"""
Refactoring Agent

Automatically refactors code to improve quality, maintainability,
and performance while preserving functionality.
"""

from typing import Any, Dict, List
from agents.base import BaseAgent


class RefactoringAgent(BaseAgent):
    """
    Automated code refactoring for improved code quality.

    Capabilities:
    - Extract methods/functions
    - Rename variables/functions
    - Remove code duplication
    - Simplify complex conditionals
    - Optimize imports
    - Apply design patterns
    """

    def __init__(self):
        super().__init__(
            name='refactoring-agent',
            description='Refactor code for better quality and maintainability',
            category='engineering',
            version='1.0.0',
            tags=['refactoring', 'code-quality', 'maintenance', 'optimization']
        )

    async def execute(self, params: Dict[str, Any]) -> Dict[str, Any]:
        """
        Refactor code.

        Args:
            params: {
                'file_path': str,
                'language': 'python|javascript|typescript|go|rust',
                'refactoring_type': 'extract_method|rename|remove_duplication|simplify|optimize',
                'target': str,           # Specific code element to refactor
                'options': {
                    'preserve_comments': bool,
                    'update_tests': bool,
                    'dry_run': bool,
                    'backup': bool
                }
            }

        Returns:
            {
                'status': 'success|failed',
                'refactorings_applied': List[Dict],
                'files_modified': List[str],
                'lines_changed': int,
                'quality_improvement': float,
                'complexity_reduction': float,
                'duplication_removed': int,
                'diff': str,
                'warnings': List[str]
            }
        """
        file_path = params.get('file_path')
        language = params.get('language', 'python')
        refactoring_type = params.get('refactoring_type', 'optimize')
        options = params.get('options', {})

        self.logger.info(
            f"Refactoring {file_path} ({refactoring_type})"
        )

        # Mock refactoring results
        refactorings = [
            {
                'type': 'extract_method',
                'location': 'src/services.py:45-67',
                'description': 'Extracted complex validation logic into validate_user_input()',
                'benefit': 'Improved readability and reusability'
            },
            {
                'type': 'remove_duplication',
                'location': 'src/utils.py:128,156,203',
                'description': 'Removed duplicated error handling code',
                'benefit': 'Reduced code size by 45 lines'
            },
            {
                'type': 'simplify_conditional',
                'location': 'src/models.py:89-102',
                'description': 'Simplified nested if-else into guard clauses',
                'benefit': 'Reduced cyclomatic complexity from 12 to 4'
            },
            {
                'type': 'rename',
                'location': 'src/main.py:23',
                'description': 'Renamed variable "d" to "user_data"',
                'benefit': 'Improved code clarity'
            }
        ]

        return {
            'status': 'success',
            'file_path': file_path,
            'language': language,
            'refactoring_type': refactoring_type,
            'refactorings_applied': refactorings,
            'files_modified': [
                'src/main.py',
                'src/services.py',
                'src/utils.py',
                'src/models.py'
            ],
            'lines_changed': 234,
            'lines_added': 87,
            'lines_removed': 147,
            'quality_improvement': 15.3,  # percentage
            'complexity_reduction': 32.5,  # percentage
            'duplication_removed': 45,     # lines
            'dry_run': options.get('dry_run', False),
            'backup_created': options.get('backup', True),
            'metrics_before': {
                'cyclomatic_complexity': 15.2,
                'maintainability_index': 65.3,
                'duplicated_lines': 127
            },
            'metrics_after': {
                'cyclomatic_complexity': 10.3,
                'maintainability_index': 75.3,
                'duplicated_lines': 82
            },
            'diff_summary': {
                'files_changed': 4,
                'insertions': 87,
                'deletions': 147
            },
            'warnings': [
                'Some comments may need updating after refactoring',
                'Please review extracted methods for proper naming'
            ],
            'next_steps': [
                'Run tests to verify functionality preserved',
                'Update documentation if needed',
                'Review changes before committing'
            ]
        }

    def validate_params(self, params: Dict[str, Any]) -> bool:
        """Validate refactoring parameters."""
        if 'file_path' not in params:
            self.logger.error("Missing required field: file_path")
            return False

        valid_types = [
            'extract_method', 'rename', 'remove_duplication',
            'simplify', 'optimize'
        ]
        refactoring_type = params.get('refactoring_type', 'optimize')

        if refactoring_type not in valid_types:
            self.logger.error(f"Invalid refactoring type: {refactoring_type}")
            return False

        return True
