LocalAI/backend/go/parakeet-cpp/live_test.go

package main

import (
	"sync"
	"time"
	"unsafe"

	"github.com/mudler/LocalAI/pkg/grpc/grpcerrors"
	pb "github.com/mudler/LocalAI/pkg/grpc/proto"
	. "github.com/onsi/ginkgo/v2"
	. "github.com/onsi/gomega"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/status"
)

// The live-RPC specs drive AudioTranscriptionLive entirely against stubbed
// Cpp* package vars (the same seam batcher_test.go uses), so they run
// without libparakeet.so.

// liveCstrPool hands out NUL-terminated C-style strings backed by Go memory
// and keeps them alive for the duration of a spec (goStringFromCPtr reads
// through the raw pointer; Go's GC must not collect the backing array while
// a stub's return value is in flight).
type liveCstrPool struct {
	mu   sync.Mutex
	bufs [][]byte
}

func (p *liveCstrPool) cstr(s string) uintptr {
	p.mu.Lock()
	defer p.mu.Unlock()
	b := append([]byte(s), 0)
	p.bufs = append(p.bufs, b)
	return uintptr(unsafe.Pointer(&b[0]))
}

// liveStubs swaps every C entry point the live path touches and returns a
// restore func for AfterEach.
func liveStubs() (restore func()) {
	savedBegin, savedBeginLang := CppStreamBegin, CppStreamBeginLang
	savedFeed, savedFeedJSON := CppStreamFeed, CppStreamFeedJSON
	savedFinalize, savedFinalizeJSON := CppStreamFinalize, CppStreamFinalizeJSON
	savedFree, savedLastError := CppStreamFree, CppLastError
	savedFreeString := CppFreeString
	savedSceneOptsDefault := CppSceneOptsDefault
	savedSceneBegin := CppSceneStreamBegin
	savedSceneFeedJSON := CppSceneStreamFeedJSON
	savedSceneLastError := CppSceneStreamLastError
	savedSceneFree := CppSceneStreamFree
	savedSceneBeginSpk := CppSceneStreamBeginSpeaker
	savedRegNew, savedRegFree := CppSpeakerRegistryNew, CppSpeakerRegistryFree
	savedRegAdd, savedSpkDim := CppSpeakerRegistryAddEmbedding, CppSpeakerDim
	return func() {
		CppSceneStreamBeginSpeaker = savedSceneBeginSpk
		CppSpeakerRegistryNew, CppSpeakerRegistryFree = savedRegNew, savedRegFree
		CppSpeakerRegistryAddEmbedding, CppSpeakerDim = savedRegAdd, savedSpkDim
		CppStreamBegin, CppStreamBeginLang = savedBegin, savedBeginLang
		CppStreamFeed, CppStreamFeedJSON = savedFeed, savedFeedJSON
		CppStreamFinalize, CppStreamFinalizeJSON = savedFinalize, savedFinalizeJSON
		CppStreamFree, CppLastError = savedFree, savedLastError
		CppFreeString = savedFreeString
		CppSceneOptsDefault = savedSceneOptsDefault
		CppSceneStreamBegin = savedSceneBegin
		CppSceneStreamFeedJSON = savedSceneFeedJSON
		CppSceneStreamLastError = savedSceneLastError
		CppSceneStreamFree = savedSceneFree
	}
}

// liveSceneStubs wires a minimal scene stream stub set onto p (a diarization
// and/or sound companion context so sceneWanted() is true) and returns the
// call-count trackers the specs assert on. feedJSON is called once per scene
// feed (including the is_last flush) with the stream handle the C side would
// have received (so a reset spec can tell a pre-reset feed from a post-reset
// one) and must return the canned document for that call.
func liveSceneStubs(feedJSON func(calls int, s uintptr, isLast int32) uintptr) (begun, freed *int) {
	begun, freed = new(int), new(int)
	CppSceneOptsDefault = func(o *cSceneOpts) { *o = cSceneOpts{} }
	CppSceneStreamBegin = func(asr, diar, tagger uintptr, o *cSceneOpts) uintptr {
		*begun++
		return uintptr(100 + *begun)
	}
	calls := 0
	CppSceneStreamFeedJSON = func(s uintptr, pcm *float32, n int32, isLast int32) uintptr {
		calls++
		return feedJSON(calls, s, isLast)
	}
	CppSceneStreamLastError = func(s uintptr) string { return "scene stub error" }
	CppSceneStreamFree = func(s uintptr) { *freed++ }
	return begun, freed
}

