yoloyolo/.planning/milestones/v1.1-phases/07-custom-rules-and-print-config/07-01-PLAN.md

---
phase: 07-custom-rules-and-print-config
plan: 01
type: tdd
wave: 1
depends_on: []
files_modified:
  - config/config.go
  - config/config_test.go
autonomous: true
requirements:
  - RULE-01
  - RULE-02
  - RULE-03

must_haves:
  truths:
    - "TOML [[rules]] blocks parse into classify.Rule slices"
    - "Missing protocol or class in a rule produces a clear error at startup"
    - "User rules are returned separately from FreqCfgs for caller to prepend"
    - "New class names without explicit sound config get auto-assigned frequencies in 1200-2400 Hz range"
    - "Built-in class names in user rules do not get overwritten by auto-freq"
  artifacts:
    - path: "config/config.go"
      provides: "RawRule, LoadResult, validateRules, convertRules, autoAssignFreq, addAutoFreqEntries"
      contains: "type LoadResult struct"
    - path: "config/config_test.go"
      provides: "Tests for rule parsing, validation, auto-freq, LoadResult"
      contains: "TestLoadCustomRules"
  key_links:
    - from: "config/config.go"
      to: "classify/rules.go"
      via: "convertRules produces []classify.Rule"
      pattern: "classify\\.Rule"
    - from: "config/config.go"
      to: "synth/config.go"
      via: "autoAssignFreq creates FreqConfig entries with WaveformPresetHarmonics"
      pattern: "synth\\.WaveformPresetHarmonics"
---

<objective>
Extend the config package to parse `[[rules]]` TOML blocks into classification rules, validate them, auto-assign frequencies for new class names, and return a `LoadResult` struct from `Load()`.

Purpose: This is the data layer for user-defined classification rules (RULE-01, RULE-02, RULE-03). The LoadResult struct becomes the contract consumed by Plan 02 for CLI wiring and print-config.

Output: Updated `config/config.go` with RawRule, LoadResult, validation, auto-freq; comprehensive tests in `config/config_test.go`.
</objective>

<execution_context>
@$HOME/.claude/get-shit-done/workflows/execute-plan.md
@$HOME/.claude/get-shit-done/templates/summary.md
</execution_context>

<context>
@.planning/PROJECT.md
@.planning/ROADMAP.md
@.planning/STATE.md
@.planning/phases/07-custom-rules-and-print-config/07-CONTEXT.md
@.planning/phases/07-custom-rules-and-print-config/07-RESEARCH.md

@config/config.go
@config/config_test.go
@classify/rules.go
@classify/types.go
@synth/config.go

<interfaces>
<!-- Key types and contracts the executor needs. -->

From classify/rules.go:
```go
type Rule struct {
    Protocol string
    DstPort  uint16
    Class    TrafficClass
}
var DefaultRules = []Rule{ ... } // 12 rules, first-match-wins
```

From classify/types.go:
```go
type TrafficClass string
func AllClasses() []TrafficClass // returns 14 built-in classes
```

From synth/config.go:
```go
type WaveformType int
const WaveformSine WaveformType = 1
type FreqConfig struct {
    BaseHz       float64
    Harmonics    []HarmonicDef
    Pan          float64
    WaveformType WaveformType
}
var ClassFreqConfigs = map[classify.TrafficClass]FreqConfig{ ... } // 14 entries, max 1047 Hz
func WaveformPresetHarmonics(wt WaveformType, baseHz float64, sampleRate int) []HarmonicDef
const SampleRate = 44100
```

From config/config.go (current):
```go
type SoundOverride struct {
    Frequency *float64 `toml:"frequency"`
    Waveform  *string  `toml:"waveform"`
}
type rawConfig struct {
    Sounds map[string]SoundOverride `toml:"sounds"`
}
func Load(configPath string) (map[classify.TrafficClass]synth.FreqConfig, error)
```

From config/config_test.go (patterns):
```go
func writeTOML(t *testing.T, content string) string // creates temp TOML file
// Tests call config.Load(path) and check returned map
```
</interfaces>
</context>

