---
phase: 11
plan: 02
subsystem: config
tags: [print-config, group-headers, toml-groups, user-facing-output]
dependency_graph:
  requires: [synth/config.go FreqConfig.Group field from Phase 11 Plan 01, classify/types.go AllClasses() with 35 entries]
  provides: [Group-ordered PrintConfig output, [groups] TOML support, applyGroupOverrides function]
  affects: [config/config.go, config/config_test.go]
tech_stack:
  added: []
  patterns: [rawConfig Groups field for TOML [groups] table, groupOrder canonical slice for section ordering]
key_files:
  created: []
  modified:
    - config/config.go
    - config/config_test.go
decisions:
  - "Non-canonical group names (user-invented via [groups]) emitted after canonical groups in alphabetical order"
  - "builtinByGroup built from result.FreqCfgs[cls].Group (effective group after reassignment) not from synth defaults"
metrics:
  duration: ~5min
  completed: "2026-03-27"
  tasks: 2
  files_modified: 2
---

# Phase 11 Plan 02: Group-Ordered PrintConfig and [groups] TOML Support Summary

**One-liner:** Refactored PrintConfig to emit group section headers (Infrastructure, Web, Mail, Remote Access, File Transfer, Database, Discovery, VoIP, Unknown) with classes sorted by ascending BaseHz, and added [groups] TOML table support for user-defined protocol-to-group reassignment.

## What Was Built

### Task 1: Add [groups] TOML support and refactor PrintConfig for group headers

**config/config.go** — Three changes:

**1. Groups field on rawConfig:**
```go
type rawConfig struct {
    Sounds map[string]SoundOverride `toml:"sounds"`
    Rules  []RawRule                `toml:"rules"`
    Groups map[string]string        `toml:"groups"`
}
```

**2. applyGroupOverrides function** — overlays [groups] reassignments onto FreqConfig.Group in-place. Unknown class names emit a stderr warning and are skipped (not an error). Unknown group names are silently accepted (users can invent custom groups). Called in Load() after merge().

**3. PrintConfig refactored** — replaced flat AllClasses() iteration with:
- `groupOrder` canonical slice: `["Infrastructure", "Web", "Mail", "Remote Access", "File Transfer", "Database", "Discovery", "VoIP", "Unknown"]`
- Built-in classes grouped by their effective Group field, sorted ascending by BaseHz within each group
- Section headers emitted as `# GroupName\n\n`
- Non-canonical group names (user-invented) emitted after canonical groups in alphabetical order
- User-defined classes (not in AllClasses()) emitted under `# User-defined` section

### Task 2: Add tests for group headers, group reassignment, and unknown class warning

**config/config_test.go** — 4 new test functions:

| Test | What It Covers |
|------|---------------|
| `TestPrintConfigGroupHeaders` | GRP-02: all 8 populated group headers present in canonical order |
| `TestLoadGroupOverride` | GRP-03: [groups] reassigns IMAP from Mail to Web, Hz/waveform unchanged |
| `TestLoadGroupUnknownClass` | D-09: unknown class in [groups] produces no error, map size unchanged |
| `TestPrintConfigGroupReassignment` | GRP-03: PrintConfig places reassigned IMAP between Web and Mail headers |

## Verification Results

```
go test ./...
ok  github.com/netsynth/netsynth/aggregate  (cached)
ok  github.com/netsynth/netsynth/capture    (cached)
ok  github.com/netsynth/netsynth/classify
ok  github.com/netsynth/netsynth/cmd/netsynth
ok  github.com/netsynth/netsynth/config
ok  github.com/netsynth/netsynth/encode
ok  github.com/netsynth/netsynth/synth
```

All 7 packages pass.

## Commits

| Task | Commit | Description |
|------|--------|-------------|
| 1 | 374282e | feat(11-02): add [groups] TOML support and group-ordered PrintConfig |
| 2 | 7bf3ea1 | test(11-02): add group header and reassignment tests (GRP-02, GRP-03) |

## Deviations from Plan

None - plan executed exactly as written.

## Known Stubs

None — PrintConfig group output is fully wired to FreqConfig.Group field populated in Phase 11 Plan 01. No placeholder data.

## Self-Check: PASSED