// runLive starts the RPC on its own goroutine and returns the request
// channel plus a collector for everything the backend emitted. GinkgoRecover
// turns an Expect/Fail failure inside a stub called from this goroutine into
// a normal spec failure instead of a panic that would crash the whole test
// binary (Ginkgo's failure handling is goroutine-local).
func runLive(p *ParakeetCpp) (chan *pb.TranscriptLiveRequest, chan *pb.TranscriptLiveResponse, chan error) {
	in := make(chan *pb.TranscriptLiveRequest)
	out := make(chan *pb.TranscriptLiveResponse, 32)
	errCh := make(chan error, 1)
	go func() {
		defer GinkgoRecover()
		errCh <- p.AudioTranscriptionLive(in, out)
	}()
	return in, out, errCh
}

func liveConfig(lang string) *pb.TranscriptLiveRequest {
	return &pb.TranscriptLiveRequest{
		Payload: &pb.TranscriptLiveRequest_Config{Config: &pb.TranscriptLiveConfig{Language: lang}},
	}
}

func liveAudio(pcm []float32) *pb.TranscriptLiveRequest {
	return &pb.TranscriptLiveRequest{
		Payload: &pb.TranscriptLiveRequest_Audio{Audio: &pb.TranscriptLiveAudio{Pcm: pcm}},
	}
}

func collectLive(out chan *pb.TranscriptLiveResponse) []*pb.TranscriptLiveResponse {
	var got []*pb.TranscriptLiveResponse
	for r := range out {
		got = append(got, r)
	}
	return got
}

var _ = Describe("AudioTranscriptionLive (stubbed C API)", func() {
	var (
		pool    *liveCstrPool
		restore func()
		p       *ParakeetCpp
	)

	BeforeEach(func() {
		pool = &liveCstrPool{}
		restore = liveStubs()
		p = &ParakeetCpp{ctxPtr: 1}

		CppStreamBeginLang = nil
		CppStreamBegin = func(ctx uintptr) uintptr { return 7 }
		CppStreamFree = func(s uintptr) {}
		CppFreeString = func(s uintptr) {}
		CppLastError = func(ctx uintptr) string { return "stub error" }
		CppStreamFeed = nil
		CppStreamFeedJSON = nil
		CppStreamFinalize = nil
		CppStreamFinalizeJSON = nil
	})

	AfterEach(func() { restore() })

	It("names the loaded role instead of a generic model-not-loaded error for a sound primary", func() {
		// The ctxPtr==0 check returns before AudioTranscriptionLive ever reads
		// from `in`, so nothing may be sent on it (unbuffered: a send would
		// block forever waiting for a read that never happens).
		p2 := &ParakeetCpp{tagCtx: 1}
		in, out, errCh := runLive(p2)
		close(in)

		err := <-errCh
		Expect(err).To(MatchError(ContainSubstring("sound model")))
		Expect(collectLive(out)).To(BeEmpty())
	})

	It("rejects a stream whose first message is not a config", func() {
		in, out, errCh := runLive(p)
		in <- liveAudio([]float32{0.1})
		close(in)

		err := <-errCh
		Expect(status.Code(err)).To(Equal(codes.InvalidArgument))
		Expect(collectLive(out)).To(BeEmpty())
	})

	It("rejects a non-16k sample rate", func() {
		in, _, errCh := runLive(p)
		in <- &pb.TranscriptLiveRequest{
			Payload: &pb.TranscriptLiveRequest_Config{Config: &pb.TranscriptLiveConfig{SampleRate: 8000}},
		}
		close(in)
		Expect(status.Code(<-errCh)).To(Equal(codes.InvalidArgument))
	})

	It("returns the typed Unimplemented signal for non-streaming models, before any ack", func() {
		CppStreamBegin = func(ctx uintptr) uintptr { return 0 }

		in, out, errCh := runLive(p)
		in <- liveConfig("")
		close(in)

		err := <-errCh
		Expect(grpcerrors.IsLiveTranscriptionUnsupported(err)).To(BeTrue())
		Expect(collectLive(out)).To(BeEmpty())
	})

	It("streams deltas, eou flags and words on the JSON path and finalizes on close", func() {
		var freed []uintptr
		CppStreamFree = func(s uintptr) { freed = append(freed, s) }
		feeds := 0
		CppStreamFeedJSON = func(s uintptr, pcm []float32, n int32) uintptr {
			feeds++
			switch feeds {
			case 1:
				return pool.cstr(`{"text":"hello ","eou":0,"frame_sec":0.08,` +
					`"words":[{"w":"hello","start":0.1,"end":0.4,"conf":0.9}]}`)
			default:
				return pool.cstr(`{"text":"world","eou":1,"frame_sec":0.08,` +
					`"words":[{"w":"world","start":0.5,"end":0.8,"conf":0.9}]}`)
			}
		}
		CppStreamFinalizeJSON = func(s uintptr) uintptr {
			return pool.cstr(`{"text":"","eou":0,"frame_sec":0.08,"words":[]}`)
		}

		in, out, errCh := runLive(p)
		in <- liveConfig("en")
		in <- liveAudio(make([]float32, 100))
		in <- liveAudio(make([]float32, 200))
		close(in)
		Expect(<-errCh).NotTo(HaveOccurred())

		got := collectLive(out)
		Expect(got).To(HaveLen(4)) // ready, two deltas, final

		Expect(got[0].Ready).To(BeTrue())

