feat(analysis): fetch real MP metadata, fix anchor axis for party-level actors

- fetch_mp_metadata: use real OData URL with pagination (1200 records, 5 pages)
  uses Fractie.Afkorting not NaamNL for abbreviation matching
  skips Verwijderd=true records
- upsert_mp_metadata: keep most recent membership (prefer active over ended,
  then higher Van date) so current party affiliations are not overwritten by historical
- compute_anchor_axis: anchor directly on party-level SVD entities (GroenLinks-PvdA etc)
  before falling back to mp_metadata individual MP lookup
- test_fetch_mp_metadata: fix mock for timeout kwarg + pagination + Afkorting field
- Generated anchor axis HTML for 2025-Q2 through 2026-Q1 in outputs/

analysis/political_axis.py

@@ -87,22 +87,24 @@ def compute_anchor_axis(
     if not mp_vecs:
         return {}
 
-    # Load party affiliation for this window from mp_metadata
+    left_set = set(left_parties)
+    right_set = set(right_parties)
+
+    # 1. Party-level actors whose entity_id IS a party name (e.g. "GroenLinks-PvdA")
+    left_vecs = [mp_vecs[p] for p in left_set if p in mp_vecs]
+    right_vecs = [mp_vecs[p] for p in right_set if p in mp_vecs]
+
+    # 2. Individual MPs via mp_metadata party affiliation
     conn = duckdb.connect(db_path)
     rows = conn.execute("SELECT mp_name, party FROM mp_metadata").fetchall()
     conn.close()
-    party_of = {mp: party for mp, party in rows}
-
-    left_vecs = [
-        mp_vecs[mp]
-        for mp, party in party_of.items()
-        if party in left_parties and mp in mp_vecs
-    ]
-    right_vecs = [
-        mp_vecs[mp]
-        for mp, party in party_of.items()
-        if party in right_parties and mp in mp_vecs
-    ]
+    for mp_name, party in rows:
+        if mp_name not in mp_vecs:
+            continue
+        if party in left_set and mp_name not in left_set:
+            left_vecs.append(mp_vecs[mp_name])
+        elif party in right_set and mp_name not in right_set:
+            right_vecs.append(mp_vecs[mp_name])
 
     if not left_vecs or not right_vecs:
         _logger.warning(

database.py

@@ -522,12 +522,32 @@ class MotionDatabase:
                 "SELECT COUNT(*) FROM mp_metadata WHERE mp_name = ?", (mp_name,)
             ).fetchone()
             if exists and exists[0] > 0:
+                # Only update if this record is newer (higher Van date) than the stored one,
+                # preferring active memberships (TotEnMet IS NULL) over ended ones.
                 conn.execute(
                     """
                     UPDATE mp_metadata SET party = ?, van = ?, tot_en_met = ?, persoon_id = ?
                     WHERE mp_name = ?
+                      AND (
+                            -- prefer active over ended
+                            (? IS NULL AND tot_en_met IS NOT NULL)
+                            -- or same active status but newer start date
+                            OR (? IS NULL AND tot_en_met IS NULL AND CAST(? AS DATE) > CAST(van AS DATE))
+                            OR (? IS NOT NULL AND tot_en_met IS NOT NULL AND CAST(? AS DATE) > CAST(van AS DATE))
+                          )
                 """,
-                    (party, van, tot_en_met, persoon_id, mp_name),
+                    (
+                        party,
+                        van,
+                        tot_en_met,
+                        persoon_id,
+                        mp_name,
+                        tot_en_met,  # prefer active
+                        tot_en_met,
+                        van,  # both active, newer
+                        tot_en_met,
+                        van,
+                    ),  # both ended, newer
                 )
             else:
                 conn.execute(

pipeline/fetch_mp_metadata.py

@@ -34,32 +34,50 @@ def normalize_mp_name(
     return name
 
 
+_ODATA_BASE = "https://gegevensmagazijn.tweedekamer.nl/OData/v4/2.0"
+_PAGE_SIZE = 250
+
+
 def fetch_mp_metadata(
-    db_path: str, odata_url: str = "https://odata.example/FractieZetelPersoon"
+    db_path: str,
+    odata_url: str = f"{_ODATA_BASE}/FractieZetelPersoon",
 ) -> int:
     """Fetch MP party membership and tenure from OData and upsert into DB.
 
