"""The Quality-Control Web Application entry point"""
import os
import logging
from pathlib import Path

from flask import Flask, request
from flask_session import Session

from uploader.oauth2.client import authserver_authorise_uri

from .entry import entrybp
from .upload import upload
from .parse import parsebp
from .samples import samples
from .base_routes import base
from .dbinsert import dbinsertbp
from .errors import register_error_handlers

def override_settings_with_envvars(
        app: Flask, ignore: tuple[str, ...]=tuple()) -> None:
    """Override settings in `app` with those in ENVVARS"""
    for setting in (key for key in app.config if key not in ignore):
        app.config[setting] = os.environ.get(setting) or app.config[setting]


def create_app():
    """The application factory"""
    app = Flask(__name__)
    app.config.from_pyfile(
        Path(__file__).parent.joinpath("default_settings.py"))
    if "UPLOADER_CONF" in os.environ:
        app.config.from_envvar("UPLOADER_CONF") # Override defaults with instance path

    override_settings_with_envvars(app, ignore=tuple())

    secretsfile = app.config.get("UPLOADER_SECRETS", "").strip()
    if bool(secretsfile):
        secretsfile = Path(secretsfile).absolute()
        app.config["UPLOADER_SECRETS"] = secretsfile
        if secretsfile.exists():
            # Silently ignore secrets if the file does not exist.
            app.config.from_pyfile(secretsfile)

    # setup jinja2 symbols
    app.add_template_global(lambda : request.url, name="request_url")
    app.add_template_global(authserver_authorise_uri)
    app.add_template_global(lambda: app.config["GN2_SERVER_URL"],
                            name="gn2server_uri")

    Session(app)

    # setup blueprints
    app.register_blueprint(base, url_prefix="/")
    app.register_blueprint(entrybp, url_prefix="/")
    app.register_blueprint(parsebp, url_prefix="/parse")
    app.register_blueprint(upload, url_prefix="/upload")
    app.register_blueprint(dbinsertbp, url_prefix="/dbinsert")
    app.register_blueprint(samples, url_prefix="/samples")

    register_error_handlers(app)
    return app