MeterVault/CLAUDE.md

# CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

## What this repo is

MeterVault is a self-hosted, local-first energy & utility metering platform: it ingests meter data from Home Assistant, Tasmota and MQTT on a schedule, stores every reading timestamped and immutable, normalizes it into consumption, and turns it into cost dashboards. Energy types (electricity, water, heating oil, gas, …) and meters are **user-defined, never hardcoded**.

**Status: pre-code.** The repository currently contains only the design spec and reference data — no solution, projects, or build yet. The first coding task is milestone **M0** (scaffold) from the spec.

## Source of truth

`docs/SDD.md` is the authoritative spec and build brief — read it before implementing anything. Key protocol from §0 that governs all work here:

- **Build strictly in milestone order (§12, M0→M7).** Each milestone is independently runnable and testable; do not start Mn+1 until Mn's tests pass.
- **The four CSVs in `sampledata/` are golden fixtures.** Every parsing / consumption / cost rule must reconcile against them (§13). **If a computed number disagrees with the spreadsheet, the spreadsheet wins** unless the discrepancy is a deliberately documented correctness fix.
- When a design decision is ambiguous, check §14 (open questions): if listed, take the stated default and flag it; if not listed, ask before guessing.
- Keep the **domain layer free of infrastructure concerns** (the domain model and DB schema are UI-agnostic by design).

## Committed tech stack (do not re-litigate; see SDD §4.1)

.NET (current LTS — .NET 10, .NET 8 acceptable), C# · ASP.NET Core + **Blazor Server** · **MudBlazor** components · **ApexCharts** (Blazor-ApexCharts) · **MQTTnet** · **PostgreSQL + TimescaleDB** · **EF Core (Npgsql)** for schema/CRUD + **Dapper** for hot-path time-series reads · `BackgroundService` hosted services for ingestion/aggregation · **xUnit + Testcontainers** (Timescale image) · Docker Compose + GHCR.

## Intended project layout (created during M0, per SDD §11)

```
/src/Core            domain entities, enums, interfaces, expression evaluator  (no infra deps)
/src/Infrastructure  EF Core + Npgsql, Dapper repos, Timescale raw-SQL migrations, MQTT/HA clients, CSV importer
/src/App             ASP.NET Core host: Blazor Server UI + REST API + hosted workers
/tests/Core.Tests            unit: deltas, swaps, tariff resolution, oil rate, CSV parsing
/tests/Integration.Tests     Testcontainers (Timescale): ingest→aggregate→cost e2e
/tests/fixtures              the 4 reference CSVs + expected outputs
/deploy              Dockerfile, docker-compose.yml (app + timescaledb), unraid-template.xml
```

## Commands (apply once M0 has scaffolded the solution)

```powershell
dotnet build                                   # build the solution
dotnet test                                    # all tests (Integration.Tests needs Docker for Testcontainers)
dotnet test tests/Core.Tests                   # unit tests only (no Docker needed)
dotnet test --filter "FullyQualifiedName~Csv"  # a single test / class by name filter
dotnet run --project src/App                   # run app + workers locally
docker compose -f deploy/docker-compose.yml up # app + TimescaleDB together
```

## Core architecture (the part that spans multiple files)

**Data pipeline — one direction, layered (SDD §4.2, §5, §7):**

```
sources (Tasmota/HA/MQTT/manual/CSV)
  → Ingestion workers write raw `reading` rows (immutable audit truth)
  → Normalization derives append-only `consumption` (deltas in base unit)
  → TimescaleDB continuous aggregates roll consumption to hourly/daily/monthly/yearly
  → Cost engine joins aggregates with time-ranged `tariff`
  → Blazor dashboard + REST API read aggregates + cost views
```

**Invariants that shape everything:**

- **Raw `reading` is immutable audit truth.** Everything derived (consumption, cost, balances, forecasts) is computed on top and must be reproducible. Never mutate readings to fix a derived number.
- **Dashboards and charts read aggregates only — never scan `reading`.** This is what makes 1000 meters × 50 years feasible (§5.5). Raw is kept for a bounded window (default 3y); `consumption` + aggregates are the long-term source of truth.
- **`meter.mode` (measurement mode) is the central abstraction** for how raw readings become consumption (SDD §5.2): `cumulative_counter`, `generation_counter`, `runtime_counter` (Δhours × rate), `consumable_balance` (tank: deliveries − usage + forecast), `direct_delta`, `instant_rate`, `virtual` (expression over other meters). New ingestion/normalization logic dispatches on mode.
- **Nothing domain-specific is hardcoded.** Energy types are data. Cost **categories are decoupled from energy types** (Heizung may be oil today, heat-pump tomorrow). PV self-consumption/savings/net are **virtual meters** with user-defined expressions, not special-cased code. Tariffs are time-ranged (price history), scoped global / per-type / per-meter.

**Timescale vs EF split (SDD §5.3):** EF Core migrations own the relational tables. **Timescale-specific DDL — `create_hypertable`, compression policies, continuous aggregates, retention — is not expressible via EF's model builder and must live in raw-SQL migrations.** `reading` and `consumption` are hypertables.

**Time & DST (SDD §10):** store UTC everywhere; bucket and display in the instance timezone (default `Europe/Berlin`). "Daily cost" boundaries are local-midnight — use `time_bucket(..., 'Europe/Berlin')`.

**Secrets (SDD §6.4):** broker/HA tokens are **never** stored in DB plaintext. `ingestion_endpoint.config` holds a *reference* (env var name / Docker secret path) resolved at runtime.

## Reference-data behaviours the code must reproduce (from `sampledata/`)

These CSVs are the German-dialect *Energiebilanz* spreadsheet export and define the minimum feature bar (SDD §2, Appendix A). When writing the importer or normalization, honour:

- **German number dialect:** decimal comma (`180,8244706`), thousands dot (`2.940,19`), trailing-`€` currency (`120,00 €`), **unit suffixes on values** (`411kWh`, `49` cm, `2287` L) — strip and validate.
- **Two date formats:** `Monat YYYY` (German month names, monthly tables) and `DD.MM.YYYY` (event rows).
- **Skip inline summary rows** (`Total`, `Heute`, `Seitbeginn Tage`, `Seit YYYY`) and **all-zero future placeholder rows** (e.g. Dec 2026) — do not ingest them. **Negatives are valid** (savings, grid balance).
- **Water register swaps mid-series** (…861 → 2 → 15): consumption must stay continuous across the boundary via a `meter_swap` event.
- **Electricity has 5 meters** (Haus, Netz, Auto, Solar 1, Solar 2) plus derived columns. Verified relations to reproduce: `Netz Einsparung = Haus − Netz`, `Ersparnis = Netz Einsparung × €/kWh`, `Kosten = Verbrauchskosten − Ersparnis` — but implement these as **user-definable virtual-meter expressions**, not hardcoded formulas.
- **Heating oil is the versatility stress test:** a consumable/tank model where consumption is derivable two ways — tank-level Δ, or burner runtime × rate (rate `fixed` from nozzle spec, or `empirical` = Δlevel ÷ Δhours). Early rows (1997–2004) carry deliveries only (no burner hours yet). Includes cm→litre dipstick calibration and forecast-to-empty.

## Git

Remote `origin` is `https://git.finalfactory.de/FinalFactory/MeterVault.git` (default branch `main`).