"""Base constraint classes."""
from dataclasses import dataclass, field
from typing import List, Set, Dict, Optional, Any
from enum import Enum


class ConstraintType(Enum):
    """Types of constraints in the scheduling system."""
    HARD = "hard"  # Must be satisfied
    SOFT = "soft"  # Should be satisfied if possible
    PREFERENCE = "preference"  # Operator preferences


@dataclass
class Constraint:
    """Base constraint class with common functionality."""
    constraint_id: str
    constraint_type: ConstraintType
    description: str
    severity: int = 0  # Higher = more important
    enabled: bool = True
    metadata: Dict[str, Any] = field(default_factory=dict)

    def is_satisfied(self, context: Dict[str, Any]) -> bool:
        """Check if constraint is satisfied in given context."""
        # Base implementation - subclasses should override this
        return True

    def get_violation(self, context: Dict[str, Any]) -> Optional['ConstraintViolation']:
        """Get violation if constraint is not satisfied."""
        if self.is_satisfied(context):
            return None
        return ConstraintViolation(
            constraint_id=self.constraint_id,
            constraint_type=self.constraint_type,
            description=self.description,
            severity=self.severity,
            context=context
        )


@dataclass
class ConstraintViolation:
    """Represents a constraint violation."""
    constraint_id: str
    constraint_type: ConstraintType
    description: str
    severity: int
    context: Dict[str, Any]
    violation_message: str = field(init=False)

    def __post_init__(self):
        self.violation_message = f"{self.constraint_id}: {self.description}"

    def to_dict(self) -> Dict[str, Any]:
        """Convert violation to dictionary."""
        return {
            'constraint_id': self.constraint_id,
            'constraint_type': self.constraint_type.value,
            'description': self.description,
            'severity': self.severity,
            'context': self.context,
            'violation_message': self.violation_message
        }