#!/usr/bin/env python3
"""
Simple wallet operations for AITBC blockchain
Compatible with existing keystore structure
"""

import json
import sys
import os
import argparse
from pathlib import Path
from cryptography.hazmat.primitives.asymmetric import ed25519
from cryptography.hazmat.primitives.ciphers.aead import AESGCM
from cryptography.hazmat.primitives.kdf.pbkdf2 import PBKDF2HMAC
from cryptography.hazmat.primitives import hashes
import requests
from typing import Optional

# Default paths
DEFAULT_KEYSTORE_DIR = Path("/var/lib/aitbc/keystore")
DEFAULT_RPC_URL = "http://localhost:8006"


def decrypt_private_key(keystore_path: Path, password: str) -> str:
    """Decrypt private key from keystore file"""
    with open(keystore_path) as f:
        ks = json.load(f)
    
    crypto = ks['crypto']
    salt = bytes.fromhex(crypto['kdfparams']['salt'])
    kdf = PBKDF2HMAC(hashes.SHA256(), 32, salt, crypto['kdfparams']['c'])
    key = kdf.derive(password.encode())
    aesgcm = AESGCM(key)
    nonce = bytes.fromhex(crypto['cipherparams']['nonce'])
    priv = aesgcm.decrypt(nonce, bytes.fromhex(crypto['ciphertext']), None)
    return priv.hex()


def create_wallet(name: str, password: str, keystore_dir: Path = DEFAULT_KEYSTORE_DIR) -> str:
    """Create a new wallet"""
    keystore_dir.mkdir(parents=True, exist_ok=True)
    
    # Generate new key pair
    private_key = ed25519.Ed25519PrivateKey.generate()
    private_key_hex = private_key.private_bytes_raw().hex()
    public_key = private_key.public_key()
    public_key_hex = public_key.public_bytes_raw().hex()
    
    # Calculate address (simplified - in real implementation this would be more complex)
    address = f"ait1{public_key_hex[:40]}"
    
    # Encrypt private key
    salt = os.urandom(32)
    kdf = PBKDF2HMAC(hashes.SHA256(), 32, salt, 100000)
    key = kdf.derive(password.encode())
    aesgcm = AESGCM(key)
    nonce = os.urandom(12)
    ciphertext = aesgcm.encrypt(nonce, bytes.fromhex(private_key_hex), None)
    
    # Create keystore file
    keystore_data = {
        "address": address,
        "public_key": public_key_hex,
        "crypto": {
            "kdf": "pbkdf2",
            "kdfparams": {
                "salt": salt.hex(),
                "c": 100000,
                "dklen": 32,
                "prf": "hmac-sha256"
            },
            "cipher": "aes-256-gcm",
            "cipherparams": {
                "nonce": nonce.hex()
            },
            "ciphertext": ciphertext.hex()
        },
        "version": 1
    }
    
    keystore_path = keystore_dir / f"{name}.json"
    with open(keystore_path, 'w') as f:
        json.dump(keystore_data, f, indent=2)
    
    print(f"Wallet created: {name}")
    print(f"Address: {address}")
    print(f"Keystore: {keystore_path}")
    
    return address


def send_transaction(from_wallet: str, to_address: str, amount: float, fee: float, 
                   password: str, keystore_dir: Path = DEFAULT_KEYSTORE_DIR, 
                   rpc_url: str = DEFAULT_RPC_URL) -> Optional[str]:
    """Send transaction from one wallet to another"""
    
    # Get sender wallet info
    sender_keystore = keystore_dir / f"{from_wallet}.json"
    if not sender_keystore.exists():
        print(f"Error: Wallet '{from_wallet}' not found")
        return None
    
    with open(sender_keystore) as f:
        sender_data = json.load(f)
    
    sender_address = sender_data['address']
    
    # Decrypt private key
    try:
        private_key_hex = decrypt_private_key(sender_keystore, password)
        private_key = ed25519.Ed25519PrivateKey.from_private_bytes(bytes.fromhex(private_key_hex))
    except Exception as e:
        print(f"Error decrypting wallet: {e}")
        return None
    
