import json
from flask_cors import CORS
import os
import logging

from engine.basic_queries import basicQueries


def config(flask_app):

    # Get environment label, define conf file name
    env_label = os.environ.get('APP_ENVIRONMENT')    
    if env_label is not None and env_label!="":
        confFileName = "config_" + env_label + ".json"
    # Default
    else:
        confFileName = "basic_config.json"

    # Read configuration file
    confFileName = os.path.join(os.path.dirname(os.path.abspath(__file__)), confFileName)
    flask_app.config.from_file(confFileName, load=json.load)

    doCommonConfig(flask_app)

    # Local environment
    if flask_app.config['LOCAL_ENVIRONMENT']:
        # This will enable CORS for all routes
        CORS(flask_app)
        # CORS enabling is useful to prevent annoying CORS error when developing locally


def doCommonConfig(flask_app):

    # Config DB access
    try:
        dataConfigObject = flask_app.config['DATA_CONFIG']
        dbPath = dataConfigObject['dbPath']
        flask_app.config['DATA_CONFIG']['dbPath'] = os.path.join(flask_app.root_path, os.pardir, dbPath)
        if dataConfigObject['dynamic_occ_tables']:
            # Find the list of occurrences tables dynamically
            flask_app.config['DATA_CONFIG']['listOcc'] = get_occ_tables(flask_app.config['DATA_CONFIG'])
        else:
            if dataConfigObject.get('listOcc') is None:
                raise Exception
    except:
        raise Exception('Error in initializing data configuration')

    # Config logging
    if flask_app.config['LOGGER_CONFIG'].get('level')=='info':
        logging_level = logging.INFO
    else:
        logging_level = logging.DEBUG
    logging.basicConfig(filename = flask_app.config['LOGGER_CONFIG']['filename'],
                        filemode = 'w',
                        format = '%(asctime)s %(message)s',
                        level=logging_level)


def get_occ_tables(dataConfig):
    handler = basicQueries(dataConfig)
    all_tables = handler.queryHandler.query({'queryType': 'occ_tables'})
    occ_tables = [table['name'] for table in all_tables if table['name'].startswith('Occ')]
    return occ_tables