		Expect(got[1].Delta).To(Equal("hello "))
		Expect(got[1].Eou).To(BeFalse())
		Expect(got[1].Words).To(HaveLen(1))
		Expect(got[1].Words[0].Text).To(Equal("hello"))

		Expect(got[2].Delta).To(Equal("world"))
		Expect(got[2].Eou).To(BeTrue())

		final := got[3].FinalResult
		Expect(final).NotTo(BeNil())
		Expect(final.Text).To(Equal("hello world"))
		// The live FinalResult carries only Text. Per-utterance segments,
		// duration and the terminal eou flag are an offline-path concern (see
		// boundary.go / AudioTranscriptionStream); the realtime core reads the
		// streamed per-feed tokens above plus this Text.
		Expect(final.Eou).To(BeFalse())
		Expect(final.Segments).To(BeEmpty())
		Expect(final.Duration).To(BeZero())

		Expect(freed).To(Equal([]uintptr{7}))
	})

	It("falls back to the text feed (eou out-param) when the JSON entry points are absent", func() {
		feeds := 0
		CppStreamFeed = func(s uintptr, pcm []float32, n int32, eouOut unsafe.Pointer) uintptr {
			feeds++
			if feeds == 2 {
				*(*int32)(eouOut) = 1
				return pool.cstr("done")
			}
			return pool.cstr("first ")
		}
		CppStreamFinalize = func(s uintptr) uintptr { return pool.cstr("") }

		in, out, errCh := runLive(p)
		in <- liveConfig("")
		in <- liveAudio(make([]float32, 10))
		in <- liveAudio(make([]float32, 10))
		close(in)
		Expect(<-errCh).NotTo(HaveOccurred())

		got := collectLive(out)
		Expect(got).To(HaveLen(4))
		Expect(got[1].Delta).To(Equal("first "))
		Expect(got[1].Eou).To(BeFalse())
		Expect(got[2].Delta).To(Equal("done"))
		Expect(got[2].Eou).To(BeTrue())
		Expect(got[3].FinalResult.Text).To(Equal("first done"))
	})

	It("forwards <EOB> as eob — a backchannel, never an eou (ABI v5 JSON)", func() {
		feeds := 0
		CppStreamFeedJSON = func(s uintptr, pcm []float32, n int32) uintptr {
			feeds++
			if feeds == 1 {
				return pool.cstr(`{"text":"uh-huh","eou":0,"eob":1,"frame_sec":0.08,` +
					`"words":[{"w":"uh-huh","start":0.1,"end":0.3,"conf":0.9}]}`)
			}
			return pool.cstr(`{"text":"the turn","eou":1,"eob":0,"frame_sec":0.08,` +
				`"words":[{"w":"the","start":0.5,"end":0.6,"conf":0.9},{"w":"turn","start":0.6,"end":0.8,"conf":0.9}]}`)
		}
		CppStreamFinalizeJSON = func(s uintptr) uintptr {
			return pool.cstr(`{"text":"","eou":0,"eob":0,"frame_sec":0.08,"words":[]}`)
		}

		in, out, errCh := runLive(p)
		in <- liveConfig("")
		in <- liveAudio(make([]float32, 10))
		in <- liveAudio(make([]float32, 10))
		close(in)
		Expect(<-errCh).NotTo(HaveOccurred())

		got := collectLive(out)
		Expect(got).To(HaveLen(4))
		Expect(got[1].Eob).To(BeTrue())
		Expect(got[1].Eou).To(BeFalse(), "a backchannel must not masquerade as a turn boundary")
		Expect(got[2].Eou).To(BeTrue())
	})

	It("maps the v5 eou_out bitmask on the text path (bit0 <EOU>, bit1 <EOB>)", func() {
		feeds := 0
		CppStreamFeed = func(s uintptr, pcm []float32, n int32, eouOut unsafe.Pointer) uintptr {
			feeds++
			if feeds == 1 {
				*(*int32)(eouOut) = 2 // <EOB> only
				return pool.cstr("uh-huh")
			}
			*(*int32)(eouOut) = 1 // <EOU>
			return pool.cstr(" done")
		}
		CppStreamFinalize = func(s uintptr) uintptr { return pool.cstr("") }

		in, out, errCh := runLive(p)
		in <- liveConfig("")
		in <- liveAudio(make([]float32, 10))
		in <- liveAudio(make([]float32, 10))
		close(in)
		Expect(<-errCh).NotTo(HaveOccurred())

		got := collectLive(out)
		Expect(got).To(HaveLen(4))
		Expect(got[1].Eob).To(BeTrue())
		Expect(got[1].Eou).To(BeFalse())
		Expect(got[2].Eou).To(BeTrue())
		Expect(got[2].Eob).To(BeFalse())
	})

