"""
Migration Planner for Hephaestus

Interactive migration planning with step-by-step guidance,
risk assessment, and rollback capabilities.
"""

from typing import Dict, List, Any, Optional, Tuple
from dataclasses import dataclass
from enum import Enum
from pathlib import Path

from ..analyzers.legacy_pattern_detector import LegacyPattern
from ..analyzers.pattern_compatibility import (
    PatternCompatibilityMatrix,
    MigrationPath,
    MigrationComplexity,
)


class MigrationPhase(Enum):
    """Migration phases."""

    ASSESSMENT = "assessment"
    PREPARATION = "preparation"
    MIGRATION = "migration"
    VALIDATION = "validation"
    CLEANUP = "cleanup"


class RiskLevel(Enum):
    """Risk levels for migration steps."""

    LOW = "low"
    MEDIUM = "medium"
    HIGH = "high"
    CRITICAL = "critical"


@dataclass
class MigrationStep:
    """Represents a single migration step."""

    id: str
    name: str
    description: str
    phase: MigrationPhase
    complexity: MigrationComplexity
    risk_level: RiskLevel
    estimated_time: str  # "hours", "days", "weeks"
    dependencies: List[str]  # Step IDs that must be completed first
    commands: List[str]  # Commands to execute
    validation_steps: List[str]  # How to validate the step
    rollback_commands: List[str]  # How to rollback the step
    files_affected: List[Path]
    prerequisites: List[str]
    success_criteria: List[str]
    failure_recovery: List[str]


@dataclass
class MigrationPlan:
    """Comprehensive migration plan."""

    project_name: str
    source_patterns: List[str]
    target_patterns: List[str]
    steps: List[MigrationStep]
    total_complexity: MigrationComplexity
    estimated_timeline: str
    total_risk_level: RiskLevel
    prerequisites: List[str]
    rollback_strategy: str
    success_metrics: List[str]
    monitoring_points: List[str]


@dataclass
class MigrationProgress:
    """Tracks migration progress."""

    plan_id: str
    completed_steps: List[str]
    current_step: Optional[str]
    failed_steps: List[str]
    start_time: str
    estimated_completion: str
    progress_percentage: float
    blockers: List[str]
    notes: List[str]


class MigrationPlanner:
    """Interactive migration planning with comprehensive guidance."""

    def __init__(self, file_system, project_manager):
        self.file_system = file_system
        self.project_manager = project_manager
        self.compatibility_matrix = PatternCompatibilityMatrix()

        # Migration templates for common scenarios
        self._migration_templates = self._initialize_migration_templates()

        # Risk assessment rules
        self._risk_rules = self._initialize_risk_rules()

        # Validation strategies
        self._validation_strategies = self._initialize_validation_strategies()

    def create_migration_plan(
        self,
        project_path: Path,
        source_patterns: List[str],
        target_patterns: List[str],
        options: Optional[Dict[str, Any]] = None,
    ) -> MigrationPlan:
        """
        Create comprehensive migration plan.

        Args:
            project_path: Path to Anvil project
            source_patterns: Current patterns in project
            target_patterns: Target patterns to migrate to
            options: Additional options for migration planning

        Returns:
            Comprehensive migration plan
        """
        if not self.project_manager.is_anvil_project(project_path):
            raise ValueError(f"Not an Anvil project: {project_path}")

        options = options or {}
        project_name = project_path.name

        # Get migration paths from compatibility matrix
        migration_paths = self.compatibility_matrix.get_migration_plan(
            source_patterns, target_patterns
        )

        # Generate migration steps
        steps = self._generate_migration_steps(
            project_path, source_patterns, target_patterns, migration_paths, options
        )

        # Calculate overall complexity and risk
        total_complexity = self._calculate_total_complexity(steps)
        total_risk_level = self._calculate_total_risk_level(steps)

        # Estimate timeline
        estimated_timeline = self._estimate_timeline(steps)

        # Generate prerequisites
        prerequisites = self._generate_prerequisites(
            source_patterns, target_patterns, steps
        )

        # Create rollback strategy
        rollback_strategy = self._generate_rollback_strategy(steps)

        # Define success metrics
        success_metrics = self._generate_success_metrics(
            source_patterns, target_patterns
        )

        # Define monitoring points
        monitoring_points = self._generate_monitoring_points(steps)

        return MigrationPlan(
            project_name=project_name,
            source_patterns=source_patterns,
            target_patterns=target_patterns,
            steps=steps,
            total_complexity=total_complexity,
            estimated_timeline=estimated_timeline,
            total_risk_level=total_risk_level,
            prerequisites=prerequisites,
            rollback_strategy=rollback_strategy,
            success_metrics=success_metrics,
            monitoring_points=monitoring_points,
        )

    def execute_migration_plan(
        self,
        plan: MigrationPlan,
        project_path: Path,
        options: Optional[Dict[str, Any]] = None,
    ) -> MigrationProgress:
        """
        Execute migration plan with progress tracking.

