"""BalanceBoard Flask application factory."""

import logging
import time

from flask import Flask, redirect, render_template, request, url_for
from flask_login import current_user
from markupsafe import Markup, escape

from blueprints.api import create_api_blueprint
from config import Config, DEFAULT_PORT
from database import db, init_db
from extensions import get_filter_engine, get_polling_service, login_manager, oauth
from models import User, bcrypt
from routes.admin import register_admin_routes
from routes.assets import register_asset_routes
from routes.auth import register_auth_routes
from routes.pages import register_page_routes
from routes.settings import register_settings_routes
from user_service import UserService

logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s - %(name)s - %(levelname)s - %(message)s",
    handlers=[logging.FileHandler("app.log"), logging.StreamHandler()],
)
logger = logging.getLogger(__name__)


def create_app(config_class=Config):
    """Create and configure the Flask application."""
    app = Flask(__name__, static_folder="themes", template_folder="templates")
    app.config.from_object(config_class)

    init_db(app)
    bcrypt.init_app(app)
    login_manager.init_app(app)
    oauth.init_app(app)

    user_service = UserService()
    services_started = {"value": False}

    @app.before_request
    def _ensure_services_started():
        """Initialize background services lazily on the first request."""
        if services_started["value"]:
            return

        filter_engine = get_filter_engine()
        logger.info(
            "FilterEngine initialized with %s filtersets",
            len(filter_engine.get_available_filtersets()),
        )
        polling_service = get_polling_service()
        polling_service.init_app(app)
        polling_service.start()
        services_started["value"] = True

    auth0 = oauth.register(
        "auth0",
        client_id=app.config["AUTH0_CLIENT_ID"],
        client_secret=app.config["AUTH0_CLIENT_SECRET"],
        server_metadata_url=f"https://{app.config['AUTH0_DOMAIN']}/.well-known/openid_configuration",
        client_kwargs={"scope": "openid profile email"},
    )

    app.register_blueprint(create_api_blueprint(), url_prefix="/api/v1")
    register_asset_routes(app)
    register_page_routes(app)
    register_settings_routes(app, user_service)
    register_admin_routes(app, user_service)
    register_auth_routes(app, user_service, auth0)

    register_template_filters(app)
    register_login_loader(user_service)
    register_request_guards(app)
    register_context_processors(app)
    register_error_handlers(app)

    return app


def register_template_filters(app):
    """Register Jinja filters used by legacy templates."""

    @app.template_filter("nl2br")
    def nl2br_filter(text):
        """Convert newlines to escaped <br> tags."""
        if not text:
            return text
        return Markup(str(escape(text)).replace("\n", "<br>\n"))

    @app.template_filter("timeago")
    def timeago_filter(timestamp):
        """Format a unix timestamp as a relative age string."""
        if not timestamp:
            return "Recently"
        try:
            ts = float(timestamp)
        except (TypeError, ValueError):
            return "Recently"

        diff = time.time() - ts
        if diff < 0:
            return "Recently"
        if diff < 3600:
            return f"{int(diff // 60)}m ago"
        if diff < 86400:
            return f"{int(diff // 3600)}h ago"
        if diff < 604800:
            return f"{int(diff // 86400)}d ago"
        return time.strftime("%Y-%m-%d", time.localtime(ts))


def register_login_loader(user_service):
    """Register Flask-Login user loading."""

    @login_manager.user_loader
    def load_user(user_id):
        return user_service.get_user_by_id(user_id)


def register_request_guards(app):
    """Register request guards shared by page routes."""

    @app.before_request
    def check_first_user():
        """Redirect to admin setup if no users exist yet."""
        if request.endpoint and (
            request.endpoint.startswith("static")
            or request.endpoint in ["login", "signup", "admin_setup", "serve_theme", "serve_logo"]
        ):
            return

        if current_user.is_authenticated:
            return

        try:
            if User.query.count() == 0:
                return redirect(url_for("admin_setup"))
        except Exception as e:
            logger.warning(f"Database not ready for user count check: {e}")


def register_context_processors(app):
    """Register template context processors."""

    @app.context_processor
    def inject_app_config():
        return {"APP_NAME": app.config["APP_NAME"]}


def register_error_handlers(app):
    """Register error pages for the legacy Jinja UI."""

    @app.errorhandler(404)
    def not_found(e):
        return render_template("404.html"), 404

    @app.errorhandler(500)
    def server_error(e):
        return render_template("500.html"), 500


if __name__ == "__main__":
    flask_app = create_app()
    print("BalanceBoard starting...")
    print("Database: PostgreSQL with SQLAlchemy")
    print("Password hashing: bcrypt")
    print("Authentication: Flask-Login")
    flask_app.run(host="0.0.0.0", port=DEFAULT_PORT, debug=True)