Implements extracting last_modified_date of a resource where availa…

…ble. (#547)

* Adds `getLastModified` for `SparklingArchiveRecord`
* Adds `CovertLastModifiedDate` to convert RFC 1123 dates to `yyyyMMddHHmmss`
  * See: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Last-Modified
* Implement `last_modified_date` column for
  * `.all()`
  * `.webpages()`
  * `.images()`
  * `.pdfs()`
  * `.audio()`
  * `.videos()`
  * `.spreadsheets()`
  * `.presentationProgramFiles()`
  * `.wordProcessorFiles()`
  * `.css()`
  * `.html()`
  * `.js()`
  * `.json()`
  * `.plainText()`
  * `.xml()`
* Update tests
* Resolves #546

src/main/scala/io/archivesunleashed/ArchiveRecord.scala

@@ -48,4 +48,7 @@ trait ArchiveRecord extends Serializable {
 
   /** Returns payload digest (SHA1). */
   def getPayloadDigest: String
+
+  /** Returns last-modified date from HTTPS headers as a string. */
+  def getLastModified: String
 }

src/main/scala/io/archivesunleashed/SparklingArchiveRecord.scala

@@ -22,7 +22,11 @@ import io.archivesunleashed.matchbox.ExtractDomain
 import org.apache.tika.io.BoundedInputStream
 import org.archive.webservices.sparkling.http.HttpMessage
 import org.archive.webservices.sparkling.io.IOUtil
-import org.archive.webservices.sparkling.util.{ManagedVal, ValueSupplier}
+import org.archive.webservices.sparkling.util.{
+  ManagedVal,
+  RegexUtil,
+  ValueSupplier
+}
 import org.archive.webservices.sparkling.warc.{WarcHeaders, WarcRecord}
 import scala.util.Try
 
@@ -60,6 +64,11 @@ class SparklingArchiveRecord(
     new SparklingArchiveRecord(filename, meta, payload, maxBodyLength)
   }
 
+  override def getLastModified: String =
+    http(warc)
+      .flatMap(_.headerMap.get("last-modified"))
+      .getOrElse("")
+
   override def getArchiveFilename: String = filename
 
   override def getCrawlDate: String =

src/main/scala/io/archivesunleashed/app/AudioInformationExtractor.scala

@@ -35,6 +35,7 @@ object AudioInformationExtractor {
     // scalastyle:on
     d.select(
       $"crawl_date",
+      $"last_modified_date",
       $"url",
       $"filename",
       $"extension",

src/main/scala/io/archivesunleashed/app/ImageInformationExtractor.scala

@@ -35,6 +35,7 @@ object ImageInformationExtractor {
     // scalastyle:on
     d.select(
       $"crawl_date",
+      $"last_modified_date",
       $"url",
       $"filename",
       $"extension",

src/main/scala/io/archivesunleashed/app/PDFInformationExtractor.scala

@@ -35,6 +35,7 @@ object PDFInformationExtractor {
     // scalastyle:on
     d.select(
       $"crawl_date",
+      $"last_modified_date",
       $"url",
       $"filename",
       $"extension",

src/main/scala/io/archivesunleashed/app/PresentationProgramInformationExtractor.scala

@@ -35,6 +35,7 @@ object PresentationProgramInformationExtractor {
     // scalastyle:on
     d.select(
       $"crawl_date",
+      $"last_modified_date",
       $"url",
       $"filename",
       $"extension",

src/main/scala/io/archivesunleashed/app/SpreadsheetInformationExtractor.scala

@@ -35,6 +35,7 @@ object SpreadsheetInformationExtractor {
     // scalastyle:on
     d.select(
       $"crawl_date",
+      $"last_modified_date",
       $"url",
       $"filename",
       $"extension",

src/main/scala/io/archivesunleashed/app/VideoInformationExtractor.scala

@@ -35,6 +35,7 @@ object VideoInformationExtractor {
     // scalastyle:on
     d.select(
       $"crawl_date",
+      $"last_modified_date",
       $"url",
       $"filename",
       $"extension",

src/main/scala/io/archivesunleashed/app/WordProcessorInformationExtractor.scala

@@ -35,6 +35,7 @@ object WordProcessorInformationExtractor {
     // scalastyle:on
     d.select(
       $"crawl_date",
+      $"last_modified_date",
       $"url",
       $"filename",
       $"extension",

src/main/scala/io/archivesunleashed/matchbox/CovertLastModifiedDate.scala

@@ -0,0 +1,65 @@
+/*
+ * Copyright © 2017 The Archives Unleashed Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.archivesunleashed.matchbox
+
+/** Converts RFC 1123 dates to yyyyMMddHHmmss. */
+object CovertLastModifiedDate {
+  val months = Seq(
+    "jan",
+    "feb",
+    "mar",
+    "apr",
+    "may",
+    "jun",
+    "jul",
+    "aug",
+    "sep",
+    "oct",
+    "nov",
+    "dec"
+  ).zipWithIndex.map { case (s, d) => (s, ("0" + (d + 1)).takeRight(2)) }
+
+  /** Converts last_modified_date to yyyyMMddHHmmss.
+    *
+    * @param lastModifiedDate date returned by `getLastModified`, formatted as RFC 1123
+    * @return last_modified_date as yyyyMMddHHmmss.
+    */
+  def apply(lastModifiedDate: String): String = {
+    if (lastModifiedDate.isEmpty) {
+      ""
+    } else {
+      // Credit: Helge Holzmann (@helgeho)
+      // Adapted from https://github.com/archivesunleashed/aut/pull/547#issuecomment-1302094573
+      val lc = lastModifiedDate.toLowerCase
+      val date = months.find(m => lc.contains(m._1)).map(_._2).flatMap { m =>
+        val d = lc
+          .replace(":", "")
+          .split(' ')
+          .drop(1)
+          .map(d => (d.length, d))
+          .toMap
+        for (y <- d.get(4); n <- d.get(2); t <- d.get(6))
+          yield y + m + n + t
+      }
+      date match {
+        case Some(date) =>
+          date
+        case None =>
+          ""
+      }
+    }
+  }
+}