from __future__ import annotations

import logging
from datetime import timedelta
from logging.handlers import RotatingFileHandler
from pathlib import Path

from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from sqlalchemy import event
from sqlalchemy.engine import Engine
from sqlalchemy.engine.url import make_url

from .services import Office365Service
from .settings import Settings, load_settings


db = SQLAlchemy()


def _ensure_sqlite_directory(database_url: str) -> None:
    url = make_url(database_url)
    if url.drivername != "sqlite" or not url.database or url.database == ":memory:":
        return
    Path(url.database).parent.mkdir(parents=True, exist_ok=True)


def _configure_logging(app: Flask) -> None:
    log_dir = Path(app.root_path).parent / "logs"
    log_dir.mkdir(parents=True, exist_ok=True)
    log_path = log_dir / "office365_self_service.log"

    root_logger = logging.getLogger()
    formatter = logging.Formatter("%(asctime)s [%(levelname)s] %(name)s - %(message)s")

    if not any(isinstance(handler, RotatingFileHandler) for handler in root_logger.handlers):
        file_handler = RotatingFileHandler(
            log_path,
            maxBytes=2 * 1024 * 1024,
            backupCount=5,
            encoding="utf-8",
        )
        file_handler.setFormatter(formatter)
        root_logger.addHandler(file_handler)

    root_logger.setLevel(logging.INFO)
    app.logger.info("Logging initialized at %s", log_path)


@event.listens_for(Engine, "connect")
def set_sqlite_pragma(dbapi_conn, connection_record):
    if "sqlite" in str(type(dbapi_conn)):
        cursor = dbapi_conn.cursor()
        cursor.execute("PRAGMA foreign_keys=ON")
        cursor.close()


def create_app(
    settings_override: Settings | None = None,
    service_factory=None,
) -> Flask:
    settings = settings_override or load_settings()
    app = Flask(__name__, template_folder="templates", static_folder="static")
    app.config["SETTINGS"] = settings
    app.config["JSON_AS_ASCII"] = False
    app.config["SECRET_KEY"] = settings.session_secret
    app.config["PERMANENT_SESSION_LIFETIME"] = timedelta(hours=8)
    app.config["SESSION_COOKIE_SAMESITE"] = "Lax"
    app.config["SQLALCHEMY_DATABASE_URI"] = settings.database_url
    app.config["SQLALCHEMY_TRACK_MODIFICATIONS"] = False

    _configure_logging(app)
    _ensure_sqlite_directory(settings.database_url)

    db.init_app(app)

    with app.app_context():
        from .models import AuditEvent, RedemptionCode
        db.create_all()

    if service_factory is None:
        service = Office365Service(settings)
    elif callable(service_factory):
        service = service_factory(settings)
    else:
        service = service_factory

    app.extensions["office365_service"] = service

    from .routes import bp_admin, bp_user

    app.register_blueprint(bp_admin)
    app.register_blueprint(bp_user)

    return app