add cmd/shipper/main.go

cmd/shipper/main.go

@@ -0,0 +1,119 @@
+// Command shipper runs on the generator machine.
+//
+// Each cycle:
+//  1. Read the ai-radio library (index.json of FLAC tracks).
+//  2. Build the rolling, newest-biased playlist (domain policy).
+//  3. Transcode the playlist's FLAC -> MP3 (title tagged for stereo displays).
+//  4. Ship the MP3s + playlist.m3u8 to the streaming VPS (playlist last).
+//
+// Config: environment variables (see .env.example).
+package main
+
+import (
+	"encoding/json"
+	"flag"
+	"log"
+	"os"
+	"path/filepath"
+	"time"
+
+	"radio-go/internal/app"
+	"radio-go/internal/domain"
+	"radio-go/internal/infra"
+)
+
+func env(k, def string) string {
+	if v := os.Getenv(k); v != "" {
+		return v
+	}
+	return def
+}
+
+func main() {
+	once := flag.Bool("once", false, "run one cycle and exit")
+	flag.Parse()
+
+	libraryDir := env("LIBRARY_DIR", "library")
+	outDir := env("SHIP_STAGING_DIR", "ship_out")
+	target := env("SHIP_REMOTE_TARGET", "")
+	keyPath := env("SHIP_SSH_KEY", "")
+	station := env("STATION_NAME", "AI Radio")
+	size := parseInt(env("PLAYLIST_SIZE", "40"))
+	bias := parseInt(env("NEWNESS_BIAS", "3"))
+	bitrate := env("MP3_BITRATE", "128k")
+	poll := time.Duration(parseInt(env("SHIP_POLL_INTERVAL_S", "60"))) * time.Second
+
+	os.MkdirAll(outDir, 0o755)
+
+	for {
+		if err := cycle(libraryDir, outDir, target, keyPath, station, size, bias, bitrate); err != nil {
+			log.Printf("cycle failed: %v", err)
+		}
+		if *once {
+			return
+		}
+		time.Sleep(poll)
+	}
+}
+
+func cycle(libraryDir, outDir, target, keyPath, station string, size, bias int, bitrate string) error {
+	tracks, err := app.LoadLibrary(libraryDir)
+	if err != nil {
+		return err
+	}
+	if len(tracks) == 0 {
+		log.Printf("library empty — nothing to ship")
+		return nil
+	}
+	pl := domain.BuildPlaylist(tracks, size, bias, time.Now().UnixNano())
+
+	var files []string
+	for _, t := range pl {
+		dst := filepath.Join(outDir, t.ID+".mp3")
+		if st, err := os.Stat(dst); err != nil || st.Size() == 0 {
+			src := filepath.Join(libraryDir, t.Filename)
+			if err := app.Transcode(src, dst, bitrate, t.DisplayTitle(), station); err != nil {
+				return err
+			}
+			log.Printf("transcoded %s -> %s", t.Filename, filepath.Base(dst))
+		}
+		files = append(files, dst)
+	}
+
+	m3u := infra.WriteM3U(station, pl)
+	listPath := filepath.Join(outDir, "playlist.m3u8")
+	if err := os.WriteFile(listPath, []byte(m3u), 0o644); err != nil {
+		return err
+	}
+	files = append(files, listPath) // playlist last
+
+	// sidecar: id -> display title, so the streamer can publish real
+	// now-playing metadata without parsing ID3 tags
+	titles := map[string]string{}
+	for _, t := range pl {
+		titles[t.ID] = t.DisplayTitle()
+	}
+	tb, _ := json.Marshal(titles)
+	titlePath := filepath.Join(outDir, "titles.json")
+	if err := os.WriteFile(titlePath, tb, 0o644); err != nil {
+		return err
+	}
+	files = append(files, titlePath)
+
+	if err := app.Ship(files, target, keyPath); err != nil {
+		return err
+	}
+	log.Printf("shipped %d tracks (library: %d) to %s", len(pl), len(tracks), target)
+	return nil
+}
+
+func parseInt(s string) int {
+	var n int
+	for _, c := range s {
+		if c < '0' || c > '9' {
+			return 0
+		}
+		n = n*10 + int(c-'0')
+	}
+	return n
+}