	It("accumulates trailing text after an EOU into the final transcript", func() {
		feeds := 0
		CppStreamFeedJSON = func(s uintptr, pcm []float32, n int32) uintptr {
			feeds++
			if feeds == 1 {
				return pool.cstr(`{"text":"turn one","eou":1,"frame_sec":0.08,"words":[]}`)
			}
			return pool.cstr(`{"text":" and more","eou":0,"frame_sec":0.08,"words":[]}`)
		}
		CppStreamFinalizeJSON = func(s uintptr) uintptr {
			return pool.cstr(`{"text":"","eou":0,"frame_sec":0.08,"words":[]}`)
		}

		in, out, errCh := runLive(p)
		in <- liveConfig("")
		in <- liveAudio(make([]float32, 10))
		in <- liveAudio(make([]float32, 10))
		close(in)
		Expect(<-errCh).NotTo(HaveOccurred())

		got := collectLive(out)
		final := got[len(got)-1].FinalResult
		Expect(final.Text).To(Equal("turn one and more"))
	})

	It("resets the decode session on a mid-stream config", func() {
		var begun, freed int
		CppStreamBegin = func(ctx uintptr) uintptr { begun++; return uintptr(10 + begun) }
		CppStreamFree = func(s uintptr) { freed++ }
		CppStreamFeedJSON = func(s uintptr, pcm []float32, n int32) uintptr {
			return pool.cstr(`{"text":"x","eou":0,"frame_sec":0.08,"words":[]}`)
		}
		CppStreamFinalizeJSON = func(s uintptr) uintptr {
			return pool.cstr(`{"text":"","eou":0,"frame_sec":0.08,"words":[]}`)
		}

		in, out, errCh := runLive(p)
		in <- liveConfig("")
		in <- liveAudio(make([]float32, 10))
		in <- liveConfig("") // reset
		in <- liveAudio(make([]float32, 10))
		close(in)
		Expect(<-errCh).NotTo(HaveOccurred())

		got := collectLive(out)
		final := got[len(got)-1].FinalResult
		Expect(final.Text).To(Equal("x"), "pre-reset transcript dropped")
		Expect(begun).To(Equal(2))
		Expect(freed).To(Equal(2), "old session freed on reset, new one on unwind")
	})

	It("does not hold engineMu between feeds (unary work interleaves with a live session)", func() {
		CppStreamFeedJSON = func(s uintptr, pcm []float32, n int32) uintptr {
			return pool.cstr(`{"text":"","eou":0,"frame_sec":0.08,"words":[]}`)
		}
		CppStreamFinalizeJSON = func(s uintptr) uintptr {
			return pool.cstr(`{"text":"","eou":0,"frame_sec":0.08,"words":[]}`)
		}

		in, out, errCh := runLive(p)
		in <- liveConfig("")
		in <- liveAudio(make([]float32, 10))

		// The session is open and idle between feeds: the engine lock must be
		// acquirable, which is what lets batched unary transcription proceed
		// mid-session. Under stream-lifetime locking this probe would block
		// until the stream ended and the Eventually would time out.
		locked := make(chan struct{})
		go func() {
			p.engineMu.Lock()
			p.engineMu.Unlock() //nolint:staticcheck // probe: acquire-release proves availability
			close(locked)
		}()
		Eventually(locked, time.Second).Should(BeClosed())

		close(in)
		Expect(<-errCh).NotTo(HaveOccurred())
		collectLive(out)
	})

	It("errors out and reads last_error under the lock when a feed fails", func() {
		CppStreamFeedJSON = func(s uintptr, pcm []float32, n int32) uintptr { return 0 }

		in, out, errCh := runLive(p)
		in <- liveConfig("")
		in <- liveAudio(make([]float32, 10))

		err := <-errCh
		Expect(err).To(MatchError(ContainSubstring("stub error")))
		got := collectLive(out)
		Expect(got).To(HaveLen(1)) // just the ready ack
		close(in)
	})

	It("makes no scene C call and behaves unchanged when no companion is loaded", func() {
		// p has ctxPtr only (no diarCtx/tagCtx): sceneWanted() must be false,
		// and none of the scene entry points may be touched.
		CppSceneOptsDefault = func(o *cSceneOpts) { Fail("scene_opts_default called with no companions loaded") }
		CppSceneStreamBegin = func(asr, diar, tagger uintptr, o *cSceneOpts) uintptr {
			Fail("scene_stream_begin called with no companions loaded")
			return 0
		}
		CppSceneStreamFeedJSON = func(s uintptr, pcm *float32, n int32, isLast int32) uintptr {
			Fail("scene_stream_feed_json called with no companions loaded")
			return 0
		}
		CppSceneStreamFree = func(s uintptr) { Fail("scene_stream_free called with no companions loaded") }

