Harden resource cost evidence contract

tests/test_exchange.py

@@ -0,0 +1,207 @@
+from datetime import date, datetime, timezone
+from decimal import Decimal
+from pathlib import Path
+
+import pytest
+from pydantic import ValidationError
+
+from fin_hub.models.engagement_price import EngagementPrice, _validate_engagement_price
+from fin_hub.schemas.exchange import (
+    AllocationEvidence,
+    BookedCostEvidence,
+    ForecastEvidence,
+)
+from fin_hub.services.exchange import (
+    booked_cost_projection,
+    ingest_planning_evidence,
+    ingest_resource_forecast,
+)
+from fin_hub.services.ledger import import_csv
+
+
+def _common_planning() -> dict:
+    return {
+        "schema_version": "0.1",
+        "record_id": "forecast:platform-audit-storage:2026-08",
+        "revision_of": None,
+        "resource_id": "resource:platform_audit_storage",
+        "service_id": "object-storage",
+        "workload_id": "platform-pg",
+        "tenant_id": None,
+        "environment": "production",
+        "cost_attribution_key": "platform:audit-storage",
+        "period_start": "2026-09-01",
+        "period_end": "2027-08-31",
+        "currency": "eur",
+        "source_evidence": ["resource-control:data/forecasts/platform-audit-storage"],
+        "created_at": "2026-08-10T17:10:00Z",
+    }
+
+
+def test_booked_cost_money_relationships_and_decimal_json():
+    record = BookedCostEvidence(
+        financial_fact_id="fact:1",
+        correction_of=None,
+        adjustment_kind="charge",
+        source_type="provider_invoice",
+        source_document_id="invoice:1",
+        source_line_id="invoice:1:line:1",
+        content_fingerprint="sha256:abc",
+        provider="provider",
+        accounting_period="2026-07",
+        currency="eur",
+        net_amount="10.005",
+        discount_amount="1.00",
+        tax_status="known",
+        tax_amount="1.90",
+        gross_amount="10.90",
+        adjustment_amount="0",
+        effective_amount="10.90",
+        source_evidence_ref="invoice:1",
+        recorded_at=datetime.now(timezone.utc),
+    )
+
+    assert record.net_amount == Decimal("10.00")
+    assert record.currency == "EUR"
+    assert '"gross_amount":"10.90"' in record.model_dump_json()
+
+
+def test_booked_cost_rejects_invalid_relationships():
+    with pytest.raises(ValidationError, match="gross_amount"):
+        BookedCostEvidence(
+            financial_fact_id="fact:1",
+            adjustment_kind="charge",
+            source_type="invoice",
+            source_document_id="doc",
+            source_line_id="line",
+            content_fingerprint="hash",
+            provider="provider",
+            accounting_period="2026-07",
+            currency="EUR",
+            net_amount="10",
+            discount_amount="0",
+            tax_status="known",
+            tax_amount="1.90",
+            gross_amount="12",
+            effective_amount="12",
+            source_evidence_ref="doc",
+            recorded_at=datetime.now(timezone.utc),
+        )
+
+
+def test_planning_forecast_is_typed_and_idempotent(tmp_path: Path):
+    payload = {
+        **_common_planning(),
+        "record_type": "forecast",
+        "scenario": "base",
+        "forecast_version": "2026-08-base",
+        "costs": {
+            "infrastructure": "2.89",
+            "internal_labor": "60",
+            "external_services": "0",
+            "setup": "0",
+            "other": "0",
+        },
+        "uncertainty": "provider price excludes unknown tax",
+        "assumptions": ["180 GB stored"],
+    }
+    ledger = tmp_path / "ledger.db"
+
+    first = ingest_planning_evidence(payload, ledger_path=ledger)
+    second = ingest_planning_evidence(payload, ledger_path=ledger)
+
+    assert isinstance(first, ForecastEvidence)
+    assert first.costs.total == Decimal("62.89")
+    assert second.record_id == first.record_id
+
+
+def test_resource_control_backup_forecast_enters_planning_store(tmp_path: Path):
+    payload = {
+        "schema_version": "0.1",
+        "record_type": "forecast",
+        "workload": "platform-pg",
+        "cost_attribution_key": "platform:audit-storage",
+        "provider_id": "scaleway-standard-multi-az",
+        "created_at": "2026-08-10T17:10:00Z",
+        "scenario": "base",
+        "forecast_ref": None,
+        "rows": [
+            {
+                "period": "2026-09",
+                "database_gb": 5,
+                "stored_gb": 180,
+                "wal_gb": 30,
+                "restore_egress_gb": 5,
+                "write_requests": 2500,
+                "read_requests": 1000,
+                "infrastructure_eur": 2.89,
+                "internal_labor_hours": 1,
+                "internal_labor_eur": 60,
+                "total_eur": 62.89,
+            }
+        ],
+    }
+    records = ingest_resource_forecast(
+        payload,
+        resource_id="resource:platform_audit_storage",
+        source_evidence_ref="resource-control:data/forecasts/platform-audit-storage",
+        ledger_path=tmp_path / "ledger.db",
+    )
+
+    assert len(records) == 1
+    assert isinstance(records[0], ForecastEvidence)
+    assert records[0].costs.total == Decimal("62.89")
+
+
+def test_allocation_requires_shares_and_residual_to_reconcile():
+    payload = {
+        **_common_planning(),
+        "record_type": "allocation",
+        "record_id": "allocation:1",
+        "financial_fact_ids": ["fact:1"],
+        "method": "namespace-cpu-v1",
+        "allocated_amount": "10.00",
+        "shares": [{"target_key": "client:acme", "share": "0.75"}],
+        "residual_share": "0.20",
+    }
+    with pytest.raises(ValidationError, match="must equal 1"):
+        AllocationEvidence.model_validate(payload)
+
+
+def test_booked_cost_projection_uses_current_corrected_fact(tmp_path: Path):
+    source = tmp_path / "cost.csv"
+    ledger = tmp_path / "ledger.db"
+    source.write_text(
+        "product,amount,currency,invoice_date,environment\n"
+        "Server,10.00,EUR,2026-07-01,production\n",
+        encoding="utf-8",
+    )
+    import_csv(source, "hosteurope", ledger_path=ledger)
+    source.write_text(
+        "product,amount,currency,invoice_date,environment\n"
+        "Server,12.00,EUR,2026-07-01,production\n",
+        encoding="utf-8",
+    )
+    import_csv(source, "hosteurope", ledger_path=ledger, force=True)
+
+    records = booked_cost_projection(ledger_path=ledger)
+
+    assert len(records) == 1
+    assert records[0].effective_amount == Decimal("12.00")
+    assert records[0].correction_of is not None
+    assert records[0].environment == "production"
+
+
+def test_sqlalchemy_price_uses_shared_invariants():
+    price = EngagementPrice(
+        client_id="acme",
+        application_id="portal",
+        app_instance_id="prod-01",
+        cost_attribution_key="wrong",
+        effective_from=date(2026, 7, 1),
+        amount=Decimal("100.001"),
+        currency="eur",
+        source="agreement",
+    )
+    with pytest.raises(ValueError, match="does not match"):
+        _validate_engagement_price(None, None, price)