import os
from flask import Flask
from app.config import config
from app.extensions import db, login_manager, migrate, csrf
from app.utils.formatters import format_currency, format_percent, format_large_number


def create_app(config_name=None):
    if config_name is None:
        config_name = os.environ.get('FLASK_ENV', 'development')
        if config_name == 'production':
            config_name = 'production'
        else:
            config_name = 'development'

    app = Flask(__name__)
    app.config.from_object(config[config_name])

    # Init extensions
    db.init_app(app)
    login_manager.init_app(app)
    migrate.init_app(app, db)
    csrf.init_app(app)

    # Register blueprints
    from app.routes.auth import auth_bp
    from app.routes.dashboard import dashboard_bp

    app.register_blueprint(auth_bp)
    app.register_blueprint(dashboard_bp)

    # Import all models so Flask-Migrate can see them
    with app.app_context():
        from app.models import (
            User, Account, Category, Receipt, RecurringRule,
            Transaction, Budget, Goal, GoalContribution,
            Investment, InvestmentTransaction, NetWorthSnapshot,
            AiInsight, FxRate
        )

    # Jinja2 template globals
    app.jinja_env.globals['format_currency'] = format_currency
    app.jinja_env.globals['format_percent'] = format_percent
    app.jinja_env.globals['format_large_number'] = format_large_number

    # Jinja2 filters
    @app.template_filter('currency')
    def currency_filter(value, symbol=None):
        return format_currency(value, symbol)

    @app.template_filter('percent')
    def percent_filter(value):
        return format_percent(value)

    return app