		CppStreamFeedJSON = func(s uintptr, pcm []float32, n int32) uintptr {
			return pool.cstr(`{"text":"hi","eou":0,"frame_sec":0.08,"words":[]}`)
		}
		CppStreamFinalizeJSON = func(s uintptr) uintptr {
			return pool.cstr(`{"text":"","eou":0,"frame_sec":0.08,"words":[]}`)
		}

		in, out, errCh := runLive(p)
		in <- liveConfig("")
		in <- liveAudio(make([]float32, 10))
		close(in)
		Expect(<-errCh).NotTo(HaveOccurred())

		got := collectLive(out)
		Expect(got).To(HaveLen(3)) // ready, delta, final
		Expect(got[1].Speakers).To(BeEmpty())
		Expect(got[1].Sounds).To(BeEmpty())
	})
})

var _ = Describe("AudioTranscriptionLive scene events (stubbed C API)", func() {
	var (
		pool    *liveCstrPool
		restore func()
		p       *ParakeetCpp
	)

	BeforeEach(func() {
		pool = &liveCstrPool{}
		restore = liveStubs()
		p = &ParakeetCpp{ctxPtr: 1, diarCtx: 2}

		CppStreamBeginLang = nil
		CppStreamBegin = func(ctx uintptr) uintptr { return 7 }
		CppStreamFree = func(s uintptr) {}
		CppFreeString = func(s uintptr) {}
		CppLastError = func(ctx uintptr) string { return "stub error" }
		CppStreamFeed = nil
		CppStreamFeedJSON = func(s uintptr, pcm []float32, n int32) uintptr {
			return pool.cstr(`{"text":"","eou":0,"frame_sec":0.08,"words":[]}`)
		}
		CppStreamFinalize = nil
		CppStreamFinalizeJSON = func(s uintptr) uintptr {
			return pool.cstr(`{"text":"","eou":0,"frame_sec":0.08,"words":[]}`)
		}
	})

	AfterEach(func() { restore() })

	It("emits a closed speaker segment as its own response", func() {
		liveSceneStubs(func(calls int, s uintptr, isLast int32) uintptr {
			if calls == 1 {
				return pool.cstr(`{"speakers":[{"speaker":0,"start":0.1,"end":0.6}],"sounds":[]}`)
			}
			return pool.cstr(`{"speakers":[],"sounds":[]}`)
		})

		in, out, errCh := runLive(p)
		in <- liveConfig("")
		in <- liveAudio(make([]float32, 10))
		close(in)
		Expect(<-errCh).NotTo(HaveOccurred())

		got := collectLive(out)
		Expect(got).To(HaveLen(3)) // ready, speaker-only response, final
		Expect(got[1].Delta).To(BeEmpty())
		Expect(got[1].Speakers).To(HaveLen(1))
		Expect(got[1].Speakers[0].Speaker).To(Equal("0"))
		Expect(got[1].Speakers[0].Start).To(Equal(int64(0.1 * 1e9)))
		Expect(got[1].Speakers[0].End).To(Equal(int64(0.6 * 1e9)))
	})

	It("sends the ASR delta and a scene sound event as two responses, ASR first", func() {
		CppStreamFeedJSON = func(s uintptr, pcm []float32, n int32) uintptr {
			return pool.cstr(`{"text":"hello ","eou":0,"frame_sec":0.08,` +
				`"words":[{"w":"hello","start":0.1,"end":0.4,"conf":0.9}]}`)
		}
		liveSceneStubs(func(calls int, s uintptr, isLast int32) uintptr {
			if calls == 1 {
				return pool.cstr(`{"speakers":[],"sounds":[{"index":99,` +
					`"label":"Chicken, rooster","start":24.0,"end":30.0,"peak":0.86}]}`)
			}
			return pool.cstr(`{"speakers":[],"sounds":[]}`)
		})

		in, out, errCh := runLive(p)
		in <- liveConfig("")
		in <- liveAudio(make([]float32, 10))
		close(in)
		Expect(<-errCh).NotTo(HaveOccurred())

		got := collectLive(out)
		Expect(got).To(HaveLen(4)) // ready, ASR delta, sound-only, final
		Expect(got[1].Delta).To(Equal("hello "))
		Expect(got[1].Sounds).To(BeEmpty(), "the ASR response must not wait on the scene feed")
		Expect(got[2].Delta).To(BeEmpty())
		Expect(got[2].Sounds).To(HaveLen(1))
		Expect(got[2].Sounds[0].Label).To(Equal("Chicken, rooster"))
		Expect(got[2].Sounds[0].Index).To(Equal(int32(99)))
		Expect(got[2].Sounds[0].Peak).To(BeNumerically("~", 0.86, 1e-6))
		Expect(got[2].Sounds[0].Start).To(Equal(int64(24.0 * 1e9)))
		Expect(got[2].Sounds[0].End).To(Equal(int64(30.0 * 1e9)))
	})

