"""
Compliance Rule Validators for Cloud Foundations Assessment.

This module provides validation logic for different compliance frameworks
and security standards including:

- Security validation rules
- Compliance framework validation (SOC2, PCI-DSS, HIPAA)
- Operational best practices validation
- Custom validation rule support

Each validator implements specific validation logic and generates
assessment results with appropriate severity levels and remediation
guidance.
"""

from abc import ABC, abstractmethod
from datetime import datetime
from typing import Any, Dict, List, Optional

from loguru import logger

from runbooks.cfat.models import (
    AssessmentResult,
    CheckStatus,
    Severity,
)


class BaseValidator(ABC):
    """Base class for compliance validators."""

    def __init__(self, name: str, category: str, severity: Severity = Severity.WARNING):
        """
        Initialize validator.

        Args:
            name: Validator name
            category: Assessment category
            severity: Default severity level
        """
        self.name = name
        self.category = category
        self.severity = severity

    @abstractmethod
    def validate(self, resource_data: Dict[str, Any]) -> AssessmentResult:
        """
        Validate resource data against compliance rules.

        Args:
            resource_data: AWS resource data to validate

        Returns:
            Assessment result with validation outcome
        """
        pass

    def _create_result(
        self,
        status: CheckStatus,
        message: str,
        finding_id: Optional[str] = None,
        resource_arn: Optional[str] = None,
        recommendations: Optional[List[str]] = None,
        execution_time: float = 0.0,
    ) -> AssessmentResult:
        """
        Create standardized assessment result.

        Args:
            status: Check status
            message: Human-readable message
            finding_id: Unique finding identifier
            resource_arn: AWS resource ARN
            recommendations: Remediation recommendations
            execution_time: Validation execution time

        Returns:
            Formatted assessment result
        """
        return AssessmentResult(
            finding_id=finding_id or f"{self.category.upper()}-{self.name.upper()}",
            check_name=self.name,
            check_category=self.category,
            status=status,
            severity=self.severity,
            message=message,
            resource_arn=resource_arn,
            recommendations=recommendations or [],
            execution_time=execution_time,
            timestamp=datetime.utcnow(),
        )


class SecurityValidator(BaseValidator):
    """Security-focused validation rules."""

    def __init__(self):
        """Initialize security validator."""
        super().__init__("security_validator", "security", Severity.CRITICAL)

    def validate(self, resource_data: Dict[str, Any]) -> AssessmentResult:
        """
        Validate security configuration.

        Args:
            resource_data: Resource data to validate

        Returns:
            Security validation result
        """
        logger.debug(f"Running security validation: {self.name}")

        # Example security validation logic
        # TODO: Implement actual security validation rules

        if self._check_root_mfa(resource_data):
            return self._create_result(
                status=CheckStatus.PASS,
                message="Root account MFA is properly configured",
                recommendations=["Continue monitoring root account access"],
            )
        else:
            return self._create_result(
                status=CheckStatus.FAIL,
                message="Root account MFA is not enabled",
                recommendations=[
                    "Enable MFA for the root account immediately",
                    "Use hardware MFA device for enhanced security",
                    "Restrict root account usage to emergency situations only",
                ],
            )

    def _check_root_mfa(self, resource_data: Dict[str, Any]) -> bool:
        """Check if root account MFA is enabled."""
        # Placeholder implementation
        iam_data = resource_data.get("iam", {})
        return iam_data.get("root_account_mfa", False)


class ComplianceValidator(BaseValidator):
    """Compliance framework validation rules."""

    def __init__(self, framework: str = "SOC2"):
        """
        Initialize compliance validator.

        Args:
            framework: Target compliance framework
        """
        super().__init__(f"compliance_{framework.lower()}", "compliance", Severity.WARNING)
        self.framework = framework

    def validate(self, resource_data: Dict[str, Any]) -> AssessmentResult:
        """
        Validate compliance requirements.

