From 63307611049843a40a6d4e9614482c7dcb72cb40 Mon Sep 17 00:00:00 2001
From: Tyler Pauly <tapastro@gmail.com>
Date: Mon, 27 Jan 2025 17:28:23 -0500
Subject: [PATCH] drop sci asns when not with paired bkgd

---
 .../generator/generate_per_candidate.py       | 26 ++++++++++++++++---
 jwst/associations/main.py                     |  3 ++-
 2 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/jwst/associations/generator/generate_per_candidate.py b/jwst/associations/generator/generate_per_candidate.py
index 888b8658d6..98c5375d29 100644
--- a/jwst/associations/generator/generate_per_candidate.py
+++ b/jwst/associations/generator/generate_per_candidate.py
@@ -13,7 +13,8 @@
 
 
 def generate_per_candidate(pool, rule_defs, candidate_ids=None, all_candidates=True, discover=False,
-                           version_id=None, finalize=True, merge=False, ignore_default=False):
+                           version_id=None, finalize=True, merge=False, ignore_default=False,
+                           DMS_enabled=False):
     """Generate associations in the pool according to the rules.
 
     Parameters
@@ -48,6 +49,9 @@ def generate_per_candidate(pool, rule_defs, candidate_ids=None, all_candidates=T
     ignore_default : bool
         Ignore the default rules. Use only the user-specified ones.
 
+    DMS_enabled : bool
+        Flag for DMS processing, true if command-line argument '--DMS' was used.
+
     Returns
     -------
     associations : [Association[,...]]
@@ -86,7 +90,8 @@ def generate_per_candidate(pool, rule_defs, candidate_ids=None, all_candidates=T
             pool,
             rule_defs,
             version_id=version_id,
-            ignore_default=ignore_default
+            ignore_default=ignore_default,
+            DMS_enabled=DMS_enabled
         )
 
         # Add to the list
@@ -136,7 +141,8 @@ def generate_per_candidate(pool, rule_defs, candidate_ids=None, all_candidates=T
     return finalized_asns
 
 
-def generate_on_candidate(cid_ctype, pool, rule_defs, version_id=None, ignore_default=False):
+def generate_on_candidate(cid_ctype, pool, rule_defs, version_id=None, ignore_default=False,
+                          DMS_enabled=False):
     """Generate associations based on a candidate ID
 
     Parameters
@@ -159,6 +165,9 @@ def generate_on_candidate(cid_ctype, pool, rule_defs, version_id=None, ignore_de
     ignore_default : bool
         Ignore the default rules. Use only the user-specified ones.
 
+    DMS_enabled : bool
+        Flag for DMS processing, true if command-line argument '--DMS' was used.
+
     Returns
     -------
     associations : [Association[,...]]
@@ -169,6 +178,17 @@ def generate_on_candidate(cid_ctype, pool, rule_defs, version_id=None, ignore_de
 
     # Get the pool
     pool_cid = pool_from_candidate(pool, cid)
+
+    # DMS processing excludes generation of o-type candidates for science exposures
+    # with linked backgrounds, i.e. without the background member present, as it
+    # would be for c-type background association candidates.
+    if DMS_enabled and 'observation' in ctype:
+        skip_rows = []
+        for i, row in enumerate(pool_cid):
+            if 'background' in row['asn_candidate'] and row['bkgdtarg'] == 'f':
+                skip_rows.append(i)
+        pool_cid.remove_rows(skip_rows)
+
     pool_cid['asn_candidate'] = [f"[('{cid}', '{ctype}')]"] * len(pool_cid)
     logger.info(f'Length of pool for {cid}: {len(pool_cid)}')
 
diff --git a/jwst/associations/main.py b/jwst/associations/main.py
index a177dce398..069438fda2 100644
--- a/jwst/associations/main.py
+++ b/jwst/associations/main.py
@@ -184,7 +184,8 @@ def generate(self):
                 version_id=parsed.version_id,
                 finalize=not parsed.no_finalize,
                 merge=parsed.merge,
-                ignore_default=parsed.ignore_default
+                ignore_default=parsed.ignore_default,
+                DMS_enabled=parsed.DMS_enabled
             )