import logging

from flask import abort, request

from config_app.config_endpoints.api.suconfig_models_pre_oci import pre_oci_model as model
from config_app.config_endpoints.api import resource, ApiResource, nickname, validate_json_request
from config_app.c_app import (app, config_provider, superusers, ip_resolver,
                              instance_keys, INIT_SCRIPTS_LOCATION)

from data.database import configure
from data.runmigration import run_alembic_migration
from util.config.configutil import add_enterprise_config_defaults
from util.config.validator import validate_service_for_config, ValidatorContext, \
  is_valid_config_upload_filename

logger = logging.getLogger(__name__)


def database_is_valid():
  """ Returns whether the database, as configured, is valid. """
  return model.is_valid()


def database_has_users():
  """ Returns whether the database has any users defined. """
  return model.has_users()


@resource('/v1/superuser/config')
class SuperUserConfig(ApiResource):
  """ Resource for fetching and updating the current configuration, if any. """
  schemas = {
    'UpdateConfig': {
      'type': 'object',
      'description': 'Updates the YAML config file',
      'required': [
        'config',
      ],
      'properties': {
        'config': {
          'type': 'object'
        },
        'password': {
          'type': 'string'
        },
      },
    },
  }

  @nickname('scGetConfig')
  def get(self):
    """ Returns the currently defined configuration, if any. """
    config_object = config_provider.get_config()
    return {
      'config': config_object
    }

  @nickname('scUpdateConfig')
  @validate_json_request('UpdateConfig')
  def put(self):
    """ Updates the config override file. """
    # Note: This method is called to set the database configuration before super users exists,
    # so we also allow it to be called if there is no valid registry configuration setup.
    config_object = request.get_json()['config']

    # Add any enterprise defaults missing from the config.
    add_enterprise_config_defaults(config_object, app.config['SECRET_KEY'])

    # Write the configuration changes to the config override file.
    config_provider.save_config(config_object)

    # now try to connect to the db provided in their config to validate it works
    combined = dict(**app.config)
    combined.update(config_provider.get_config())
    configure(combined, testing=app.config['TESTING'])

    return {
      'exists': True,
      'config': config_object
    }


@resource('/v1/superuser/registrystatus')
class SuperUserRegistryStatus(ApiResource):
  """ Resource for determining the status of the registry, such as if config exists,
      if a database is configured, and if it has any defined users.
  """

  @nickname('scRegistryStatus')
  def get(self):
    """ Returns the status of the registry. """

    # If there is no config file, we need to setup the database.
    if not config_provider.config_exists():
      return {
        'status': 'config-db'
      }

    # If the database isn't yet valid, then we need to set it up.
    if not database_is_valid():
      return {
        'status': 'setup-db'
      }

    return {
      'status': 'create-superuser' if not database_has_users() else 'config'
    }


class _AlembicLogHandler(logging.Handler):
  def __init__(self):
    super(_AlembicLogHandler, self).__init__()
    self.records = []

  def emit(self, record):
    self.records.append({
      'level': record.levelname,
      'message': record.getMessage()
    })


@resource('/v1/superuser/setupdb')
class SuperUserSetupDatabase(ApiResource):
  """ Resource for invoking alembic to setup the database. """

  @nickname('scSetupDatabase')
  def get(self):
    """ Invokes the alembic upgrade process. """
    # Note: This method is called after the database configured is saved, but before the
    # database has any tables. Therefore, we only allow it to be run in that unique case.
    if config_provider.config_exists() and not database_is_valid():
      # Note: We need to reconfigure the database here as the config has changed.
      combined = dict(**app.config)
      combined.update(config_provider.get_config())

      configure(combined)
      app.config['DB_URI'] = combined['DB_URI']
      db_uri = app.config['DB_URI']

      log_handler = _AlembicLogHandler()

      try:
        run_alembic_migration(db_uri, log_handler, setup_app=False)
      except Exception as ex:
        return {
          'error': str(ex)
        }

      return {
        'logs': log_handler.records
      }

    abort(403)