        Args:
            resource_data: Resource data to validate

        Returns:
            Compliance validation result
        """
        logger.debug(f"Running {self.framework} compliance validation")

        # Framework-specific validation logic
        if self.framework.upper() == "SOC2":
            return self._validate_soc2(resource_data)
        elif self.framework.upper() == "PCI-DSS":
            return self._validate_pci_dss(resource_data)
        elif self.framework.upper() == "HIPAA":
            return self._validate_hipaa(resource_data)
        else:
            return self._create_result(
                status=CheckStatus.SKIP, message=f"Unknown compliance framework: {self.framework}"
            )

    def _validate_soc2(self, resource_data: Dict[str, Any]) -> AssessmentResult:
        """Validate SOC2 compliance requirements."""
        # Placeholder SOC2 validation
        cloudtrail_data = resource_data.get("cloudtrail", {})
        trails = cloudtrail_data.get("trails", [])

        if trails:
            return self._create_result(
                status=CheckStatus.PASS,
                message="SOC2: CloudTrail logging is enabled for audit trail",
                recommendations=["Ensure CloudTrail logs are protected and monitored"],
            )
        else:
            return self._create_result(
                status=CheckStatus.FAIL,
                message="SOC2: CloudTrail logging is not enabled",
                recommendations=[
                    "Enable CloudTrail in all regions",
                    "Configure log file validation",
                    "Set up CloudTrail log monitoring and alerting",
                ],
            )

    def _validate_pci_dss(self, resource_data: Dict[str, Any]) -> AssessmentResult:
        """Validate PCI-DSS compliance requirements."""
        # Placeholder PCI-DSS validation
        return self._create_result(status=CheckStatus.SKIP, message="PCI-DSS validation not yet implemented")

    def _validate_hipaa(self, resource_data: Dict[str, Any]) -> AssessmentResult:
        """Validate HIPAA compliance requirements."""
        # Placeholder HIPAA validation
        return self._create_result(status=CheckStatus.SKIP, message="HIPAA validation not yet implemented")


class OperationalValidator(BaseValidator):
    """Operational best practices validation."""

    def __init__(self):
        """Initialize operational validator."""
        super().__init__("operational_validator", "operational", Severity.INFO)

    def validate(self, resource_data: Dict[str, Any]) -> AssessmentResult:
        """
        Validate operational best practices.

        Args:
            resource_data: Resource data to validate

        Returns:
            Operational validation result
        """
        logger.debug("Running operational best practices validation")

        # Example operational validation
        # TODO: Implement actual operational validation rules

        config_data = resource_data.get("config", {})
        recorders = config_data.get("configuration_recorders", [])

        if recorders:
            return self._create_result(
                status=CheckStatus.PASS,
                message="AWS Config is enabled for configuration tracking",
                recommendations=["Ensure Config rules are defined for compliance monitoring"],
            )
        else:
            return self._create_result(
                status=CheckStatus.FAIL,
                message="AWS Config is not enabled",
                severity=Severity.WARNING,
                recommendations=[
                    "Enable AWS Config to track configuration changes",
                    "Configure Config rules for automated compliance checking",
                    "Set up Config remediation for automatic fixes",
                ],
            )


# Validation rule registry
VALIDATION_RULES = {
    "security": SecurityValidator,
    "compliance_soc2": lambda: ComplianceValidator("SOC2"),
    "compliance_pci_dss": lambda: ComplianceValidator("PCI-DSS"),
    "compliance_hipaa": lambda: ComplianceValidator("HIPAA"),
    "operational": OperationalValidator,
}


def get_validator(rule_name: str) -> Optional[BaseValidator]:
    """
    Get validator instance by rule name.

    Args:
        rule_name: Name of the validation rule

    Returns:
        Validator instance or None if not found
    """
    validator_class = VALIDATION_RULES.get(rule_name)
    if validator_class:
        return validator_class()
    return None


def list_available_validators() -> List[str]:
    """
    Get list of available validation rules.

    Returns:
        List of available validator names
    """
    return list(VALIDATION_RULES.keys())
