# Parliamentary Embedding Pipeline (Late Fusion) Implementation Plan

Goal: Implement an MVP late-fusion pipeline that (1) extracts MP-level votes from the existing motions.voting_results JSON, (2) builds aligned SVD representations per time-window, (3) ensures text embeddings coverage, and (4) fuses SVD motion vectors with text embeddings into a fused_embeddings table — all using DuckDB and in-Python compute.

Design reference: thoughts/shared/designs/2026-03-21-parliamentary-embedding-pipeline-design.md

---

## Dependency Graph

```
Batch 1 (parallel): 1.1, 1.2, 1.3, 1.4 [foundation - no deps]
Batch 2 (parallel): 2.1, 2.2, 2.3, 2.4, 2.5 [core - depends on batch 1]
Batch 3 (parallel): 3.1, 3.2 [integration & CI - depends on batch 2]
```

---

## Batch 1: Foundation (parallel)

### Task 1.1: Add scientific dependencies
- File to modify: pyproject.toml
- Test: tests/test_pyproject_deps.py
- Hours: 1.0 | Priority: high | Depends: none
- Acceptance: scipy>=1.11, umap-learn>=0.5, plotly>=5.0 present in pyproject.toml

### Task 1.2: Add migration file placeholders
- Files to create: migrations/2026_03_21__create_mp_votes.sql, migrations/2026_03_21__create_mp_metadata.sql, migrations/2026_03_21__create_svd_vectors.sql, migrations/2026_03_21__create_fused_embeddings.sql
- Test: tests/test_migration_pipeline_tables.py (follows existing pattern in tests/test_migration_embeddings.py)
- Hours: 1.5 | Priority: high | Depends: none
- Acceptance: Migration files exist; test applies them to temp DuckDB and asserts expected tables/columns

### Task 1.3: Extend database.py with new tables + helpers
- File to modify: database.py (_init_database + new helpers)
- Test: tests/test_database_schema_and_helpers.py
- Hours: 3.5 | Priority: highest | Depends: 1.2
- Helpers to add: mp_votes_exists_for_motion, insert_mp_vote, upsert_mp_metadata(mp_name, party, van, tot_en_met, persoon_id), store_svd_vector, store_fused_embedding
- Acceptance: Tables created, helpers tested against temp DuckDB via round-trip insert/select; logging not prints

### Task 1.4: Add test fixtures
- File to create: tests/fixtures/sample_voting_results.json (5–10 motions with mixed party + MP keys)
- Hours: 0.5 | Priority: medium | Depends: none

---

## Batch 2: Core Pipeline (parallel, depends on Batch 1)

### Task 2.1: pipeline/extract_mp_votes.py
- Extract MP rows from voting_results JSON; comma-in-key = MP name, else = party (skip party rows)
- Test: tests/test_extract_mp_votes.py
- Hours: 4.0 | Priority: highest | Depends: 1.3, 1.4
- Acceptance: Idempotent; correct MP rows inserted; party keys ignored; re-run produces no duplicates

### Task 2.2: pipeline/fetch_mp_metadata.py
- Fetch MP party membership and tenure from OData using confirmed endpoints (spike resolved: Persoon + FractieZetelPersoon are available)
- OData query: `/FractieZetelPersoon?$filter=Verwijderd eq false&$expand=Persoon($select=Id,Achternaam,Initialen,Tussenvoegsel),FractieZetel($expand=Fractie($select=NaamNL))`
- Key fields: FractieZetelPersoon.Van (entry_date), FractieZetelPersoon.TotEnMet (exit_date, null=active), Persoon.Achternaam, Persoon.Initialen, Persoon.Tussenvoegsel, Fractie.NaamNL (party name)
- Name normalization: reconstruct ActorNaam format from Persoon fields: `"{Tussenvoegsel} {Achternaam}, {Initialen}".strip()` (must match keys in voting_results JSON, e.g. "Yesilgöz-Zegerius, D.")
- Persoon.Id stored as source_id (GUID) for deduplication
- Stores via MotionDatabase.upsert_mp_metadata; idempotent on re-run
- Test: tests/test_fetch_mp_metadata.py — monkeypatch requests.get with canned FractieZetelPersoon+Persoon response; assert name normalization and DB rows
- Hours: 3.5 | Priority: highest | Depends: 1.3
- Acceptance: mp_metadata rows correct; name normalization tested for tussenvoegsel variants; TotEnMet=null handled correctly; re-run idempotent

### Task 2.3: pipeline/text_pipeline.py
- Ensure every motion has a text embedding; delegates to existing ai_provider.get_embedding
- Text priority: body_text > layman_explanation > description
- Test: tests/test_text_pipeline.py (monkeypatch ai_provider)
- Hours: 3.0 | Priority: high | Depends: 1.3, 1.1

