fm-rds-tx/internal/ingest/factory/factory.go

package factory

import (
	"fmt"
	"io"
	"net/http"
	"os"
	"strings"

	"github.com/jan/fm-rds-tx/internal/config"
	"github.com/jan/fm-rds-tx/internal/ingest"
	"github.com/jan/fm-rds-tx/internal/ingest/adapters/httpraw"
	"github.com/jan/fm-rds-tx/internal/ingest/adapters/icecast"
	"github.com/jan/fm-rds-tx/internal/ingest/adapters/stdinpcm"
)

type Deps struct {
	Stdin io.Reader
	HTTP  *http.Client
}

type AudioIngress interface {
	WritePCM16(data []byte) (int, error)
}

func BuildSource(cfg config.Config, deps Deps) (ingest.Source, AudioIngress, error) {
	switch normalizeIngestKind(cfg.Ingest.Kind) {
	case "", "none":
		return nil, nil, nil
	case "stdin", "stdin-pcm":
		reader := deps.Stdin
		if reader == nil {
			reader = os.Stdin
		}
		src := stdinpcm.New("stdin-main", reader, cfg.Ingest.Stdin.SampleRateHz, cfg.Ingest.Stdin.Channels, 1024)
		return src, nil, nil
	case "http-raw":
		src := httpraw.New("http-raw-main", cfg.Ingest.HTTPRaw.SampleRateHz, cfg.Ingest.HTTPRaw.Channels)
		return src, src, nil
	case "icecast":
		src := icecast.New(
			"icecast-main",
			cfg.Ingest.Icecast.URL,
			deps.HTTP,
			icecast.ReconnectConfig{
				Enabled:          cfg.Ingest.Reconnect.Enabled,
				InitialBackoffMs: cfg.Ingest.Reconnect.InitialBackoffMs,
				MaxBackoffMs:     cfg.Ingest.Reconnect.MaxBackoffMs,
			},
			icecast.WithDecoderPreference(cfg.Ingest.Icecast.Decoder),
		)
		return src, nil, nil
	default:
		return nil, nil, fmt.Errorf("unsupported ingest kind: %s", cfg.Ingest.Kind)
	}
}

func SampleRateForKind(cfg config.Config) int {
	switch normalizeIngestKind(cfg.Ingest.Kind) {
	case "stdin", "stdin-pcm":
		if cfg.Ingest.Stdin.SampleRateHz > 0 {
			return cfg.Ingest.Stdin.SampleRateHz
		}
	case "http-raw":
		if cfg.Ingest.HTTPRaw.SampleRateHz > 0 {
			return cfg.Ingest.HTTPRaw.SampleRateHz
		}
	case "icecast":
		return 44100
	}
	return 44100
}

func normalizeIngestKind(kind string) string {
	return strings.ToLower(strings.TrimSpace(kind))
}