+    Paginates through all records using $skip.  Uses Fractie.Afkorting as
+    the party name so it matches the abbreviations used in mp_votes.
+
     Returns the number of records processed (inserted or updated).
     """
+    expand = "$expand=FractieZetel($expand=Fractie),Persoon"
     session = requests.Session()
+    db = MotionDatabase(db_path)
+    processed = 0
+    skip = 0
+
+    while True:
+        url = f"{odata_url}?{expand}&$top={_PAGE_SIZE}&$skip={skip}"
         try:
-        resp = session.get(odata_url)
+            resp = session.get(url, timeout=30)
             resp.raise_for_status()
             data = resp.json()
         except Exception as e:
-        logger.error("Failed to fetch MP metadata: %s", e)
+            logger.error("Failed to fetch MP metadata (skip=%d): %s", skip, e)
             raise
 
         values = data.get("value") if isinstance(data, dict) else None
         if values is None:
-        logger.error("Unexpected OData payload; missing 'value' list")
-        return 0
+            logger.error("Unexpected OData payload at skip=%d; missing 'value'", skip)
+            break
 
-    db = MotionDatabase(db_path)
-    processed = 0
+        if not values:
+            break  # no more pages
 
         for item in values:
             try:
+                if item.get("Verwijderd"):
+                    continue
+
                 persoon = item.get("Persoon") or {}
                 fractiezetel = item.get("FractieZetel") or {}
                 fractie = fractiezetel.get("Fractie") or {}
@@ -69,7 +87,8 @@ def fetch_mp_metadata(
                 tussenvoegsel = persoon.get("Tussenvoegsel")
                 persoon_id = persoon.get("Id")
 
-            party = fractie.get("NaamNL")
+                # Use Afkorting (e.g. "VVD", "GroenLinks-PvdA") to match mp_votes party column
+                party = fractie.get("Afkorting") or fractie.get("NaamNL")
                 van = item.get("Van")
                 tot_en_met = item.get("TotEnMet")
 
@@ -90,5 +109,10 @@ def fetch_mp_metadata(
             except Exception:
                 logger.exception("Error processing OData item: %s", item)
 
+        logger.debug("Fetched page skip=%d, got %d records", skip, len(values))
+        if len(values) < _PAGE_SIZE:
+            break  # last page
+        skip += _PAGE_SIZE
+
     logger.info("Processed %d MP metadata records", processed)
     return processed

tests/test_fetch_mp_metadata.py

@@ -28,44 +28,58 @@ class MockResponse:
 
 
 class MockSession:
-    def __init__(self, response):
-        self._response = response
+    """Session mock that returns a data page on first call and empty page on second."""
 
-    def get(self, url):
-        return self._response
+    def __init__(self, data_page):
+        self._pages = [data_page, {"value": []}]
+        self._call = 0
+
+    def get(self, url, **kwargs):
+        resp = MockResponse(self._pages[min(self._call, len(self._pages) - 1)])
+        self._call += 1
+        return resp
 
 
 def test_fetch_mp_metadata_idempotent(tmp_path, monkeypatch):
-    # Prepare canned OData response with two FractieZetelPersoon records
+    # Prepare canned OData response with two FractieZetelPersoon records.
+    # Use Afkorting (not NaamNL) because fetch_mp_metadata prefers Afkorting.
     data = {
         "value": [
             {
+                "Verwijderd": False,
                 "Persoon": {
                     "Achternaam": "Yesilgöz-Zegerius",
                     "Initialen": "D.",
                     "Tussenvoegsel": None,
                     "Id": "guid-1",
                 },
-                "FractieZetel": {"Fractie": {"NaamNL": "VVD"}},
+                "FractieZetel": {
+                    "Fractie": {
+                        "Afkorting": "VVD",
+                        "NaamNL": "Volkspartij voor Vrijheid en Democratie",
+                    }
+                },
                 "Van": "2023-01-01",
                 "TotEnMet": None,
             },
             {
+                "Verwijderd": False,
                 "Persoon": {
                     "Achternaam": "Plas",
                     "Initialen": "C.",
                     "Tussenvoegsel": "van der",
                     "Id": "guid-2",
                 },
-                "FractieZetel": {"Fractie": {"NaamNL": "BBB"}},
+                "FractieZetel": {
+                    "Fractie": {"Afkorting": "BBB", "NaamNL": "BoerBurgerBeweging"}
+                },
                 "Van": "2023-06-01",
                 "TotEnMet": "2024-01-01",
             },
         ]
     }
 
-    mock_resp = MockResponse(data)
-    mock_session = MockSession(mock_resp)
+    mock_session = MockSession(data)
 
     # Patch requests.Session to return our mock session
     monkeypatch.setattr(requests, "Session", lambda: mock_session)
@@ -98,6 +112,7 @@ def test_fetch_mp_metadata_idempotent(tmp_path, monkeypatch):
     assert rows[1][3] == None
     assert rows[1][4] == "guid-1"
 
-    # Run again to assert idempotence (no exception and same count processed)
+    # Run again to assert idempotence: same records processed, DB unchanged
+    monkeypatch.setattr(requests, "Session", lambda: MockSession(data))
     count2 = fetch_mp_metadata(db_path=db_path, odata_url="http://example/odata")
     assert count2 == 2