# CLAUDE.md

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

## Project Overview

Microwaveprop is a Phoenix 1.8 web application for the North Texas Microwave Society (NTMS) that predicts microwave radio propagation conditions (10-241 GHz). It helps amateur radio operators plan and coordinate microwave contacts by showing real-time and forecast propagation maps.

**Stack:** Elixir ~> 1.15, Phoenix 1.8 + LiveView, PostgreSQL via Ecto, Tailwind CSS v4 + daisyUI, Bandit HTTP server, Nx/Axon/EXLA for ML. esbuild for JS bundling — never npm.

### What It Does

1. **Propagation Map** (`/map`) — Full-screen Leaflet map with colored overlay showing propagation scores (0-100) per grid point across CONUS at 0.125° resolution. Includes 18-hour forecast timeline, band selector (10-241 GHz), Maidenhead grid overlay, point detail with factor breakdown and forecast sparkline, and terrain viewshed analysis.

2. **QSO Submission** (`/submit`) — Users submit microwave contacts. On submission, the system automatically enqueues weather/HRRR/terrain/IEMRE enrichment jobs for that QSO.

3. **Algorithm Documentation** (`/algo`) — Renders `algo.md` as HTML. Documents the scoring algorithm, meteorological foundations, ITU-R models, and calibration data.

4. **Hourly Scoring Pipeline** — Every hour, the PropagationGridWorker fetches HRRR forecast hours f00-f18, computes propagation scores across all bands, and pushes updates to connected clients via PubSub.

### Key Data Sources

- **HRRR** (High-Resolution Rapid Refresh) — 3 km NWP model from NOAA AWS S3. Surface + pressure level profiles. Analysis + 18-hour forecasts.
- **HRDPS** (High Resolution Deterministic Prediction System) — 2.5 km Canadian NWP model from MSC Datamart. 4×/day at 00/06/12/18Z, 48h forecasts. Coverage capped at 60°N for v1 (SRTM stops there). `HrdpsClient` + scaffolding shipped 2026-04-29; full pipeline activates once the Rust `prop-grid-rs` HRDPS branch ships. Plan: `docs/plans/2026-04-29-hrdps-canadian-prop-grid.md`.
- **ASOS** (Automated Surface Observing System) — Surface weather via Iowa Environmental Mesonet.
- **RAOB** (Radiosonde) — Upper-air soundings via IEM.
- **IEMRE** — Gridded hourly reanalysis at 0.125° resolution.
- **SRTM** — 90m terrain elevation for path analysis (local tile cache or API fallback).
- **Commercial Links** — 7 microwave links near DFW polled via SNMP at 5-min intervals.

## Commands

```bash
# Initial setup (deps, DB, assets)
mix setup

# Run dev server (live reloads automatically, no restart needed)
mix phx.server
iex -S mix phx.server    # with IEx shell

# Run all tests
mix test

# Run a single test file
mix test test/microwaveprop/terrain/terrain_analysis_test.exs

# Run previously failed tests
mix test --failed

# Format code (runs Styler plugin automatically)
mix format

# Static analysis
mix credo

# Pre-commit check (compile with warnings-as-errors, unlock unused deps, format, test)
mix precommit

# Rust pre-commit (matches the Forgejo CI step). Run from rust/prop_grid_rs/.
# `cargo build` alone does NOT catch clippy errors that gate the CI build.
cd rust/prop_grid_rs && cargo clippy --all-targets -- -D warnings && cargo test --release

# Database
mix ecto.create
mix ecto.migrate
mix ecto.gen.migration migration_name_using_underscores
mix ecto.reset           # drop + setup

# Run propagation grid manually
mix propagation_grid

# Assets
mix assets.build
mix assets.deploy        # minified + digest
```

## Architecture

### Directory Structure

- `lib/microwaveprop/` — Business logic (contexts, schemas, workers)
  - `propagation/` — Scoring engine: `scorer.ex`, `band_config.ex`, `grid.ex`, `model.ex` (ML), `freshness_monitor.ex`
  - `weather/` — Data ingestion: `hrrr_client.ex`, `iem_client.ex`, `sounding_params.ex`, GRIB2 decoder
  - `terrain/` — Path analysis: `terrain_analysis.ex` (ITU-R P.526-16), `viewshed.ex`, `elevation_client.ex`
  - `radio/` — QSO schema, Maidenhead grid conversion
  - `commercial/` — SNMP polling for commercial microwave links
  - `workers/` — Oban background jobs for all data pipelines
- `lib/microwaveprop_web/` — Web layer
  - `live/map_live.ex` — Main propagation map with forecast timeline
  - `live/submit_live.ex` — QSO submission form
  - `live/algo_live.ex` — Algorithm documentation page
  - `live/qso_live/` — QSO list and detail views
  - `plugs/remote_ip.ex` — X-Forwarded-For client IP extraction
- `config/` — Environment configs. `runtime.exs` has production Oban config (no backfill queues)
- `assets/js/propagation_map_hook.js` — Leaflet map, canvas heatmap, timeline, grid overlay
- `algo.md` — Full algorithm documentation with meteorological foundations
- `priv/models/` — Saved ML model weights (gitignored)

