Log filament usage to FilamentDB when starting a job

- filamentdb.get_ams_slots(): parses /ams/ HTML to extract slot, material,
  color, weight_remaining_g, roll_id for each loaded AMS slot
- filamentdb.find_matching_ams_roll(): filters by material+color (case-insensitive),
  picks the roll with least filament remaining
- filamentdb.log_print_on_roll(): POSTs to /rolls/{id}/prints
- start_job: after setting job to printing, looks up AMS, computes weight
  (math.ceil of estimate), logs against matching roll, writes result to job log
- Verified parser against live AMS: PLA Black → slot 3 (30g) over slot 1 (1000g)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/filamentdb.py

@@ -1,5 +1,7 @@
 import logging
+import math
 import os
+import re
 import time
 
 import httpx
@@ -64,6 +66,70 @@ def spool_counts() -> dict[tuple[str, str], int]:
     return result
 
 
+def _parse_ams_html(html: str) -> list[dict]:
+    """
+    Parse the /ams/ HTML page to extract slot info.
+    Each card yields: slot, material, color, weight_remaining_g, roll_id (numeric).
+    """
+    slots = []
+    for card in re.split(r'class="card ams-card"', html)[1:]:
+        slot_m    = re.search(r'<h4>Slot (\d+)</h4>', card)
+        matcol_m  = re.search(
+            r'<strong>.*?</strong><br>\s*(.*?)<br>\s*(.*?)\s*</p>', card, re.DOTALL
+        )
+        weight_m  = re.search(r'~(\d+)g', card)
+        roll_id_m = re.search(r'action="/rolls/(\d+)/prints"', card)
+        if slot_m and matcol_m and weight_m and roll_id_m:
+            slots.append({
+                "slot":               int(slot_m.group(1)),
+                "material":           matcol_m.group(1).strip(),
+                "color":              matcol_m.group(2).strip(),
+                "weight_remaining_g": int(weight_m.group(1)),
+                "roll_id":            int(roll_id_m.group(1)),
+            })
+    return slots
+
+
+def get_ams_slots() -> list[dict]:
+    """Return currently loaded AMS slots (live, not cached — state changes often)."""
+    try:
+        r = httpx.get(f"{_base()}/ams/", timeout=5, verify=False)
+        r.raise_for_status()
+        return _parse_ams_html(r.text)
+    except Exception:
+        logger.warning("FilamentDB AMS endpoint unreachable")
+        return []
+
+
+def find_matching_ams_roll(material: str, color: str) -> dict | None:
+    """
+    Find the best roll in AMS1/slots 1-4 matching material+color.
+    If multiple match, pick the one with least filament remaining (use it up first).
+    """
+    matches = [
+        s for s in get_ams_slots()
+        if s["material"].lower() == material.lower()
+        and s["color"].lower() == color.lower()
+    ]
+    return min(matches, key=lambda s: s["weight_remaining_g"]) if matches else None
+
+
+def log_print_on_roll(roll_id: int, weight_g: int, note: str) -> bool:
+    """POST a print log entry to FilamentDB for the given roll."""
+    try:
+        r = httpx.post(
+            f"{_base()}/rolls/{roll_id}/prints",
+            data={"weight_used_g": weight_g, "note": note, "redirect_to": ""},
+            timeout=5,
+            verify=False,
+        )
+        r.raise_for_status()
+        return True
+    except Exception:
+        logger.warning("FilamentDB print log failed for roll %s", roll_id)
+        return False
+
+
 def available_colors(material: str | None = None) -> list[str]:
     """Unique color names in stock, optionally filtered by material."""
     rows = get_stock()