        Args:
            plan: Migration plan to execute
            project_path: Path to project
            options: Execution options

        Returns:
            Migration progress tracker
        """
        options = options or {}

        # Initialize progress tracking
        progress = MigrationProgress(
            plan_id=f"{plan.project_name}_{hash(str(plan))}",
            completed_steps=[],
            current_step=None,
            failed_steps=[],
            start_time=self._get_current_timestamp(),
            estimated_completion=self._calculate_estimated_completion(plan),
            progress_percentage=0.0,
            blockers=[],
            notes=[],
        )

        # Validate prerequisites
        if not self._validate_prerequisites(plan.prerequisites, project_path):
            progress.blockers.append("Prerequisites not met")
            return progress

        # Execute steps in order
        for step in plan.steps:
            if self._can_execute_step(step, progress):
                progress.current_step = step.id

                try:
                    # Execute step
                    success = self._execute_step(step, project_path, options)

                    if success:
                        progress.completed_steps.append(step.id)
                        progress.progress_percentage = (
                            self._calculate_progress_percentage(
                                len(progress.completed_steps), len(plan.steps)
                            )
                        )
                        progress.notes.append(f"Completed step: {step.name}")
                    else:
                        progress.failed_steps.append(step.id)
                        progress.blockers.append(f"Failed step: {step.name}")
                        break

                except Exception as e:
                    progress.failed_steps.append(step.id)
                    progress.blockers.append(f"Error in step {step.name}: {str(e)}")
                    progress.notes.append(f"Error: {str(e)}")
                    break

        progress.current_step = None
        return progress

    def validate_migration_plan(
        self, plan: MigrationPlan, project_path: Path
    ) -> Dict[str, Any]:
        """
        Validate migration plan for feasibility and risks.

        Args:
            plan: Migration plan to validate
            project_path: Path to project

        Returns:
            Validation results
        """
        validation_results = {
            "is_valid": True,
            "warnings": [],
            "errors": [],
            "risk_assessment": {},
            "resource_requirements": {},
            "timeline_feasibility": {},
            "dependency_analysis": {},
        }

        # Check step dependencies
        dependency_issues = self._validate_step_dependencies(plan.steps)
        if dependency_issues:
            validation_results["errors"].extend(dependency_issues)
            validation_results["is_valid"] = False

        # Check file access
        file_issues = self._validate_file_access(plan.steps, project_path)
        if file_issues:
            validation_results["warnings"].extend(file_issues)

        # Assess resource requirements
        resource_requirements = self._assess_resource_requirements(plan)
        validation_results["resource_requirements"] = resource_requirements

        # Validate timeline
        timeline_feasibility = self._validate_timeline(plan)
        validation_results["timeline_feasibility"] = timeline_feasibility

        # Risk assessment
        risk_assessment = self._assess_migration_risks(plan)
        validation_results["risk_assessment"] = risk_assessment

        # Dependency analysis
        dependency_analysis = self._analyze_dependencies(plan)
        validation_results["dependency_analysis"] = dependency_analysis

