From 9f52bec00561d7d481b79a38fa02586626b4b5cd Mon Sep 17 00:00:00 2001
From: Tom Smeding <tom@tomsmeding.com>
Date: Mon, 20 Jul 2026 10:10:21 +0100
Subject: Prev/next buttons on calendar-day

Thanks jreicher for suggesting!
---
 pages/calendar-day.mustache |  8 +++++++-
 src/Index.hs                | 25 ++++++++++++++-----------
 src/Main.hs                 | 10 ++++++++--
 src/Pages.hs                |  5 +++++
 4 files changed, 34 insertions(+), 14 deletions(-)

diff --git a/pages/calendar-day.mustache b/pages/calendar-day.mustache
index a40f072..f47a41b 100644
--- a/pages/calendar-day.mustache
+++ b/pages/calendar-day.mustache
@@ -18,7 +18,13 @@
     </header>
     <main>
       <h1>Logs on {{date}} ({{network}}/{{channel}})</h1>
-      <div class="viewopts">
+      <div class="pagepicker">
+        {{#picker}}
+          {{#prevpage}}<a href="/cal/{{&alias}}/{{.}}">{{/prevpage}}&larr;Prev{{#prevpage}}</a>{{/prevpage}}&nbsp;
+          {{#nextpage}}<a href="/cal/{{&alias}}/{{.}}">{{/nextpage}}Next&rarr;{{#nextpage}}</a>{{/nextpage}}
+        {{/picker}}
+      </div>
+      <div class="viewopts" style="margin-left: 15px">
         View:
         {{^efAll}}<a href="?ef=all">{{/efAll}}All{{^efAll}}</a>{{/efAll}}&nbsp;
         {{^efCompr}}<a href="?ef=compr">{{/efCompr}}Compressed{{^efCompr}}</a>{{/efCompr}}
diff --git a/src/Index.hs b/src/Index.hs
index 4b852bf..eedd1cd 100644
--- a/src/Index.hs
+++ b/src/Index.hs
@@ -466,24 +466,27 @@ indexCalendar (Index _ mp _) chan = do
              else coAll (scan IGV.! i) - coAll (scan IGV.! (i - 1))
           | i <- [0 .. IGV.length scan - 1]])
 
-indexGetEventsDay :: Index -> Channel -> CountKind -> Day -> IO [(HMS, EventID, Event)]
+-- | Returns the first and last day of this channel's logs, as well as the actual events on the requested day
+indexGetEventsDay :: Index -> Channel -> CountKind -> Day -> IO ((Day, Day), [(HMS, EventID, Event)])
 indexGetEventsDay index@(Index _ mp _) chan kind day = do
   ci <- readIORef (mp Map.! chan)
+  let firstlast = (ciStartDay ci, ciEndDay ci)
   let ymd = dayToYMD day
   if day < ciStartDay ci || day > ciEndDay ci
-    then return []
+    then return (firstlast, [])
     else loadDay index chan ymd <&> \case
            Just (bs, _lineStarts) ->
              let events = parseLog bs
-             in case kind of
-                  CKAll ->
-                    [(hms, genEventID (YMDHMS ymd hms) off, ev)
-                    | ((hms, ev), off) <- zip events [0..]]
-                  CKCompressed ->
-                    [(hms, genEventID (YMDHMS ymd hms) off, ev)
-                    | ((hms, off), ev) <- compressEvents [((hms, off), ev)
-                                                         | ((hms, ev), off) <- zip events [0..]]]
-           Nothing -> []  -- if the file doesn't exist, there ain't no events
+                 events' = case kind of
+                   CKAll ->
+                     [(hms, genEventID (YMDHMS ymd hms) off, ev)
+                     | ((hms, ev), off) <- zip events [0..]]
+                   CKCompressed ->
+                     [(hms, genEventID (YMDHMS ymd hms) off, ev)
+                     | ((hms, off), ev) <- compressEvents [((hms, off), ev)
+                                                          | ((hms, ev), off) <- zip events [0..]]]
+             in (firstlast, events')
+           Nothing -> (firstlast, [])  -- if the file doesn't exist, there ain't no events
 
 -- utilities
 
diff --git a/src/Main.hs b/src/Main.hs
index 78098af..a06aef8 100644
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -16,7 +16,7 @@ import Data.Map.Strict qualified as Map
 import Data.Text (Text)
 import Data.Text qualified as T
 import Data.Text.Encoding qualified as TE
-import Data.Time (Day, toGregorian, fromGregorianValid)
+import Data.Time (Day, toGregorian, fromGregorianValid, addDays)
 import System.Directory (listDirectory)
 import System.Environment
 import System.Exit (die)
@@ -145,7 +145,7 @@ pageCalendarDay conf index req alias datestr =
               Just "all" -> (CKAll, Just "ef=all; Path=/")
               Just "compr" -> (CKCompressed, Just "ef=compr; Path=/")
               _ -> (CKAll, Nothing)
-      events <- indexGetEventsDay index chan kind day
+      ((firstday, lastday), events) <- indexGetEventsDay index chan kind day
       mpagehighlight <-
         if | Just (TE.decodeASCII' -> Just eventID) <- query req "eid" -> do
                mevidx <- findEventIDLinear index chan kind eventID
@@ -166,6 +166,12 @@ pageCalendarDay conf index req alias datestr =
           , efAll = kind == CKAll
           , efCompr = kind == CKCompressed
           , date = T.pack (ymdToString (dayToYMD day))
+          , picker = CalendarPickerData
+              { prevpage = if firstday < day then Just (T.pack (ymdToString (dayToYMD (addDays (-1) day))))
+                                             else Nothing
+              , nextpage = if day < lastday then Just (T.pack (ymdToString (dayToYMD (addDays 1 day))))
+                                            else Nothing
+              }
           , events =
               [EventData
                 { classlist = if mpagehighlight == Just dayidx
diff --git a/src/Pages.hs b/src/Pages.hs
index 1a076ec..8bd7514 100644
--- a/src/Pages.hs
+++ b/src/Pages.hs
@@ -72,6 +72,7 @@ data CalendarDayData = CalendarDayData
   , efAll :: Bool
   , efCompr :: Bool
   , date :: Text
+  , picker :: CalendarPickerData
   , events :: [EventData Text ()]
   }
 
@@ -88,6 +89,10 @@ data PickerData = PickerData
   , npages :: Int
   }
 
+data CalendarPickerData = CalendarPickerData
+  { prevpage :: Maybe Text
+  , nextpage :: Maybe Text }
+
 data EventData tm dttm = EventData
   { classlist :: Maybe Text
   , time :: tm
-- 
cgit v1.3.1