# -*- coding: utf-8 -*-
# Copyright (c) 2017 Tomek Wójcik <tomek@bthlabs.pl>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
#

"""
q3stats.web_app.application
===========================

This module contains the Web application core.
"""

import flask
from werkzeug.exceptions import HTTPException

from q3stats import __version__ as app_version
import q3stats.database
from q3stats.lib.config import get_config_path


class Q3StatsApplication(flask.Flask):
    """Customized ``flask.Flask`` subclass."""

    def init_db(self):
        """Creates the SQLAlchemy engine and session for this instance."""
        if q3stats.database.db_engine is None:
            q3stats.database.db_engine = q3stats.database.create_engine(
                self.config
            )

        if q3stats.database.db_session is None:
            q3stats.database.db_session = q3stats.database.create_session(
                q3stats.database.db_engine, self.config
            )

        @self.teardown_request
        def shutdown_session(exception=None):
            q3stats.database.db_session.remove()

    @property
    def db_session(self):
        """The SQLAlchemy session for the current context."""
        return q3stats.database.db_session


def create_app(config_path=None):
    """The application factory.

    Creates an instance of :py:class:`Q3StatsApplication` and sets its config
    from file located at *config_path*."""
    app = Q3StatsApplication(__name__)

    if config_path is None:
        config_path = get_config_path()

    app.config.from_pyfile(config_path)
    app.init_db()

    @app.context_processor
    def app_context_processor():
        return {
            'version': app_version
        }

    @app.errorhandler(400)
    @app.errorhandler(404)
    @app.errorhandler(500)
    def app_handle_error(error):
        error_code = 500
        if isinstance(error, HTTPException):
            error_code = error.code

        return flask.render_template(
            'error.html', error_code=error_code
        ), error_code

    from .blueprints.frontend import frontend_blueprint
    app.register_blueprint(frontend_blueprint)

    from .blueprints.api_v1 import api_v1_blueprint
    app.register_blueprint(api_v1_blueprint)

    return app