<tasks>

<task type="auto" tdd="true">
  <name>Task 1: RawRule, LoadResult, validation, conversion, and auto-freq with TDD</name>
  <files>config/config.go, config/config_test.go</files>
  <read_first>config/config.go, config/config_test.go, classify/rules.go, classify/types.go, synth/config.go</read_first>
  <behavior>
    - TestLoadCustomRules: TOML with `[[rules]]` block (port=8080, protocol="tcp", class="MyApp") + `[sounds.MyApp]` (frequency=300.0) parses successfully; LoadResult.UserRules has len 1 with Protocol="tcp", DstPort=8080, Class="MyApp"; LoadResult.FreqCfgs["MyApp"].BaseHz == 300.0
    - TestLoadCustomRuleNoPort: TOML with `[[rules]]` (protocol="udp", class="AllUDP", no port field) parses; UserRules[0].DstPort == 0
    - TestLoadCustomRuleMissingProtocol: TOML `[[rules]]` with class="X" but no protocol field -> error containing "protocol is required"
    - TestLoadCustomRuleMissingClass: TOML `[[rules]]` with protocol="tcp" but no class field -> error containing "class is required"
    - TestLoadCustomRuleInvalidProtocol: TOML `[[rules]]` with protocol="ftp" -> error containing "invalid protocol"
    - TestLoadCustomRuleUnknownField: TOML `[[rules]]` with typo_field="bad" -> error containing "typo_field" (from Undecoded())
    - TestUserRulesPrepend: Load returns UserRules separately from FreqCfgs; caller can do `append(result.UserRules, classify.DefaultRules...)` to get user rules first
    - TestAutoFreqAssignment: TOML with `[[rules]]` (class="GameServer", protocol="tcp") and NO `[sounds.GameServer]` -> FreqCfgs contains "GameServer" entry with BaseHz in range [1200, 2350] and WaveformType == WaveformSine
    - TestAutoFreqDeterministic: Two Load() calls with same class name produce same BaseHz
    - TestAutoFreqSkipsBuiltins: TOML with `[[rules]]` (class="HTTPS", protocol="tcp", port=443) -> FreqCfgs["HTTPS"].BaseHz == 175.0 (the default), NOT an auto-assigned value
    - TestLoadResultConfigPath: Load(explicit_path) -> LoadResult.ConfigPath == explicit_path; Load("") with no file -> LoadResult.ConfigPath == ""
    - TestLoadNoConfigReturnsLoadResult: Load("") in empty dir returns LoadResult with len(FreqCfgs)==14, len(UserRules)==0, ConfigPath==""
    - TestExistingTestsStillPass: All 8 existing tests in config_test.go continue to pass after Load() signature change (they need updating to use LoadResult)
  </behavior>
  <action>
RED phase -- Write all test functions listed in behavior above in config/config_test.go. Tests call config.Load() and assert on LoadResult fields. Update the 8 existing tests to use the new LoadResult return type (e.g., `result, err := config.Load(path); cfgs := result.FreqCfgs`). Run tests -- they must all fail (Load still returns bare map).

GREEN phase -- Modify config/config.go:

1. Add RawRule struct (per D-01):
```go
type RawRule struct {
    Port     *uint16 `toml:"port"`
    Protocol string  `toml:"protocol"`
    Class    string  `toml:"class"`
}
```

2. Add Rules field to rawConfig:
```go
type rawConfig struct {
    Sounds map[string]SoundOverride `toml:"sounds"`
    Rules  []RawRule                `toml:"rules"`
}
```

3. Add LoadResult struct (per D-13, Claude's Discretion: struct over tuple):
```go
type LoadResult struct {
    FreqCfgs   map[classify.TrafficClass]synth.FreqConfig
    UserRules  []classify.Rule
    ConfigPath string
}
```

4. Add validateRules function called from validate():
```go
func validateRules(rules []RawRule) error {
    validProtocols := map[string]bool{"tcp": true, "udp": true, "icmp": true}
    for i, r := range rules {
        if r.Protocol == "" {
            return fmt.Errorf("config: rules[%d]: protocol is required", i)
        }
        if !validProtocols[r.Protocol] {
            return fmt.Errorf("config: rules[%d]: invalid protocol %q -- valid: tcp, udp, icmp", i, r.Protocol)
        }
        if r.Class == "" {
            return fmt.Errorf("config: rules[%d]: class is required", i)
        }
    }
    return nil
}
```

5. Add convertRules function:
```go
func convertRules(raw []RawRule) []classify.Rule {
    result := make([]classify.Rule, len(raw))
    for i, r := range raw {
        var port uint16
        if r.Port != nil {
            port = *r.Port
        }
        result[i] = classify.Rule{
            Protocol: r.Protocol,
            DstPort:  port,
            Class:    classify.TrafficClass(r.Class),
        }
    }
    return result
}
```

6. Add autoAssignFreq function (per D-07/D-08, using FNV-32a):
```go
import "hash/fnv"

func autoAssignFreq(className string) float64 {
    h := fnv.New32a()
    h.Write([]byte(className))
    const (
        baseHz   = 1200.0
        stepHz   = 50.0
        numSteps = uint32(24)
    )
    return baseHz + float64(h.Sum32()%numSteps)*stepHz
}
```

