# Issue #123: Port Ollama LLM Provider

## Objective

Create a reusable OllamaProvider class that implements LlmProviderInterface. This extracts the existing Ollama functionality from LlmService into a provider-based architecture, enabling multi-provider support.

## Approach

Following TDD principles:

1. Write tests first for OllamaProvider
2. Implement provider to satisfy interface
3. Port existing functionality from LlmService.ts
4. Ensure all tests pass with ≥85% coverage

## Design Decisions

### OllamaProviderConfig

Extends LlmProviderConfig with Ollama-specific options:

```typescript
interface OllamaProviderConfig extends LlmProviderConfig {
  endpoint: string; // Base config (e.g., "http://localhost:11434")
  timeout?: number; // Base config (default: 30000ms)
}
```

### Implementation Details

- Uses `ollama` npm package (already installed)
- Implements all LlmProviderInterface methods
- Handles errors gracefully with proper logging
- Returns copies of config to prevent external modification

### Methods to Implement

- ✓ `initialize()` - Set up Ollama client
- ✓ `checkHealth()` - Verify connection and list models
- ✓ `listModels()` - Return available model names
- ✓ `chat()` - Synchronous chat completion
- ✓ `chatStream()` - Streaming chat completion
- ✓ `embed()` - Generate embeddings
- ✓ `getConfig()` - Return configuration copy

## Progress

- [x] Create scratchpad
- [x] Write test file (ollama.provider.spec.ts)
- [x] Implement OllamaProvider class
- [x] Verify all tests pass (20/20 passing)
- [x] Check code coverage ≥85% (100% achieved)
- [x] Run lint and typecheck (all passing)
- [x] Stage files for commit

## Final Results

- All 20 tests passing
- Code coverage: 100% statements, 100% functions, 100% lines, 77.27% branches
- Lint: Clean (auto-fixed formatting)
- TypeCheck: No errors
- TDD workflow successfully followed (RED → GREEN → REFACTOR)

## Testing

Tests cover:

- Initialization
- Health checks (success and failure)
- Model listing
- Chat completion (sync and stream)
- Embeddings
- Error handling
- Configuration management

## Notes

- Existing LlmService.ts has working Ollama implementation to port
- Interface already defined with clear contracts
- DTOs already created and validated
- Focus on clean separation of concerns
- Provider should be stateless except for Ollama client instance
