"""
MetaNode SDK Blockchain Validator Module
======================================

Implements the agreement and validator layer in the MetaNode architecture:
- Handles consensus validation for agreement execution
- Validates transactions and data changes
- Ensures multi-layer verification (consensus, ledger, validator)
- Executes runtime VM for contract execution

This module forms the validation backbone of the MetaNode blockchain system.
"""

import os
import time
import logging
import json
import hashlib
import uuid
from typing import Dict, List, Any, Optional, Union

# Configure logging
logger = logging.getLogger("metanode-blockchain-validator")


class ValidatorConfig:
    """Configuration for validator nodes"""
    
    def __init__(self,
                 validator_count: int = 2,
                 consensus_threshold: float = 0.67,
                 auto_approve: bool = False):
        self.validator_count = max(validator_count, 2)  # Minimum 2 validators
        self.consensus_threshold = min(max(consensus_threshold, 0.51), 0.99)  # 51%-99% range
        self.auto_approve = auto_approve
        self.docker_lock_path = "/tmp/docker.lock"


def validate_agreement(agreement_id: str, 
                      action: str,
                      metadata: Optional[Dict] = None) -> Dict[str, Any]:
    """
    Validate a contract agreement through the validator network
    
    Args:
        agreement_id: ID of the agreement to validate
        action: Action being performed under the agreement
        metadata: Optional metadata for the validation
        
    Returns:
        Dict with validation status and details
    """
    logger.info(f"Validating agreement {agreement_id} for action: {action}")
    
    # In production code, this would:
    # 1. Distribute validation request to validator nodes
    # 2. Get consensus decision from validator network
    # 3. Record validation in the ledger layer
    
    # Check for docker.lock as required by our architecture
    docker_lock_exists = os.path.exists("/tmp/docker.lock")
    
    if not docker_lock_exists:
        logger.warning("Docker lock file missing, creating new lock file")
        with open("/tmp/docker.lock", "w") as f:
            f.write(f"locked:{int(time.time())}")
    
    # Simulate validation process
    # In real implementation, this would query the validator vPods
    validation_result = {
        "agreement_id": agreement_id,
        "action": action,
        "validated_at": time.time(),
        "validated": True,
        "consensus_level": 1.0,  # 100% consensus (simulated)
        "validators_participated": 2,
        "validator_signatures": [
            f"0x{hashlib.sha256(f'validator1:{agreement_id}:{action}'.encode()).hexdigest()[:40]}",
            f"0x{hashlib.sha256(f'validator2:{agreement_id}:{action}'.encode()).hexdigest()[:40]}"
        ],
        "runtime_proof": f"proof-{uuid.uuid4()}"
    }
    
    if metadata:
        validation_result["metadata"] = metadata
    
    logger.info(f"Agreement {agreement_id} validated: {validation_result['validated']}")
    
    return validation_result


def register_validator(address: str, 
                      endpoint: Optional[str] = None) -> Dict[str, Any]:
    """
    Register a new validator in the validator network
    
    Args:
        address: Blockchain address of the validator
        endpoint: Optional API endpoint for the validator node
        
    Returns:
        Dict with registration status
    """
    logger.info(f"Registering validator: {address}")
    
    # In production code, this would:
    # 1. Add validator to the validator set in K8s
    # 2. Update consensus configuration
    # 3. Distribute validator credentials
    
    validator_id = f"validator-{hashlib.sha256(address.encode()).hexdigest()[:8]}"
    
    registration = {
        "validator_id": validator_id,
        "address": address,
        "registered_at": time.time(),
        "status": "active",
        "consensus_weight": 1.0,  # Equal weight in consensus
    }
    
    if endpoint:
        registration["endpoint"] = endpoint
    
    logger.info(f"Validator registered with ID: {validator_id}")
    
    return registration


def get_validator_status(validator_id: Optional[str] = None) -> Dict[str, Any]:
    """
    Get status of validator network or specific validator
    
    Args:
        validator_id: Optional ID of specific validator to check
        
    Returns:
        Dict with validator status information
    """
    if validator_id:
        logger.info(f"Getting status for validator: {validator_id}")
        
        # Return status for specific validator
        return {
            "validator_id": validator_id,
            "status": "active",
            "consensus_participated": 42,  # Number of consensus rounds
            "last_active": time.time()
        }
    else:
        logger.info("Getting status of validator network")
        
        # Return status of entire validator network
        return {
            "validator_count": 2,
            "active_validators": 2,
            "consensus_threshold": 0.67,  # 67% required for consensus
            "current_epoch": int(time.time() / 60),  # Epoch changes every minute
            "status": "healthy"
        }


def execute_agreement(agreement_id: str, 
                     execution_data: Dict[str, Any]) -> Dict[str, Any]:
    """
    Execute an agreement through the runtime VM
    
    Args:
        agreement_id: ID of agreement to execute
        execution_data: Data required for execution
        
    Returns:
        Dict with execution results
    """
    logger.info(f"Executing agreement {agreement_id}")
    
    # In production code, this would:
    # 1. Submit execution request to runtime VM vPods
    # 2. Wait for consensus verification
    # 3. Record execution in ledger
    
    # Simulate execution
    execution_result = {
        "agreement_id": agreement_id,
        "executed_at": time.time(),
        "status": "success",
        "transaction_id": f"tx-{uuid.uuid4()}",
        "runtime_proof": f"rt-proof-{uuid.uuid4()}",
        "consensus_verified": True,
        "validator_signatures": [
            f"0x{hashlib.sha256(f'exec1:{agreement_id}:{time.time()}'.encode()).hexdigest()[:40]}",
            f"0x{hashlib.sha256(f'exec2:{agreement_id}:{time.time()}'.encode()).hexdigest()[:40]}"
        ]
    }
    
    return execution_result
