def byteArrayToString(bytes: Array[Byte]): Option[String] =
+	Try(String(bytes, StandardCharsets.UTF_8))
+		.toOption
+
 /** Reads n characters from the given InputStream blockingly.
   *
   * @param input the InputStream to read from
@@ -25,5 +38,33 @@ def getNCharsFromSocket(input: InputStream, n: Int): Option[String] =
 		val res = input.read(buffer, i, n - i)
 		if res < 0 then failed = true
 		i += res
-	// TODO: better error handling
-	if failed then None else Some(String(buffer, StandardCharsets.UTF_8))
+	if failed then None else byteArrayToString(buffer)
+
+def isPrintable(s: String): Boolean =
+	FORBIDDEN_CHARACTERS.forall((c: Char) => !(s contains c))
+
+
+/** Gets input from STDIN until the line entered is appoved
+  * by a validator function.
+  *
+  * @param message   A query to represent the user with when requesting input
+  * @param validator A validator function. Should return Right[A] when the
+  *                  input is valid and Left[String] when the input is invalid,
+  *                  where the string will be printed to the user to notify
+  *                  their input was invalid.
+  * @return          The first encountered valid string, see `validator`.
+  */
+def getValidInput[A](
+	message: String,
+	validator: String => Either[String, A]
+): A =
+	LazyList.continually(readLine(s"$message\n> "))
+		.flatMap(input =>
+			validator(input) match
+				case Left(s) =>
+					println(s)
+					None
+				case Right(a) =>
+					Some(a)
+		).head
+