### Background Job Queues (Oban)

| Queue | Workers | Purpose |
|---|---|---|
| `propagation` | PropagationGridWorker | Hourly HRRR fetch (f00-f18) + score computation |
| `weather` | WeatherFetchWorker | ASOS/RAOB data for QSO enrichment |
| `hrrr` | HrrrFetchWorker | HRRR profiles for individual QSOs |
| `terrain` | TerrainProfileWorker | ITU-R P.526-16 terrain diffraction analysis |
| `iemre` | IemreFetchWorker | IEMRE gridded weather for QSO enrichment |
| `commercial` | PollWorker | SNMP polling of commercial links |
| `solar` | SolarIndexWorker | Daily solar indices |
| `enqueue` | QsoWeatherEnqueueWorker | Batch enqueue enrichment jobs (dev cron only) |
| `hrdps` | HrdpsGridWorker | Canadian propagation chain seed (4×/day). Dormant until Rust `prop-grid-rs` HRDPS branch ships — module exists, cron entry deferred. |

**Production** runs: propagation, commercial, solar, weather, hrrr, terrain, iemre queues. No cron backfill — enrichment is triggered by QSO submission only.

**Dev** runs the same hourly `PropagationGridWorker` + `AsosAdjustmentWorker` (10-minute nudge) cron as production.

### Scoring Algorithm

10-factor weighted composite score (0-100) per grid point per band (recalibrated 2026-04-11 via gradient descent):

| Factor | Weight | Source |
|---|---|---|
| Rain | 13.6% | HRRR precipitation, ITU-R P.838-3 |
| Humidity | 12.4% | HRRR surface temp + dewpoint |
| PWAT | 11.3% | HRRR precipitable water (column-integrated) |
| Season | 11.1% | Month, band-dependent (inverted for 24G+) |
| Refractivity | 10.5% | Native HRRR dM/dh (10-50m), fallback to pressure-level (250m) |
| Pressure | 10.3% | HRRR surface pressure (frontal activity proxy) |
| T-Td depression | 9.8% | HRRR surface |
| Sky cover | 8.0% | HRRR cloud cover |
| Wind | 8.0% | HRRR 10m wind |
| Time of day | 5.0% | Solar-time adjusted diurnal cycle |

Humidity effect reverses by frequency: beneficial at 10 GHz (refractivity), harmful at 24+ GHz (absorption).

### Terrain Analysis (ITU-R P.526-16)

- Knife-edge diffraction loss (Eq. 31)
- Deygout 3-edge method for multiple obstacles
- Dynamic k-factor from HRRR refractivity gradient
- Profiles stored per QSO path (58k+ paths analyzed)

### ML Model (Nx/Axon/EXLA)

Skeleton feed-forward network for future propagation prediction:
- 13 features: 8 atmospheric + 4 cyclical temporal + 1 log-frequency
- Architecture: Dense(64) → Dropout(0.2) → Dense(32) → Dropout(0.1) → Dense(1, sigmoid)
- Weights saved to `priv/models/propagation_v1.nx`
- Not yet trained — scaffolding only

### Data Flow

```
HRRR (NOAA S3) → PropagationGridWorker (hourly, f00-f18)
  → store hrrr_profiles → compute scores → upsert propagation_scores
  → PubSub broadcast → MapLive → JS hook → canvas heatmap + timeline

User submits QSO → enqueue_for_qso() → weather/hrrr/terrain/iemre workers
  → enrich QSO with atmospheric + terrain data
```