    # Create transaction
    transaction = {
        "sender": sender_address,
        "recipient": to_address,
        "value": int(amount),
        "fee": int(fee),
        "nonce": 0,  # In real implementation, get current nonce
        "type": "transfer",
        "payload": {}
    }
    
    # Sign transaction (simplified)
    message = json.dumps(transaction, sort_keys=True).encode()
    signature = private_key.sign(message)
    transaction["signature"] = signature.hex()
    
    # Submit transaction
    try:
        response = requests.post(f"{rpc_url}/sendTx", json=transaction)
        if response.status_code == 200:
            result = response.json()
            print(f"Transaction submitted successfully")
            print(f"From: {sender_address}")
            print(f"To: {to_address}")
            print(f"Amount: {amount} AIT")
            print(f"Fee: {fee} AIT")
            return result.get("hash")
        else:
            print(f"Error submitting transaction: {response.text}")
            return None
    except Exception as e:
        print(f"Error: {e}")
        return None


def list_wallets(keystore_dir: Path = DEFAULT_KEYSTORE_DIR) -> list:
    """List all wallets"""
    wallets = []
    if keystore_dir.exists():
        for wallet_file in keystore_dir.glob("*.json"):
            try:
                with open(wallet_file) as f:
                    data = json.load(f)
                wallets.append({
                    "name": wallet_file.stem,
                    "address": data["address"],
                    "file": str(wallet_file)
                })
            except Exception:
                pass
    return wallets


def main():
    parser = argparse.ArgumentParser(description="AITBC Wallet CLI")
    subparsers = parser.add_subparsers(dest="command", help="Available commands")
    
    # Create wallet command
    create_parser = subparsers.add_parser("create", help="Create a new wallet")
    create_parser.add_argument("--name", required=True, help="Wallet name")
    create_parser.add_argument("--password", help="Wallet password")
    create_parser.add_argument("--password-file", help="File containing wallet password")
    
    # Send transaction command
    send_parser = subparsers.add_parser("send", help="Send AIT")
    send_parser.add_argument("--from", required=True, dest="from_wallet", help="From wallet name")
    send_parser.add_argument("--to", required=True, dest="to_address", help="To address")
    send_parser.add_argument("--amount", type=float, required=True, help="Amount to send")
    send_parser.add_argument("--fee", type=float, default=10.0, help="Transaction fee")
    send_parser.add_argument("--password", help="Wallet password")
    send_parser.add_argument("--password-file", help="File containing wallet password")
    send_parser.add_argument("--rpc-url", default=DEFAULT_RPC_URL, help="RPC URL")
    
    # List wallets command
    list_parser = subparsers.add_parser("list", help="List wallets")
    list_parser.add_argument("--format", choices=["table", "json"], default="table", help="Output format")
    
    args = parser.parse_args()
    
    if args.command == "create":
        # Get password
        password = None
        if args.password:
            password = args.password
        elif args.password_file:
            with open(args.password_file) as f:
                password = f.read().strip()
        else:
            import getpass
            password = getpass.getpass("Enter wallet password: ")
        
        if not password:
            print("Error: Password is required")
            sys.exit(1)
        
        address = create_wallet(args.name, password)
        print(f"Wallet address: {address}")
    
    elif args.command == "send":
        # Get password
        password = None
        if args.password:
            password = args.password
        elif args.password_file:
            with open(args.password_file) as f:
                password = f.read().strip()
        else:
            import getpass
            password = getpass.getpass(f"Enter password for wallet '{args.from_wallet}': ")
        
        if not password:
            print("Error: Password is required")
            sys.exit(1)
        
        tx_hash = send_transaction(
            args.from_wallet, 
            args.to_address, 
            args.amount, 
            args.fee, 
            password,
            rpc_url=args.rpc_url
        )
        
        if tx_hash:
            print(f"Transaction hash: {tx_hash}")
        else:
            sys.exit(1)
    
    elif args.command == "list":
        wallets = list_wallets()
        
        if args.format == "json":
            print(json.dumps(wallets, indent=2))
        else:
            print("Wallets:")
            for wallet in wallets:
                print(f"  {wallet['name']}: {wallet['address']}")
    
    else:
        parser.print_help()


if __name__ == "__main__":
    main()