# 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 os
import subprocess
import logging

DEFAULT_DAGS_ZIP_NAME = 'liminal.zip'
DEFAULT_LIMINAL_HOME = os.path.expanduser('~/liminal_home')
DEFAULT_PIPELINES_SUBDIR = "pipelines"
LIMINAL_HOME_PARAM_NAME = "LIMINAL_HOME"
LIMINAL_VERSION_PARAM_NAME = 'LIMINAL_VERSION'


def get_liminal_home():
    if not os.environ.get(LIMINAL_HOME_PARAM_NAME):
        logging.info("no environment parameter called LIMINAL_HOME detected")
        logging.info(f"registering {DEFAULT_LIMINAL_HOME} as the LIMINAL_HOME directory")
        os.environ[LIMINAL_HOME_PARAM_NAME] = DEFAULT_LIMINAL_HOME
    return os.environ.get(LIMINAL_HOME_PARAM_NAME, DEFAULT_LIMINAL_HOME)


def get_dags_dir():
    # if we are inside airflow, we will take it from the configured dags folder
    base_dir = os.environ.get("AIRFLOW__CORE__DAGS_FOLDER", get_liminal_home())
    return os.path.join(base_dir, DEFAULT_PIPELINES_SUBDIR)


def get_liminal_version():
    result = os.environ.get(LIMINAL_VERSION_PARAM_NAME, None)
    if not result:
        output = subprocess.run(['pip freeze | grep \'apache-liminal\''], capture_output=True,
                                env=os.environ, shell=True)
        pip_res = output.stdout.decode('UTF-8').strip()
        scripts_dir = os.path.join(
            os.path.dirname(os.path.dirname(os.path.dirname(__file__))),
            'scripts'
        )
        whl_files = [file for file in os.listdir(scripts_dir) if file.endswith(".whl")]
        if whl_files:
            value = 'file://' + os.path.join(scripts_dir, whl_files[0])
        elif ' @ ' in pip_res:
            value = pip_res[pip_res.index(' @ ') + 3:]
        else:
            value = pip_res
        logging.info(f'LIMINAL_VERSION not set. Setting it to currently installed version: {value}')
        os.environ[LIMINAL_VERSION_PARAM_NAME] = value
    return os.environ.get(LIMINAL_VERSION_PARAM_NAME, 'apache-liminal')