        return validation_results

    def _initialize_migration_templates(self) -> Dict[str, Dict[str, Any]]:
        """Initialize migration templates for common scenarios."""
        return {
            "anvil_extras_to_official_routing": {
                "description": "Migrate from Anvil Extras routing to official routing",
                "steps": [
                    {
                        "id": "backup_routing",
                        "name": "Backup current routing",
                        "description": "Create backup of existing routing configuration",
                        "phase": MigrationPhase.PREPARATION,
                        "complexity": MigrationComplexity.SIMPLE,
                        "risk_level": RiskLevel.LOW,
                        "estimated_time": "hours",
                        "commands": [
                            "cp -r server_code server_code_backup",
                            "git add .",
                            "git commit -m 'Backup before routing migration'",
                        ],
                        "validation_steps": [
                            "Verify backup exists",
                            "Check git commit created",
                        ],
                        "rollback_commands": [
                            "git reset --hard HEAD~1",
                        ],
                    },
                    {
                        "id": "install_official_routing",
                        "name": "Install official routing",
                        "description": "Add official routing dependency",
                        "phase": MigrationPhase.PREPARATION,
                        "complexity": MigrationComplexity.SIMPLE,
                        "risk_level": RiskLevel.LOW,
                        "estimated_time": "hours",
                        "commands": [
                            "pip install anvil-routing",
                            "Add to requirements.txt",
                        ],
                        "validation_steps": [
                            "Verify import works",
                            "Check version compatibility",
                        ],
                        "rollback_commands": [
                            "pip uninstall anvil-routing",
                            "git checkout requirements.txt",
                        ],
                    },
                    {
                        "id": "migrate_route_decorators",
                        "name": "Migrate route decorators",
                        "description": "Replace @anvil_extras.routing.route with @anvil.routing.route",
                        "phase": MigrationPhase.MIGRATION,
                        "complexity": MigrationComplexity.MODERATE,
                        "risk_level": RiskLevel.MEDIUM,
                        "estimated_time": "days",
                        "commands": [
                            "Find all route decorators",
                            "Replace with official routing syntax",
                            "Update route parameters",
                        ],
                        "validation_steps": [
                            "Test all routes",
                            "Check URL patterns",
                        ],
                        "rollback_commands": [
                            "git checkout -- server_code/",
                        ],
                    },
                    {
                        "id": "update_navigation_calls",
                        "name": "Update navigation calls",
                        "description": "Replace anvil_extras routing calls with official routing",
                        "phase": MigrationPhase.MIGRATION,
                        "complexity": MigrationComplexity.MODERATE,
                        "risk_level": RiskLevel.MEDIUM,
                        "estimated_time": "days",
                        "commands": [
                            "Replace set_url_hash calls",
                            "Update get_url_hash calls",
                            "Fix navigation components",
                        ],
                        "validation_steps": [
                            "Test navigation functionality",
                            "Check URL updates",
                        ],
                        "rollback_commands": [
                            "git checkout -- client_code/",
                        ],
                    },
                    {
                        "id": "remove_legacy_routing",
                        "name": "Remove legacy routing",
                        "description": "Remove Anvil Extras routing dependency",
                        "phase": MigrationPhase.CLEANUP,
                        "complexity": MigrationComplexity.SIMPLE,
                        "risk_level": RiskLevel.LOW,
                        "estimated_time": "hours",
                        "commands": [
                            "pip uninstall anvil-extras-routing",
                            "Remove unused imports",
                        ],
                        "validation_steps": [
                            "Verify app still works",
                            "Check no import errors",
                        ],
                        "rollback_commands": [
                            "pip install anvil-extras-routing",
                        ],
                    },
                ],
            },
            "raw_tables_to_model_classes": {
                "description": "Migrate from raw table access to model classes",
                "steps": [
                    {
                        "id": "analyze_data_access",
                        "name": "Analyze data access patterns",
                        "description": "Document all current data table access patterns",
                        "phase": MigrationPhase.ASSESSMENT,
                        "complexity": MigrationComplexity.MODERATE,
                        "risk_level": RiskLevel.LOW,
                        "estimated_time": "days",
                        "commands": [
                            "Search for app_tables usage",
                            "Document data operations",
                            "Create data flow diagram",
                        ],
                        "validation_steps": [
                            "Complete documentation",
                            "Review with team",
                        ],
                        "rollback_commands": [],
                    },
                    {
                        "id": "design_model_schema",
                        "name": "Design model schema",
                        "description": "Create model class definitions based on current tables",
                        "phase": MigrationPhase.PREPARATION,
                        "complexity": MigrationComplexity.COMPLEX,
                        "risk_level": RiskLevel.MEDIUM,
                        "estimated_time": "weeks",
                        "commands": [
                            "Analyze table schemas",
                            "Design model relationships",
                            "Create model class files",
                        ],
                        "validation_steps": [
                            "Review schema design",
                            "Validate relationships",
                        ],
                        "rollback_commands": [
                            "rm -rf server_code/models/",
                        ],
                    },
                    {
                        "id": "implement_data_layer",
                        "name": "Implement data layer",
                        "description": "Create data access layer using model classes",
                        "phase": MigrationPhase.MIGRATION,
                        "complexity": MigrationComplexity.COMPLEX,
                        "risk_level": RiskLevel.HIGH,
                        "estimated_time": "weeks",
                        "commands": [
                            "Create model classes",
                            "Implement CRUD operations",
                            "Add data validation",
                        ],
                        "validation_steps": [
                            "Test model operations",
                            "Validate data integrity",
                            "Performance testing",
                        ],
                        "rollback_commands": [
                            "git checkout -- server_code/",
                        ],
                    },
                    {
                        "id": "migrate_data_operations",
                        "name": "Migrate data operations",
                        "description": "Replace raw table access with model operations",
                        "phase": MigrationPhase.MIGRATION,
                        "complexity": MigrationComplexity.COMPLEX,
                        "risk_level": RiskLevel.HIGH,
                        "estimated_time": "weeks",
                        "commands": [
                            "Replace app_tables calls",
                            "Update server functions",
                            "Add error handling",
                        ],
                        "validation_steps": [
                            "Test all data operations",
                            "Check data consistency",
                            "Performance benchmarks",
                        ],
                        "rollback_commands": [
                            "git checkout -- server_code/",
                        ],
                    },
                    {
                        "id": "cleanup_legacy_code",
                        "name": "Cleanup legacy code",
                        "description": "Remove unused raw table access code",
                        "phase": MigrationPhase.CLEANUP,
                        "complexity": MigrationComplexity.MODERATE,
                        "risk_level": RiskLevel.MEDIUM,
                        "estimated_time": "days",
                        "commands": [
                            "Remove unused imports",
                            "Clean up commented code",
                            "Update documentation",
                        ],
                        "validation_steps": [
                            "Code review",
                            "Test coverage check",
                        ],
                        "rollback_commands": [
                            "git checkout -- server_code/",
                        ],
                    },
                ],
            },
        }

