#!/usr/bin/env python3
"""
Covenant-based UTXO Management Analysis
OP_CHECKTEMPLATEVERIFY and dust elimination solutions
"""

import json
import hashlib
import math
from typing import Dict, List, Optional, Any
from dataclasses import dataclass
from datetime import datetime

@dataclass
class UTXO:
    """UTXO model with covenant constraints"""
    txid: str
    vout: int
    value: int
    script_pubkey: str
    covenant_template: Optional[str] = None
    min_value: int = 546  # Current dust limit

@dataclass
class CovenantTemplate:
    """CTV covenant template specification"""
    template_hash: str
    allowed_outputs: List[Dict]
    min_total_value: int
    max_total_value: int
    expiration_block: Optional[int]

class CovenantAnalyzer:
    """Analyzes covenant-based solutions for dust elimination"""
    
    def __init__(self):
        self.dust_limit = 546
        self.covenant_templates = {}
        
    def create_aggregation_template(self, inputs: List[UTXO]) -> CovenantTemplate:
        """Create CTV template for UTXO aggregation"""
        total_value = sum(utxo.value for utxo in inputs)
        
        # Template that aggregates dust UTXOs into one output
        template = {
            "version": 1,
            "locktime": 0,
            "inputs": [{"prevout": f"{utxo.txid}:{utxo.vout}"} for utxo in inputs],
            "outputs": [{
                "value": total_value - 1000,  # Minus fee
                "script": "p2wpkh"  # Standard output
            }]
        }
        
        template_hash = hashlib.sha256(
            json.dumps(template, sort_keys=True).encode()
        ).hexdigest()
        
        return CovenantTemplate(
            template_hash=template_hash,
            allowed_outputs=template["outputs"],
            min_total_value=total_value - 2000,
            max_total_value=total_value,
            expiration_block=None
        )
    
    def analyze_dust_elimination(self, utxos: List[UTXO]) -> Dict[str, Any]:
        """Analyze dust elimination potential with covenants"""
        dust_utxos = [u for u in utxos if u.value <= self.dust_limit]
        non_dust_utxos = [u for u in utxos if u.value > self.dust_limit]
        
        total_dust_value = sum(u.value for u in dust_utxos)
        aggregation_potential = len(dust_utxos) > 1
        
        # Model CTV-based aggregation
        if aggregation_potential:
            template = self.create_aggregation_template(dust_utxos)
            recovered_value = total_dust_value - 1000  # Estimated fee
            
            return {
                "dust_utxos_count": len(dust_utxos),
                "total_dust_value": total_dust_value,
                "aggregation_possible": True,
                "covenant_template": template.template_hash,
                "recoverable_value": recovered_value,
                "efficiency_gain": (recovered_value / total_dust_value) * 100 if total_dust_value > 0 else 0
            }
        
        return {
            "dust_utxos_count": len(dust_utxos),
            "total_dust_value": total_dust_value,
            "aggregation_possible": False,
            "covenant_template": None,
            "recoverable_value": 0,
            "efficiency_gain": 0
        }
    
    def model_vault_covenant(self, deposit_value: int) -> Dict[str, Any]:
        """Model vault covenant for dust prevention"""
        if deposit_value <= self.dust_limit:
            return {"error": "Deposit below dust limit"}
        
        # Vault template with withdrawal restrictions
        vault_template = {
            "outputs": [{
                "value": deposit_value,
                "script": "vault_covenant",
                "constraints": {
                    "min_withdrawal": self.dust_limit * 2,
                    "timelock": 144,  # 1 day
                    "allowed_recipients": ["owner", "backup"]
                }
            }]
        }
        
        return {
            "vault_created": True,
            "deposit_value": deposit_value,
            "min_withdrawal": self.dust_limit * 2,
            "dust_prevention": "active",
            "template_hash": hashlib.sha256(
                json.dumps(vault_template, sort_keys=True).encode()
            ).hexdigest()
        }

def test_covenant_analysis():
    """Test covenant-based dust elimination"""
    analyzer = CovenantAnalyzer()
    
    # Create test UTXOs
    test_utxos = [
        UTXO("tx1", 0, 300, "script1"),  # Dust
        UTXO("tx2", 0, 400, "script2"),  # Dust
        UTXO("tx3", 0, 500, "script3"),  # Dust
        UTXO("tx4", 0, 10000, "script4"),  # Non-dust
    ]
    
    # Run analysis
    results = analyzer.analyze_dust_elimination(test_utxos)
    
    print("=== Covenant Analysis Results ===")
    print(f"Dust UTXOs: {results['dust_utxos_count']}")
    print(f"Total Dust Value: {results['total_dust_value']} satoshis")
    print(f"Aggregation Possible: {results['aggregation_possible']}")
    print(f"Recoverable Value: {results['recoverable_value']} satoshis")
    print(f"Efficiency Gain: {results['efficiency_gain']:.2f}%")
    
    # Test vault covenant
    vault_results = analyzer.model_vault_covenant(5000)
    print(f"\n=== Vault Covenant ===")
    print(f"Vault Created: {vault_results['vault_created']}")
    print(f"Min Withdrawal: {vault_results['min_withdrawal']} satoshis")
    
    return results

if __name__ == "__main__":
    test_covenant_analysis()