### Task 2.4: pipeline/svd_pipeline.py
- Per-window: build sparse MP×Motion csr_matrix → scipy svds → Procrustes alignment → store svd_vectors
- CRITICAL: enforce k < min(n_mps, n_motions); reduce k dynamically if needed; test this path
- Procrustes: log disparity score; flag HIGH_DISPARITY if overlap < 30%
- Test: tests/test_svd_pipeline.py (synthetic 5×6 matrix, k reduction test, alignment test)
- Hours: 6.0 | Priority: highest | Depends: 1.3

### Task 2.5: pipeline/fusion.py
- For each motion in window: fetch SVD motion vector + text embedding → concatenate → store fused_embeddings
- Skip and log if either vector missing
- Test: tests/test_fusion.py (verify vector length = svd_dims + text_dims)
- Hours: 3.0 | Priority: high | Depends: 2.3, 2.4

---

## Batch 3: Integration & CI (depends on Batch 2)

### Task 3.1: tests/integration/test_pipeline_end_to_end.py
- Apply migrations → seed motions → monkeypatch ai_provider → run extract → SVD → text → fuse
- Assert fused_embeddings rows and vector dimensions
- Hours: 4.0 | Priority: highest | Depends: 2.1, 2.3, 2.4, 2.5
- Use numpy.random.seed(0); dataset ≤50 motions for CI speed

### Task 3.2: tests/conftest.py (fixtures + test helpers)
- Fixtures: temp_duckdb_path, apply_migrations, monkeypatch_ai_provider, mock_odata_client
- Add tests/README.md section on monkeypatching strategy
- Hours: 2.0 | Priority: high | Depends: 1.3

---

## Migration filenames
- migrations/2026_03_21__create_mp_votes.sql — columns: id, motion_id, mp_name, party, vote, date, created_at
- migrations/2026_03_21__create_mp_metadata.sql — columns: mp_name (PK), party, van (entry_date), tot_en_met (exit_date, nullable), persoon_id (GUID source_id)
- migrations/2026_03_21__create_svd_vectors.sql — columns: window_id, entity_type, entity_id, vector, model, created_at
- migrations/2026_03_21__create_fused_embeddings.sql — columns: motion_id, window_id, vector, svd_dims, text_dims, created_at

---

## CI / Test instructions

- Run all tests: pytest -q
- Run unit tests only: pytest -q tests/ --ignore=tests/integration
- Run integration test: pytest -q tests/integration/test_pipeline_end_to_end.py
- Monkeypatch ai_provider.get_embedding with a function returning [0.01]*16 for fast tests
- Monkeypatch OData/API calls via requests-mock or monkeypatch.setattr on TweedeKamerAPIClient methods
- Temp DuckDB: use pytest tmp_path fixture; apply migration SQL files at test setup
- Determinism: numpy.random.seed(0) in all tests calling scipy/numpy

---

## 3-Sprint Schedule (2-week sprints)

Sprint 1 (Weeks 1–2): Tasks 1.1, 1.2, 1.3, 1.4, 2.2
- Deliverables: DB schema extended, migrations present, mp_metadata fetch implemented and tested

Sprint 2 (Weeks 3–4): Tasks 2.1, 2.3, 2.4, 2.5
- Deliverables: All pipeline modules implemented with passing unit tests

Sprint 3 (Weeks 5–6): Tasks 3.1, 3.2
- Deliverables: Integration test passing end-to-end; CI docs written

---

## Key assumptions

1. Vectors stored as JSON (consistent with existing embeddings table)
2. Use existing ai_provider.get_embedding for text embeddings — no new model calls
3. SVD k enforced dynamically (k < min(n_mps, n_motions)); tests cover this path
4. Procrustes rotation matrices NOT persisted in MVP (aligned vectors stored directly)
5. mp_metadata: fetch from OData FractieZetelPersoon endpoint (confirmed available); Van/TotEnMet give tenure windows
6. Default quarterly time windows, but parameterized for Annual validation in Sprint 2
7. All new helpers go into existing database.py MotionDatabase class (not a new module)
8. Analysis/visualization (UMAP, Plotly plots) is a follow-up sprint, NOT included here

## Open questions

1. [RESOLVED] OData FractieZetelPersoon confirmed available with Van/TotEnMet tenure dates; Stemming.ActorFractie gives party for each individual vote; name normalization from Persoon.Achternaam+Initialen+Tussenvoegsel confirmed feasible
2. Should Procrustes rotation matrices be persisted? (MVP: no; revisit after)
3. Time-window granularity: annual first for stability validation, then quarterly?
4. Production k value for SVD: default 50 but must be validated against real data sizes
5. Who runs migrations in production, and how? (Out of scope for MVP)
