replaced inotify with a polling loop

watch-imports.sh

@@ -1,13 +1,14 @@
 #!/usr/bin/env bash
-# watch-imports.sh - Watch for new CSV files, flip sign on 4th column for
+# watch-imports.sh - Poll for new CSV files, flip sign on 4th column for
 # specific accounts, then stage them in the imports/ directory.
 #
+# Uses polling — compatible with NFS and other network filesystems.
+#
 # Usage:
-#   ./watch-imports.sh          # watch continuously (requires inotify-tools)
+#   ./watch-imports.sh          # poll continuously
 #   ./watch-imports.sh --once   # process existing files in INCOMING_DIR and exit
 #
-# Requires: inotify-tools (sudo apt-get install inotify-tools)
-#           python3 (standard on Ubuntu)
+# Requires: python3 (standard on Ubuntu)
 
 set -euo pipefail
 
@@ -35,6 +36,8 @@ fi
 INCOMING_DIR="${INCOMING_DIR:-$SCRIPT_DIR/incoming}"
 IMPORT_DIR="${IMPORT_DIR:-$SCRIPT_DIR/imports}"
 AUTO_IMPORT="${AUTO_IMPORT:-false}"
+POLL_INTERVAL="${POLL_INTERVAL:-10}"     # seconds between directory scans
+FILE_STABLE_AGE="${FILE_STABLE_AGE:-3}" # seconds a file must be unmodified before processing
 
 # Files whose 4th column values should have their sign flipped
 FLIP_FILES=(
@@ -62,6 +65,17 @@ needs_flip() {
   return 1
 }
 
+# Returns true if the file hasn't been modified in the last FILE_STABLE_AGE seconds.
+# Prevents processing a file that's still being uploaded over the network.
+is_stable() {
+  local filepath="$1"
+  local mtime now age
+  mtime=$(stat -c%Y "$filepath" 2>/dev/null) || return 1
+  now=$(date +%s)
+  age=$(( now - mtime ))
+  [[ "$age" -ge "$FILE_STABLE_AGE" ]]
+}
+
 # Flip the sign of all numeric values in the 4th column using python3.
 # Handles quoted CSV fields correctly.
 flip_fourth_column() {
@@ -124,35 +138,29 @@ process_csv() {
   fi
 }
 
+poll_once() {
+  while IFS= read -r filepath; do
+    if ! is_stable "$filepath"; then
+      info "Still writing: $(basename "$filepath") — will retry next poll"
+      continue
+    fi
+    process_csv "$filepath"
+  done < <(find "$INCOMING_DIR" -maxdepth 1 -name '*.csv' 2>/dev/null | sort)
+}
+
 # ---------------------------------------------------------------------------
 # Main
 # ---------------------------------------------------------------------------
 mkdir -p "$INCOMING_DIR" "$IMPORT_DIR"
 
 if $ONCE_MODE; then
-  mapfile -t existing < <(find "$INCOMING_DIR" -maxdepth 1 -name '*.csv' | sort)
-  if [[ ${#existing[@]} -eq 0 ]]; then
-    info "No CSV files found in $INCOMING_DIR"
-    exit 0
-  fi
-  for f in "${existing[@]}"; do
-    process_csv "$f"
-  done
+  poll_once
   exit 0
 fi
 
-# Continuous watch mode
-if ! command -v inotifywait &>/dev/null; then
-  echo "inotify-tools not found. Install with:"
-  echo "  sudo apt-get install inotify-tools"
-  exit 1
-fi
+info "Polling $INCOMING_DIR every ${POLL_INTERVAL}s... (Ctrl+C to stop)"
 
-info "Watching $INCOMING_DIR for new CSV files... (Ctrl+C to stop)"
-
-inotifywait -m -e close_write -e moved_to --format '%f' "$INCOMING_DIR" \
-  | while IFS= read -r filename; do
-      if [[ "$filename" == *.csv ]]; then
-        process_csv "$INCOMING_DIR/$filename"
-      fi
-    done
+while true; do
+  poll_once
+  sleep "$POLL_INTERVAL"
+done