"""
MCP Transaction Layer - Handles secure, atomic transactions between agents.

This module provides transaction management for the Model Context Protocol (MCP),
ensuring reliable and secure interactions between agents.
"""

import asyncio
from typing import Dict, Any, Optional
from enum import Enum
from dataclasses import dataclass
import uuid

class TransactionStatus(Enum):
    PENDING = "pending"
    COMMITTED = "committed"
    ROLLED_BACK = "rolled_back"
    FAILED = "failed"

@dataclass
class TransactionMetadata:
    transaction_id: str
    sender: str
    receiver: str
    timestamp: float
    value: Optional[float] = None
    payment_info: Optional[Dict] = None

class MCPTransaction:
    """Handles atomic transactions between agents"""
    
    def __init__(self):
        self.pending_transactions: Dict[str, TransactionMetadata] = {}
        self.completed_transactions: Dict[str, TransactionMetadata] = {}
        
    async def begin_transaction(
        self,
        sender: str,
        receiver: str,
        metadata: Dict[str, Any]
    ) -> str:
        """Start a new transaction"""
        transaction_id = str(uuid.uuid4())
        self.pending_transactions[transaction_id] = TransactionMetadata(
            transaction_id=transaction_id,
            sender=sender,
            receiver=receiver,
            timestamp=asyncio.get_event_loop().time(),
            **metadata
        )
        return transaction_id
    
    async def commit_transaction(self, transaction_id: str) -> bool:
        """Commit a transaction"""
        if transaction_id not in self.pending_transactions:
            return False
            
        # Move to completed
        transaction = self.pending_transactions.pop(transaction_id)
        self.completed_transactions[transaction_id] = transaction
        return True
        
    async def rollback_transaction(self, transaction_id: str) -> bool:
        """Rollback a transaction"""
        if transaction_id not in self.pending_transactions:
            return False
            
        # Remove from pending
        self.pending_transactions.pop(transaction_id)
        return True
        
    async def get_transaction_status(self, transaction_id: str) -> TransactionStatus:
        """Get the current status of a transaction"""
        if transaction_id in self.pending_transactions:
            return TransactionStatus.PENDING
        elif transaction_id in self.completed_transactions:
            return TransactionStatus.COMMITTED
        return TransactionStatus.FAILED

class MCPPayment:
    """Handles payment processing for agent services"""
    
    async def process_payment(
        self,
        sender: str,
        receiver: str,
        amount: float,
        currency: str = "USD"
    ) -> str:
        """Process a payment between agents"""
        # TODO: Implement payment processing
        pass
        
    async def verify_payment(self, payment_id: str) -> bool:
        """Verify a payment was successful"""
        # TODO: Implement payment verification
        pass
