feat(backend): add reconcile.match with date-window + multi-claim fallback

backend/tests/test_reconcile.py

@@ -0,0 +1,114 @@
+"""Tests for the pure reconciliation functions.
+
+These tests use lightweight stand-in objects (namedtuples) rather than
+SQLAlchemy ORM instances, so the reconcile module has zero DB dependency.
+"""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+from datetime import date
+from typing import Optional
+
+import pytest
+
+from cyclone import reconcile
+
+
+# --- Stand-in types -----------------------------------------------------------
+
+
+@dataclass
+class FakeClaim:
+    id: str
+    patient_control_number: str
+    service_date_from: Optional[date]
+    state: str = "submitted"
+    matched_remittance_id: Optional[str] = None
+
+
+@dataclass
+class FakeRemit:
+    id: str
+    payer_claim_control_number: str
+    service_date: Optional[date]
+    is_reversal: bool = False
+
+
+# --- match() ------------------------------------------------------------------
+
+
+def test_match_same_pcn_within_window_matches():
+    claims = [FakeClaim("CLM-1", "PCN-A", date(2026, 6, 1))]
+    remits = [FakeRemit("CLP-1", "PCN-A", date(2026, 6, 2))]
+    matches = reconcile.match(claims, remits, window_days=7)
+    assert len(matches) == 1
+    assert matches[0].claim.id == "CLM-1"
+    assert matches[0].remittance.id == "CLP-1"
+    assert matches[0].strategy == "auto"
+
+
+def test_match_dates_outside_window_unmatched():
+    claims = [FakeClaim("CLM-1", "PCN-A", date(2026, 6, 1))]
+    remits = [FakeRemit("CLP-1", "PCN-A", date(2026, 7, 1))]  # 30d apart
+    matches = reconcile.match(claims, remits, window_days=7)
+    assert matches == []
+
+
+def test_match_different_pcn_unmatched():
+    claims = [FakeClaim("CLM-1", "PCN-A", date(2026, 6, 1))]
+    remits = [FakeRemit("CLP-1", "PCN-B", date(2026, 6, 1))]
+    matches = reconcile.match(claims, remits)
+    assert matches == []
+
+
+def test_match_multiple_claims_same_pcn_picks_closest_date():
+    claims = [
+        FakeClaim("CLM-1", "PCN-A", date(2026, 5, 1)),
+        FakeClaim("CLM-2", "PCN-A", date(2026, 6, 1)),  # closer
+    ]
+    remits = [FakeRemit("CLP-1", "PCN-A", date(2026, 6, 2))]
+    matches = reconcile.match(claims, remits)
+    assert len(matches) == 1
+    assert matches[0].claim.id == "CLM-2"
+
+
+def test_match_multiple_remits_same_pcn_each_gets_own_claim():
+    claims = [
+        FakeClaim("CLM-1", "PCN-A", date(2026, 6, 1)),
+        FakeClaim("CLM-2", "PCN-A", date(2026, 6, 15)),
+    ]
+    remits = [
+        FakeRemit("CLP-1", "PCN-A", date(2026, 6, 2)),
+        FakeRemit("CLP-2", "PCN-A", date(2026, 6, 16)),
+    ]
+    matches = reconcile.match(claims, remits)
+    assert len(matches) == 2
+    claim_ids = {m.claim.id for m in matches}
+    assert claim_ids == {"CLM-1", "CLM-2"}
+
+
+def test_match_skips_already_matched_claims():
+    claims = [FakeClaim("CLM-1", "PCN-A", date(2026, 6, 1), matched_remittance_id="OLD")]
+    remits = [FakeRemit("CLP-1", "PCN-A", date(2026, 6, 1))]
+    matches = reconcile.match(claims, remits)
+    assert matches == []
+
+
+def test_match_falls_back_to_first_claim_when_no_service_date():
+    """When the remit has no service_date, match the first claim for that PCN."""
+    claims = [
+        FakeClaim("CLM-1", "PCN-A", None),
+        FakeClaim("CLM-2", "PCN-A", None),
+    ]
+    remits = [FakeRemit("CLP-1", "PCN-A", None)]
+    matches = reconcile.match(claims, remits)
+    assert len(matches) == 1
+    assert matches[0].claim.id == "CLM-1"
+
+
+def test_match_reversal_flag_propagates():
+    claims = [FakeClaim("CLM-1", "PCN-A", date(2026, 6, 1))]
+    remits = [FakeRemit("CLP-1", "PCN-A", date(2026, 6, 1), is_reversal=True)]
+    matches = reconcile.match(claims, remits)
+    assert matches[0].is_reversal is True