prop/CLAUDE.md

# 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.
- **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

# 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) |

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

**Dev** currently has propagation disabled for backfill. Re-enable by removing the Oban override in `config/dev.exs`.

### Scoring Algorithm

9-factor weighted composite score (0-100) per grid point per band:

| Factor | Weight | Source |
|---|---|---|
| Humidity | 20% | HRRR surface temp + dewpoint |
| Time of day | 20% | UTC hour, cyclical |
| T-Td depression | 12% | HRRR surface |
| Refractivity | 10% | HRRR profile gradient (thresholds calibrated for HRRR resolution) |
| Sky cover | 10% | HRRR cloud cover |
| Season | 10% | Month, band-dependent (inverted for 24G+) |
| Rain | 8% | HRRR precipitation, ITU-R P.838-3 |
| Wind | 6% | HRRR 10m wind |
| Pressure | 4% | HRRR surface pressure |

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`

### 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

### 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`

### Deployment
- Production runs on Dokku with nginx proxy
- Push to `github` remote for code. Push to `dokku` remote only when explicitly asked — it triggers production deploy.
- Production Oban config in `config/runtime.exs` — no backfill cron, enrichment triggered by QSO submission
- SRTM tiles at `/srtm` in production container