from flask import Flask
from app.extensions import db, migrate, login_manager, mail
from config import config
import os

def create_app(config_name=None):
    app = Flask(__name__)
    
    config_name = config_name or os.environ.get('FLASK_CONFIG') or 'default'
    app.config.from_object(config[config_name])
    
    # Initialize extensions
    db.init_app(app)
    migrate.init_app(app, db)
    login_manager.init_app(app)
    mail.init_app(app)
    
    # Configure login manager
    login_manager.login_view = 'auth.login'
    login_manager.login_message = 'Please log in to access this page.'
    login_manager.login_message_category = 'info'
    
    @login_manager.user_loader
    def load_user(user_id):
        from app.models import User
        return User.query.get(int(user_id))
    
    # Page view tracking
    @app.before_request
    def track_page_views():
        from app.models import PageView
        from flask import request
        from flask_login import current_user
        import re
        
        # Skip tracking for static files, admin API calls, and certain paths
        if (request.endpoint and 
            (request.endpoint.startswith('static') or 
             request.endpoint.startswith('admin.api') or
             request.path.startswith('/favicon') or
             request.path.startswith('/_'))) :
            return
            
        # Extract post_id from community post URLs
        post_id = None
        if request.endpoint == 'community.post_detail':
            post_id = request.view_args.get('post_id')
        
        # Create page view record
        page_view = PageView(
            path=request.path,
            user_agent=request.headers.get('User-Agent', ''),
            ip_address=request.remote_addr,
            referer=request.headers.get('Referer'),
            user_id=current_user.id if current_user.is_authenticated else None,
            post_id=post_id
        )
        
        try:
            db.session.add(page_view)
            db.session.commit()
        except Exception:
            # Don't let page view tracking break the app
            db.session.rollback()
    
    # Import models
    from app.models import User, Post, PostImage, GPXFile, Comment, Like, PageView
    
    # Add custom template filters
    @app.template_filter('nl2br')
    def nl2br_filter(text):
        """Convert newlines to <br> tags"""
        if text is None:
            return ''
        return text.replace('\n', '<br>')
    
    # Register blueprints
    from app.routes.main import main
    app.register_blueprint(main)
    
    from app.routes.auth import auth
    app.register_blueprint(auth, url_prefix='/auth')
    
    from app.routes.community import community
    app.register_blueprint(community, url_prefix='/community')
    
    from app.routes.admin import admin
    app.register_blueprint(admin, url_prefix='/admin')
    
    # Create upload directories
    upload_dir = os.path.join(app.instance_path, 'uploads')
    os.makedirs(upload_dir, exist_ok=True)
    os.makedirs(os.path.join(upload_dir, 'images'), exist_ok=True)
    os.makedirs(os.path.join(upload_dir, 'gpx'), exist_ok=True)

    # --- Initial Admin Creation from .env ---
    from app.models import User
    with app.app_context():
        admin_email = os.environ.get('ADMIN_EMAIL')
        admin_nickname = os.environ.get('ADMIN_NICKNAME')
        admin_password = os.environ.get('ADMIN_PASSWORD')
        if admin_email and admin_nickname and admin_password:
            if not User.query.filter_by(email=admin_email).first():
                user = User(nickname=admin_nickname, email=admin_email, is_admin=True, is_active=True)
                user.set_password(admin_password)
                db.session.add(user)
                db.session.commit()
                print(f"[INFO] Admin user {admin_nickname} <{admin_email}> created from .env.")
            else:
                print(f"[INFO] Admin with email {admin_email} already exists.")
        else:
            print("[INFO] ADMIN_EMAIL, ADMIN_NICKNAME, or ADMIN_PASSWORD not set in .env. Skipping admin creation.")
    
    return app