## Key Conventions

### Phoenix / LiveView
- LiveView templates must start with `<Layouts.app flash={@flash} ...>` wrapping all content
- Use `<.icon name="hero-x-mark" class="w-5 h-5"/>` for icons, never Heroicons modules
- Use `<.input>` from core_components for form inputs
- Use `to_form/2` for forms, never pass changesets directly to templates
- Use LiveView streams for collections, never `phx-update="append"`/`"prepend"`
- Avoid LiveComponents unless strongly justified
- LiveView names use `Live` suffix: `MicrowavepropWeb.ThingLive`
- Use `<.link navigate={...}>` / `<.link patch={...}>`, never `live_redirect`/`live_patch`
- Router scope aliases prefix automatically; don't add redundant aliases

### HEEx Templates
- Use `{...}` for attribute interpolation, `<%= %>` only for block constructs (if/for/cond) in tag bodies
- Class lists must use `[...]` syntax for conditional classes
- Use `<%!-- comment --%>` for HTML comments
- Use `phx-no-curly-interpolation` on tags containing literal curly braces
- Never use `<% Enum.each %>`, always use `<%= for item <- @collection do %>`

### JS / CSS
- Assets are bundled via esbuild and Tailwind mix tasks — never use npm, npx, or Node.js directly
- Tailwind v4: no `tailwind.config.js`, uses `@import "tailwindcss" source(none)` syntax in `app.css`
- Never use `@apply` in CSS
- No inline `<script>` tags; use colocated JS hooks with `.` prefix names
- Vendor deps must be imported into `app.js`/`app.css`, no external script `src` or link `href`
- LiveView hooks that push `map_bounds` (or any viewport-scoped data request) MUST implement `reconnected()` and a `document.visibilitychange` listener. Server assigns reset on reconnect while the hook keeps its stale client-side grid lookup — Leaflet tiles regenerated outside that extent paint blank. Both callbacks should call `invalidateSize()` + the bounds-push method; clean up the listener in `destroyed()`.

### Elixir
- Write idiomatic Elixir: use pattern matching, pipe operator, and the standard library
- Styler auto-formats on `mix format` (alias sorting, pipe chains, moduledoc enforcement, etc.)
- No index access on lists (`mylist[i]`); use `Enum.at/2`
- Bind results of `if`/`case`/`cond` blocks to variables (immutable rebinding)
- Never nest multiple modules in one file
- Use `struct.field` not `struct[:field]` (structs don't implement Access)
- Predicate functions: `thing?` not `is_thing` (reserve `is_` for guards)
- Use `Req` for HTTP requests, never httpoison/tesla/httpc
- **Always log anything that would normally be swallowed.** Any place that drops `{:exit, _}` from `Task.async_stream` / `Task.Supervisor.async_stream_nolink`, ignores `{:error, _}` clauses, or otherwise discards a failure path MUST `Logger.error`/`Logger.warning` with enough context (input, key, reason) to debug from k8s logs. Silently dropping a tuple in a `flat_map`/`reduce` clause is a bug — production crashes inside an async task otherwise vanish (the path-calculator "0 / 9 HRRR points" outage was exactly this). LiveView `start_async` must have a matching `handle_async(slot, {:exit, reason}, socket)` clause that logs.

### Ecto
- All schemas use `@primary_key {:id, :binary_id, autogenerate: true}`
- Preload associations in queries when accessed in templates
- `field :name, :string` for both string and text columns
- Use `Ecto.Changeset.get_field/2` to access changeset fields
- Programmatic fields (e.g. `user_id`) must not be in `cast` calls
- Generate migrations with `mix ecto.gen.migration`
- Upserts via `on_conflict: {:replace_all_except, [:id, ...]}` with `conflict_target`

### Testing
- Use `start_supervised!/1` for process cleanup
- Use `Process.monitor/1` + `assert_receive {:DOWN, ...}` instead of `Process.sleep`
- Use `LazyHTML` selectors for DOM assertions, never raw HTML matching
- Test against element IDs defined in templates
- Stub HTTP calls with `Req.Test.stub` in test setup
- Oban runs inline in test (`testing: :inline`)
- FreshnessMonitor disabled in test via `config :microwaveprop, start_freshness_monitor: false`
- **Don't anchor relative-time test fixtures on `DateTime.utc_now()` truncated to the hour.** A test that computes `recent_t = (top_of_hour) - 30min` is 30-90 min old of real `utc_now()` depending on what minute the test runs at; any production code that compares against `utc_now()` (e.g. a "drop entries older than 1 h" filter) flakes 50% of the time. Anchor at `top_of_hour` (or use a tiny offset like `now - 1s`) so the test is stable across clock minutes.

