4 files changed, 63 insertions, 7 deletions

diff --git a/compiler/package.yaml b/compiler/package.yaml
index 0922c36..fd44ccc 100644
--- a/compiler/package.yaml
+++ b/compiler/package.yaml
@@ -27,6 +27,8 @@ dependencies:
 - JuicyPixels-extra
 - parallel-io
 - Glob
+- safe
+- time >= 1.9.3 && < 1.10
 
 default-extensions:
 - DuplicateRecordFields
diff --git a/compiler/src/Resource.hs b/compiler/src/Resource.hs
index 261191b..207239f 100644
--- a/compiler/src/Resource.hs
+++ b/compiler/src/Resource.hs
@@ -30,6 +30,10 @@ import Data.Char (toLower)
 import Data.Maybe (mapMaybe, fromMaybe)
 import Data.Function ((&))
 import qualified Data.Set as Set
+import Data.Time.LocalTime (ZonedTime, utc, utcToZonedTime, zonedTimeToUTC)
+import Data.Time.Format.ISO8601 (iso8601ParseM)
+import System.Directory (getModificationTime)
+import Safe.Foldable (maximumByMay)
 
 import GHC.Generics (Generic)
 import Data.Aeson (FromJSON, ToJSON, genericToJSON, genericToEncoding)
@@ -75,7 +79,7 @@ instance ToJSON GalleryItemProps where
 
 data GalleryItem = GalleryItem
   { title :: String
-  , date :: String -- TODO: checked ISO8601 date
+  , date :: ZonedTime
   , description :: String
   , tags :: [Tag]
   , path :: Path
@@ -103,18 +107,22 @@ buildGalleryTree processItem processThumbnail tagsFromDirectories galleryName in
       do
         properties <- processItem path
         processedThumbnail <- processThumbnail path
+        fileModTime <- lastModTime path
         return GalleryItem
           { title = itemTitle
-          , date = optMeta date "" -- TODO: check and normalise dates
+          , date = fromMaybe fileModTime itemDate
           , description = optMeta description ""
           , tags = (optMeta tags []) ++ implicitParentTags parents
           , path = parents </ itemTitle
           , thumbnail = processedThumbnail
-          , properties = properties } -- TODO
+          , properties = properties }
       where
         itemTitle :: String
         itemTitle = optMeta title $ fromMaybe "" $ fileName path
 
+        itemDate :: Maybe ZonedTime
+        itemDate = Input.date sidecar >>= iso8601ParseM
+
         optMeta :: (Sidecar -> Maybe a) -> a -> a
         optMeta get fallback = fromMaybe fallback $ get sidecar
 
@@ -122,11 +130,10 @@ buildGalleryTree processItem processThumbnail tagsFromDirectories galleryName in
       do
         processedThumbnail <- maybeThumbnail dirThumbnailPath
         processedItems <- parallel $ map (mkGalleryItem Nothing itemPath) items
+        dirModTime <- lastModTime path
         return GalleryItem
           { title = itemTitle
-            -- TODO: consider using the most recent item's date? what if empty?
-          , date = ""
-            -- TODO: consider allowing metadata sidecars for directories too
+          , date = fromMaybe dirModTime $ mostRecentChildModTime processedItems
           , description = ""
           , tags = (aggregateChildTags processedItems) ++ implicitParentTags parents
           , path = itemPath
@@ -143,6 +150,13 @@ buildGalleryTree processItem processThumbnail tagsFromDirectories galleryName in
         maybeThumbnail Nothing = return Nothing
         maybeThumbnail (Just thumbnailPath) = processThumbnail thumbnailPath
 
+        mostRecentChildModTime :: [GalleryItem] -> Maybe ZonedTime
+        mostRecentChildModTime =
+          maximumByMay comparingDates . map (date::(GalleryItem -> ZonedTime))
+
+        comparingDates :: ZonedTime -> ZonedTime -> Ordering
+        comparingDates l r = compare (zonedTimeToUTC l) (zonedTimeToUTC r)
+
         aggregateChildTags :: [GalleryItem] -> [Tag]
         aggregateChildTags = unique . concatMap (\item -> tags (item::GalleryItem))
 