    def _initialize_risk_rules(self) -> Dict[str, Dict[str, Any]]:
        """Initialize risk assessment rules."""
        return {
            "data_migration": {
                "base_risk": RiskLevel.HIGH,
                "factors": {
                    "data_volume": {"large": 1, "medium": 0.5, "small": 0},
                    "complexity": {"complex": 1, "moderate": 0.5, "simple": 0},
                    "downtime_tolerance": {"low": 1, "medium": 0.5, "high": 0},
                },
            },
            "routing_migration": {
                "base_risk": RiskLevel.MEDIUM,
                "factors": {
                    "route_count": {"many": 1, "moderate": 0.5, "few": 0},
                    "complexity": {"complex": 1, "moderate": 0.5, "simple": 0},
                    "user_impact": {"high": 1, "medium": 0.5, "low": 0},
                },
            },
            "component_migration": {
                "base_risk": RiskLevel.MEDIUM,
                "factors": {
                    "component_count": {"many": 1, "moderate": 0.5, "few": 0},
                    "custom_components": {"many": 1, "some": 0.5, "none": 0},
                    "styling_complexity": {"complex": 1, "moderate": 0.5, "simple": 0},
                },
            },
        }

    def _initialize_validation_strategies(self) -> Dict[str, List[str]]:
        """Initialize validation strategies for different migration types."""
        return {
            "routing": [
                "Test all routes return correct responses",
                "Verify URL patterns work as expected",
                "Check navigation between routes",
                "Test route parameters and query strings",
                "Verify error handling for invalid routes",
            ],
            "data_layer": [
                "Verify data integrity after migration",
                "Test all CRUD operations",
                "Check performance benchmarks",
                "Validate data constraints and relationships",
                "Test error handling and edge cases",
            ],
            "components": [
                "Test all components render correctly",
                "Verify component properties and events",
                "Check responsive design behavior",
                "Test component interactions",
                "Validate accessibility features",
            ],
            "state_management": [
                "Test state updates correctly",
                "Verify state persistence",
                "Check state synchronization",
                "Test state reset and cleanup",
                "Validate performance with large state",
            ],
        }

    def _generate_migration_steps(
        self,
        project_path: Path,
        source_patterns: List[str],
        target_patterns: List[str],
        migration_paths: Dict[str, Any],
        options: Dict[str, Any],
    ) -> List[MigrationStep]:
        """Generate migration steps based on patterns and migration paths."""
        steps = []

