import logging

import peewee

from flask import Flask

from app import app, config_provider, get_app_url, OVERRIDE_CONFIG_DIRECTORY
from auth.auth_context import get_authenticated_user
from bitbucket import BitBucket
from data.database import validate_database_url
from data.users import LDAP_CERT_FILENAME
from oauth.services.github import GithubOAuthService
from oauth.services.google import GoogleOAuthService
from oauth.services.gitlab import GitLabOAuthService

from util.config.validators.validate_database import DatabaseValidator
from util.config.validators.validate_redis import RedisValidator
from util.config.validators.validate_storage import StorageValidator
from util.config.validators.validate_email import EmailValidator
from util.config.validators.validate_ldap import LDAPValidator
from util.config.validators.validate_keystone import KeystoneValidator
from util.config.validators.validate_jwt import JWTAuthValidator
from util.config.validators.validate_secscan import SecurityScannerValidator
from util.config.validators.validate_signer import SignerValidator
from util.config.validators.validate_torrent import BittorrentValidator
from util.config.validators.validate_ssl import SSLValidator, SSL_FILENAMES

logger = logging.getLogger(__name__)

class ConfigValidationException(Exception):
  """ Exception raised when the configuration fails to validate for a known reason. """
  pass


# Note: Only add files required for HTTPS to the SSL_FILESNAMES list.
DB_SSL_FILENAMES = ['database.pem']
JWT_FILENAMES = ['jwt-authn.cert']
ACI_CERT_FILENAMES = ['signing-public.gpg', 'signing-private.gpg']
LDAP_FILENAMES = [LDAP_CERT_FILENAME]
CONFIG_FILENAMES = (SSL_FILENAMES + DB_SSL_FILENAMES + JWT_FILENAMES + ACI_CERT_FILENAMES +
                    LDAP_FILENAMES)
EXTRA_CA_DIRECTORY = 'extra_ca_certs'


def validate_service_for_config(service, config, password=None):
  """ Attempts to validate the configuration for the given service. """
  if not service in VALIDATORS:
    return {
      'status': False
    }

  try:
    VALIDATORS[service](config, get_authenticated_user(), password)
    return {
      'status': True
    }
  except Exception as ex:
    logger.exception('Validation exception')
    return {
      'status': False,
      'reason': str(ex)
    }


def _validate_database(config, user_obj, _):
  """ Validates connecting to the database. """
  try:
    validate_database_url(config['DB_URI'], config.get('DB_CONNECTION_ARGS', {}))
  except peewee.OperationalError as ex:
    if ex.args and len(ex.args) > 1:
      raise ConfigValidationException(ex.args[1])
    else:
      raise ex


def _validate_gitlab(config, user_obj, _):
  """ Validates the OAuth credentials and API endpoint for a GitLab service. """
  github_config = config.get('GITLAB_TRIGGER_CONFIG')
  if not github_config:
    raise ConfigValidationException('Missing GitLab client id and client secret')

  endpoint = github_config.get('GITLAB_ENDPOINT')
  if not endpoint:
    raise ConfigValidationException('Missing GitLab Endpoint')

  if endpoint.find('http://') != 0 and endpoint.find('https://') != 0:
    raise ConfigValidationException('GitLab Endpoint must start with http:// or https://')

  if not github_config.get('CLIENT_ID'):
    raise ConfigValidationException('Missing Client ID')

  if not github_config.get('CLIENT_SECRET'):
    raise ConfigValidationException('Missing Client Secret')

  client = app.config['HTTPCLIENT']
  oauth = GitLabOAuthService(config, 'GITLAB_TRIGGER_CONFIG')
  result = oauth.validate_client_id_and_secret(client, app.config)
  if not result:
    raise ConfigValidationException('Invalid client id or client secret')


def _validate_github(config_key):
  return lambda config, user_obj, _: _validate_github_with_key(config_key, config)


def _validate_github_with_key(config_key, config):
  """ Validates the OAuth credentials and API endpoint for a Github service. """
  github_config = config.get(config_key)
  if not github_config:
    raise ConfigValidationException('Missing GitHub client id and client secret')

