From 7d688954f7d8a940a0c404a7bb55fe973db424d3 Mon Sep 17 00:00:00 2001
From: Paul Campbell <pcampbell@kemitix.net>
Date: Thu, 9 May 2019 17:34:17 +0100
Subject: [PATCH] [uploadselectionfilter] implement with tests

---
 .../s3thorp/UploadSelectionFilter.scala       | 24 ++++++++----
 .../s3thorp/UploadSelectionFilterSuite.scala  | 39 +++++++++++++++++++
 .../kemitix/s3thorp/test-file-for-hash.txt    |  1 +
 3 files changed, 57 insertions(+), 7 deletions(-)
 create mode 100644 src/test/scala/net/kemitix/s3thorp/UploadSelectionFilterSuite.scala
 create mode 100644 src/test/scala/net/kemitix/s3thorp/test-file-for-hash.txt

diff --git a/src/main/scala/net/kemitix/s3thorp/UploadSelectionFilter.scala b/src/main/scala/net/kemitix/s3thorp/UploadSelectionFilter.scala
index b22dc46..a2e8609 100644
--- a/src/main/scala/net/kemitix/s3thorp/UploadSelectionFilter.scala
+++ b/src/main/scala/net/kemitix/s3thorp/UploadSelectionFilter.scala
@@ -1,21 +1,31 @@
 package net.kemitix.s3thorp
 
-import java.io.File
-
 import fs2.Stream
 import cats.effect.IO
-import net.kemitix.s3thorp.Main.putStrLn
+import net.kemitix.s3thorp.Sync.{Hash, LocalFile}
+import java.security.{MessageDigest, DigestInputStream}
+import java.io.{File, FileInputStream}
 
 trait UploadSelectionFilter {
 
+  private def md5File(localFile: LocalFile): Hash =  {
+    val buffer = new Array[Byte](8192)
+    val md5 = MessageDigest.getInstance("MD5")
+
+    val dis = new DigestInputStream(new FileInputStream(localFile), md5)
+    try { while (dis.read(buffer) != -1) { } } finally { dis.close() }
+
+    md5.digest.map("%02x".format(_)).mkString
+  }
+
   def uploadRequiredFilter: Either[File, S3MetaData] => Stream[IO, File] = {
     case Left(file) => Stream(file)
     case Right(s3Metadata) =>
       Stream.eval(for {
-        _ <- putStrLn(s"upload required: ${s3Metadata.localFile}")
-        //md5File(localFile)
-        //filter(localHash => options.force || localHash != metadataHash)
-      } yield s3Metadata.localFile)
+        localHash <- IO(md5File(s3Metadata.localFile))
+      } yield (s3Metadata.localFile, localHash)).
+        filter { case (_, localHash) => localHash != s3Metadata.remoteHash }.
+        map {case (localFile,_) => localFile}
   }
 
 }
diff --git a/src/test/scala/net/kemitix/s3thorp/UploadSelectionFilterSuite.scala b/src/test/scala/net/kemitix/s3thorp/UploadSelectionFilterSuite.scala
new file mode 100644
index 0000000..184cb35
--- /dev/null
+++ b/src/test/scala/net/kemitix/s3thorp/UploadSelectionFilterSuite.scala
@@ -0,0 +1,39 @@
+package net.kemitix.s3thorp
+
+import java.io.File
+import java.time.Instant
+
+import org.scalatest.FunSpec
+
+class UploadSelectionFilterSuite extends FunSpec {
+
+  new UploadSelectionFilter {
+    describe("uploadRequiredFilter") {
+      val localFile = new File("src/test/scala/net/kemitix/s3thorp/test-file-for-hash.txt")
+      val localHash = "0cbfe978783bd7950d5da4ff85e4af37"
+      def invokeSubject(input: Either[File, S3MetaData]) = {
+        uploadRequiredFilter(input).compile.toList.unsafeRunSync()
+      }
+      describe("when supplied a file") {
+        val input = Left(localFile)
+        it("should be marked for upload") {
+          assertResult(List(localFile))(invokeSubject(input))
+        }
+      }
+      describe("when supplied S3MetaData") {
+        describe("when hash is different") {
+          val input = Right(S3MetaData(localFile, "", "doesn't match any hash", Instant.now))
+          it("should be marked for upload") {
+            assertResult(List(localFile))(invokeSubject(input))
+          }
+        }
+        describe("when hash is the same") {
+          val input = Right(S3MetaData(localFile, "", localHash, Instant.now))
+          it("should not be marked for upload") {
+            assertResult(List())(invokeSubject(input))
+          }
+        }
+      }
+    }
+  }
+}
diff --git a/src/test/scala/net/kemitix/s3thorp/test-file-for-hash.txt b/src/test/scala/net/kemitix/s3thorp/test-file-for-hash.txt
new file mode 100644
index 0000000..941de6f
--- /dev/null
+++ b/src/test/scala/net/kemitix/s3thorp/test-file-for-hash.txt
@@ -0,0 +1 @@
+This is a test file for checking the md5 hash generator.