polygon_digest.py

"""
Módulo de integración con Polygon para publicación de digest de cumplimiento

Este módulo publica hashes mensuales de autorizaciones en Polygon blockchain
para garantizar trazabilidad y cumplimiento normativo público (AI Act, GDPR).
"""

import os
import json
import hashlib
from typing import Dict, Any, List, Optional
from datetime import datetime, timezone
from dataclasses import dataclass
import logging

# Imports comentados hasta configuración
# from web3 import Web3

# Configuración
logger = logging.getLogger(__name__)

@dataclass
class DigestRecord:
    """Registro de digest para publicación en Polygon"""
    period: str  # "2025-11" formato YYYY-MM
    root_hash: str  # Hash SHA-256 de todas las autorizaciones del período
    authorization_count: int
    timestamp: str
    publisher_address: str
    transaction_hash: Optional[str] = None
    block_number: Optional[int] = None
    gas_used: Optional[int] = None

class PolygonDigestPublisher:
    """Publicador de digest en Polygon blockchain"""
    
    def __init__(self):
        # Configuración Web3 (comentada hasta activación)
        """
        self.w3 = Web3(Web3.HTTPProvider(os.getenv("POLYGON_RPC_URL")))
        self.private_key = os.getenv("POLYGON_WALLET_PRIVATE_KEY")
        self.account = self.w3.eth.account.from_key(self.private_key)
        self.chain_id = int(os.getenv("POLYGON_CHAIN_ID", "137"))  # 137 mainnet, 80002 Amoy testnet
        
        self.contract_addr = os.getenv("DIGEST_CONTRACT_ADDR")
        self.contract_abi = json.loads(os.getenv("DIGEST_CONTRACT_ABI", "[]"))
        """
        
        # Temporal: configuración simulada
        self.w3 = None
        self.account = None
        self.contract_addr = "0x0000000000000000000000000000000000000000"  # Placeholder
        self.chain_id = 137
        
        logger.info("PolygonDigestPublisher inicializado (modo simulado)")
    
    def _compute_monthly_digest(self, authorizations: List[Dict[str, Any]]) -> str:
        """
        Calcula hash SHA-256 de todas las autorizaciones del mes
        
        Args:
            authorizations: Lista de registros de autorización del período
            
        Returns:
            Hash hexadecimal de 64 caracteres
        """
        # Ordenar autorizaciones por timestamp para consistencia
        sorted_auths = sorted(authorizations, key=lambda x: x.get('timestamp', ''))
        
        # Crear string concatenado con todos los datos relevantes
        digest_data = ""
        for auth in sorted_auths:
            # Campos relevantes para el digest
            relevant_data = {
                'user_email': auth.get('user_email', ''),
                'video_hash': auth.get('video_hash', ''),
                'timestamp': auth.get('timestamp', ''),
                'consent_accepted': auth.get('consent_accepted', False),
                'validation_status': auth.get('validation_status', ''),
                'document_id': auth.get('document_id', '')
            }
            
            # Convertir a JSON ordenado y añadir al digest
            auth_json = json.dumps(relevant_data, sort_keys=True, separators=(',', ':'))
            digest_data += auth_json + "|"
        
        # Calcular hash SHA-256
        digest_hash = hashlib.sha256(digest_data.encode('utf-8')).hexdigest()
        
        logger.info(f"Digest calculado: {len(authorizations)} autorizaciones → {digest_hash[:16]}...")
        return digest_hash
    
    def _get_period_from_timestamp(self, timestamp: str) -> str:
        """
        Extrae período YYYY-MM del timestamp ISO
        
        Args:
            timestamp: Timestamp en formato ISO 8601
            
        Returns:
            Período en formato YYYY-MM
        """
        try:
            dt = datetime.fromisoformat(timestamp.replace('Z', '+00:00'))
            return dt.strftime("%Y-%m")
        except Exception as e:
            logger.error(f"Error parseando timestamp {timestamp}: {e}")
            return datetime.now(timezone.utc).strftime("%Y-%m")
    
    def publish_monthly_digest(self, authorizations: List[Dict[str, Any]]) -> Optional[DigestRecord]:
        """
        Publica digest mensual en Polygon blockchain
        