        # Use templates if available
        for source_pattern in source_patterns:
            for target_pattern in target_patterns:
                template_key = f"{source_pattern}_to_{target_pattern}"
                if template_key in self._migration_templates:
                    template_steps = self._migration_templates[template_key]["steps"]
                    for template_step in template_steps:
                        step = MigrationStep(
                            id=template_step["id"],
                            name=template_step["name"],
                            description=template_step["description"],
                            phase=template_step["phase"],
                            complexity=template_step["complexity"],
                            risk_level=template_step["risk_level"],
                            estimated_time=template_step["estimated_time"],
                            dependencies=template_step.get("dependencies", []),
                            commands=template_step["commands"],
                            validation_steps=template_step["validation_steps"],
                            rollback_commands=template_step["rollback_commands"],
                            files_affected=self._get_files_affected(
                                template_step["commands"], project_path
                            ),
                            prerequisites=template_step.get("prerequisites", []),
                            success_criteria=template_step.get("success_criteria", []),
                            failure_recovery=template_step.get("failure_recovery", []),
                        )
                        steps.append(step)

        # Sort steps by dependencies and phase
        steps = self._sort_steps_by_dependencies(steps)

        return steps

    def _calculate_total_complexity(
        self, steps: List[MigrationStep]
    ) -> MigrationComplexity:
        """Calculate total complexity of migration plan."""
        complexity_scores = {
            MigrationComplexity.TRIVIAL: 1,
            MigrationComplexity.SIMPLE: 2,
            MigrationComplexity.MODERATE: 3,
            MigrationComplexity.COMPLEX: 4,
            MigrationComplexity.EXPERT: 5,
        }

        total_score = sum(complexity_scores.get(step.complexity, 3) for step in steps)

        average_score = total_score / len(steps) if steps else 0

        if average_score <= 1.5:
            return MigrationComplexity.TRIVIAL
        elif average_score <= 2.5:
            return MigrationComplexity.SIMPLE
        elif average_score <= 3.5:
            return MigrationComplexity.MODERATE
        elif average_score <= 4.5:
            return MigrationComplexity.COMPLEX
        else:
            return MigrationComplexity.EXPERT

    def _calculate_total_risk_level(self, steps: List[MigrationStep]) -> RiskLevel:
        """Calculate total risk level of migration plan."""
        risk_scores = {
            RiskLevel.LOW: 1,
            RiskLevel.MEDIUM: 2,
            RiskLevel.HIGH: 3,
            RiskLevel.CRITICAL: 4,
        }

        total_score = sum(risk_scores.get(step.risk_level, 2) for step in steps)

        average_score = total_score / len(steps) if steps else 0

        if average_score <= 1.5:
            return RiskLevel.LOW
        elif average_score <= 2.5:
            return RiskLevel.MEDIUM
        elif average_score <= 3.5:
            return RiskLevel.HIGH
        else:
            return RiskLevel.CRITICAL

    def _estimate_timeline(self, steps: List[MigrationStep]) -> str:
        """Estimate total timeline for migration."""
        time_multipliers = {
            "hours": 1,
            "days": 8,
            "weeks": 40,  # 5 days per week
        }

        total_hours = 0
        for step in steps:
            multiplier = time_multipliers.get(step.estimated_time, 8)
            complexity_multiplier = {
                MigrationComplexity.TRIVIAL: 0.5,
                MigrationComplexity.SIMPLE: 1.0,
                MigrationComplexity.MODERATE: 2.0,
                MigrationComplexity.COMPLEX: 4.0,
                MigrationComplexity.EXPERT: 8.0,
            }
            total_hours += multiplier * complexity_multiplier.get(step.complexity, 1.0)

        # Convert to human-readable format
        if total_hours <= 8:
            return f"{total_hours} hours"
        elif total_hours <= 40:
            return f"{total_hours / 8:.1f} days"
        elif total_hours <= 160:  # 4 weeks
            return f"{total_hours / 40:.1f} weeks"
        else:
            return f"{total_hours / 40:.1f} weeks ({total_hours / 160:.1f} months)"

    def _generate_prerequisites(
        self,
        source_patterns: List[str],
        target_patterns: List[str],
        steps: List[MigrationStep],
    ) -> List[str]:
        """Generate list of prerequisites for migration."""
        prerequisites = []

        # Common prerequisites
        prerequisites.extend(
            [
                "Complete backup of codebase",
                "Version control up to date",
                "Testing environment available",
                "Team notification and coordination",
            ]
        )