@@ -152,6 +166,12 @@ buildGalleryTree processItem processThumbnail tagsFromDirectories galleryName in
     implicitParentTags :: Path -> [Tag]
     implicitParentTags (Path elements) = take tagsFromDirectories elements
 
+    lastModTime :: Path -> IO ZonedTime
+    lastModTime path =
+      localPath path
+      &   getModificationTime
+      >>= return . utcToZonedTime utc
+
 
 flattenGalleryTree :: GalleryItem -> [GalleryItem]
 flattenGalleryTree dir@(GalleryItem _ _ _ _ _ _ (Directory items)) =
diff --git a/compiler/stack.yaml b/compiler/stack.yaml
index 29f8539..146f46b 100644
--- a/compiler/stack.yaml
+++ b/compiler/stack.yaml
@@ -41,6 +41,12 @@ packages:
 #
 # extra-deps: []
 
+extra-deps:
+- time-1.9.3@sha256:8f1b5448722a12a952248b356c9eb366e351226543d9086a2da71270522d5f45,5679
+- directory-1.3.4.0@sha256:500019f04494324d1df16cf83eefeb3f809b2b20b32a32ccd755ee0439c18bfd,2829
+- process-1.6.7.0@sha256:305bcf44c42a96425e77af1748183f505a701648f68cc299d5ad8ac1b866a6a1,2468
+- unix-2.7.2.2@sha256:e69269a17b9fa26cb77f3f55e86c39d0a4940ccfa0c4bc20826919d2572076ad,3496
+
 # Override default flag values for local packages and extra-deps
 # flags: {}
 
diff --git a/compiler/stack.yaml.lock b/compiler/stack.yaml.lock
index fc538c1..8e833c5 100644
--- a/compiler/stack.yaml.lock
+++ b/compiler/stack.yaml.lock
@@ -3,7 +3,35 @@
 # For more information, please see the documentation at:
 #   https://docs.haskellstack.org/en/stable/lock_files
 
-packages: []
+packages:
+- completed:
+    hackage: time-1.9.3@sha256:8f1b5448722a12a952248b356c9eb366e351226543d9086a2da71270522d5f45,5679
+    pantry-tree:
+      size: 6558
+      sha256: a1043c1719491764f0fa37a1fd70d9451080548a41632fee88d8e1b8db4942d6
+  original:
+    hackage: time-1.9.3@sha256:8f1b5448722a12a952248b356c9eb366e351226543d9086a2da71270522d5f45,5679
+- completed:
+    hackage: directory-1.3.4.0@sha256:500019f04494324d1df16cf83eefeb3f809b2b20b32a32ccd755ee0439c18bfd,2829
+    pantry-tree:
+      size: 3365
+      sha256: 00c09e0c014d29ebfb921b64c1459e61a0ad6f10e70128d795246a47c06394b0
+  original:
+    hackage: directory-1.3.4.0@sha256:500019f04494324d1df16cf83eefeb3f809b2b20b32a32ccd755ee0439c18bfd,2829
+- completed:
+    hackage: process-1.6.7.0@sha256:305bcf44c42a96425e77af1748183f505a701648f68cc299d5ad8ac1b866a6a1,2468
+    pantry-tree:
+      size: 1211
+      sha256: 49c3e531d2473fe455c1cde655f074a320fa4ec8569d650262bf382f9c5796fb
+  original:
+    hackage: process-1.6.7.0@sha256:305bcf44c42a96425e77af1748183f505a701648f68cc299d5ad8ac1b866a6a1,2468
+- completed:
+    hackage: unix-2.7.2.2@sha256:e69269a17b9fa26cb77f3f55e86c39d0a4940ccfa0c4bc20826919d2572076ad,3496
+    pantry-tree:
+      size: 3536
+      sha256: c355f7924ce67e5bf8f20767462af18f09b8c0d1f7161117221cbb94c15deee3
+  original:
+    hackage: unix-2.7.2.2@sha256:e69269a17b9fa26cb77f3f55e86c39d0a4940ccfa0c4bc20826919d2572076ad,3496
 snapshots:
 - completed:
     size: 524799