Move mimetype detection to docspell-files

modules/files/src/main/scala/docspell/files/TikaMimetype.scala

@@ -0,0 +1,41 @@
+package docspell.files
+
+import cats.implicits._
+import cats.effect.Sync
+import docspell.common._
+import fs2.Stream
+import org.apache.tika.config.TikaConfig
+import org.apache.tika.metadata.{HttpHeaders, Metadata, TikaMetadataKeys}
+import org.apache.tika.mime.MediaType
+
+object TikaMimetype {
+  private val tika = new TikaConfig().getDetector
+
+  private def convert(mt: MediaType): MimeType =
+    Option(mt)
+      .map(_.toString)
+      .map(MimeType.parse)
+      .flatMap(_.toOption)
+      .map(normalize)
+      .getOrElse(MimeType.octetStream)
+
+  private def makeMetadata(hint: MimeTypeHint): Metadata = {
+    val md = new Metadata
+    hint.filename.foreach(md.set(TikaMetadataKeys.RESOURCE_NAME_KEY, _))
+    hint.advertised.foreach(md.set(HttpHeaders.CONTENT_TYPE, _))
+    md
+  }
+
+  private def normalize(in: MimeType): MimeType = in match {
+    case MimeType(_, sub) if sub contains "xhtml" =>
+      MimeType.html
+    case _ => in
+  }
+
+  private def fromBytes(bv: Array[Byte], hint: MimeTypeHint): MimeType =
+    convert(tika.detect(new java.io.ByteArrayInputStream(bv), makeMetadata(hint)))
+
+  def detect[F[_]: Sync](data: Stream[F, Byte], hint: MimeTypeHint): F[MimeType] =
+    data.take(64).compile.toVector.map(bytes => fromBytes(bytes.toArray, hint))
+
+}