	It("flushes the scene stream is_last before the final result, then frees it", func() {
		begun, freed := liveSceneStubs(func(calls int, s uintptr, isLast int32) uintptr {
			if calls == 2 {
				Expect(isLast).To(Equal(int32(1)))
				return pool.cstr(`{"speakers":[{"speaker":1,"start":1.0,"end":2.0}],"sounds":[]}`)
			}
			Expect(isLast).To(Equal(int32(0)))
			return pool.cstr(`{"speakers":[],"sounds":[]}`)
		})

		in, out, errCh := runLive(p)
		in <- liveConfig("")
		in <- liveAudio(make([]float32, 10))
		close(in)
		Expect(<-errCh).NotTo(HaveOccurred())

		got := collectLive(out)
		Expect(got).To(HaveLen(3)) // ready, speaker from the is_last flush, final
		Expect(got[1].Speakers).To(HaveLen(1))
		Expect(got[1].Speakers[0].Speaker).To(Equal("1"))
		Expect(got[2].FinalResult).NotTo(BeNil())
		Expect(*begun).To(Equal(1))
		Expect(*freed).To(Equal(1))
	})

	It("frees and begins the scene stream again on a mid-stream config reset", func() {
		streamBegun := 0
		CppStreamBegin = func(ctx uintptr) uintptr { streamBegun++; return uintptr(10 + streamBegun) }
		var seenStreams []uintptr
		begun, freed := liveSceneStubs(func(calls int, s uintptr, isLast int32) uintptr {
			seenStreams = append(seenStreams, s)
			return pool.cstr(`{"speakers":[],"sounds":[]}`)
		})

		in, out, errCh := runLive(p)
		in <- liveConfig("")
		in <- liveAudio(make([]float32, 10))
		in <- liveConfig("") // reset
		in <- liveAudio(make([]float32, 10))
		close(in)
		Expect(<-errCh).NotTo(HaveOccurred())
		collectLive(out)

		Expect(*begun).To(Equal(2), "scene stream begun again on reset")
		Expect(*freed).To(Equal(2), "old scene stream freed on reset, new one on unwind")
		// One scene feed per audio message (pre-reset, post-reset) plus the
		// close is_last flush, which runs on the post-reset stream.
		Expect(seenStreams).To(HaveLen(3))
		Expect(seenStreams[0]).NotTo(Equal(seenStreams[1]), "post-reset audio must go to the new scene stream handle")
		Expect(seenStreams[2]).To(Equal(seenStreams[1]), "the close flush uses the post-reset stream too")
	})

	It("returns without a C call when Free() ran between begin and a scene feed", func() {
		feedCalls := 0
		CppSceneOptsDefault = func(o *cSceneOpts) { *o = cSceneOpts{} }
		CppSceneStreamBegin = func(asr, diar, tagger uintptr, o *cSceneOpts) uintptr { return 999 }
		CppSceneStreamFeedJSON = func(s uintptr, pcm *float32, n int32, isLast int32) uintptr {
			feedCalls++
			return pool.cstr(`{"speakers":[],"sounds":[]}`)
		}

		h := p.sceneBegin(nil)
		Expect(h.s).NotTo(BeZero())

		// Simulate a Free() racing in between the begin and the next feed: it
		// zeroes the companion context under engineMu, exactly as the real
		// Free() does.
		p.diarCtx = 0

		_, err := p.sceneFeed(h, make([]float32, 10), false)
		Expect(grpcerrors.IsModelNotLoaded(err)).To(BeTrue())
		Expect(feedCalls).To(Equal(0), "no C call once the scene stream's contexts were freed")
	})

	It("degrades to ASR-only after a mid-session scene feed failure: freed once, no more scene events, ASR keeps working", func() {
		CppStreamFeedJSON = func(s uintptr, pcm []float32, n int32) uintptr {
			return pool.cstr(`{"text":"hi ","eou":0,"frame_sec":0.08,` +
				`"words":[{"w":"hi","start":0.1,"end":0.3,"conf":0.9}]}`)
		}
		sceneFeedCalls := 0
		begun, freed := liveSceneStubs(func(calls int, s uintptr, isLast int32) uintptr {
			sceneFeedCalls++
			return 0 // fails every call; only the first should ever be reached
		})

		in, out, errCh := runLive(p)
		in <- liveConfig("")
		in <- liveAudio(make([]float32, 10)) // scene feed fails here: warn, free, zero the handle
		in <- liveAudio(make([]float32, 10)) // ASR-only: no scene C call at all
		close(in)
		Expect(<-errCh).NotTo(HaveOccurred())

		got := collectLive(out)
		// ready, ASR delta (msg 1), ASR delta (msg 2), final: no scene-only
		// response ever appears, before or after the failure.
		Expect(got).To(HaveLen(4))
		Expect(got[0].Ready).To(BeTrue())
		Expect(got[1].Delta).To(Equal("hi "))
		Expect(got[2].Delta).To(Equal("hi "))
		for _, r := range got {
			Expect(r.Speakers).To(BeEmpty(), "no speaker events once the scene stream has failed")
			Expect(r.Sounds).To(BeEmpty(), "no sound events once the scene stream has failed")
		}
		Expect(got[3].FinalResult).NotTo(BeNil())
		Expect(got[3].FinalResult.Text).To(Equal("hi hi"))

