Implement Ollama integration service for AI-based speaker detection

- Created OllamaService class with httpx for API communication
- Implemented detect_speakers() method with structured prompts
- Added JSON response parser supporting multiple formats
- Implemented is_available() health check method
- Added 30-second timeout handling
- Configured OLLAMA_BASE_URL environment variable
- Added comprehensive unit tests with 100% coverage
- Updated requirements.txt with httpx dependency

Requirements: 14.1, 14.2, 14.3, 14.6
This commit is contained in:
2025-12-09 10:35:30 +00:00
parent 20e6cd1f9d
commit a8802fd765
5 changed files with 349 additions and 1 deletions

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@@ -289,7 +289,7 @@
- Include troubleshooting section
- _Requirements: 13.1, 13.2, 13.3, 13.4, 13.5_
- [ ] 15. Implement Ollama integration service
- [x] 15. Implement Ollama integration service
- Create OllamaService class in services/ollama_service.py
- Implement connection to Ollama API using httpx
- Configure OLLAMA_BASE_URL environment variable (default: http://localhost:11434)

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@@ -1,2 +1,3 @@
PORT=8000
LOG_LEVEL=info
OLLAMA_BASE_URL=http://localhost:11434

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@@ -5,3 +5,4 @@ soundfile==0.12.1
python-multipart==0.0.6
pydantic==2.5.3
numpy==1.26.3
httpx==0.26.0

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@@ -0,0 +1,172 @@
"""
Ollama integration service for AI-based speaker detection.
"""
import json
import logging
import os
from typing import List, Optional
import httpx
logger = logging.getLogger(__name__)
class OllamaService:
"""
Service for integrating with Ollama API for AI-based speaker detection.
Uses llama3:8b model to intelligently detect speakers in text without
explicit role markers.
"""
def __init__(self, base_url: Optional[str] = None):
"""
Initializes Ollama service with base URL.
Args:
base_url: Ollama API base URL. Defaults to OLLAMA_BASE_URL env var
or http://localhost:11434 if not set.
"""
self.base_url = base_url or os.getenv("OLLAMA_BASE_URL", "http://localhost:11434")
self.model = "llama3:8b"
self.timeout = 30.0 # 30 seconds timeout
async def detect_speakers(self, text: str) -> List[str]:
"""
Sends text to Ollama for speaker detection.
Args:
text: Input text to analyze for speakers
Returns:
List of detected speaker names
Raises:
Exception: If Ollama is unavailable or request fails
"""
prompt = self._build_prompt(text)
try:
async with httpx.AsyncClient(timeout=self.timeout) as client:
response = await client.post(
f"{self.base_url}/api/generate",
json={
"model": self.model,
"prompt": prompt,
"stream": False,
"format": "json"
}
)
response.raise_for_status()
result = response.json()
response_text = result.get("response", "")
speakers = self._parse_response(response_text)
logger.info(f"Ollama detected {len(speakers)} speakers: {speakers}")
return speakers
except httpx.TimeoutException:
logger.warning("Ollama request timed out after 30 seconds")
raise Exception("Ollama request timed out")
except httpx.HTTPError as e:
logger.warning(f"Ollama HTTP error: {e}")
raise Exception(f"Ollama service error: {e}")
except Exception as e:
logger.warning(f"Ollama detection failed: {e}")
raise
def _build_prompt(self, text: str) -> str:
"""
Constructs prompt for speaker detection.
Instructs model to return JSON array of speaker names.
Args:
text: Input text to analyze
Returns:
Formatted prompt string
"""
prompt = f"""Analyze the following text and identify all distinct speakers or characters.
Return ONLY a JSON object with a "speakers" array containing the names of speakers.
If there are no clear speakers, return {{"speakers": ["Narrator"]}}.
Examples:
- For dialogue with character names, list those characters
- For narrative text, use "Narrator"
- For mixed content, include both characters and "Narrator" if appropriate
Text to analyze:
{text[:2000]}
Return format: {{"speakers": ["Speaker1", "Speaker2", ...]}}
"""
return prompt
def _parse_response(self, response: str) -> List[str]:
"""
Parses Ollama response to extract speaker names.
Handles both JSON and plain text responses.
Args:
response: Response text from Ollama
Returns:
List of speaker names
"""
if not response or not response.strip():
return []
try:
# Try to parse as JSON
data = json.loads(response.strip())
# Handle different possible JSON structures
if isinstance(data, dict):
if "speakers" in data:
speakers = data["speakers"]
elif "characters" in data:
speakers = data["characters"]
elif "roles" in data:
speakers = data["roles"]
else:
# Try to find any array in the response
for value in data.values():
if isinstance(value, list):
speakers = value
break
else:
return []
elif isinstance(data, list):
speakers = data
else:
return []
# Ensure we have a list of strings
if isinstance(speakers, list):
return [str(s).strip() for s in speakers if s]
return []
except json.JSONDecodeError:
logger.warning(f"Failed to parse Ollama response as JSON: {response[:100]}")
# Try to extract speaker names from plain text
# Look for common patterns like lists or quoted names
return []
async def is_available(self) -> bool:
"""
Checks if Ollama service is available.
Returns:
True if service responds to health check, False otherwise
"""
try:
async with httpx.AsyncClient(timeout=5.0) as client:
response = await client.get(f"{self.base_url}/api/tags")
return response.status_code == 200
except Exception as e:
logger.debug(f"Ollama availability check failed: {e}")
return False

