# Feature Specification Template

> **Instructions**: Copy this template for new features. Replace placeholders with actual requirements. Delete instruction blocks when done.

## Feature: [Feature Name]

**GitHub Issue**: #[issue-number]  
**Branch**: `feat/issue-[number]-[description]`  
**Protocol(s)**: [List any protocols from specs/interfaces/ that this feature implements]

---

## 📋 Overview

**What**: [One-sentence description of what this feature does]

**Why**: [Business justification - why is this needed?]

**Who**: [Target users - library consumers, CLI users, internal developers]

---

## 🎯 Acceptance Criteria

> **Instructions**: Use "Given/When/Then" format for clear, testable criteria

### Core Functionality
- [ ] **Given** [initial state], **When** [action occurs], **Then** [expected outcome]
- [ ] **Given** [initial state], **When** [action occurs], **Then** [expected outcome]
- [ ] **Given** [initial state], **When** [action occurs], **Then** [expected outcome]

### Edge Cases & Error Handling
- [ ] **Given** [error condition], **When** [action occurs], **Then** [expected error behavior]
- [ ] **Given** [boundary condition], **When** [action occurs], **Then** [expected behavior]

### Performance & Quality
- [ ] **Given** [performance scenario], **When** [action occurs], **Then** [meets performance requirement]
- [ ] Test coverage: 90%+ for all new code
- [ ] All public functions have docstrings with examples
- [ ] Type hints for all function parameters and returns

---

## 🔧 Technical Specification

### Python Protocols
> **Instructions**: Reference specific protocols from `specs/interfaces/`. If none exist, specify "None" or create new protocol first.

- **Implements**: `[ProtocolName]` from `specs/interfaces/[file].py`
- **Extends**: `[BaseProtocol]` (if applicable)
- **Dependencies**: [List any new dependencies required]

### API Design
> **Instructions**: Show the public interface design - function signatures, class structure, etc.

```python
# Main public API
def [function_name]([parameters]) -> [return_type]:
    """[Brief description].

    Args:
        [param]: [description]

    Returns:
        [description]

    Raises:
        [ExceptionType]: [when this occurs]
    """
    pass

# Alternative: Class-based API
class [ClassName]:
    """[Brief description]."""

    def __init__(self, [parameters]) -> None:
        """[Brief description]."""
        pass

    def [method_name](self, [parameters]) -> [return_type]:
        """[Brief description]."""
        pass
```

### Configuration
> **Instructions**: List any new configuration options, environment variables, or settings

- **Environment Variables**:
  - `[VAR_NAME]`: [description] (default: `[value]`)
- **Configuration Options**:
  - `[option_name]`: [description]

---

## 🧪 Test Scenarios

### Happy Path Tests
```python
def test_[feature]_happy_path():
    """Test normal operation with valid inputs."""
    # Arrange
    [setup_code]

    # Act
    result = [action_code]

    # Assert
    assert [expected_result]
    assert [additional_assertions]
```

### Edge Case Tests
```python
def test_[feature]_[edge_case]():
    """Test [specific edge case scenario]."""
    # Arrange
    [setup_edge_case]

    # Act & Assert
    with pytest.raises([ExpectedException]):
        [action_that_should_fail]
```

### Integration Tests
```python
@pytest.mark.slow
def test_[feature]_integration():
    """Test feature integration with external systems."""
    # [Integration test details]
```

---

## 📚 Usage Examples

### Basic Usage
```python
from augint_library import [import_what]

# Basic example
[example_code]
```

### Advanced Usage  
```python
# Advanced example with options
[advanced_example_code]
```

### CLI Usage (if applicable)
```bash
# Command line example
ai-test-script [command] [options]
```

---

## 🚀 Implementation Plan

### Phase 1: Core Implementation
1. [ ] Create failing tests based on acceptance criteria
2. [ ] Implement minimal version to pass tests  
3. [ ] Add error handling and validation
4. [ ] Add comprehensive docstrings

### Phase 2: Integration & Polish
1. [ ] Add integration tests
2. [ ] Update CLI interface (if needed)
3. [ ] Update documentation
4. [ ] Performance optimization (if needed)

### Phase 3: Validation
1. [ ] Run full test suite (`make test-all`)
2. [ ] Run security scans (`make security`)  
3. [ ] Generate documentation (`make docs`)
4. [ ] Manual testing of examples

---

## 🔗 Related Work

**Dependencies**:
- [List any new dependencies to add to pyproject.toml]

**Documentation Updates**:
- [ ] Update README.md with new feature
- [ ] Add examples to module docstrings
- [ ] Update CLI help text (if applicable)

**Follow-up Issues**:
- [Link to any follow-up work that this feature enables]

---

## 🎛️ AI Implementation Notes

> **For AI Assistants**: Key guidance for implementing this feature

### Implementation Order
1. **Read the Protocol** in `specs/interfaces/` first
2. **Write failing tests** based on acceptance criteria  
3. **Implement minimal code** to pass tests
4. **Refactor and enhance** while maintaining test coverage

### Key Patterns to Follow
- Use existing library patterns from `src/augint_library/`
- Follow Google docstring format
- Add type hints for all parameters and returns
- Use `pytest.mark.slow` for integration tests
- Raise appropriate exceptions with clear messages

### Code Quality Checks
Before completing implementation:
```bash
make lint      # Fix any linting issues
make test      # All tests must pass
make security  # No security issues
make docs      # Documentation builds
```

---

**Implementation Status**: ❌ Not Started | 🔄 In Progress | ✅ Complete