		Expect(*begun).To(Equal(1))
		Expect(sceneFeedCalls).To(Equal(1), "the second audio message must not retry the broken scene stream")
		Expect(*freed).To(Equal(1), "the broken scene stream is freed exactly once, not again at RPC unwind")
	})

	It("continues without scene events when scene begin fails", func() {
		CppSceneOptsDefault = func(o *cSceneOpts) { *o = cSceneOpts{} }
		CppSceneStreamBegin = func(asr, diar, tagger uintptr, o *cSceneOpts) uintptr { return 0 }
		sceneFeedCalled := false
		CppSceneStreamFeedJSON = func(s uintptr, pcm *float32, n int32, isLast int32) uintptr {
			sceneFeedCalled = true
			return 0
		}
		CppSceneStreamFree = func(s uintptr) {}

		in, out, errCh := runLive(p)
		in <- liveConfig("")
		in <- liveAudio(make([]float32, 10))
		close(in)
		Expect(<-errCh).NotTo(HaveOccurred())

		got := collectLive(out)
		Expect(got).To(HaveLen(2)) // ready, final only: no scene events, no ASR delta this stub sends
		Expect(sceneFeedCalled).To(BeFalse(), "no feed call once begin failed")
	})
})

var _ = Describe("AudioTranscriptionLive named speakers (stubbed C API)", func() {
	var (
		pool    *liveCstrPool
		restore func()
		p       *ParakeetCpp
		regs    []uintptr
		plain   int
		spkBeg  int
		gotReg  uintptr
		order   []string
	)

	liveVoicesConfig := func(voices ...*pb.KnownVoice) *pb.TranscriptLiveRequest {
		return &pb.TranscriptLiveRequest{
			Payload: &pb.TranscriptLiveRequest_Config{Config: &pb.TranscriptLiveConfig{KnownVoices: voices}},
		}
	}
	ada := &pb.KnownVoice{Name: "Ada", Embedding: []float32{1, 0}}

	BeforeEach(func() {
		pool = &liveCstrPool{}
		restore = liveStubs()
		p = &ParakeetCpp{ctxPtr: 1, diarCtx: 2, spkCtx: 3, speakerAccept: 0.7, speakerMargin: 0.05}
		regs, plain, spkBeg, gotReg, order = nil, 0, 0, 0, nil

		CppStreamBeginLang = nil
		CppStreamBegin = func(ctx uintptr) uintptr { return 7 }
		CppStreamFree = func(s uintptr) {}
		CppFreeString = func(s uintptr) {}
		CppLastError = func(ctx uintptr) string { return "stub error" }
		CppStreamFeed = nil
		CppStreamFeedJSON = func(s uintptr, pcm []float32, n int32) uintptr {
			return pool.cstr(`{"text":"","eou":0,"frame_sec":0.08,"words":[]}`)
		}
		CppStreamFinalize = nil
		CppStreamFinalizeJSON = func(s uintptr) uintptr {
			return pool.cstr(`{"text":"","eou":0,"frame_sec":0.08,"words":[]}`)
		}

		CppSceneOptsDefault = func(o *cSceneOpts) { *o = cSceneOpts{} }
		CppSceneStreamBegin = func(asr, diar, tagger uintptr, o *cSceneOpts) uintptr { plain++; return 100 }
		CppSceneStreamBeginSpeaker = func(asr, diar, tag, spk, reg uintptr, o *cSceneOpts) uintptr {
			spkBeg++
			gotReg = reg
			return 200
		}
		CppSceneStreamFeedJSON = func(s uintptr, pcm *float32, n int32, isLast int32) uintptr {
			return pool.cstr(`{"speakers":[{"speaker":0,"start":0.1,"end":0.6}],"sounds":[],` +
				`"names":{"0":{"name":"Ada","score":0.9}}}`)
		}
		CppSceneStreamLastError = func(s uintptr) string { return "" }
		CppSceneStreamFree = func(s uintptr) { order = append(order, "stream") }
		CppSpeakerDim = func(uintptr) int32 { return 2 }
		CppSpeakerRegistryNew = func() uintptr { return 9 }
		CppSpeakerRegistryAddEmbedding = func(uintptr, string, *float32, int32) int32 { return 0 }
		CppSpeakerRegistryFree = func(r uintptr) { regs = append(regs, r); order = append(order, "registry") }
	})

	AfterEach(func() { restore() })

