"""
MetaNode SDK Blockchain Transaction Module
========================================

Handles blockchain transactions within the vPods K8s architecture:
- Transaction creation and signing
- Transaction submission to the blockchain layer
- Verification through multiple validator nodes
- Integration with runtime VM for execution

This module completes the full-stack blockchain integration.
"""

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-transaction")


class TransactionConfig:
    """Configuration for blockchain transactions"""
    
    def __init__(self,
                 require_validation: bool = True,
                 auto_submit: bool = False,
                 confirmation_blocks: int = 1):
        self.require_validation = require_validation
        self.auto_submit = auto_submit
        self.confirmation_blocks = max(confirmation_blocks, 1)
        self.docker_lock_path = "/tmp/docker.lock"


def create_transaction(operation: str,
                      data: Dict[str, Any],
                      agreement_id: Optional[str] = None) -> Dict[str, Any]:
    """
    Create a blockchain transaction
    
    Args:
        operation: Type of operation for the transaction
        data: Transaction data payload
        agreement_id: Optional agreement ID related to this transaction
        
    Returns:
        Dict with transaction details
    """
    logger.info(f"Creating transaction for operation: {operation}")
    
    # Generate a unique transaction ID
    tx_id = f"tx-{hashlib.sha256(f'{operation}:{time.time()}'.encode()).hexdigest()[:16]}"
    
    # Structure the transaction
    transaction = {
        "tx_id": tx_id,
        "operation": operation,
        "data": data,
        "created_at": time.time(),
        "status": "created",
        "nonce": int(time.time() * 1000) % 10000  # Simple nonce generation
    }
    
    if agreement_id:
        transaction["agreement_id"] = agreement_id
        logger.info(f"Transaction linked to agreement: {agreement_id}")
    
    logger.info(f"Transaction created: {tx_id}")
    
    return transaction


def sign_transaction(transaction: Dict[str, Any], 
                    private_key: Optional[str] = None) -> Dict[str, Any]:
    """
    Sign a transaction for submission
    
    Args:
        transaction: Transaction object to sign
        private_key: Optional private key (if None, uses default)
        
    Returns:
        Dict with signed transaction
    """
    logger.info(f"Signing transaction: {transaction['tx_id']}")
    
    # In production code, this would:
    # 1. Use Web3 or similar library to properly sign with the private key
    # 2. Create a valid signature that can be verified on-chain
    
    # For demonstration, we simulate the signing process
    if private_key is None:
        # Use a simulated default key
        private_key = "0x" + "1" * 64
    
    # Create signature (simulated)
    tx_data = json.dumps(transaction, sort_keys=True)
    signature = f"0x{hashlib.sha256((tx_data + private_key).encode()).hexdigest()}"
    
    # Add signature to transaction
    signed_tx = transaction.copy()
    signed_tx["signature"] = signature
    signed_tx["status"] = "signed"
    signed_tx["signed_at"] = time.time()
    
    logger.info(f"Transaction {transaction['tx_id']} signed successfully")
    
    return signed_tx


def submit_transaction(transaction: Dict[str, Any], 
                      wait_for_receipt: bool = False) -> Dict[str, Any]:
    """
    Submit a signed transaction to the blockchain
    
    Args:
        transaction: Signed transaction to submit
        wait_for_receipt: Whether to wait for transaction receipt
        
    Returns:
        Dict with submission status
    """
    tx_id = transaction.get("tx_id", "unknown")
    logger.info(f"Submitting transaction: {tx_id}")
    
    # Check if transaction is signed
    if "signature" not in transaction:
        logger.error(f"Transaction {tx_id} not signed")
        return {
            "status": "error",
            "error": "Transaction not signed",
            "tx_id": tx_id
        }
    
    # In production code, this would:
    # 1. Send transaction to blockchain vPods
    # 2. Distribute to validator nodes for consensus
    # 3. Execute in runtime VM if needed
    # 4. Wait for confirmation if requested
    
    # 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 transaction submission
    tx_hash = f"0x{hashlib.sha256(f'{tx_id}:{time.time()}'.encode()).hexdigest()}"
    
    receipt = {
        "tx_hash": tx_hash,
        "tx_id": tx_id,
        "submitted_at": time.time(),
        "status": "pending",
        "block_number": None
    }
    
    if wait_for_receipt:
        # Simulate waiting for receipt
        time.sleep(0.5)  # Just a small delay for demonstration
        receipt["block_number"] = int(time.time()) % 1000000  # Simulated block number
        receipt["status"] = "confirmed"
        receipt["confirmations"] = 1
        receipt["confirmed_at"] = time.time()
        
        logger.info(f"Transaction {tx_id} confirmed in block {receipt['block_number']}")
    else:
        logger.info(f"Transaction {tx_id} submitted with hash {tx_hash}")
    
    return receipt


def get_transaction_status(tx_hash: str) -> Dict[str, Any]:
    """
    Get status of a submitted transaction
    
    Args:
        tx_hash: Transaction hash to check
        
    Returns:
        Dict with transaction status
    """
    logger.info(f"Checking status for transaction: {tx_hash}")
    
    # In production code, this would:
    # 1. Query the blockchain vPods for transaction status
    # 2. Check consensus state across validator nodes
    
    # Simulate transaction status check
    # For demonstration, we determine status based on the hash value
    hash_num = int(tx_hash[-6:], 16)  # Convert last 6 chars to number
    
    if hash_num % 10 == 0:
        status = "pending"
    elif hash_num % 10 == 1:
        status = "failed"
    else:
        status = "confirmed"
    
    # Create status response
    tx_status = {
        "tx_hash": tx_hash,
        "status": status,
        "checked_at": time.time()
    }
    
    if status == "confirmed":
        tx_status["block_number"] = int(time.time()) % 1000000  # Simulated block number
        tx_status["confirmations"] = hash_num % 5 + 1  # 1-5 confirmations
        tx_status["confirmed_at"] = time.time() - (hash_num % 60)  # 0-59 seconds ago
    
    logger.info(f"Transaction {tx_hash} status: {status}")
    
    return tx_status


def estimate_gas(transaction: Dict[str, Any]) -> Dict[str, Any]:
    """
    Estimate gas cost for a transaction
    
    Args:
        transaction: Transaction to estimate gas for
        
    Returns:
        Dict with gas estimation
    """
    logger.info(f"Estimating gas for transaction: {transaction.get('tx_id', 'new')}")
    
    # In production code, this would:
    # 1. Submit estimation request to blockchain vPods
    # 2. Calculate based on operation complexity
    
    # Simulate gas estimation
    # For demonstration, base it on the size of the data
    data_size = len(json.dumps(transaction.get("data", {})))
    base_gas = 21000  # Base transaction cost
    data_gas = data_size * 68  # 68 gas per byte
    
    gas_estimate = {
        "gas_estimate": base_gas + data_gas,
        "gas_price": 20000000000,  # 20 Gwei
        "total_cost_wei": (base_gas + data_gas) * 20000000000,
        "estimated_at": time.time()
    }
    
    logger.info(f"Gas estimate: {gas_estimate['gas_estimate']} units")
    
    return gas_estimate