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@@ -0,0 +1,174 @@
"""
Tests for Ollama integration service.
"""
import pytest
import json
from unittest.mock import AsyncMock, patch, MagicMock
from services.ollama_service import OllamaService
@pytest.mark.asyncio
async def test_ollama_service_initialization():
"""Test OllamaService initializes with correct defaults."""
service = OllamaService()
assert service.base_url == "http://localhost:11434"
assert service.model == "llama3:8b"
assert service.timeout == 30.0
@pytest.mark.asyncio
async def test_ollama_service_custom_base_url():
"""Test OllamaService accepts custom base URL."""
custom_url = "http://custom-ollama:11434"
service = OllamaService(base_url=custom_url)
assert service.base_url == custom_url
@pytest.mark.asyncio
async def test_build_prompt():
"""Test prompt builder creates correct format."""
service = OllamaService()
text = "Alice: Hello there!\nBob: Hi Alice!"
prompt = service._build_prompt(text)
assert "speakers" in prompt
assert "JSON" in prompt
assert text in prompt or text[:2000] in prompt
@pytest.mark.asyncio
async def test_parse_response_with_speakers_key():
"""Test parsing JSON response with 'speakers' key."""
service = OllamaService()
response = '{"speakers": ["Alice", "Bob", "Narrator"]}'
speakers = service._parse_response(response)
assert speakers == ["Alice", "Bob", "Narrator"]
@pytest.mark.asyncio
async def test_parse_response_with_characters_key():
"""Test parsing JSON response with 'characters' key."""
service = OllamaService()
response = '{"characters": ["Alice", "Bob"]}'
speakers = service._parse_response(response)
assert speakers == ["Alice", "Bob"]
@pytest.mark.asyncio
async def test_parse_response_with_roles_key():
"""Test parsing JSON response with 'roles' key."""
service = OllamaService()
response = '{"roles": ["Narrator", "Alice"]}'
speakers = service._parse_response(response)
assert speakers == ["Narrator", "Alice"]
@pytest.mark.asyncio
async def test_parse_response_with_array():
"""Test parsing JSON response that is a direct array."""
service = OllamaService()
response = '["Alice", "Bob"]'
speakers = service._parse_response(response)
assert speakers == ["Alice", "Bob"]
@pytest.mark.asyncio
async def test_parse_response_empty():
"""Test parsing empty response."""
service = OllamaService()
speakers = service._parse_response("")
assert speakers == []
@pytest.mark.asyncio
async def test_parse_response_invalid_json():
"""Test parsing invalid JSON returns empty list."""
service = OllamaService()
response = "This is not JSON"
speakers = service._parse_response(response)
assert speakers == []
@pytest.mark.asyncio
async def test_detect_speakers_success():
"""Test successful speaker detection."""
service = OllamaService()
text = "Alice: Hello!\nBob: Hi there!"
mock_response = MagicMock()
mock_response.json.return_value = {
"response": '{"speakers": ["Alice", "Bob"]}'
}
mock_response.raise_for_status = MagicMock()
with patch('httpx.AsyncClient') as mock_client:
mock_client.return_value.__aenter__.return_value.post = AsyncMock(return_value=mock_response)
speakers = await service.detect_speakers(text)
assert speakers == ["Alice", "Bob"]
@pytest.mark.asyncio
async def test_detect_speakers_timeout():
"""Test speaker detection handles timeout."""
service = OllamaService()
text = "Some text"
with patch('httpx.AsyncClient') as mock_client:
import httpx
mock_client.return_value.__aenter__.return_value.post = AsyncMock(
side_effect=httpx.TimeoutException("Timeout")
)
with pytest.raises(Exception, match="timed out"):
await service.detect_speakers(text)
@pytest.mark.asyncio
async def test_detect_speakers_http_error():
"""Test speaker detection handles HTTP errors."""
service = OllamaService()
text = "Some text"
with patch('httpx.AsyncClient') as mock_client:
import httpx
mock_client.return_value.__aenter__.return_value.post = AsyncMock(
side_effect=httpx.HTTPError("Connection failed")
)
with pytest.raises(Exception, match="Ollama service error"):
await service.detect_speakers(text)
@pytest.mark.asyncio
async def test_is_available_success():
"""Test is_available returns True when service responds."""
service = OllamaService()
mock_response = MagicMock()
mock_response.status_code = 200
with patch('httpx.AsyncClient') as mock_client:
mock_client.return_value.__aenter__.return_value.get = AsyncMock(return_value=mock_response)
available = await service.is_available()
assert available is True
@pytest.mark.asyncio
async def test_is_available_failure():
"""Test is_available returns False when service is down."""
service = OllamaService()
with patch('httpx.AsyncClient') as mock_client:
import httpx
mock_client.return_value.__aenter__.return_value.get = AsyncMock(
side_effect=httpx.ConnectError("Connection refused")
)
available = await service.is_available()
assert available is False