fix: read amp log from start and use totalCredits for accuracy

Amp-Thread-ID:
https://ampcode.com/threads/T-5a2ca80d-5cba-409f-a262-6b5c652c257d
Co-authored-by: Amp <amp@ampcode.com>

1 files changed, 6 insertions, 6 deletions

diff --git a/Omni/Agent/Worker.hs b/Omni/Agent/Worker.hs
index 4ff9042..7afc849 100644
--- a/Omni/Agent/Worker.hs
+++ b/Omni/Agent/Worker.hs
@@ -227,8 +227,7 @@ monitorLog :: FilePath -> IO ()
 monitorLog logPath = do
   waitForFile logPath
   IO.withFile logPath IO.ReadMode <| \h -> do
-    -- Tail the file
-    IO.hSeek h IO.SeekFromEnd 0
+    -- Start from beginning of file (don't seek to end)
     forever <| do
       eof <- IO.hIsEOF h
       if eof
@@ -263,11 +262,12 @@ parseAndUpdate line = do
         _ -> pure ()
 
       -- Extract cost from usage-ledger:event
-      -- Pattern: {"addedCredits": 0.123, "message": "usage-ledger:event", ...}
-      case KM.lookup "addedCredits" obj of
+      -- Pattern: {"totalCredits": 1.54, "message": "usage-ledger:event", ...}
+      -- We use totalCredits to be robust against missed lines and restarts.
+      case KM.lookup "totalCredits" obj of
         Just (Aeson.Number n) ->
-          let cost = Scientific.toRealFloat n
-           in AgentLog.update (\s -> s {AgentLog.statusCredits = AgentLog.statusCredits s + cost})
+          let total = Scientific.toRealFloat n
+           in AgentLog.update (\s -> s {AgentLog.statusCredits = total})
         _ -> pure ()
 
 timeTicker :: IO ()