	It("begins a speaker scene stream and emits the slot name on the closed segment", func() {
		in, out, errCh := runLive(p)
		in <- liveVoicesConfig(ada)
		in <- liveAudio(make([]float32, 10))
		close(in)
		Expect(<-errCh).NotTo(HaveOccurred())

		got := collectLive(out)
		Expect(spkBeg).To(Equal(1))
		Expect(plain).To(Equal(0))
		Expect(gotReg).To(Equal(uintptr(9)))
		var named *pb.LiveSpeakerSegment
		for _, r := range got {
			if len(r.Speakers) > 0 {
				named = r.Speakers[0]
			}
		}
		Expect(named).NotTo(BeNil())
		Expect(named.Speaker).To(Equal("0"))
		Expect(named.Name).To(Equal("Ada"))
		Expect(regs).To(Equal([]uintptr{9}), "the registry is freed once when the session ends")
		Expect(order).To(Equal([]string{"stream", "registry"}))
	})

	It("uses the plain scene begin and emits empty names without known voices", func() {
		CppSceneStreamFeedJSON = func(s uintptr, pcm *float32, n int32, isLast int32) uintptr {
			return pool.cstr(`{"speakers":[{"speaker":0,"start":0.1,"end":0.6}],"sounds":[]}`)
		}
		in, out, errCh := runLive(p)
		in <- liveConfig("")
		in <- liveAudio(make([]float32, 10))
		close(in)
		Expect(<-errCh).NotTo(HaveOccurred())

		got := collectLive(out)
		Expect(plain).To(Equal(1))
		Expect(spkBeg).To(Equal(0))
		Expect(regs).To(BeEmpty())
		found := false
		for _, r := range got {
			for _, s := range r.Speakers {
				found = true
				Expect(s.Name).To(BeEmpty())
			}
		}
		Expect(found).To(BeTrue())
	})

	It("names the restarted scene stream after a config reset and frees every registry once", func() {
		in, out, errCh := runLive(p)
		in <- liveVoicesConfig(ada)
		in <- liveAudio(make([]float32, 10))
		in <- liveVoicesConfig(ada) // reset
		in <- liveAudio(make([]float32, 10))
		close(in)
		Expect(<-errCh).NotTo(HaveOccurred())
		collectLive(out)

		Expect(spkBeg).To(Equal(2))
		Expect(regs).To(HaveLen(2), "one registry per scene stream, each freed exactly once")
	})

	It("frees the registry once when a feed failure disables the scene stream", func() {
		CppSceneStreamFeedJSON = func(s uintptr, pcm *float32, n int32, isLast int32) uintptr { return 0 }
		in, out, errCh := runLive(p)
		in <- liveVoicesConfig(ada)
		in <- liveAudio(make([]float32, 10))
		in <- liveAudio(make([]float32, 10))
		close(in)
		Expect(<-errCh).NotTo(HaveOccurred())
		collectLive(out)

		Expect(regs).To(Equal([]uintptr{9}))
	})
})

var _ = Describe("stripEouMarker", func() {
	It("strips a trailing <EOU> and reports it", func() {
		text, eou := stripEouMarker("it is certainly very like the old portrait<EOU>")
		Expect(text).To(Equal("it is certainly very like the old portrait"))
		Expect(eou).To(BeTrue())
	})

	It("strips a trailing <EOB> WITHOUT reporting an utterance end", func() {
		// A decode ending on a backchannel must not confirm the
		// retranscribe gate — the user was acknowledging, not yielding.
		text, eou := stripEouMarker("uh-huh<EOB>")
		Expect(text).To(Equal("uh-huh"))
		Expect(eou).To(BeFalse())
	})

	It("leaves marker-free text alone", func() {
		text, eou := stripEouMarker("plain transcript")
		Expect(text).To(Equal("plain transcript"))
		Expect(eou).To(BeFalse())
	})

	It("does not strip a marker in the middle of the text", func() {
		text, eou := stripEouMarker("a<EOU>b")
		Expect(text).To(Equal("a<EOU>b"))
		Expect(eou).To(BeFalse())
	})
})

var _ = Describe("transcriptResultFromDoc EOU handling", func() {
	It("strips the offline marker from text and sets the result flag", func() {
		doc := transcriptJSON{Text: "the old portrait<EOU>"}
		res := transcriptResultFromDoc(doc, &pb.TranscriptRequest{}, 0)
		Expect(res.Text).To(Equal("the old portrait"))
		Expect(res.Eou).To(BeTrue())
		Expect(res.Segments).To(HaveLen(1))
		Expect(res.Segments[0].Text).To(Equal("the old portrait"))
	})

	It("reports eou=false for marker-free decodes", func() {
		doc := transcriptJSON{Text: "no marker here"}
		res := transcriptResultFromDoc(doc, &pb.TranscriptRequest{}, 0)
		Expect(res.Text).To(Equal("no marker here"))
		Expect(res.Eou).To(BeFalse())
	})
})