"""
Real Bitcoin mining integration with your GPU system
"""
from typing import Dict, Any, Optional
import time
import struct
import hashlib
from bitcoinlib.services.services import Service
from .sha256d_processor import SHA256dProcessor

class RealBitcoinMiner:
    def __init__(self, gpu_manager, wallet_address: str, network='bitcoin'):
        self.gpu_manager = gpu_manager
        self.wallet_address = wallet_address
        self.sha256d = SHA256dProcessor(num_gpus=gpu_manager.num_gpus)
        self.service = Service(network=network)
        self.current_target = None
        self.current_block = None
        
    def start_mining(self):
        """Start real Bitcoin mining using your GPU infrastructure"""
        while True:
            try:
                # Get real block template
                template = self._get_block_template()
                
                # Prepare block header
                header = self._create_block_header(template)
                
                # Get current target
                self.current_target = self._bits_to_target(template['bits'])
                
                # Mine using your GPU system
                result = self._mine_block(header, template)
                
                if result:
                    # Submit to real network
                    success = self._submit_block(result, template)
                    if success:
                        print(f"Block successfully mined and submitted! Hash: {result['hash'].hex()}")
                        
            except Exception as e:
                print(f"Mining error: {str(e)}")
                time.sleep(5)
                
    def _get_block_template(self) -> Dict[str, Any]:
        """Get real block template from Bitcoin network"""
        latest_block = self.service.getblock(self.service.getbestblockhash())
        
        return {
            'version': 0x20000000,  # Version 2 with BIP9 support
            'previous_block': latest_block['hash'],
            'timestamp': int(time.time()),
            'bits': latest_block['bits'],
            'height': latest_block['height'] + 1,
            'transactions': self.service.getmempool()
        }
        
    def _create_block_header(self, template: Dict[str, Any]) -> bytes:
        """Create real Bitcoin block header"""
        header = struct.pack('<I', template['version'])
        header += bytes.fromhex(template['previous_block'])
        header += bytes.fromhex(self._calculate_merkle_root(template['transactions']))
        header += struct.pack('<I', template['timestamp'])
        header += struct.pack('<I', int(template['bits'], 16))
        header += struct.pack('<I', 0)  # Initial nonce
        return header
        
    def _mine_block(self, header: bytes, template: Dict[str, Any]) -> Optional[Dict[str, Any]]:
        """Mine block using your GPU infrastructure"""
        start_time = time.time()
        nonce = 0
        batch_size = self.gpu_manager.get_optimal_batch_size()
        
        while nonce < 0xFFFFFFFF:
            # Prepare work for all GPUs
            headers = self.sha256d.prepare_mining_batch(header, nonce, batch_size)
            
            # Distribute work across GPUs
            work_distribution = self.sha256d.distribute_work(headers)
            
            # Process on all GPUs in parallel using your system
            for gpu_id, gpu_headers in work_distribution.items():
                hashes = self.sha256d.process_on_gpu(gpu_id, gpu_headers)
                
                # Check results
                for i, hash_result in enumerate(hashes):
                    if int.from_bytes(hash_result, 'little') < self.current_target:
                        # Found a valid block!
                        block_nonce = nonce + i
                        header = self._update_header_nonce(header, block_nonce)
                        
                        return {
                            'header': header,
                            'hash': hash_result,
                            'nonce': block_nonce,
                            'template': template
                        }
                        
            nonce += batch_size
            
            # Update mining stats
            elapsed = time.time() - start_time
            if elapsed >= 30:  # Log every 30 seconds
                hashes_per_second = (nonce / elapsed)
                print(f"Mining at {hashes_per_second/1e6:.2f} MH/s")
                start_time = time.time()
                
        return None
        
    def _submit_block(self, block: Dict[str, Any], template: Dict[str, Any]) -> bool:
        """Submit mined block to real Bitcoin network"""
        try:
            # Create full block with transactions
            block_data = block['header']
            
            # Add transaction count
            block_data += self._encode_varint(len(template['transactions']) + 1)
            
            # Add coinbase transaction
            coinbase_tx = self._create_coinbase_tx(template)
            block_data += coinbase_tx
            
            # Add all other transactions
            for tx in template['transactions']:
                block_data += bytes.fromhex(tx['hex'])
                
            # Submit to network
            result = self.service.sendrawtransaction(block_data.hex())
            return bool(result)
            
        except Exception as e:
            print(f"Block submission failed: {str(e)}")
            return False
            
    def _calculate_merkle_root(self, transactions: list) -> str:
        """Calculate real merkle root from transactions"""
        if not transactions:
            return hashlib.sha256(hashlib.sha256(b'').digest()).digest().hex()
            
        tx_hashes = [tx['hash'] for tx in transactions]
        
        while len(tx_hashes) > 1:
            if len(tx_hashes) % 2 == 1:
                tx_hashes.append(tx_hashes[-1])
                
            next_level = []
            for i in range(0, len(tx_hashes), 2):
                combined = bytes.fromhex(tx_hashes[i] + tx_hashes[i+1])
                next_level.append(hashlib.sha256(hashlib.sha256(combined).digest()).digest().hex())
            tx_hashes = next_level
            
        return tx_hashes[0]
        
    def _bits_to_target(self, bits: str) -> int:
        """Convert bits to target"""
        bits = int(bits, 16)
        shift = bits >> 24
        target = (bits & 0x00FFFFFF) * (2 ** (8 * (shift - 3)))
        return target
        
    @staticmethod
    def _update_header_nonce(header: bytes, nonce: int) -> bytes:
        """Update nonce in block header"""
        return header[:-4] + struct.pack('<I', nonce)
        
    @staticmethod
    def _encode_varint(n: int) -> bytes:
        """Encode variable integer for Bitcoin protocol"""
        if n < 0xfd:
            return bytes([n])
        elif n <= 0xffff:
            return bytes([0xfd]) + struct.pack('<H', n)
        elif n <= 0xffffffff:
            return bytes([0xfe]) + struct.pack('<I', n)
        else:
            return bytes([0xff]) + struct.pack('<Q', n)
            
    def _create_coinbase_tx(self, template: Dict[str, Any]) -> bytes:
        """Create real coinbase transaction"""
        # Calculate block reward
        halvings = template['height'] // 210000
        reward = 50 * 100000000  # Initial reward in satoshis
        reward >>= halvings  # Divide by 2 for each halving
        
        # Create coinbase input
        tx = bytes.fromhex("01000000")  # Version
        tx += bytes([1])  # One input
        tx += bytes.fromhex("0" * 64)  # Previous output hash
        tx += struct.pack('<I', 0xFFFFFFFF)  # Previous output index
        
        # Coinbase script
        script = struct.pack('<I', template['height'])  # BIP34
        tx += self._encode_varint(len(script))
        tx += script
        
        tx += struct.pack('<I', 0xFFFFFFFF)  # Sequence
        
        # Outputs
        tx += bytes([1])  # One output
        tx += struct.pack('<Q', reward)  # Reward amount
        
        # Output script
        script = bytes.fromhex("76a914") + \
                hashlib.new('ripemd160', hashlib.sha256(self.pubkey).digest()).digest() + \
                bytes.fromhex("88ac")
        tx += self._encode_varint(len(script))
        tx += script
        
        # Locktime
        tx += struct.pack('<I', 0)
        
        return tx