        Args:
            authorizations: Lista de autorizaciones del período a publicar
            
        Returns:
            DigestRecord con resultado de la publicación
        """
        if not authorizations:
            logger.warning("No hay autorizaciones para publicar")
            return None
        
        try:
            # Calcular período y hash
            first_auth = authorizations[0]
            period = self._get_period_from_timestamp(first_auth.get('timestamp', ''))
            root_hash = self._compute_monthly_digest(authorizations)
            
            # Crear registro
            digest_record = DigestRecord(
                period=period,
                root_hash=root_hash,
                authorization_count=len(authorizations),
                timestamp=datetime.now(timezone.utc).isoformat(),
                publisher_address=self.account.address if self.account else "0x0000000000000000000000000000000000000000"
            )
            
            # Publicar en blockchain (comentado hasta activación)
            """
            contract = self.w3.eth.contract(
                address=Web3.to_checksum_address(self.contract_addr), 
                abi=self.contract_abi
            )
            
            nonce = self.w3.eth.get_transaction_count(self.account.address)
            
            tx = contract.functions.publish(
                Web3.to_bytes(hexstr=root_hash), 
                period
            ).build_transaction({
                "from": self.account.address,
                "nonce": nonce,
                "gas": 120000,
                "maxFeePerGas": self.w3.to_wei('60', 'gwei'),
                "maxPriorityFeePerGas": self.w3.to_wei('2', 'gwei'),
                "chainId": self.chain_id
            })
            
            signed = self.w3.eth.account.sign_transaction(tx, self.private_key)
            tx_hash = self.w3.eth.send_raw_transaction(signed.rawTransaction)
            receipt = self.w3.eth.wait_for_transaction_receipt(tx_hash)
            
            # Actualizar registro con datos de la transacción
            digest_record.transaction_hash = receipt.transactionHash.hex()
            digest_record.block_number = receipt.blockNumber
            digest_record.gas_used = receipt.gasUsed
            """
            
            # Temporal: simulación de publicación
            simulated_tx_hash = f"0x{'0123456789abcdef' * 4}"  # 64 chars hex
            digest_record.transaction_hash = simulated_tx_hash
            digest_record.block_number = 12345678
            digest_record.gas_used = 87654
            
            logger.info(f"Digest publicado simulado: {period} → {simulated_tx_hash}")
            
            return digest_record
            
        except Exception as e:
            logger.error(f"Error publicando digest: {e}")
            return None
    
    def verify_digest_on_chain(self, period: str, expected_hash: str) -> bool:
        """
        Verifica que el digest publicado en blockchain coincide con el hash esperado
        
        Args:
            period: Período YYYY-MM a verificar
            expected_hash: Hash esperado del digest
            
        Returns:
            True si coincide, False si no
        """
        try:
            # Consultar blockchain (comentado hasta activación)
            """
            contract = self.w3.eth.contract(
                address=Web3.to_checksum_address(self.contract_addr), 
                abi=self.contract_abi
            )
            
            on_chain_hash = contract.functions.digests(period).call()
            on_chain_hex = self.w3.to_hex(on_chain_hash)
            
            return on_chain_hex == expected_hash
            """
            
            # Temporal: simulación de verificación
            logger.info(f"Verificación simulada: {period} → {expected_hash[:16]}...")
            return True
            
        except Exception as e:
            logger.error(f"Error verificando digest: {e}")
            return False
    
    def get_published_digests(self) -> List[Dict[str, Any]]:
        """
        Obtiene lista de todos los digest publicados (simulado)
        
        Returns:
            Lista de digest publicados con metadata
        """
        # Temporal: retorno simulado
        return [
            {
                "period": "2025-11",
                "transaction_hash": "0x0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef",
                "block_number": 12345678,
                "timestamp": "2025-11-03T14:30:00Z",
                "authorization_count": 42
            }
        ]

# Instancia global
digest_publisher = PolygonDigestPublisher()