{
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   "cell_type": "markdown",
   "metadata": {
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    "id": "ahN2Nw9ppq2Y"
   },
   "source": [
    "# Cryptocurrency Lottery\n",
    "\n",
    "Jagraj Singh"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Instructions\n",
    "\n",
    "1.) Click Run > Run All Cells.\n",
    "\n",
    "2.) Go to the last cell.\n",
    "\n",
    "3.) If you find a wallet with a nonzero balance, send me some! "
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "colab_type": "text",
    "id": "TTQFY207WTPz"
   },
   "source": [
    "## Setup"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 17,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "qZa1DEL-qgrm"
   },
   "outputs": [],
   "source": [
    "import ast\n",
    "import codecs\n",
    "import ecdsa\n",
    "from hashlib import sha256\n",
    "from Crypto.Hash import keccak\n",
    "import requests\n",
    "\n",
    "# Test Key\n",
    "api_key = '7Z99TEIBCGR4H7ACKNBU41IUY9QJGTCA82'"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "colab_type": "text",
    "id": "cq9vbuAwWVDK"
   },
   "source": [
    "## Code"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 18,
   "metadata": {
    "code_folding": [
     1,
     9,
     20,
     34,
     54
    ],
    "colab": {},
    "colab_type": "code",
    "id": "gHPjBOjHvirx"
   },
   "outputs": [],
   "source": [
    "\n",
    "def private_key_from_string(msg):\n",
    "    '''\n",
    "    Applies the SHA256 hash function to the input string which creates a cryptocurrency private key.\n",
    "    '''\n",
    "    \n",
    "    private_key = sha256(msg.encode()).hexdigest()\n",
    "    return private_key\n",
    "\n",
    "def public_key_from_private_key(private_key):\n",
    "    '''\n",
    "    Converts the private key to a public key.\n",
    "    '''\n",
    "\n",
    "    private_key_bytes = codecs.decode(private_key, 'hex')\n",
    "    key = ecdsa.SigningKey.from_string(private_key_bytes, curve=ecdsa.SECP256k1).verifying_key\n",
    "    key_bytes = key.to_string()\n",
    "    public_key = codecs.encode(key_bytes, 'hex')\n",
    "    return public_key\n",
    "\n",
    "def address_from_public_key(public_key):\n",
    "    '''\n",
    "    Converts the public key to an Ethereum wallet address with checksum.\n",
    "    '''\n",
    "\n",
    "    public_key_bytes = codecs.decode(public_key, 'hex')\n",
    "    keccak_hash = keccak.new(digest_bits=256)\n",
    "    keccak_hash.update(public_key_bytes)\n",
    "    keccak_digest = keccak_hash.hexdigest()\n",
    "    # Take the last 20 bytes\n",
    "    wallet_len = 40\n",
    "    wallet = '0x' + keccak_digest[-wallet_len:]\n",
    "    return wallet\n",
    "\n",
    "def get_balance(url):\n",
    "    '''\n",
    "    Checks the balance of the Ethereum address using the Etherscan API. \n",
    "    If the balance is 0, you did not win.\n",
    "    If the balance is nonzero, you win!\n",
    "    '''\n",
    "    \n",
    "    try:\n",
    "        response = requests.get(url)\n",
    "        status = response.status_code\n",
    "        if response.status_code == 200:\n",
    "            response = response.text\n",
    "            response = ast.literal_eval(response)\n",
    "            balance = int(response['result'])\n",
    "            return balance * 10**(-18)\n",
    "        else:\n",
    "            print('An error has occurred.')\n",
    "    except:\n",
    "        print('An error has occurred.')\n",
    "    \n",
    "def play():\n",
    "    '''\n",
    "    Asks the user for an input string.\n",
    "    Converts the string to a private key, public key, wallet address, and then checks the balance of that address.\n",
    "    Prints a win/lose statement along with wallet info (balance, address, and private key).\n",
    "    Asks the user if they want to play again.\n",
    "    '''\n",
    "\n",
    "    print('Welcome to the Ethereum Lottery! \\nYour chance of winning is about 1 in 10^70 (essentially zero), but don\\'t let that stop you!')\n",
    "\n",
    "    playing = True\n",
    "    while playing:\n",
    "\n",
    "\n",
    "        msg = input('\\nSimply enter some text and hit Enter: ')\n",
    "        private_key = private_key_from_string(msg)\n",
    "        public_key = public_key_from_private_key(private_key)\n",
    "        address = address_from_public_key(public_key)\n",
    "        url = 'https://api.etherscan.io/api?module=account&action=balance&address=' + address + '&tag=latest&apikey=' + api_key\n",
    "        balance = get_balance(url)\n",
    "        \n",
    "        if balance == 0:\n",
    "            print(\"\\nSorry, you lost...\")\n",
    "        else:\n",
    "            print('Congratulations! You won!')\n",
    "        print('\\nWallet Information', '\\nBalance: ' + str(balance), '\\nAddress: ' + address, '\\nPrivate Key: ' + private_key)\n",
    "\n",
    "        again = input(\"\\nWould you like to play again? Enter 'y' or 'n' \")\n",
    "\n",
    "        if again and again[0].lower() == 'y':\n",
    "            playing = True\n",
    "            continue\n",
    "        else:\n",
    "            print('\\nThanks for playing!')\n",
    "            break\n"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "colab_type": "text",
    "id": "i7p1Av7JRotl"
   },
   "source": [
    "## Ethereum Lottery"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "IvjPdi6RMCkS",
    "scrolled": false
   },
   "outputs": [],
   "source": [
    "play()"
   ]
  }
 ],
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