Update app.py

app.py

@@ -13,6 +13,7 @@ import matplotlib.pyplot as plt
 import sunpy.visualization.colormaps as sunpy_cm
 import traceback
 from io import BytesIO
+import re
 
 from surya.models.helio_spectformer import HelioSpectFormer
 from surya.utils.data import build_scalers
@@ -74,22 +75,40 @@ def setup_and_load_model():
     APP_CACHE["model"] = model
     yield "✅ Model setup complete."
 
-def fetch_browse_image(channel, target_dt, max_retries=15):
+def find_nearest_browse_image_url(channel, target_dt):
     url_code = CHANNEL_TO_URL_CODE[channel]
     base_url = "https://sdo.gsfc.nasa.gov/assets/img/browse"
     
-    for i in range(max_retries):
-        dt_to_try = target_dt - datetime.timedelta(minutes=i)
-        date_str = dt_to_try.strftime("%Y/%m/%d")
-        img_str = dt_to_try.strftime(f"%Y%m%d_%H%M%S_4096_{url_code}.jpg")
-        url = f"{base_url}/{date_str}/{img_str}"
+    for i in range(2): # Try today, then yesterday
+        dt_to_try = target_dt - datetime.timedelta(days=i)
+        dir_url = dt_to_try.strftime(f"{base_url}/%Y/%m/%d/")
         
-        response = requests.get(url)
-        if response.status_code == 200:
-            logger.info(f"Successfully found image for {channel} at {dt_to_try}")
-            return Image.open(BytesIO(response.content))
+        response = requests.get(dir_url)
+        if response.status_code != 200:
+            continue
+
+        filenames = re.findall(r'href="(\d{8}_\d{6}_4096_' + url_code + r'\.jpg)"', response.text)
+        if not filenames:
+            continue
+
+        best_filename = ""
+        min_diff = float('inf')
+
+        for fname in filenames:
+            try:
+                timestamp_str = fname.split('_')[1]
+                img_dt = datetime.datetime.strptime(f"{dt_to_try.strftime('%Y%m%d')}{timestamp_str}", "%Y%m%d%H%M%S")
+                diff = abs((target_dt - img_dt).total_seconds())
+                if diff < min_diff:
+                    min_diff = diff
+                    best_filename = fname
+            except (ValueError, IndexError):
+                continue
+        
+        if best_filename:
+            return dir_url + best_filename
     
-    raise FileNotFoundError(f"Could not find any recent image for {channel} within {max_retries} minutes of {target_dt}.")
+    raise FileNotFoundError(f"Could not find any browse images for {channel} in the last 48 hours.")
 
 def fetch_and_process_sdo_data(target_dt, forecast_horizon_minutes):
     config = APP_CACHE["config"]
@@ -109,10 +128,16 @@ def fetch_and_process_sdo_data(target_dt, forecast_horizon_minutes):
         images[t] = {}
         for channel in SDO_CHANNELS:
             fetches_done += 1
-            yield f"Searching [{fetches_done}/{total_fetches}]: {channel} near {t.strftime('%Y-%m-%d %H:%M')}..."
-            images[t][channel] = fetch_browse_image(channel, t)
+            yield f"Finding [{fetches_done}/{total_fetches}]: Closest image for {channel} near {t.strftime('%Y-%m-%d %H:%M')}..."
+            
+            image_url = find_nearest_browse_image_url(channel, t)
+            yield f"Downloading: {os.path.basename(image_url)}..."
+            
+            response = requests.get(image_url)
+            response.raise_for_status()
+            images[t][channel] = Image.open(BytesIO(response.content))
             
-    yield "✅ All images found. Starting preprocessing..."
+    yield "✅ All images found and downloaded. Starting preprocessing..."
     scaler = APP_CACHE["scalers"]
     processed_tensors = {}
     for t, channel_images in images.items():