import os
import sys

from flask import Flask
from flask_login import LoginManager

import logging
from logging.handlers import RotatingFileHandler
from flask.logging import default_handler

from app.models import db
from app.auth.models import User

from dotenv import load_dotenv

app_dir = os.path.join(os.path.abspath(os.path.dirname(__file__)), '..')
env_file = os.path.join(app_dir, ".flaskenv")
load_dotenv(env_file, verbose=True)

login_manager = LoginManager()

login_manager.login_view = "auth.login"
login_manager.login_message = "Veuillez vous connecter s'il vous plait"


@login_manager.user_loader
def load_user(user_id):
    return User.query.get(int(user_id))


# TODO: move the following into create_app()
#  and use app.logger system
# Please, set a config file on top project dir
# see in ../pdc_config.py
try:
    from pdc_config import Config, ProdConfig, DevConfig, TestConfig
except ImportError:
    print("Please set a pdc_config.py file in you PYTHON_PATH")
    print("See INSTALL.md for more info")
    sys.exit(-1)


def create_app(config_class=None):
    """ App Factory.
    can be called with configuration class as argument.
    """

    # Configuration Switcher
    # try to set configuration depending on environment
    # if no configuration class was given
    #
    if config_class is None:
        flask_env = os.environ.get('FLASK_ENV')
        if not flask_env:
            flask_env = 'testing'

        if flask_env == 'production':
            config_class = ProdConfig
        elif flask_env == 'development':
            config_class = DevConfig
        elif flask_env == 'testing':
            config_class = TestConfig
        else:
            config_class = Config

    # Main flask app
    #
    app = Flask(__name__)
    app.config.from_object(config_class)

    # Log to stdout or to file
    #
    app.logger.removeHandler(default_handler)
    if app.debug or app.testing or app.config['LOG_TO_STDOUT']:
        log_handler = logging.StreamHandler()
    else:
        logs_file = app.config['PDC_LOGS_FILE']
        logs_dir = os.path.dirname(logs_file)
        if not os.path.exists(logs_dir):
            os.mkdir(logs_dir)
        log_handler = RotatingFileHandler(logs_file, maxBytes=10240, backupCount=10)

    log_handler.setFormatter(logging.Formatter(
        '%(asctime)s %(levelname)s: %(message)s [in %(pathname)s:%(lineno)d]'))
    app.logger.addHandler(log_handler)

    app.logger.setLevel(app.config['PDC_LOGS_LEVEL'])
    app.logger.info("Starting PDC-WEB")

    db.init_app(app)
    login_manager.init_app(app)

    # Get and activate blueprints
    #
    from .main import bp as main_bp
    app.register_blueprint(main_bp)

    from .auth import bp as auth_bp
    app.register_blueprint(auth_bp)

    from .errors import bp as errors_bp
    app.register_blueprint(errors_bp)

    return app