        # Pattern-specific prerequisites
        if "raw_table_access" in source_patterns:
            prerequisites.extend(
                [
                    "Data backup and verification",
                    "Schema documentation",
                    "Data integrity validation tools",
                ]
            )

        if "anvil_extras_routing" in source_patterns:
            prerequisites.extend(
                [
                    "Route inventory and documentation",
                    "URL structure analysis",
                    "Navigation component audit",
                ]
            )

        if "model_classes" in target_patterns:
            prerequisites.extend(
                [
                    "Model class design review",
                    "Data validation framework",
                    "Migration testing strategy",
                ]
            )

        if "official_routing" in target_patterns:
            prerequisites.extend(
                [
                    "Official routing documentation review",
                    "Route testing plan",
                    "Navigation component updates",
                ]
            )

        # Remove duplicates
        return list(set(prerequisites))

    def _generate_rollback_strategy(self, steps: List[MigrationStep]) -> str:
        """Generate comprehensive rollback strategy."""
        rollback_commands = []
        for step in steps:
            rollback_commands.extend(step.rollback_commands)

        return f"""
        Rollback Strategy:
        
        1. Immediate Rollback Triggers:
           - Critical functionality failure
           - Data corruption detected
           - Performance degradation > 50%
           - Security vulnerabilities identified
        
        2. Rollback Procedure:
           {chr(10).join(f"   Step {i + 1}: {cmd}" for i, cmd in enumerate(rollback_commands))}
        
        3. Rollback Validation:
           - Verify all critical functionality works
           - Check data integrity
           - Confirm performance restored
           - Test user workflows
        
        4. Communication:
           - Notify team immediately
           - Document rollback reasons
           - Schedule post-mortem analysis
           - Update project documentation
        
        5. Prevention:
           - Analyze failure root causes
           - Update migration procedures
           - Improve testing coverage
           - Enhance monitoring
        """

    def _generate_success_metrics(
        self, source_patterns: List[str], target_patterns: List[str]
    ) -> List[str]:
        """Generate success metrics for migration."""
        metrics = [
            "All migration steps completed successfully",
            "Zero data loss or corruption",
            "Application functionality preserved",
            "Performance benchmarks met or exceeded",
            "User experience maintained or improved",
        ]

        # Pattern-specific metrics
        if "raw_table_access" in source_patterns and "model_classes" in target_patterns:
            metrics.extend(
                [
                    "All data operations use model classes",
                    "Data validation working correctly",
                    "Type safety improvements realized",
                ]
            )

        if (
            "anvil_extras_routing" in source_patterns
            and "official_routing" in target_patterns
        ):
            metrics.extend(
                [
                    "All routes use official routing",
                    "Navigation works correctly",
                    "URL patterns are SEO-friendly",
                ]
            )

        return metrics

    def _generate_monitoring_points(self, steps: List[MigrationStep]) -> List[str]:
        """Generate monitoring points for migration."""
        monitoring_points = [
            "Step completion status",
            "Error rates and types",
            "Performance metrics",
            "User feedback and issues",
            "Resource utilization",
        ]

        # Add step-specific monitoring
        for step in steps:
            if step.risk_level in [RiskLevel.HIGH, RiskLevel.CRITICAL]:
                monitoring_points.append(f"High-risk step: {step.name}")

        return monitoring_points

    def _validate_prerequisites(
        self, prerequisites: List[str], project_path: Path
    ) -> bool:
        """Validate that all prerequisites are met."""
        # Check for git repository
        if not (project_path / ".git").exists():
            return False

        # Check for backup
        if not (project_path / "backup").exists():
            return False

        # Check for testing environment
        # This would be more sophisticated in a real implementation

        return True

    def _can_execute_step(
        self, step: MigrationStep, progress: MigrationProgress
    ) -> bool:
        """Check if a step can be executed based on progress."""
        # Check if dependencies are met
        for dependency in step.dependencies:
            if dependency not in progress.completed_steps:
                return False

        # Check if step already completed or failed
        if step.id in progress.completed_steps or step.id in progress.failed_steps:
            return False

        return True

    def _execute_step(
        self, step: MigrationStep, project_path: Path, options: Dict[str, Any]
    ) -> bool:
        """Execute a single migration step."""
        # In a real implementation, this would execute the commands
        # For now, we'll simulate execution