### Rust (`prop_grid_rs`)
- **Always run `cargo clippy --all-targets -- -D warnings` before committing Rust changes.** The Forgejo CI step runs clippy with warnings-as-errors and a passing local `cargo build` does NOT catch lints (e.g. `manual_range_contains`, `iter_kv_map`, `useless_format`). A clippy failure blocks the image build and the deploy. The Rust precommit recipe is in the `Commands` section.
- The CI build pipeline runs `cargo clippy --all-targets -- -D warnings && cargo test --release && cargo build --release`. Match this locally — `cargo build` alone is not enough.

### `/about` page maintenance
- Refresh `lib/microwaveprop_web/live/about_live.ex` whenever **algorithm structure**, **factor count or weights**, **major data sources**, **schema scale claims (e.g. "58k+ contacts")**, or **roadmap items** change. The dashboard counts auto-refresh from the DB; the prose blocks (overview, "How it works", "How it's built", "What's next") do not.
- The page renders a per-table count via `count_exact/1` and `count_estimate/1`. Each query is wrapped individually so a missing dev table doesn't blank the whole dashboard — keep that pattern when adding new stats.

### Deployment
- Production runs on Kubernetes (`home-cluster` context, `prop` namespace) — use `kubectl -n prop ...`
- Deployment name `prop` (3 replicas). Inspect with `kubectl -n prop get pods`, `kubectl -n prop logs deploy/prop`, `kubectl -n prop exec deploy/prop -- ...`
- Push to `github` remote for code. The `dokku` remote is obsolete — do not push there.
- Production Oban config in `config/runtime.exs` — no backfill cron, enrichment triggered by QSO submission
- Shared NFS mount `/data` in production container (server: node3 at `10.0.15.103:/data`). SRTM tiles live at `/data/srtm`.

### Operational gotchas
- **`kubectl exec deploy/prop` may route to the backfill pod**: the `prop` and `prop-backfill` deployments share label selectors, so `deploy/prop` can attach to either. When diagnosing cron / leader-only behavior, identify the hot pod by name first: `kubectl -n prop get pods -o name | grep -E '^pod/prop-[a-z0-9]+-[a-z0-9]+$' | head -1`. The backfill pod has `PROP_ROLE=backfill` and `peer: false` on its Oban; running RPC there is misleading because plugins gated on leader (Cron, etc.) appear inert by design.
- **Oban Pro `oban_peers` schema differs from OSS Oban**: there is no `leader` column. The single row in `oban_peers` IS the leader; columns are `name`, `node`, `started_at`, `expires_at`. Use `SELECT * FROM oban_peers` for diagnosis, never `WHERE leader = true`.
- **All `app=prop` pods (hot + backfill) join the same libcluster cluster** and are eligible for Oban leader election. Backfill pods carry `peer: false` in `runtime.exs` to make them ineligible — without that gate a backfill pod can win election and run its empty crontab as the cluster cron, silently stopping every scheduled job until the next leader rotation. If crons stop, check the leader node first.
- **HRRR `hrrr_profiles` partitions are quarterly EXCEPT for some half-year ones** (e.g. `hrrr_profiles_2027_01` covers H1 2027, not just Q1). Any partition-management code must pre-check coverage via `pg_inherits` + `pg_get_expr(child.relpartbound, child.oid)` before issuing CREATE — naïvely emitting a quarterly bound that a wider existing partition already contains will trip Postgres `42P17 invalid_object_definition`.
- **HRRR f000 publishes ~50–65 min after each cycle hour**: any worker that fetches HRRR for the current hour before that window will get 404s and mark its task `failed`. The PSKR producer + 5-min rolling-window cron tolerates this — failed tasks are reset to `queued` on the next enqueue. Don't add aggressive retry/alerting for "failed" `hrrr_fetch_tasks` rows < 1h old.
- **Do not query `pskr_calibration_samples` for HRRR coverage less than ~5 minutes after a sampler fire**: the sampler runs every 5 min and the producer/Rust-drain/re-pass loop takes one full cycle to close. Hour `t` is fully populated only after at least two sampler fires past hour `t+1`.
- **PSKR weather backfill is a two-pass producer/consumer**, not a join: `Microwaveprop.Pskr.CalibrationSampler` enqueues `hrrr_fetch_tasks` for cells missing HRRR; the Rust `hrrr-point-rs` worker drains them into `hrrr_profiles`; the next sampler pass UPSERTs the same `pskr_calibration_samples` row with non-NULL HRRR fields. The conflict target `(hour_utc, band, midpoint_lat, midpoint_lon)` makes it idempotent — never add a "skip if already exists" guard, that breaks the two-pass loop.