  endpoint = github_config.get('GITHUB_ENDPOINT')
  if not endpoint:
    raise ConfigValidationException('Missing GitHub Endpoint')

  if endpoint.find('http://') != 0 and endpoint.find('https://') != 0:
    raise ConfigValidationException('Github Endpoint must start with http:// or https://')

  if not github_config.get('CLIENT_ID'):
    raise ConfigValidationException('Missing Client ID')

  if not github_config.get('CLIENT_SECRET'):
    raise ConfigValidationException('Missing Client Secret')

  if github_config.get('ORG_RESTRICT') and not github_config.get('ALLOWED_ORGANIZATIONS'):
    raise ConfigValidationException('Organization restriction must have at least one allowed ' +
                                    'organization')

  client = app.config['HTTPCLIENT']
  oauth = GithubOAuthService(config, config_key)
  result = oauth.validate_client_id_and_secret(client, app.config)
  if not result:
    raise ConfigValidationException('Invalid client id or client secret')

  if github_config.get('ALLOWED_ORGANIZATIONS'):
    for org_id in github_config.get('ALLOWED_ORGANIZATIONS'):
      if not oauth.validate_organization(org_id, client):
        raise ConfigValidationException('Invalid organization: %s' % org_id)


def _validate_bitbucket(config, user_obj, _):
  """ Validates the config for BitBucket. """
  trigger_config = config.get('BITBUCKET_TRIGGER_CONFIG')
  if not trigger_config:
    raise ConfigValidationException('Missing client ID and client secret')

  if not trigger_config.get('CONSUMER_KEY'):
    raise ConfigValidationException('Missing Consumer Key')

  if not trigger_config.get('CONSUMER_SECRET'):
    raise ConfigValidationException('Missing Consumer Secret')

  key = trigger_config['CONSUMER_KEY']
  secret = trigger_config['CONSUMER_SECRET']
  callback_url = '%s/oauth1/bitbucket/callback/trigger/' % (get_app_url())

  bitbucket_client = BitBucket(key, secret, callback_url)
  (result, _, _) = bitbucket_client.get_authorization_url()
  if not result:
    raise ConfigValidationException('Invalid consumer key or secret')


def _validate_google_login(config, user_obj, _):
  """ Validates the Google Login client ID and secret. """
  google_login_config = config.get('GOOGLE_LOGIN_CONFIG')
  if not google_login_config:
    raise ConfigValidationException('Missing client ID and client secret')

  if not google_login_config.get('CLIENT_ID'):
    raise ConfigValidationException('Missing Client ID')

  if not google_login_config.get('CLIENT_SECRET'):
    raise ConfigValidationException('Missing Client Secret')

  client = app.config['HTTPCLIENT']
  oauth = GoogleOAuthService(config, 'GOOGLE_LOGIN_CONFIG')
  result = oauth.validate_client_id_and_secret(client, app.config)
  if not result:
    raise ConfigValidationException('Invalid client id or client secret')


VALIDATORS = {
  DatabaseValidator.name: DatabaseValidator.validate,
  RedisValidator.name: RedisValidator.validate,
  StorageValidator.name: StorageValidator.validate,
  EmailValidator.name: EmailValidator.validate,
  'github-login': _validate_github('GITHUB_LOGIN_CONFIG'),
  'github-trigger': _validate_github('GITHUB_TRIGGER_CONFIG'),
  'gitlab-trigger': _validate_gitlab,
  'bitbucket-trigger': _validate_bitbucket,
  'google-login': _validate_google_login,
  SSLValidator.name: SSLValidator.validate,
  LDAPValidator.name: LDAPValidator.validate,
  JWTAuthValidator.name: JWTAuthValidator.validate,
  KeystoneValidator.name: KeystoneValidator.validate,
  SignerValidator.name: SignerValidator.validate,
  SecurityScannerValidator.name: SecurityScannerValidator.validate,
  BittorrentValidator.name: BittorrentValidator.validate,
}