From ca3d7435bf2a87deeabb9367cc6b68e8c81145f1 Mon Sep 17 00:00:00 2001
From: Kristen Thyng <kthyng@gmail.com>
Date: Thu, 17 Aug 2023 10:48:40 -0700
Subject: [PATCH] convert filters to jsonify for zarr

---
 tests/test_zarr_compat.py | 32 ++++++++++++++++++++++++++++++++
 xpublish/utils/zarr.py    |  8 ++++++++
 2 files changed, 40 insertions(+)

diff --git a/tests/test_zarr_compat.py b/tests/test_zarr_compat.py
index 994191b8..b149d597 100644
--- a/tests/test_zarr_compat.py
+++ b/tests/test_zarr_compat.py
@@ -3,6 +3,7 @@
 import numpy as np
 import pytest
 import xarray as xr
+from numcodecs import Shuffle, Zlib
 
 from xpublish import SingleDatasetRest
 
@@ -39,6 +40,37 @@ def test_zmetadata_identical(start, end, freq, nlats, nlons, var_const, calendar
     assert actual == expected
 
 
+@pytest.mark.parametrize(
+    'start, end, freq, nlats, nlons, var_const, calendar, use_cftime',
+    [
+        ('2018-01-01', '2021-01-01', 'MS', 180, 360, True, 'standard', False),
+        ('2018-01-01', '2021-01-01', 'D', 180, 360, False, 'noleap', True),
+        ('2018-01-01', '2021-01-01', '6H', 180, 360, True, 'gregorian', False),
+        ('2018-01-01', '2050-01-01', 'A', 180, 360, None, '360_day', True),
+    ],
+)
+def test_compressor_filters(start, end, freq, nlats, nlons, var_const, calendar, use_cftime):
+    ds = create_dataset(
+        start=start,
+        end=end,
+        freq=freq,
+        nlats=nlats,
+        nlons=nlons,
+        var_const=var_const,
+        use_cftime=use_cftime,
+        calendar=calendar,
+    )
+
+    ds = ds.chunk(ds.dims)
+    zarr_dict = {}
+    ds['time'].encoding['filters'] = [Shuffle(elementsize=8), Zlib(level=8)]
+    ds.to_zarr(zarr_dict, consolidated=True)
+    mapper = TestMapper(SingleDatasetRest(ds).app)
+    actual = json.loads(mapper['.zmetadata'].decode())
+    expected = json.loads(zarr_dict['.zmetadata'].decode())
+    assert actual == expected
+
+
 @pytest.mark.parametrize(
     'start, end, freq, nlats, nlons, var_const, calendar, use_cftime',
     [
diff --git a/xpublish/utils/zarr.py b/xpublish/utils/zarr.py
index b4dd2b74..c419e1cd 100644
--- a/xpublish/utils/zarr.py
+++ b/xpublish/utils/zarr.py
@@ -174,6 +174,14 @@ def jsonify_zmetadata(
             ].get_config()
             zjson['metadata'][f'{key}/{array_meta_key}']['compressor'] = compressor_config
 
+        # convert list of filters to dict
+        filters = zjson['metadata'][f'{key}/{array_meta_key}']['filters']
+        if filters is not None:
+            filters_configs = []
+            for Filter in zjson['metadata'][f'{key}/{array_meta_key}']['filters']:
+                filters_configs.append(Filter.get_config())
+            zjson['metadata'][f'{key}/{array_meta_key}']['filters'] = filters_configs
+
     return zjson