7. Add addAutoFreqEntries function (called AFTER merge, per Pitfall 4):
```go
func addAutoFreqEntries(cfgs map[classify.TrafficClass]synth.FreqConfig, userRules []classify.Rule) {
    for _, rule := range userRules {
        if _, exists := cfgs[rule.Class]; !exists {
            baseHz := autoAssignFreq(string(rule.Class))
            cfgs[rule.Class] = synth.FreqConfig{
                BaseHz:       baseHz,
                WaveformType: synth.WaveformSine,
                Harmonics:    synth.WaveformPresetHarmonics(synth.WaveformSine, baseHz, synth.SampleRate),
                Pan:          0.0,
            }
        }
    }
}
```

8. Change Load() signature to return LoadResult:
```go
func Load(configPath string) (LoadResult, error) {
```
- When no config found: return `LoadResult{FreqCfgs: copyDefaults(), ConfigPath: ""}`, nil
- After parseFile + validate + merge: call convertRules, call addAutoFreqEntries, return LoadResult with FreqCfgs, UserRules, and the resolved config path
- Update validate() to also call validateRules(raw.Rules)
- The `merge()` function for unknown class names should NO LONGER print a warning for classes that appear in raw.Rules -- those are legitimate custom classes. Keep the warning only for [sounds.X] where X is neither a built-in class nor a class defined in [[rules]].

9. Update the merge() function: Change the unknown-class warning logic. Instead of always warning on unknown class names in sounds, accept the `userRules []RawRule` as a parameter (or check after conversion). Simplest: after converting rules, pass the set of user-defined class names to merge so it can skip the warning for those. Alternatively, run merge first (with warnings), then let addAutoFreqEntries handle user-defined classes. The warning is acceptable for now -- it only fires for [sounds.X] where X has no matching [[rules]] entry AND is not a built-in class. Keep existing warning behavior, it is harmless.

REFACTOR phase -- Clean up if needed. Ensure all tests pass.

Run `go test ./config/...` -- all tests must pass.
Run `go test ./...` -- full suite must pass (the Load() call site in main.go will break; that is expected and fixed in Plan 02).
  </action>
  <verify>
    <automated>go test ./config/... -v -count=1</automated>
  </verify>
  <acceptance_criteria>
    - config/config.go contains `type RawRule struct` with `Port *uint16`, `Protocol string`, `Class string` fields
    - config/config.go contains `type LoadResult struct` with `FreqCfgs`, `UserRules`, `ConfigPath` fields
    - config/config.go contains `func Load(configPath string) (LoadResult, error)`
    - config/config.go contains `func validateRules(rules []RawRule) error`
    - config/config.go contains `func convertRules(raw []RawRule) []classify.Rule`
    - config/config.go contains `func autoAssignFreq(className string) float64` with `fnv.New32a()`
    - config/config.go contains `func addAutoFreqEntries(`
    - config/config.go imports `"hash/fnv"`
    - config/config_test.go contains `TestLoadCustomRules`
    - config/config_test.go contains `TestAutoFreqAssignment`
    - config/config_test.go contains `TestAutoFreqSkipsBuiltins`
    - config/config_test.go contains `TestLoadCustomRuleMissingProtocol`
    - `go test ./config/... -count=1` exits 0
  </acceptance_criteria>
  <done>
    Load() returns LoadResult with FreqCfgs + UserRules + ConfigPath. TOML [[rules]] blocks parse, validate (protocol required, class required, valid protocols only), and convert to classify.Rule slices. Auto-frequency assignment creates FreqConfig entries for new class names in 1200-2350 Hz range using FNV-32a. Built-in class names from user rules are NOT overwritten. All existing config tests updated and passing. Full config test suite green.
  </done>
</task>

</tasks>

<verification>
- `go test ./config/... -v -count=1` passes all tests including new rule-related tests
- `go vet ./config/...` reports no issues
- LoadResult struct is exported and usable from cmd/netsynth package
</verification>

<success_criteria>
- config.Load() returns LoadResult struct (not bare map)
- [[rules]] TOML blocks parse into UserRules field
- Validation catches missing protocol, missing class, invalid protocol
- Auto-freq assigns 1200-2350 Hz for new class names, skips built-ins
- All 8 existing config tests updated and passing
- All new tests passing
</success_criteria>

<output>
After completion, create `.planning/phases/07-custom-rules-and-print-config/07-01-SUMMARY.md`
</output>