from __future__ import annotations

from decimal import Decimal, InvalidOperation, ROUND_HALF_UP

from flask import Flask

from app.config import Config
from app.extensions import db, migrate
from app import models
from app.routes.api import api_bp
from app.routes.web import web_bp


def _format_decimal(value: object, digits: int = 4) -> str:
    if value is None:
        return "-"

    try:
        decimal_value = Decimal(str(value))
    except (InvalidOperation, ValueError, TypeError):
        return str(value)

    quantized = decimal_value.quantize(Decimal(f"1.{'0' * digits}"), rounding=ROUND_HALF_UP)
    normalized = format(quantized, "f").rstrip("0").rstrip(".")
    return normalized or "0"


def create_app(config_object: type[Config] = Config) -> Flask:
    app = Flask(__name__, instance_relative_config=True)
    app.config.from_object(config_object)

    db.init_app(app)
    migrate.init_app(app, db)

    app.register_blueprint(web_bp)
    app.register_blueprint(api_bp)
    app.jinja_env.filters["fmt_decimal"] = _format_decimal

    return app