        # Validate prerequisites
        for prerequisite in step.prerequisites:
            if not self._check_prerequisite(prerequisite, project_path):
                return False

        # Execute commands (simulated)
        for command in step.commands:
            # In real implementation, execute actual commands
            pass

        # Validate success criteria
        for criterion in step.success_criteria:
            if not self._validate_success_criterion(criterion, project_path):
                return False

        return True

    def _calculate_progress_percentage(
        self, completed_steps: int, total_steps: int
    ) -> float:
        """Calculate progress percentage."""
        if total_steps == 0:
            return 0.0
        return (completed_steps / total_steps) * 100.0

    def _get_current_timestamp(self) -> str:
        """Get current timestamp."""
        from datetime import datetime

        return datetime.now().isoformat()

    def _calculate_estimated_completion(self, plan: MigrationPlan) -> str:
        """Calculate estimated completion time."""
        from datetime import datetime, timedelta

        # Parse timeline to get duration
        timeline = plan.estimated_timeline
        if "hours" in timeline:
            hours = float(timeline.split()[0])
            delta = timedelta(hours=hours)
        elif "days" in timeline:
            days = float(timeline.split()[0])
            delta = timedelta(days=days)
        elif "weeks" in timeline:
            weeks = float(timeline.split()[0])
            delta = timedelta(weeks=weeks)
        else:
            delta = timedelta(days=1)  # Default

        completion_time = datetime.now() + delta
        return completion_time.isoformat()

    def _validate_step_dependencies(self, steps: List[MigrationStep]) -> List[str]:
        """Validate that step dependencies are correct."""
        errors = []
        step_ids = {step.id for step in steps}

        for step in steps:
            for dependency in step.dependencies:
                if dependency not in step_ids:
                    errors.append(
                        f"Step {step.id} depends on non-existent step {dependency}"
                    )

        # Check for circular dependencies
        # This would be more sophisticated in a real implementation

        return errors

    def _validate_file_access(
        self, steps: List[MigrationStep], project_path: Path
    ) -> List[str]:
        """Validate that all files can be accessed."""
        warnings = []

        for step in steps:
            for file_path in step.files_affected:
                if not file_path.exists():
                    warnings.append(f"File not found: {file_path}")
                elif not file_path.is_file() and not file_path.is_dir():
                    warnings.append(f"Invalid path: {file_path}")

        return warnings

    def _assess_resource_requirements(self, plan: MigrationPlan) -> Dict[str, Any]:
        """Assess resource requirements for migration."""
        return {
            "developer_hours": self._estimate_developer_hours(plan),
            "testing_environment": "required",
            "backup_storage": self._estimate_backup_storage(plan),
            "downtime": self._estimate_downtime(plan),
            "team_size": self._estimate_team_size(plan),
        }

    def _validate_timeline(self, plan: MigrationPlan) -> Dict[str, Any]:
        """Validate timeline feasibility."""
        return {
            "is_feasible": True,  # Would be more sophisticated in real implementation
            "recommended_buffer": "20%",
            "critical_path_analysis": "completed",
            "parallel_opportunities": self._identify_parallel_opportunities(plan.steps),
        }

    def _assess_migration_risks(self, plan: MigrationPlan) -> Dict[str, Any]:
        """Assess migration risks."""
        return {
            "overall_risk": plan.total_risk_level.value,
            "high_risk_steps": len(
                [s for s in plan.steps if s.risk_level == RiskLevel.HIGH]
            ),
            "critical_risk_steps": len(
                [s for s in plan.steps if s.risk_level == RiskLevel.CRITICAL]
            ),
            "mitigation_strategies": self._generate_mitigation_strategies(plan),
        }

    def _analyze_dependencies(self, plan: MigrationPlan) -> Dict[str, Any]:
        """Analyze migration dependencies."""
        return {
            "external_dependencies": self._identify_external_dependencies(plan),
            "internal_dependencies": self._identify_internal_dependencies(plan),
            "dependency_graph": self._build_dependency_graph(plan.steps),
            "bottlenecks": self._identify_bottlenecks(plan.steps),
        }

    def _get_files_affected(
        self, commands: List[str], project_path: Path
    ) -> List[Path]:
        """Get list of files affected by commands."""
        files_affected = []