@resource('/v1/superuser/config/createsuperuser')
class SuperUserCreateInitialSuperUser(ApiResource):
  """ Resource for creating the initial super user. """
  schemas = {
    'CreateSuperUser': {
      'type': 'object',
      'description': 'Information for creating the initial super user',
      'required': [
        'username',
        'password',
        'email'
      ],
      'properties': {
        'username': {
          'type': 'string',
          'description': 'The username for the superuser'
        },
        'password': {
          'type': 'string',
          'description': 'The password for the superuser'
        },
        'email': {
          'type': 'string',
          'description': 'The e-mail address for the superuser'
        },
      },
    },
  }

  @nickname('scCreateInitialSuperuser')
  @validate_json_request('CreateSuperUser')
  def post(self):
    """ Creates the initial super user, updates the underlying configuration and
        sets the current session to have that super user. """

    # Special security check: This method is only accessible when:
    #   - There is a valid config YAML file.
    #   - There are currently no users in the database (clean install)
    #
    # We do this special security check because at the point this method is called, the database
    # is clean but does not (yet) have any super users for our permissions code to check against.
    if config_provider.config_exists() and not database_has_users():
      data = request.get_json()
      username = data['username']
      password = data['password']
      email = data['email']

      # Create the user in the database.
      superuser_uuid = model.create_superuser(username, password, email)

      # Add the user to the config.
      config_object = config_provider.get_config()
      config_object['SUPER_USERS'] = [username]
      config_provider.save_config(config_object)

      # Update the in-memory config for the new superuser.
      # TODO(config): do we need to register a list of the superusers? If so, we can take out the entire superuser in c_app
      superusers.register_superuser(username)

      # Conduct login with that user.
      # TODO(config): figure out if we need validation for checking logged in user stuff
      # common_login(superuser_uuid)

      return {
        'status': True
      }

    abort(403)


@resource('/v1/superuser/config/validate/<service>')
class SuperUserConfigValidate(ApiResource):
  """ Resource for validating a block of configuration against an external service. """
  schemas = {
    'ValidateConfig': {
      'type': 'object',
      'description': 'Validates configuration',
      'required': [
        'config'
      ],
      'properties': {
        'config': {
          'type': 'object'
        },
        'password': {
          'type': 'string',
          'description': 'The users password, used for auth validation'
        }
      },
    },
  }

  @nickname('scValidateConfig')
  @validate_json_request('ValidateConfig')
  def post(self, service):
    """ Validates the given config for the given service. """
    # Note: This method is called to validate the database configuration before super users exists,
    # so we also allow it to be called if there is no valid registry configuration setup. Note that
    # this is also safe since this method does not access any information not given in the request.
    config = request.get_json()['config']
    validator_context = ValidatorContext.from_app(app, config,
                                                  request.get_json().get('password', ''),
                                                  instance_keys=instance_keys,
                                                  ip_resolver=ip_resolver,
                                                  config_provider=config_provider,
                                                  init_scripts_location=INIT_SCRIPTS_LOCATION)

    return validate_service_for_config(service, validator_context)


@resource('/v1/superuser/config/file/<filename>')
class SuperUserConfigFile(ApiResource):
  """ Resource for fetching the status of config files and overriding them. """

  @nickname('scConfigFileExists')
  def get(self, filename):
    """ Returns whether the configuration file with the given name exists. """
    if not is_valid_config_upload_filename(filename):
      abort(404)

    return {
      'exists': config_provider.volume_file_exists(filename)
    }

  @nickname('scUpdateConfigFile')
  def post(self, filename):
    """ Updates the configuration file with the given name. """
    if not is_valid_config_upload_filename(filename):
      abort(404)

    # Note: This method can be called before the configuration exists
    # to upload the database SSL cert.
    uploaded_file = request.files['file']
    if not uploaded_file:
      abort(400)

    config_provider.save_volume_file(filename, uploaded_file)
    return {
      'status': True
    }