# core/affidavit.py
from datetime import datetime
from typing import Any, Dict, Optional, List
import hashlib
import json
from sqlalchemy.orm import Session

from app.modules.affidavit_logs.models import Operation, StatusOP, AffidavitRecord


class LegalAffidavit:
    """
    Certificador Legal Digital
    Cada operación genera un acta notarial inmutable
    """

    def __init__(self, db: Session, user, operation: str, client_id: int = None):
        self.db = db
        self.user = user
        self.operation = operation
        self.client_id = client_id
        self.timestamp = datetime.utcnow()
        self.entities_affected: List[Dict] = []
        self.rules_validated: List[Dict] = []
        self.evidence: List[Dict] = []
        self._record = None

    def _get_operation_enum(self) -> Operation:
        """Convierte string de operación a Enum Operation"""
        operation_map = {
            "create": Operation.CREATED,
            "CREATE": Operation.CREATED,
            "update": Operation.UPDATED,
            "UPDATE": Operation.UPDATED,
            "delete": Operation.DELETED,
            "DELETE": Operation.DELETED,
            "cancel": Operation.CANCELED,
            "CANCEL": Operation.CANCELED,
            "tried": Operation.TRIED,
            "TRIED": Operation.TRIED,
        }
        return operation_map.get(self.operation.lower(), Operation.TRIED)

    def _get_status_enum(self, success: bool) -> StatusOP:
        """Convierte resultado a StatusOP"""
        if success:
            return StatusOP.COMPLETED
        return StatusOP.INVALID

    def _hash_data(self, data: Any) -> str:
        """Genera hash para integridad de datos"""
        data_str = json.dumps(data, sort_keys=True, default=str)
        return hashlib.sha256(data_str.encode()).hexdigest()

    def certify_entity(self, entity_type: str, entity_id: int, entity_data: Dict) -> 'LegalAffidavit':
        """Certifica que una entidad fue afectada"""
        self.entities_affected.append({
            "type": entity_type,
            "id": entity_id,
            "data_hash": self._hash_data(entity_data),
            "timestamp": self.timestamp.isoformat()
        })
        return self

    def validate_rule(self, rule_name: str, rule_result: bool, rule_details: str = "") -> 'LegalAffidavit':
        """Valida una regla de negocio"""
        self.rules_validated.append({
            "rule": rule_name,
            "passed": rule_result,
            "details": rule_details,
            "validated_at": self.timestamp.isoformat()
        })

        if not rule_result:
            raise AffidavitValidationError(f"Regla '{rule_name}' no cumplida: {rule_details}")

        return self

    def add_evidence(self, evidence_type: str, evidence_data: Any) -> 'LegalAffidavit':
        """Agrega evidencia digital"""
        self.evidence.append({
            "type": evidence_type,
            "data": evidence_data,
            "hash": self._hash_data(evidence_data),
            "timestamp": self.timestamp.isoformat()
        })
        return self

    def _generate_signature(self) -> str:
        """Genera firma digital del acta"""
        data_to_sign = f"{self.user.id}{self.timestamp.isoformat()}{self.operation}{json.dumps(self.entities_affected, sort_keys=True)}"
        return hashlib.sha512(data_to_sign.encode()).hexdigest()

    def _build_description(self) -> str:
        """Construye la descripción del acta"""
        entities = ", ".join([f"{e['type']}:{e['id']}" for e in self.entities_affected])
        rules = ", ".join([r['rule'] for r in self.rules_validated if r['passed']])
        
        desc = f"Operación {self.operation} por usuario {self.user.email}"
        if entities:
            desc += f" | Entidades: {entities}"
        if rules:
            desc += f" | Reglas: {rules}"
        return desc

    def sign(self, success: bool = True) -> Dict:
        """
        Firma y guarda el acta notarial en la base de datos
        """
        description = self._build_description()
        signature = self._generate_signature()
        status = self._get_status_enum(success)
        operation_enum = self._get_operation_enum()

        # Crear registro en BD
        self._record = AffidavitRecord(
            operation=operation_enum,
            user_id=self.user.id,
            client_id=self.client_id,
            description=description,
            adjustment=json.dumps(self.evidence) if self.evidence else None,
            status=status,
            sign=signature,
            created_at=self.timestamp,
            created_by=self.user.id
        )

        self.db.add(self._record)
        self.db.commit()
        self.db.refresh(self._record)

        return {
            "affidavit_id": self._record.id,
            "operation": self.operation,
            "user": {
                "id": self.user.id,
                "email": self.user.email,
                "user_type": self.user.user_type,
                "rol_operativo": self.user.rol_operativo
            },
            "timestamp": self.timestamp.isoformat(),
            "description": description,
            "status": status.value,
            "signature": signature,
            "entities_affected": self.entities_affected,
            "rules_validated": self.rules_validated
        }

    def get_record_id(self) -> Optional[int]:
        """Retorna el ID del registro creado"""
        return self._record.id if self._record else None


class AffidavitValidationError(Exception):
    """Error de validación notarial"""
    pass


def certify_operation(operation_name: str):
    """Decorador para certificar operaciones automáticamente"""
    def decorator(func):
        async def wrapper(*args, **kwargs):
            db = kwargs.get('db')
            user = kwargs.get('current_user')
            client_id = kwargs.get('client_id')

            if not db and args and hasattr(args[0], 'db'):
                db = args[0].db

            if db and user:
                affidavit = LegalAffidavit(db, user, operation_name, client_id)
                kwargs['affidavit'] = affidavit

                try:
                    result = await func(*args, **kwargs)
                    affidavit.sign(success=True)
                    return result
                except Exception as e:
                    affidavit.sign(success=False)
                    raise

            return await func(*args, **kwargs)
        return wrapper
    return decorator