# The Mia! Accounting Flask Demonstration Website.
# Author: imacat@mail.imacat.idv.tw (imacat), 2023/1/27

#  Copyright (c) 2023 imacat.
#
#  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.
"""The Mia! Accounting Flask demonstration website.

"""
import typing as t
from secrets import token_urlsafe

import click
from flask import Flask, Blueprint, render_template
from flask.cli import with_appcontext
from flask_babel_js import BabelJS
from flask_sqlalchemy import SQLAlchemy
from flask_wtf import CSRFProtect
from sqlalchemy import Column

bp: Blueprint = Blueprint("home", __name__)
babel_js: BabelJS = BabelJS()
csrf: CSRFProtect = CSRFProtect()
db: SQLAlchemy = SQLAlchemy()


def create_app(is_testing: bool = False) -> Flask:
    """Create and configure the application.

    :param is_testing: True if we are running for testing, or False otherwise.
    :return: The application.
    """
    import accounting

    app: Flask = Flask(__name__)
    db_uri: str = "sqlite:///" if is_testing else "sqlite:///local.sqlite"
    app.config.from_mapping({
        "SECRET_KEY": token_urlsafe(32),
        "SQLALCHEMY_DATABASE_URI": db_uri,
        "BABEL_DEFAULT_LOCALE": "en",
        "ALL_LINGUAS": "zh_Hant|正體中文,en|English,zh_Hans|简体中文",
    })
    if is_testing:
        app.config["TESTING"] = True
    app.config["SQLALCHEMY_ECHO"] = True

    babel_js.init_app(app)
    csrf.init_app(app)
    db.init_app(app)

    app.register_blueprint(bp, url_prefix="/")
    app.cli.add_command(init_db_command)

    from . import locale
    locale.init_app(app)

    from . import auth
    auth.init_app(app)

    class UserUtils(accounting.AbstractUserUtils[auth.User]):

        @property
        def cls(self) -> t.Type[auth.User]:
            return auth.User

        @property
        def pk_column(self) -> Column:
            return auth.User.id

        @property
        def current_user(self) -> auth.User:
            return auth.current_user()

        def get_by_username(self, username: str) -> auth.User | None:
            return auth.User.query\
                .filter(auth.User.username == username).first()

        def get_pk(self, user: auth.User) -> int:
            return user.id

    can_view: t.Callable[[], bool] = lambda: auth.current_user() is not None \
        and auth.current_user().username in ["viewer", "editor"]
    can_edit: t.Callable[[], bool] = lambda: auth.current_user() is not None \
        and auth.current_user().username == "editor"
    accounting.init_app(app, user_utils=UserUtils(),
                        can_view_func=can_view, can_edit_func=can_edit)

    return app


@click.command("init-db")
@with_appcontext
def init_db_command() -> None:
    """Initializes the database."""
    db.create_all()
    from .auth import User
    for username in ["viewer", "editor", "nobody"]:
        if User.query.filter(User.username == username).first() is None:
            db.session.add(User(username=username))
    db.session.commit()
    click.echo("Database initialized successfully.")


@bp.get("/", endpoint="home")
def get_home() -> str:
    """Returns the home page.

    :return: The home page.
    """
    return render_template("home.html")