# 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: implemented (M0–M7) + SDD §8 panels.** The full solution is built and green — five projects, ~108 tests, working Docker deploy. `docs/SDD.md` remains the design reference; the milestone map (§12) matches the git history (M0…M7 commits). The dedicated **PV/Solar** (`/solar`), **Oil/consumable** (`/consumables`) and **meter-detail** (`/meters/{id}`) views (SDD §8.4–§8.6) are implemented as read models in `Infrastructure/Dashboard` (`SolarService`, `ConsumableService`, `MeterDetailService`) — PV meters are found by `Mode == GenerationCounter` and grid/load meters by a `role` tag in `Meter.Meta` (`MeterRoles`/`MeterMeta`), so nothing is hardcoded by name. **Admin write-CRUD** (SDD §8.7) is implemented as MudBlazor inline-dialog pages: energy types, meters (+ recompute on mode/baseline change), a meter's ingest sources (meter-detail Sources tab), tariffs, cost categories + members, and connectors (`ingestion_endpoint`, secrets by env-var reference only). `/admin/settings` is a read-only effective-config view (settings are env-driven and reproducible, not DB-stored). **Home Assistant reading** is configured here: an HA connector (`BaseUrl` + `TokenEnv`) + an HA source (entity id) drives `HomeAssistantWorker`'s REST poll, or — with the connector's **WebSocket push** toggle (`HaEndpointConfig.UseWebSocket`) — `HomeAssistantWebSocketWorker` holds a persistent `state_changed` subscription and ingests in real time (the poll worker skips WS endpoints, so each is served once; `HaWebSocketProtocol` is the pure, unit-tested handshake/parse logic). `HaConnectionTester` powers the connector "Test connection" button. **Meter topology & flow**: `MeterLink` (a directed `from→to` edge; a downstream meter is a *subsection* of an upstream one, multi-parent allowed) drives a per-energy-type page `/energy/{id}` with a hand-rolled SVG **Sankey** (`SankeyChart.razor`, since ApexCharts has no Sankey type) computed by `FlowService` (link value = downstream consumption, split proportionally across multiple parents; unaccounted remainder → an "Other" node). Upstream meters are wired cycle-safely in the meter editor; the nav lists a link per energy type. **CSV mapping wizard** (`/import/wizard`): upload an arbitrary CSV, map columns → meters/roles, dry-run preview, then commit as a revertible `import_batch` (the `/import` page lists batches with one-click revert). The `instant_rate` mode is normalized (`InstantRateNormalizer`: rate integrated over time, trapezoidal). Remaining refinement: full de-DE UI-string localization (data parsing is already de-DE) — noted at its commit. Set `MeterVault__SeedReferenceData=true` (compose: `METERVAULT_SEED=true`) for a one-command populated demo.

## 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.

## Project layout

```
/src/Core            domain entities + enums; pure Normalization engine (mode strategies,
                     expression evaluator); Parsing (German dialect); Costing (TariffResolver)
/src/Infrastructure  MeterVaultDbContext + migrations (relational + raw-SQL Timescale);
                     Import (CsvImporter, profiles, ImportService), Ingestion (MQTT/HA workers,
                     IngestionService), Normalization service, Costing/Dashboard/Backup services
/src/App             ASP.NET Core host: Blazor Server UI (Components/), REST API (Api/), hosted
                     workers, Program.cs (Serilog, migrate+seed on startup, /healthz)
/tests/Core.Tests            unit (no Docker): parsers, normalizers, swap→12, tariff resolver
/tests/Integration.Tests     Testcontainers (Timescale): reconciliation vs the 4 fixtures,
                             import commit/revert, ingestion, cost, CAgg refresh, API, export, render
/deploy              Dockerfile, docker-compose.yml (app + timescaledb), build-and-push.ps1, unraid-template.xml
```

Central package versions live in `Directory.Packages.props`; shared build/style in
`Directory.Build.props` + `.editorconfig`. Snake_case table/column mapping via
`UseSnakeCaseNamingConvention`. EF migrations are exempt from code-style enforcement (see `.editorconfig`).

## Commands

```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 tests/Integration.Tests --filter "FullyQualifiedName~Reconciliation"  # one class/area
dotnet ef migrations add <Name> -p src/Infrastructure -s src/App -o Persistence/Migrations
dotnet run --project src/App                   # run app + workers locally (needs a Timescale DB)
docker compose -f deploy/docker-compose.yml up # app + TimescaleDB together
```

**Timescale-in-EF gotchas** (already handled — follow the pattern): hypertable/CAgg DDL lives in
raw-SQL migrations; continuous-aggregate creation + policies use `migrationBuilder.Sql(..., suppressTransaction: true)`, one statement each; CAgg policy `end_offset` must be ≥ one bucket. Tests
pause the compression job (historical fixture data would otherwise deadlock imports).

## 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. Live ingestion recomputes the meter inline (`IngestionService.RenormalizeAsync`) — without it, polled readings never become consumption.
- **Long gaps are apportioned, short ones are not** (`GapAttribution`, SDD §7.1). An interval containing ≥2 whole calendar months is split across those months, proportional to elapsed time, marked `Estimated`. A monthly series contains exactly one and is untouched — that's what keeps the golden fixtures reconciling. `GapSplittingIsInertOnFixturesTests` asserts the rule declines to fire on the reference data, so this can't silently drift.
- **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')`.

**In-app update (`UpdateRunner`):** the dashboard shows a banner when a newer tag exists (`UpdateCheckService`, cached, never blocks a render). Triggering an update is **off by default**; `MeterVault__AllowInAppUpdate` is the *only* gate — no API key, by explicit owner decision. With it on, anything that can reach the app can trigger a rebuild+restart as root (realistically a DoS, since the build comes from the owner's own repo; RCE if that repo is compromised). The REST endpoint additionally requires an `X-MeterVault-Update` header — a CSRF guard, not auth, so a foreign page cannot drive it via a LAN browser. Launches detached via `systemd-run` because the update restarts the service. Treat any change here as security-critical; `UpdateRunnerTests` pins that the flag defaults off and that API keys alone don't enable it.

**Secrets (SDD §6.4):** broker/HA tokens are **never** stored in DB plaintext. Two forms, chosen per connector in the admin UI: a *reference* (`token_env`/`password_env` naming an env var or Docker secret path) resolved at runtime, or *encrypted at rest* (`token_enc`/`password_enc`) via `SecretProtector` over the ASP.NET Core data-protection key ring. Exactly one survives a save; `EndpointSecret.Resolve` is the single resolution path (encrypted wins). The key ring lives outside the app directory (`MeterVault__DataProtectionKeyPath`, default `/var/lib/metervault/keys`) because the LXC updater republishes `/opt/metervault`. `ExportService` drops `*_enc` values — they are bound to the originating key ring.

## 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` (Gitea; default branch `master`). CI/release is **Gitea Actions** under `.gitea/workflows/` — edit `VERSION` on `master` to tag + publish the image to the Gitea container registry.