1 files changed, 151 insertions, 0 deletions
diff --git a/src/main/scala/xyz/driver/core/file.scala b/src/main/scala/xyz/driver/core/file.scala
new file mode 100644
index 0000000..93715d0
--- /dev/null
+++ b/src/main/scala/xyz/driver/core/file.scala
@@ -0,0 +1,151 @@
+package xyz.driver.core
+
+import java.io.File
+import java.nio.file.{Path, Paths}
+import java.util.UUID._
+
+import com.amazonaws.services.s3.AmazonS3
+import com.amazonaws.services.s3.model.{Bucket, GetObjectRequest, ListObjectsV2Request}
+import xyz.driver.core.revision.Revision
+import xyz.driver.core.time.Time
+
+import scala.concurrent.{ExecutionContext, Future}
+import scalaz.{ListT, OptionT}
+
+object file {
+
+  final case class FileLink(
+          name: Name[File],
+          location: Path,
+          revision: Revision[File],
+          lastModificationDate: Time
+  )
+
+  trait FileService {
+
+    def getFileLink(id: Name[File]): FileLink
+
+    def getFile(fileLink: FileLink): File
+  }
+
+  trait FileStorage {
+
+    def upload(localSource: File, destination: Path): Future[Unit]
+
+    def download(filePath: Path): OptionT[Future, File]
+
+    def delete(filePath: Path): Future[Unit]
+
+    def list(path: Path): ListT[Future, FileLink]
+
+    /** List of characters to avoid in S3 (I would say file names in general)
+      *
+      * @see http://stackoverflow.com/questions/7116450/what-are-valid-s3-key-names-that-can-be-accessed-via-the-s3-rest-api
+      */
+    private val illegalChars = "\\^`><{}][#%~|&@:,$=+?; "
+
+    protected def checkSafeFileName[T](filePath: Path)(f: => T): T = {
+      filePath.toString.find(c => illegalChars.contains(c)) match {
+        case Some(illegalCharacter) =>
+          throw new IllegalArgumentException(s"File name cannot contain character `$illegalCharacter`")
+        case None => f
+      }
+    }
+  }
+
+  class S3Storage(s3: AmazonS3, bucket: Name[Bucket], executionContext: ExecutionContext) extends FileStorage {
+    implicit private val execution = executionContext
+
+    def upload(localSource: File, destination: Path): Future[Unit] = Future {
+      checkSafeFileName(destination) {
+        val _ = s3.putObject(bucket, destination.toString, localSource).getETag
+      }
+    }
+
+    def download(filePath: Path): OptionT[Future, File] =
+      OptionT.optionT(Future {
+        val tempDir             = System.getProperty("java.io.tmpdir")
+        val randomFolderName    = randomUUID().toString
+        val tempDestinationFile = new File(Paths.get(tempDir, randomFolderName, filePath.toString).toString)
+
+        if (!tempDestinationFile.getParentFile.mkdirs()) {
+          throw new Exception(s"Failed to create temp directory to download file `$tempDestinationFile`")
+        } else {
+          Option(s3.getObject(new GetObjectRequest(bucket, filePath.toString), tempDestinationFile)).map { _ =>
+            tempDestinationFile
+          }
+        }
+      })
+
+    def delete(filePath: Path): Future[Unit] = Future {
+      s3.deleteObject(bucket, filePath.toString)
+    }
+
+    def list(path: Path): ListT[Future, FileLink] =
+      ListT.listT(Future {
+        import scala.collection.JavaConverters._
+        val req = new ListObjectsV2Request().withBucketName(bucket).withPrefix(path.toString).withMaxKeys(2)
+
+        def isInSubFolder(path: Path)(fileLink: FileLink) =
+          fileLink.location.toString.replace(path.toString + "/", "").contains("/")
+
+        Iterator.continually(s3.listObjectsV2(req)).takeWhile { result =>
+          req.setContinuationToken(result.getNextContinuationToken)
+          result.isTruncated
+        } flatMap { result =>
+          result.getObjectSummaries.asScala.toList.map { summary =>
+            FileLink(Name[File](summary.getKey),
+                     Paths.get(path.toString + "/" + summary.getKey),
+                     Revision[File](summary.getETag),
+                     Time(summary.getLastModified.getTime))
+          } filterNot isInSubFolder(path)
+        } toList
+      })
+  }
+
+  class FileSystemStorage(executionContext: ExecutionContext) extends FileStorage {
+    implicit private val execution = executionContext
+
+    def upload(localSource: File, destination: Path): Future[Unit] = Future {
+      checkSafeFileName(destination) {
+        val destinationFile = destination.toFile
+
+        if (destinationFile.getParentFile.exists() || destinationFile.getParentFile.mkdirs()) {
+          if (localSource.renameTo(destinationFile)) ()
+          else {
+            throw new Exception(
+              s"Failed to move file from `${localSource.getCanonicalPath}` to `${destinationFile.getCanonicalPath}`")
+          }
+        } else {
+          throw new Exception(s"Failed to create parent directories for file `${destinationFile.getCanonicalPath}`")
+        }
+      }
+    }
+
+    def download(filePath: Path): OptionT[Future, File] =
+      OptionT.optionT(Future {
+        Option(new File(filePath.toString)).filter(file => file.exists() && file.isFile)
+      })
+
+    def delete(filePath: Path): Future[Unit] = Future {
+      val file = new File(filePath.toString)
+      if (file.delete()) ()
+      else {
+        throw new Exception(s"Failed to delete file $file" + (if (!file.exists()) ", file does not exist." else "."))
+      }
+    }
+
+    def list(path: Path): ListT[Future, FileLink] =
+      ListT.listT(Future {
+        val file = new File(path.toString)
+        if (file.isDirectory) {
+          file.listFiles().toList.filter(_.isFile).map { file =>
+            FileLink(Name[File](file.getName),
+                     Paths.get(file.getPath),
+                     Revision[File](file.hashCode.toString),
+                     Time(file.lastModified()))
+          }
+        } else List.empty[FileLink]
+      })
+  }
+}