Create billing.py

src/billing.py

@@ -0,0 +1,101 @@
+# src/billing.py
+from __future__ import annotations
+"""Billing helpers: CPT autosuggest and 837 claim builder (demo-only)."""
+
+from dataclasses import dataclass
+from typing import List, Dict, Any, Optional
+from datetime import datetime, timezone
+import json
+from pathlib import Path
+
+from .config import CPT, PROVIDER
+
+@dataclass
+class CPTSuggestion:
+    code: str
+    rate: float
+    descriptor: str
+    eligible: bool
+    why: str
+
+def _why_for_minutes(code: str, minutes: int, spoke: bool) -> str:
+    if code == "99451":
+        if not spoke:
+            return "Eligible when no live interprofessional call; written report only; requires ≥5 minutes."
+        return "Ineligible: 99451 is for written report without live discussion; 'spoke' was checked."
+    ranges = {
+        "99446": (5, 10),
+        "99447": (11, 20),
+        "99448": (21, 30),
+        "99449": (31, 10**9),
+    }
+    lo, hi = ranges[code]
+    base = f"Eligible minutes window {lo}–{hi if hi<10**9 else '∞'}; requires live discussion with referring clinician."
+    if not spoke:
+        return f"Ineligible: requires live discussion (spoke=False). Suggested 99451 if ≥5 minutes."
+    if minutes < lo:
+        return f"Ineligible for {code}: minutes below required threshold ({minutes}<{lo})."
+    return base
+
+def autosuggest_cpt(minutes: int, spoke: bool) -> List[CPTSuggestion]:
+    """Suggest CPT codes based on minutes and whether a live discussion occurred."""
+    suggestions: List[CPTSuggestion] = []
+    if spoke:
+        for code in ["99446", "99447", "99448", "99449"]:
+            lo_hi = {
+                "99446": (5, 10),
+                "99447": (11, 20),
+                "99448": (21, 30),
+                "99449": (31, 10**9),
+            }[code]
+            eligible = (minutes >= lo_hi[0]) and (minutes <= lo_hi[1])
+            suggestions.append(CPTSuggestion(
+                code=code,
+                rate=float(CPT[code]["rate"]),
+                descriptor=str(CPT[code]["descriptor"]),
+                eligible=eligible,
+                why=_why_for_minutes(code, minutes, spoke),
+            ))
+    else:
+        eligible = minutes >= 5
+        suggestions.append(CPTSuggestion(
+            code="99451",
+            rate=float(CPT["99451"]["rate"]),
+            descriptor=str(CPT["99451"]["descriptor"]),
+            eligible=eligible,
+            why=_why_for_minutes("99451", minutes, spoke),
+        ))
+    return suggestions
+
+def build_837_claim(case: Dict[str, Any], code: str, rate: float, minutes: int,
+                    spoke: bool, attested: bool, *, template_path: Optional[Path] = None) -> Dict[str, Any]:
+    """Build a demo 837 claim JSON from a case and billing selection."""
+    now = datetime.now(timezone.utc).isoformat()
+    # Load optional template
+    template: Dict[str, Any] = {}
+    try:
+        if template_path and Path(template_path).exists():
+            template = json.loads(Path(template_path).read_text(encoding="utf-8"))
+    except Exception:
+        template = {}
+
+    claim_id = f"EC-{case.get('case_id','UNKNOWN')}-{datetime.now(timezone.utc).strftime('%Y%m%dT%H%M%SZ')}"
+    out: Dict[str, Any] = {
+        "schema_version": 2,
+        "demo_only": True,
+        "claim_id": claim_id,
+        "created_at": now,
+        "provider": PROVIDER,
+        "patient": case.get("patient", {}),
+        "referring": {"name": (case.get("referrer") or {}).get("name", "Referring Clinician")},
+        "service": {
+            "cpt_code": code,
+            "minutes": minutes,
+            "spoke_to_referrer": bool(spoke),
+            "amount": float(rate),
+        },
+        "attested": bool(attested),
+        "source_case_id": case.get("case_id"),
+    }
+    out = {**template, **out}
+    return out