        # In a real implementation, this would parse commands to extract file paths
        # For now, return common project files
        common_files = [
            "server_code",
            "client_code",
            "requirements.txt",
            "package.json",
        ]

        for file_name in common_files:
            file_path = project_path / file_name
            if file_path.exists():
                files_affected.append(file_path)

        return files_affected

    def _sort_steps_by_dependencies(
        self, steps: List[MigrationStep]
    ) -> List[MigrationStep]:
        """Sort steps by dependencies using topological sort."""
        # Simple implementation - would be more sophisticated in real code
        return sorted(steps, key=lambda s: (s.phase.value, len(s.dependencies)))

    def _check_prerequisite(self, prerequisite: str, project_path: Path) -> bool:
        """Check if a prerequisite is met."""
        # In a real implementation, this would check actual prerequisites
        return True

    def _validate_success_criterion(self, criterion: str, project_path: Path) -> bool:
        """Validate a success criterion."""
        # In a real implementation, this would check actual criteria
        return True

    def _estimate_developer_hours(self, plan: MigrationPlan) -> int:
        """Estimate total developer hours required."""
        hours = 0
        for step in plan.steps:
            step_hours = {
                MigrationComplexity.TRIVIAL: 2,
                MigrationComplexity.SIMPLE: 8,
                MigrationComplexity.MODERATE: 24,
                MigrationComplexity.COMPLEX: 80,
                MigrationComplexity.EXPERT: 160,
            }
            hours += step_hours.get(step.complexity, 24)
        return hours

    def _estimate_backup_storage(self, plan: MigrationPlan) -> str:
        """Estimate backup storage required."""
        # In a real implementation, this would calculate actual storage needs
        return "1GB"

    def _estimate_downtime(self, plan: MigrationPlan) -> str:
        """Estimate potential downtime."""
        if plan.total_risk_level in [RiskLevel.HIGH, RiskLevel.CRITICAL]:
            return "2-4 hours"
        elif plan.total_risk_level == RiskLevel.MEDIUM:
            return "1-2 hours"
        else:
            return "< 1 hour"

    def _estimate_team_size(self, plan: MigrationPlan) -> int:
        """Estimate optimal team size."""
        if plan.total_complexity in [
            MigrationComplexity.COMPLEX,
            MigrationComplexity.EXPERT,
        ]:
            return 3
        elif plan.total_complexity == MigrationComplexity.MODERATE:
            return 2
        else:
            return 1

    def _identify_parallel_opportunities(self, steps: List[MigrationStep]) -> List[str]:
        """Identify steps that can be executed in parallel."""
        # In a real implementation, this would analyze dependencies more carefully
        return []

    def _generate_mitigation_strategies(self, plan: MigrationPlan) -> List[str]:
        """Generate risk mitigation strategies."""
        strategies = [
            "Comprehensive testing before each step",
            "Rollback plan for each step",
            "Team communication protocol",
            "Progress monitoring and alerts",
        ]

        if plan.total_risk_level in [RiskLevel.HIGH, RiskLevel.CRITICAL]:
            strategies.extend(
                [
                    "Staged rollout approach",
                    "Feature flags for gradual deployment",
                    "Enhanced monitoring and alerting",
                ]
            )

        return strategies

    def _identify_external_dependencies(self, plan: MigrationPlan) -> List[str]:
        """Identify external dependencies."""
        # In a real implementation, this would analyze actual dependencies
        return []

    def _identify_internal_dependencies(self, plan: MigrationPlan) -> List[str]:
        """Identify internal dependencies."""
        # In a real implementation, this would analyze actual dependencies
        return []

    def _build_dependency_graph(
        self, steps: List[MigrationStep]
    ) -> Dict[str, List[str]]:
        """Build dependency graph for steps."""
        graph = {}
        for step in steps:
            graph[step.id] = step.dependencies
        return graph

    def _identify_bottlenecks(self, steps: List[MigrationStep]) -> List[str]:
        """Identify potential bottlenecks in migration."""
        bottlenecks = []

        # Find steps with many dependencies
        for step in steps:
            if len(step.dependencies) > 2:
                bottlenecks.append(
                    f"Step {step.id} has {len(step.dependencies)} dependencies"
                )

        # Find high-complexity steps
        for step in steps:
            if step.complexity in [
                MigrationComplexity.COMPLEX,
                MigrationComplexity.EXPERT,
            ]:
                bottlenecks.append(f"High complexity step: {step.name}")

        return bottlenecks
