From fa7d1fab5550822b1f4cad753f122515a818a600 Mon Sep 17 00:00:00 2001
From: Mirek Kratochvil <miroslav.kratochvil@uni.lu>
Date: Thu, 22 Jun 2023 11:34:00 +0200
Subject: [PATCH] avoid overwriting timestamps if they are forced by markdown
 already

---
 Types.hs        |  3 ++-
 cards/404.md    |  2 ++
 cards/index.md  |  1 +
 cards/search.md |  1 +
 site.hs         | 20 +++++++++++---------
 5 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/Types.hs b/Types.hs
index 455a4f4..7f09b05 100644
--- a/Types.hs
+++ b/Types.hs
@@ -132,7 +132,8 @@ siteOptions' = do
   _timestampSuffix <-
     strOption $
     long "timestamp-prefix" <>
-    help "Timestamp file suffix for markdowns" <> value ".timestamp" <> showDefault
+    help "Timestamp file suffix for markdowns" <>
+    value ".timestamp" <> showDefault
   _dumpFinalState <-
     switch $
     long "dump-state" <>
diff --git a/cards/404.md b/cards/404.md
index 60148b7..a0e09ea 100644
--- a/cards/404.md
+++ b/cards/404.md
@@ -2,6 +2,8 @@
 mount: /404
 title: Page not found
 search: off
+toc: off
+timestamp: null
 ---
 
 # Page not found!
diff --git a/cards/index.md b/cards/index.md
index b493711..fb19e6e 100644
--- a/cards/index.md
+++ b/cards/index.md
@@ -3,6 +3,7 @@ mount: /
 title: Home
 template: index.html
 toc: off
+timestamp: null
 ---
 
 #### What are How-To Cards?
diff --git a/cards/search.md b/cards/search.md
index cefd3eb..42713f0 100644
--- a/cards/search.md
+++ b/cards/search.md
@@ -4,6 +4,7 @@ title: Search
 template: search.html
 search: off
 toc: off
+timestamp: null
 ---
 
 # Search
diff --git a/site.hs b/site.hs
index 7989dff..d60486e 100644
--- a/site.hs
+++ b/site.hs
@@ -182,15 +182,17 @@ timestampFile fp = do
 
 -- | If a timestamp file for the page exists, add the timestamp metadata.
 addTimeMeta :: PageInfo -> Y.Value -> Site Y.Value
-addTimeMeta pi m'@(Y.Object m) = do
-  tspath <- timestampFile $ pi ^. pagePath
-  io $
-    ifM
-      (doesFileExist tspath)
-      (do putStrLn $ "timestamp <- " ++ tspath
-          ts <- Y.String <$> TIO.readFile tspath
-          pure . Y.Object $ KM.insert "timestamp" ts m)
-      (pure m')
+addTimeMeta pi m'@(Y.Object m)
+  | "timestamp" `KM.member` m = pure m' -- do not overwrite the timestamp if present
+  | otherwise = do
+    tspath <- timestampFile $ pi ^. pagePath
+    io $
+      ifM
+        (doesFileExist tspath)
+        (do putStrLn $ "timestamp <- " ++ tspath
+            ts <- Y.String <$> TIO.readFile tspath
+            pure . Y.Object $ KM.insert "timestamp" ts m)
+        (pure m')
 
 -- | Add page-specific information to the metadata. In this instance, this just
 -- expands the tags for rendering. Eventually would be nice to have the timestamps