feat: voice-service von lehrer nach core verschoben, Pipeline erweitert (voice, BQAS, embedding, night-scheduler)

voice-service/models/session.py

@@ -0,0 +1,152 @@
+"""
+Voice Session Models
+Transient session management - no persistent storage of audio data
+
+DSGVO Compliance:
+- Sessions are RAM-only
+- Audio chunks are processed and discarded
+- Transcripts are encrypted before any storage
+"""
+from datetime import datetime
+from enum import Enum
+from typing import Optional, List, Dict, Any
+from pydantic import BaseModel, Field
+import uuid
+
+
+class SessionStatus(str, Enum):
+    """Voice session status."""
+    CREATED = "created"
+    CONNECTED = "connected"
+    LISTENING = "listening"
+    PROCESSING = "processing"
+    RESPONDING = "responding"
+    PAUSED = "paused"
+    CLOSED = "closed"
+    ERROR = "error"
+
+
+class AudioChunk(BaseModel):
+    """
+    Audio chunk for streaming.
+    NEVER persisted - only exists in RAM during processing.
+    """
+    sequence: int = Field(..., description="Chunk sequence number")
+    timestamp_ms: int = Field(..., description="Timestamp in milliseconds")
+    data: bytes = Field(..., description="PCM audio data (Int16, 24kHz)")
+    duration_ms: int = Field(default=80, description="Chunk duration in ms")
+
+    class Config:
+        # Exclude from serialization to prevent accidental logging
+        json_encoders = {
+            bytes: lambda v: f"<audio:{len(v)} bytes>"
+        }
+
+
+class TranscriptMessage(BaseModel):
+    """
+    Transcript message - encrypted before storage.
+    """
+    id: str = Field(default_factory=lambda: str(uuid.uuid4()))
+    role: str = Field(..., description="'user' or 'assistant'")
+    content: str = Field(..., description="Transcript text (plaintext in RAM only)")
+    timestamp: datetime = Field(default_factory=datetime.utcnow)
+    confidence: Optional[float] = Field(default=None, description="ASR confidence 0-1")
+    intent: Optional[str] = Field(default=None, description="Detected intent")
+    encrypted_ref: Optional[str] = Field(default=None, description="Encrypted storage reference")
+
+    class Config:
+        json_schema_extra = {
+            "example": {
+                "id": "msg-123",
+                "role": "user",
+                "content": "Notiz zu Max: heute wiederholt gestoert",
+                "timestamp": "2026-01-26T10:30:00Z",
+                "confidence": 0.95,
+                "intent": "student_observation",
+            }
+        }
+
+
+class VoiceSession(BaseModel):
+    """
+    Voice session state.
+    Stored in Valkey with TTL, never in persistent storage.
+    """
+    id: str = Field(default_factory=lambda: str(uuid.uuid4()))
+    namespace_id: str = Field(..., description="Teacher namespace ID")
+    key_hash: str = Field(..., description="Hash of client-side encryption key")
+    status: SessionStatus = Field(default=SessionStatus.CREATED)
+    created_at: datetime = Field(default_factory=datetime.utcnow)
+    last_activity: datetime = Field(default_factory=datetime.utcnow)
+
+    # Conversation state (transient)
+    messages: List[TranscriptMessage] = Field(default_factory=list)
+    pending_tasks: List[str] = Field(default_factory=list, description="Task IDs")
+
+    # Audio state (never persisted)
+    audio_chunks_received: int = Field(default=0)
+    audio_chunks_processed: int = Field(default=0)
+
+    # Metadata (no PII)
+    device_type: Optional[str] = Field(default=None, description="'pwa' or 'app'")
+    client_version: Optional[str] = Field(default=None)
+
+    def update_activity(self):
+        """Update last activity timestamp."""
+        self.last_activity = datetime.utcnow()
+
+    class Config:
+        json_schema_extra = {
+            "example": {
+                "id": "session-abc123",
+                "namespace_id": "teacher-ns-456",
+                "key_hash": "sha256:abc...",
+                "status": "listening",
+                "created_at": "2026-01-26T10:00:00Z",
+                "last_activity": "2026-01-26T10:30:00Z",
+                "messages": [],
+                "pending_tasks": [],
+                "audio_chunks_received": 150,
+                "audio_chunks_processed": 150,
+                "device_type": "pwa",
+            }
+        }
+
+
+class SessionCreate(BaseModel):
+    """Request to create a new voice session."""
+    namespace_id: str = Field(..., description="Teacher namespace ID")
+    key_hash: str = Field(..., description="Hash of client-side encryption key")
+    device_type: Optional[str] = Field(default="pwa")
+    client_version: Optional[str] = Field(default=None)
+
+    class Config:
+        json_schema_extra = {
+            "example": {
+                "namespace_id": "teacher-ns-456",
+                "key_hash": "sha256:abc123def456...",
+                "device_type": "pwa",
+                "client_version": "1.0.0",
+            }
+        }
+
+
+class SessionResponse(BaseModel):
+    """Response after session creation."""
+    id: str
+    namespace_id: str
+    status: SessionStatus
+    created_at: datetime
+    websocket_url: str = Field(..., description="WebSocket URL for audio streaming")
+
+    class Config:
+        json_schema_extra = {
+            "example": {
+                "id": "session-abc123",
+                "namespace_id": "teacher-ns-456",
+                "status": "created",
+                "created_at": "2026-01-26T10:00:00Z",
+                "websocket_url": "ws://localhost:8091/ws/voice?session_id=session-abc123",
+            }
+        }