From df7de848353ab0e8f9824f6e1666e77b0783deb5 Mon Sep 17 00:00:00 2001
From: Jesse Cusack <jesse.cusack@oregonstate.edu>
Date: Tue, 17 Mar 2026 10:54:15 -0700
Subject: [PATCH] output file names with times

---
 src/glide/cli.py  | 23 ++++++++++++++++++++++-
 tests/test_cli.py | 38 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 60 insertions(+), 1 deletion(-)

diff --git a/src/glide/cli.py b/src/glide/cli.py
index 5798456..ed9948c 100644
--- a/src/glide/cli.py
+++ b/src/glide/cli.py
@@ -3,6 +3,7 @@
 import functools
 import inspect
 import logging
+from datetime import datetime, timezone
 from importlib.metadata import version
 from pathlib import Path
 
@@ -41,6 +42,13 @@ def wrapper(*args, **kwargs):
     return wrapper
 
 
+def generate_ioos_filename(ds, glider_name: str) -> str:
+    first_time = float(ds["time"].values[0])
+    dt = datetime.fromtimestamp(first_time, tz=timezone.utc)
+    timestamp = dt.strftime("%Y%m%dT%H%M%SZ")
+    return f"{glider_name}_{timestamp}.nc"
+
+
 # Commonly used argument annotations
 _config_annotation = Annotated[
     str | None,
@@ -129,6 +137,14 @@ def l2(
             "output.",
         ),
     ] = False,
+    glider_name: Annotated[
+        str | None,
+        typer.Option(
+            "--glider",
+            "-g",
+            help="Glider name for IOOS-style filename when output is a directory.",
+        ),
+    ] = None,
 ) -> None:
     """
     Generate L2 data from L1 data.
@@ -159,7 +175,12 @@ def l2(
 
     out.encoding["unlimited_dims"] = {}
 
-    out.to_netcdf(out_file)
+    out_path = Path(out_file)
+    if out_path.is_dir():
+        name = glider_name or conf["globals"]["trajectory"]["name"].split("_")[-1]
+        out_path = out_path / generate_ioos_filename(out, name)
+
+    out.to_netcdf(out_path)
 
     if riot_csv:
         from .riot_csv_writer import write_riot_csv
diff --git a/tests/test_cli.py b/tests/test_cli.py
index 4050e83..32fc047 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -27,6 +27,44 @@ def test_l2() -> None:
     assert result.exit_code == 0
 
 
+def test_l2_directory_output() -> None:
+    import re
+    import tempfile
+    from datetime import datetime, timezone
+
+    data_dir = Path(str(resources.files("tests").joinpath("data")))
+    sbd_files = sorted(data_dir.glob("*.sbd.csv"))
+
+    with tempfile.TemporaryDirectory() as tmpdir:
+        for sbd_file in sbd_files:
+            tbd_file = sbd_file.with_suffix("").with_suffix(".tbd.csv")
+            if not tbd_file.exists():
+                continue
+
+            glider = sbd_file.name.split("-")[0].split(".")[0]
+            result = runner.invoke(
+                app, ["l2", str(sbd_file), str(tbd_file), "-o", tmpdir, "-g", glider]
+            )
+            assert result.exit_code == 0, f"Failed for {sbd_file.name}: {result.output}"
+
+        nc_files = list(Path(tmpdir).glob("*.nc"))
+        assert len(nc_files) == len(sbd_files)
+
+        for nc_file in nc_files:
+            assert re.match(r"\w+_\d{8}T\d{6}Z\.nc", nc_file.name)
+
+            ds = xr.open_dataset(nc_file)
+            first_time = ds["time"].values[0]
+            ds.close()
+
+            dt = np.datetime64(first_time, "s").astype("datetime64[s]").astype(datetime)
+            dt = dt.replace(tzinfo=timezone.utc)
+            expected_ts = dt.strftime("%Y%m%dT%H%M%SZ")
+            assert expected_ts in nc_file.name, (
+                f"Timestamp mismatch: expected {expected_ts} in {nc_file.name}"
+            )
+
+
 def test_l3() -> None:
     l2_file = str(resources.files("tests").joinpath("data/slocum.l2.nc"))
     out_file = str(resources.files("tests").joinpath("data/slocum.l3.nc"))