import os
import json
import ast
import re
from pathlib import Path
from collections import defaultdict

class MigrationAnalyzer:
    def __init__(self, source_path, target_tech):
        self.source_path = Path(source_path)
        self.target_tech = target_tech
        self.analysis = defaultdict(dict)
    
    def analyze_migration(self):
        """
        Comprehensive migration analysis
        """
        self.analysis['source'] = self._analyze_source()
        self.analysis['complexity'] = self._assess_complexity()
        self.analysis['dependencies'] = self._analyze_dependencies()
        self.analysis['risks'] = self._identify_risks()
        self.analysis['effort'] = self._estimate_effort()
        self.analysis['strategy'] = self._recommend_strategy()
        
        return self.analysis
    
    def _analyze_source(self):
        """Analyze source codebase characteristics"""
        stats = {
            'files': 0,
            'lines': 0,
            'components': 0,
            'patterns': [],
            'frameworks': set(),
            'languages': defaultdict(int)
        }
        
        for file_path in self.source_path.rglob('*'):
            if file_path.is_file() and not self._is_ignored(file_path):
                stats['files'] += 1
                ext = file_path.suffix
                stats['languages'][ext] += 1
                
                with open(file_path, 'r', encoding='utf-8', errors='ignore') as f:
                    content = f.read()
                    stats['lines'] += len(content.splitlines())
                    
                    # Detect frameworks and patterns
                    self._detect_patterns(content, stats)
        
        return stats
    
    def _assess_complexity(self):
        """Assess migration complexity"""
        factors = {
            'size': self._calculate_size_complexity(),
            'architectural': self._calculate_architectural_complexity(),
            'dependency': self._calculate_dependency_complexity(),
            'business_logic': self._calculate_logic_complexity(),
            'data': self._calculate_data_complexity()
        }
        
        overall = sum(factors.values()) / len(factors)
        
        return {
            'factors': factors,
            'overall': overall,
            'level': self._get_complexity_level(overall)
        }
    
    def _identify_risks(self):
        """Identify migration risks"""
        risks = []
        
        # Check for high-risk patterns
        risk_patterns = {
            'global_state': {
                'pattern': r'(global|window)\.\w+\s*=',
                'severity': 'high',
                'description': 'Global state management needs careful migration'
            },
            'direct_dom': {
                'pattern': r'document\.(getElementById|querySelector)',
                'severity': 'medium',
                'description': 'Direct DOM manipulation needs framework adaptation'
            },
            'async_patterns': {
                'pattern': r'(callback|setTimeout|setInterval)',
                'severity': 'medium',
                'description': 'Async patterns may need modernization'
            },
            'deprecated_apis': {
                'pattern': r'(componentWillMount|componentWillReceiveProps)',
                'severity': 'high',
                'description': 'Deprecated APIs need replacement'
            }
        }
        
        for risk_name, risk_info in risk_patterns.items():
            occurrences = self._count_pattern_occurrences(risk_info['pattern'])
            if occurrences > 0:
                risks.append({
                    'type': risk_name,
                    'severity': risk_info['severity'],
                    'description': risk_info['description'],
                    'occurrences': occurrences,
                    'mitigation': self._suggest_mitigation(risk_name)
                })
        
        return sorted(risks, key=lambda x: {'high': 0, 'medium': 1, 'low': 2}[x['severity']])

class MigrationPlanner:
    def create_migration_plan(self, analysis):
        """
        Create co