From e5e7bc68065a662255c2d808f4e7de3fe73138c2 Mon Sep 17 00:00:00 2001
From: Jonathan Eisenhamer <eisenhamer@stsci.edu>
Date: Fri, 12 Apr 2024 17:10:36 -0400
Subject: [PATCH] Error out completely if units are not as expected

---
 romancal/flux/flux_step.py | 28 +++++++++++++++++-----------
 1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/romancal/flux/flux_step.py b/romancal/flux/flux_step.py
index 1a3a05995..13e601b86 100644
--- a/romancal/flux/flux_step.py
+++ b/romancal/flux/flux_step.py
@@ -70,11 +70,8 @@ def process(self, input):
             )
 
         for model in input_models:
-            try:
-                apply_flux_correction(model)
-                model.meta.cal_step.flux = "COMPLETE"
-            except ValueError:
-                model.meta.cal_step.flux = "SKIPPED"
+            apply_flux_correction(model)
+            model.meta.cal_step.flux = "COMPLETE"
 
         if single_model:
             return input_models[0]
@@ -102,18 +99,27 @@ def apply_flux_correction(model):
     DATA = ("data", "err")
     VARIANCES = ("var_rnoise", "var_poisson", "var_flat")
 
-    # Check for units. Must be election/second. Otherwise, it is unknown how to
-    # convert.
+    if model.data.unit == model.meta.photometry.conversion_megajanskys.unit:
+        message = (
+            f"Input data is already in flux units of {model.meta.photometry.conversion_megajanskys.unit}."
+            "\nFlux correction already applied."
+        )
+        log.info(message)
+        return
+
     if model.data.unit != LV2_UNITS:
-        message = f"Input data units {model.data.unit} is not the expected units of %s. Flux correction will not be done."
-        log.debug(message)
+        message = (
+            f"Input data units {model.data.unit} are not in the expected units of {LV2_UNITS}"
+            "\nAborting flux correction"
+        )
+        log.error(message)
         raise ValueError(message)
 
-    # Apply the correction
+    # Apply the correction.
     # The end goal in units is to have MJy/sr. The scale is in MJy/sr also.
     # Hence the extra factor of s/DN must be applied to cancel DN/s.
     log.debug("Flux correction being applied")
-    c_mj = model.meta.photometry.conversion_megajanskys / LV2_UNITS
+    c_mj = model.meta.photometry.conversion_megajanskys / model.data.unit
     for data in DATA:
         model[data] = model[data] * c_mj
     for variance in VARIANCES: