feat: integrate cli config and control scaffolding

cmd/fmrtx/main.go

@@ -0,0 +1,31 @@
+package main
+
+import (
+    "flag"
+    "fmt"
+    "log"
+    "net/http"
+
+    cfgpkg "github.com/jan/fm-rds-tx/internal/config"
+    ctrlpkg "github.com/jan/fm-rds-tx/internal/control"
+)
+
+func main() {
+    configPath := flag.String("config", "", "path to JSON config")
+    printConfig := flag.Bool("print-config", false, "print effective config and exit")
+    flag.Parse()
+
+    cfg, err := cfgpkg.Load(*configPath)
+    if err != nil {
+        log.Fatalf("load config: %v", err)
+    }
+
+    if *printConfig {
+        fmt.Printf("backend=%s freq=%.1fMHz stereo=%t rds=%t listen=%s\n", cfg.Backend.Kind, cfg.FM.FrequencyMHz, cfg.FM.StereoEnabled, cfg.RDS.Enabled, cfg.Control.ListenAddress)
+        return
+    }
+
+    srv := ctrlpkg.NewServer(cfg)
+    log.Printf("fm-rds-tx listening on %s", cfg.Control.ListenAddress)
+    log.Fatal(http.ListenAndServe(cfg.Control.ListenAddress, srv.Handler()))
+}

docs/README.md

@@ -0,0 +1,17 @@
+# fm-rds-tx docs
+
+## Build & Test
+
+### Root CLI
+- `go test ./...`
+- `go run ./cmd/fmrtx -print-config`
+- `go run ./cmd/fmrtx -config docs/config.sample.json`
+
+### Internal DSP module
+- `cd internal`
+- `go test ./...`
+
+### Examples module
+- `cd examples`
+- `go test ./...`
+- `go run ./soapy_simulated`

docs/config.sample.json

@@ -0,0 +1,31 @@
+{
+  "audio": {
+    "inputPath": "",
+    "sampleRate": 48000,
+    "gain": 1.0
+  },
+  "rds": {
+    "enabled": true,
+    "pi": "1234",
+    "ps": "FMRTX",
+    "radioText": "fm-rds-tx example config",
+    "pty": 0
+  },
+  "fm": {
+    "frequencyMHz": 100.0,
+    "stereoEnabled": true,
+    "pilotLevel": 0.1,
+    "rdsInjection": 0.03,
+    "preEmphasisUS": false,
+    "outputDrive": 0.5,
+    "compositeRateHz": 228000
+  },
+  "backend": {
+    "kind": "file",
+    "device": "",
+    "outputPath": "build/out/composite.f32"
+  },
+  "control": {
+    "listenAddress": "127.0.0.1:8088"
+  }
+}

go.mod

@@ -0,0 +1,7 @@
+module github.com/jan/fm-rds-tx
+
+go 1.24.0
+
+require github.com/jan/fm-rds-tx/internal v0.0.0
+
+replace github.com/jan/fm-rds-tx/internal => ./internal

internal/config/config.go

@@ -0,0 +1,105 @@
+package config
+
+import (
+    "encoding/json"
+    "fmt"
+    "os"
+)
+
+type Config struct {
+    Audio   AudioConfig   `json:"audio"`
+    RDS     RDSConfig     `json:"rds"`
+    FM      FMConfig      `json:"fm"`
+    Backend BackendConfig `json:"backend"`
+    Control ControlConfig `json:"control"`
+}
+
+type AudioConfig struct {
+    InputPath  string  `json:"inputPath"`
+    SampleRate int     `json:"sampleRate"`
+    Gain       float64 `json:"gain"`
+}
+
+type RDSConfig struct {
+    Enabled   bool   `json:"enabled"`
+    PI        string `json:"pi"`
+    PS        string `json:"ps"`
+    RadioText string `json:"radioText"`
+    PTY       int    `json:"pty"`
+}
+
+type FMConfig struct {
+    FrequencyMHz    float64 `json:"frequencyMHz"`
+    StereoEnabled   bool    `json:"stereoEnabled"`
+    PilotLevel      float64 `json:"pilotLevel"`
+    RDSInjection    float64 `json:"rdsInjection"`
+    PreEmphasisUS   bool    `json:"preEmphasisUS"`
+    OutputDrive     float64 `json:"outputDrive"`
+    CompositeRateHz int     `json:"compositeRateHz"`
+}
+
+type BackendConfig struct {
+    Kind       string `json:"kind"`
+    Device     string `json:"device"`
+    OutputPath string `json:"outputPath"`
+}
+
+type ControlConfig struct {
+    ListenAddress string `json:"listenAddress"`
+}
+
+func Default() Config {
+    return Config{
+        Audio: AudioConfig{SampleRate: 48000, Gain: 1.0},
+        RDS: RDSConfig{Enabled: true, PI: "1234", PS: "FMRTX", RadioText: "fm-rds-tx", PTY: 0},
+        FM: FMConfig{FrequencyMHz: 100.0, StereoEnabled: true, PilotLevel: 0.1, RDSInjection: 0.03, OutputDrive: 0.5, CompositeRateHz: 228000},
+        Backend: BackendConfig{Kind: "file", OutputPath: "build/out/composite.f32"},
+        Control: ControlConfig{ListenAddress: "127.0.0.1:8088"},
+    }
+}
+
+func Load(path string) (Config, error) {
+    cfg := Default()
+    if path == "" {
+        return cfg, cfg.Validate()
+    }
+    data, err := os.ReadFile(path)
+    if err != nil {
+        return Config{}, err
+    }
+    if err := json.Unmarshal(data, &cfg); err != nil {
+        return Config{}, err
+    }
+    return cfg, cfg.Validate()
+}
+
+func (c Config) Validate() error {
+    if c.Audio.SampleRate < 8000 || c.Audio.SampleRate > 384000 {
+        return fmt.Errorf("audio.sampleRate out of range")
+    }
+    if c.Audio.Gain < 0 || c.Audio.Gain > 4 {
+        return fmt.Errorf("audio.gain out of range")
+    }
+    if c.FM.FrequencyMHz < 65 || c.FM.FrequencyMHz > 110 {
+        return fmt.Errorf("fm.frequencyMHz out of range")
+    }
+    if c.FM.PilotLevel < 0 || c.FM.PilotLevel > 0.2 {
+        return fmt.Errorf("fm.pilotLevel out of range")
+    }
+    if c.FM.RDSInjection < 0 || c.FM.RDSInjection > 0.1 {
+        return fmt.Errorf("fm.rdsInjection out of range")
+    }
+    if c.FM.OutputDrive < 0 || c.FM.OutputDrive > 1 {
+        return fmt.Errorf("fm.outputDrive out of range")
+    }
+    if c.FM.CompositeRateHz < 96000 || c.FM.CompositeRateHz > 1520000 {
+        return fmt.Errorf("fm.compositeRateHz out of range")
+    }
+    if c.Backend.Kind == "" {
+        return fmt.Errorf("backend.kind is required")
+    }
+    if c.Control.ListenAddress == "" {
+        return fmt.Errorf("control.listenAddress is required")
+    }
+    return nil
+}

internal/control/control.go

@@ -0,0 +1,37 @@
+package control
+
+import (
+    "encoding/json"
+    "net/http"
+
+    "github.com/jan/fm-rds-tx/internal/config"
+)
+
+type Server struct {
+    cfg config.Config
+}
+
+func NewServer(cfg config.Config) *Server { return &Server{cfg: cfg} }
+
+func (s *Server) Handler() http.Handler {
+    mux := http.NewServeMux()
+    mux.HandleFunc("/healthz", s.handleHealth)
+    mux.HandleFunc("/status", s.handleStatus)
+    return mux
+}
+
+func (s *Server) handleHealth(w http.ResponseWriter, _ *http.Request) {
+    w.Header().Set("Content-Type", "application/json")
+    _ = json.NewEncoder(w).Encode(map[string]any{"ok": true})
+}
+
+func (s *Server) handleStatus(w http.ResponseWriter, _ *http.Request) {
+    w.Header().Set("Content-Type", "application/json")
+    _ = json.NewEncoder(w).Encode(map[string]any{
+        "service": "fm-rds-tx",
+        "backend": s.cfg.Backend.Kind,
+        "frequencyMHz": s.cfg.FM.FrequencyMHz,
+        "stereoEnabled": s.cfg.FM.StereoEnabled,
+        "rdsEnabled": s.cfg.RDS.Enabled,
+    })
+}

scripts/check.ps1

@@ -0,0 +1,8 @@
+$ErrorActionPreference = "Stop"
+go test ./...
+Push-Location internal
+go test ./...
+Pop-Location
+Push-Location examples
+go test ./...
+Pop-Location

scripts/run.ps1

@@ -0,0 +1,2 @@
+$ErrorActionPreference = "Stop"
+go run ./cmd/fmrtx -config docs/config.sample.json