refactor stream service helpers

internal/service/stream_service.go

@@ -0,0 +1,94 @@
+package service
+
+import (
+	"context"
+	"errors"
+
+	"go.uber.org/zap"
+
+	"github.com/ShukeBta/MediaStationGo/internal/config"
+	"github.com/ShukeBta/MediaStationGo/internal/repository"
+)
+
+const (
+	STRMEnabledSettingKey                  = "strm.enabled"
+	CloudPlaybackModeSettingKey            = "cloud.playback_mode"
+	CloudPlaybackSTRMEnabledSettingKey     = "cloud.playback_strm_enabled"
+	CloudPlaybackRedirectEnabledSettingKey = "cloud.playback_redirect_proxy_enabled"
+
+	CloudPlaybackModeSTRM          = "strm"
+	CloudPlaybackModeRedirectProxy = "redirect_proxy"
+)
+
+type CloudPlaybackOptions struct {
+	STRMEnabled          bool
+	RedirectProxyEnabled bool
+	PreferredMode        string
+}
+
+// StreamService serves media files with proper Range support so browsers can
+// seek into the stream.
+type StreamService struct {
+	cfg        *config.Config
+	log        *zap.Logger
+	repo       *repository.Container
+	transcoder *TranscoderService
+}
+
+// NewStreamService is the constructor.
+func NewStreamService(cfg *config.Config, log *zap.Logger, repo *repository.Container, transcoder *TranscoderService) *StreamService {
+	return &StreamService{
+		cfg:        cfg,
+		log:        log,
+		repo:       repo,
+		transcoder: transcoder,
+	}
+}
+
+// ErrMediaNotFound is returned when the media row or its file is missing.
+var ErrMediaNotFound = errors.New("media not found")
+
+// ErrCloudPlaybackUnavailable 表示媒体行存在但属于云盘媒体、且当前无法
+// 构造可用的播放重定向（通常是 STRMURL 缺失，需要重新扫描媒体库）。
+// 调用方应把它与「媒体不存在」区分开，避免把配置类故障当成 404 返回给播放器。
+var ErrCloudPlaybackUnavailable = errors.New("cloud media playback unavailable: media missing play url; re-scan the library")
+
+var ErrCloudPlaybackDisabled = errors.New("cloud media playback disabled by admin settings")
+
+// directPlayOnly reports whether the admin enabled「客户端直连解码」mode,
+// in which the host never transcodes (HLS is refused) and all playback is
+// handled by the client (direct play / 302 redirect).
+func (s *StreamService) directPlayOnly(ctx context.Context) bool {
+	if s.repo == nil || s.repo.Setting == nil {
+		return false
+	}
+	v, err := s.repo.Setting.Get(ctx, PlaybackDirectOnlySettingKey)
+	if err != nil {
+		return false
+	}
+	return parseBoolSetting(v, false)
+}
+
+// Probe re-runs ffprobe against an existing media row and refreshes the
+// extracted metadata. Used by the admin UI's "rescan" button.
+func (s *StreamService) Probe(ctx context.Context, mediaID string, probe *FFprobeService) error {
+	m, err := s.repo.Media.FindByID(ctx, mediaID)
+	if err != nil || m == nil {
+		return ErrMediaNotFound
+	}
+	res, err := probe.Probe(ctx, m.Path)
+	if err != nil {
+		return err
+	}
+	updates := map[string]any{
+		"duration_sec": res.DurationSec,
+		"width":        res.Width,
+		"height":       res.Height,
+		"video_codec":  res.VideoCodec,
+		"audio_codec":  res.AudioCodec,
+	}
+	if res.Container != "" {
+		updates["container"] = res.Container
+	}
+	return s.repo.DB.Model(m).Updates(updates).Error
+}