# Copyright 2022-2023 ETSI TeraFlowSDN - TFS OSG (https://tfs.etsi.org/)
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import logging, time
from sqlalchemy.orm import sessionmaker
from sqlalchemy.ext.declarative import declarative_base
from telemetry.database.TelemetryEngine import TelemetryEngine


LOGGER = logging.getLogger(__name__)
TELEMETRY_DB_NAME = "telemetryfrontend"

# Create a base class for declarative models
Base = declarative_base()

class managementDB:
    def __init__(self):
        self.db_engine = TelemetryEngine.get_engine()
        if self.db_engine is None:
            LOGGER.error('Unable to get SQLAlchemy DB Engine...')
            return False
        self.db_name = TELEMETRY_DB_NAME
        self.Session = sessionmaker(bind=self.db_engine)

    def create_database(self):
        try:
            with self.db_engine.connect() as connection:
                connection.execute(f"CREATE DATABASE {self.db_name};")
            LOGGER.info('managementDB initalizes database. Name: {self.db_name}')
            return True
        except: 
            LOGGER.exception('Failed to check/create the database: {:s}'.format(str(self.db_engine.url)))
            return False
    
    def create_tables(self):
        try:
            Base.metadata.create_all(self.db_engine)     # type: ignore
            LOGGER.info("Tables created in the DB Name: {:}".format(self.db_name))
        except Exception as e:
            LOGGER.info("Tables cannot be created in the TelemetryFrontend database. {:s}".format(str(e)))

    def verify_tables(self):
        try:
            with self.db_engine.connect() as connection:
                result = connection.execute("SHOW TABLES;")
                tables = result.fetchall()      # type: ignore
                LOGGER.info("Tables verified: {:}".format(tables))
        except Exception as e:
            LOGGER.info("Unable to fetch Table names. {:s}".format(str(e)))

    def add_row_to_db(self, row):
        session = self.Session()
        try:
            session.add(row)
            session.commit()
            LOGGER.info(f"Row inserted into {row.__class__.__name__} table. {row.__class__.__name__} Id: : {row.collector_id}")
        except Exception as e:
            session.rollback()
            LOGGER.error(f"Failed to insert new row into {row.__class__.__name__} table. {str(e)}")
        finally:
            session.close()