Add License model

Common `License` class which could be used by all apps to check if user has accepted SLUL

modules/runtime-common/src/main/scala/com/snowplowanalytics/snowplow/runtime/AcceptedLicense.scala

@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2023-present Snowplow Analytics Ltd. All rights reserved.
+ *
+ * This program is licensed to you under the Snowplow Community License Version 1.0,
+ * and you may not use this file except in compliance with the Snowplow Community License Version 1.0.
+ * You may obtain a copy of the Snowplow Community License Version 1.0 at https://docs.snowplow.io/community-license-1.0
+ */
+package com.snowplowanalytics.snowplow.runtime
+
+import io.circe.Decoder
+
+final case class AcceptedLicense()
+
+object AcceptedLicense {
+  final case class DocumentationLink(value: String)
+
+  def decoder(documentationLink: DocumentationLink): Decoder[AcceptedLicense] = {
+    val truthy = Set("true", "yes", "on", "1")
+    Decoder
+      .forProduct1("accept")((s: String) => truthy(s.toLowerCase()))
+      .or(Decoder.forProduct1("accept")((b: Boolean) => b))
+      .emap {
+        case false =>
+          Left(
+            s"Please accept the terms of the Snowplow Limited Use License Agreement to proceed. See ${documentationLink.value} for more information on the license and how to configure this."
+          )
+        case _ =>
+          Right(AcceptedLicense())
+      }
+  }
+}

modules/runtime-common/src/test/scala/com/snowplowanalytics/snowplow/runtime/LicenseSpec.scala

@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2023-present Snowplow Analytics Ltd. All rights reserved.
+ *
+ * This program is licensed to you under the Snowplow Community License Version 1.0,
+ * and you may not use this file except in compliance with the Snowplow Community License Version 1.0.
+ * You may obtain a copy of the Snowplow Community License Version 1.0 at https://docs.snowplow.io/community-license-1.0
+ */
+package com.snowplowanalytics.snowplow.runtime
+
+import cats.effect.testing.specs2.CatsEffect
+import io.circe.literal.JsonStringContext
+import io.circe.{Decoder, DecodingFailure}
+import org.specs2.Specification
+
+class LicenseSpec extends Specification with CatsEffect {
+
+  implicit val decoder: Decoder[AcceptedLicense] =
+    AcceptedLicense.decoder(AcceptedLicense.DocumentationLink("https://test.license.doc"))
+
+  private val expectedErrorMessage =
+    "DecodingFailure at : Please accept the terms of the Snowplow Limited Use License Agreement to proceed. See https://test.license.doc for more information on the license and how to configure this."
+
+  def is = s2"""
+      Decoding license should be successful for:
+        boolean true $e1
+        string "true" $e2
+        string "yes" $e3
+        string "on" $e4
+        string "1" $e5
+      Decoding license should not be successful for:
+        boolean false $e6
+        string "false" $e7
+        any 'non-truthy' string like "something" $e8
+        """
+
+  def e1 =
+    json"""{"accept": true}""".as[AcceptedLicense] must beRight(AcceptedLicense())
+
+  def e2 =
+    json"""{"accept": "true"}""".as[AcceptedLicense] must beRight(AcceptedLicense())
+
+  def e3 =
+    json"""{"accept": "yes"}""".as[AcceptedLicense] must beRight(AcceptedLicense())
+
+  def e4 =
+    json"""{"accept": "on"}""".as[AcceptedLicense] must beRight(AcceptedLicense())
+
+  def e5 =
+    json"""{"accept": "1"}""".as[AcceptedLicense] must beRight(AcceptedLicense())
+
+  def e6 =
+    json"""{"accept": false}""".as[AcceptedLicense] must beLeft.like { case er: DecodingFailure =>
+      er.getMessage must beEqualTo(expectedErrorMessage)
+    }
+
+  def e7 =
+    json"""{"accept": "false"}""".as[AcceptedLicense] must beLeft.like { case er: DecodingFailure =>
+      er.getMessage must beEqualTo(expectedErrorMessage)
+    }
+
+  def e8 =
+    json"""{"accept": "something"}""".as[AcceptedLicense] must beLeft.like { case er: DecodingFailure =>
+      er.getMessage must beEqualTo(expectedErrorMessage)
+    }
+}