from google.cloud import kms_v1
from base64 import b64encode, b64decode
from Crypto.Cipher import AES
from Crypto.Random import get_random_bytes
import random
import time
from flask import Flask
import os
import ast


def generate_api_key(prefix="EveAI-Chat"):
    parts = [str(random.randint(1000, 9999)) for _ in range(5)]
    return f"{prefix}-{'-'.join(parts)}"


class JosKMSClient(kms_v1.KeyManagementServiceClient):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.key_name = None
        self.crypto_key = None
        self.key_ring = None
        self.location = None
        self.project_id = None

    def init_app(self, app: Flask):
        self.project_id = app.config.get('GC_PROJECT_NAME')
        self.location = app.config.get('GC_LOCATION')
        self.key_ring = app.config.get('GC_KEY_RING')
        self.crypto_key = app.config.get('GC_CRYPTO_KEY')
        self.key_name = self.crypto_key_path(self.project_id, self.location, self.key_ring, self.crypto_key)
        app.logger.info(f'Project ID: {self.project_id}')
        app.logger.info(f'Location: {self.location}')
        app.logger.info(f'Key Ring: {self.key_ring}')
        app.logger.info(f'Crypto Key: {self.crypto_key}')
        app.logger.info(f'Key Name: {self.key_name}')

        app.logger.info(f'Service Account Key Path: {os.getenv('GOOGLE_APPLICATION_CREDENTIALS')}')

        os.environ["GOOGLE_CLOUD_PROJECT"] = self.project_id

    def encrypt_api_key(self, api_key):
        """Encrypts the API key using the latest version of the KEK."""
        dek = get_random_bytes(32)  # AES 256-bit key
        cipher = AES.new(dek, AES.MODE_GCM)
        ciphertext, tag = cipher.encrypt_and_digest(api_key.encode())
        # print(f'Dek: {dek}')

        # Encrypt the DEK using the latest version of the Google Cloud KMS key
        encrypt_response = self.encrypt(
            request={'name': self.key_name, 'plaintext': dek}
        )
        encrypted_dek = encrypt_response.ciphertext
        # print(f"Encrypted DEK: {encrypted_dek}")
        #
        # # Check
        # decrypt_response = self.decrypt(
        #     request={'name': self.key_name, 'ciphertext': encrypted_dek}
        # )
        # decrypted_dek = decrypt_response.plaintext
        # print(f"Decrypted DEK: {decrypted_dek}")

        # Store the version of the key used
        key_version = encrypt_response.name

        return {
            'key_version': key_version,
            'encrypted_dek': b64encode(encrypted_dek).decode('utf-8'),
            'nonce': b64encode(cipher.nonce).decode('utf-8'),
            'tag': b64encode(tag).decode('utf-8'),
            'ciphertext': b64encode(ciphertext).decode('utf-8')
        }

    def decrypt_api_key(self, encrypted_data):
        """Decrypts the API key using the specified key version."""
        if isinstance(encrypted_data, str):
            encrypted_data = ast.literal_eval(encrypted_data)
        key_version = encrypted_data['key_version']
        key_name = self.key_name
        encrypted_dek = b64decode(encrypted_data['encrypted_dek'].encode('utf-8'))
        nonce = b64decode(encrypted_data['nonce'].encode('utf-8'))
        tag = b64decode(encrypted_data['tag'].encode('utf-8'))
        ciphertext = b64decode(encrypted_data['ciphertext'].encode('utf-8'))

        # Decrypt the DEK using the specified version of the Google Cloud KMS key
        try:
            decrypt_response = self.decrypt(
                request={'name': key_name, 'ciphertext': encrypted_dek}
            )
            dek = decrypt_response.plaintext
        except Exception as e:
            print(f"Failed to decrypt DEK: {e}")
            return None

        cipher = AES.new(dek, AES.MODE_GCM, nonce=nonce)
        api_key = cipher.decrypt_and_verify(ciphertext, tag)
        return api_key.decode()

    def check_kms_access_and_latency(self):
        # key_name = self.crypto_key_path(self.project_id, self.location, self.key_ring, self.crypto_key)
        #
        # start_time = time.time()
        # try:
        #     response = self.get_crypto_key(name=key_name)
        #     end_time = time.time()
        #     print(f"Response Time: {end_time - start_time} seconds")
        #     print("Access to KMS is successful.")
        # except Exception as e:
        #     print(f"Failed to access KMS: {e}")
        pass