"""Flask application factory."""
import os
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask_login import LoginManager
from flask_migrate import Migrate
from flask_socketio import SocketIO

from config import config_map

db = SQLAlchemy()
login_manager = LoginManager()
migrate = Migrate()
socketio = SocketIO()


def create_app(config_name: str = "default") -> Flask:
    app = Flask(__name__, template_folder="templates", static_folder="static")
    app.config.from_object(config_map[config_name])

    # ── extensions ────────────────────────────────────────────────────────────
    db.init_app(app)
    migrate.init_app(app, db)
    socketio.init_app(app, cors_allowed_origins="*", async_mode="threading")

    login_manager.init_app(app)
    login_manager.login_view = "auth.login"
    login_manager.login_message = "Please log in to access this page."
    login_manager.login_message_category = "warning"

    # ── blueprints ────────────────────────────────────────────────────────────
    from app.routes.auth import auth_bp
    from app.routes.dashboard import dashboard_bp
    from app.routes.boards import boards_bp
    from app.routes.workflows import workflows_bp
    from app.routes.api import api_bp
    from app.routes.admin import admin_bp
    from app.routes.sonoff import sonoff_bp
    from app.routes.tuya import tuya_bp
    from app.routes.layouts import layouts_bp
    from app.routes.devices import devices_bp

    app.register_blueprint(auth_bp)
    app.register_blueprint(dashboard_bp)
    app.register_blueprint(boards_bp, url_prefix="/boards")
    app.register_blueprint(workflows_bp, url_prefix="/workflows")
    app.register_blueprint(api_bp, url_prefix="/api")
    app.register_blueprint(admin_bp, url_prefix="/admin")
    app.register_blueprint(sonoff_bp)
    app.register_blueprint(tuya_bp)
    app.register_blueprint(layouts_bp, url_prefix="/layouts")
    app.register_blueprint(devices_bp, url_prefix="/devices")

    # ── user loader ───────────────────────────────────────────────────────────
    from app.models.user import User

    @login_manager.user_loader
    def load_user(user_id):
        return db.session.get(User, int(user_id))

    # ── discover board drivers ─────────────────────────────────────────────────
    from app.drivers.registry import registry
    registry.discover()
    app.logger.info("Board drivers loaded: %s", [d.DRIVER_ID for d in registry.all()])

    # ── Jinja filters ─────────────────────────────────────────────────────────
    from app.drivers.tuya_cloud.driver import format_dp_value as _tuya_fmt

    @app.template_filter("tuya_dp")
    def _tuya_dp_filter(value, dp_code: str, status=None):
        """Format a raw Tuya DP value for display (temperature scaling, units…)."""
        return _tuya_fmt(dp_code, value, status)

    # ── create tables & seed admin on first run ───────────────────────────────
    with app.app_context():
        # Import all models so their tables are registered before create_all
        from app.models import board, user, workflow  # noqa: F401
        from app.models import sonoff_device  # noqa: F401
        from app.models import tuya_device  # noqa: F401
        from app.models import layout  # noqa: F401
        from app.models import device  # noqa: F401
        db.create_all()
        _seed_admin(app)
        _add_entities_column(app)
        _add_config_json_column(app)
        _migrate_board_types(app)
        _add_device_hardware_id_column(app)
        _add_device_app_id_column(app)

    return app


def _add_entities_column(app: Flask) -> None:
    """Add entities_json column to boards table if it doesn't exist yet."""
    from sqlalchemy import text
    with app.app_context():
        try:
            db.session.execute(text("ALTER TABLE boards ADD COLUMN entities_json TEXT DEFAULT '{}'"))
            db.session.commit()
            app.logger.info("Added entities_json column to boards table")
        except Exception:
            db.session.rollback()  # Column already exists — safe to ignore


def _add_config_json_column(app: Flask) -> None:
    """Add config_json column to boards table if it doesn't exist yet."""
    from sqlalchemy import text
    with app.app_context():
        try:
            db.session.execute(text("ALTER TABLE boards ADD COLUMN config_json TEXT DEFAULT '{}'"))
            db.session.commit()
            app.logger.info("Added config_json column to boards table")
        except Exception:
            db.session.rollback()  # Column already exists — safe to ignore


def _migrate_board_types(app: Flask) -> None:
    """Rename legacy board_type values to current driver IDs."""
    from app.models.board import Board
    renames = {
        "olimex_esp32_c6": "olimex_esp32_c6_evb",
    }
    total = 0
    for old, new in renames.items():
        rows = Board.query.filter_by(board_type=old).all()
        for b in rows:
            b.board_type = new
            total += 1
    if total:
        db.session.commit()
        app.logger.info("Migrated %d board(s) to updated driver IDs", total)


def _seed_admin(app: Flask) -> None:
    """Create default admin account if no users exist."""
    from app.models.user import User
    from werkzeug.security import generate_password_hash

    if User.query.count() == 0:
        admin = User(
            username="admin",
            password_hash=generate_password_hash("admin"),
            role="admin",
            is_active=True,
        )
        db.session.add(admin)
        db.session.commit()
        app.logger.info("Default admin user created  (username=admin  password=admin)")


def _add_device_app_id_column(app: Flask) -> None:
    """Add app_id column to devices table and backfill existing rows."""
    from sqlalchemy import text
    with app.app_context():
        try:
            db.session.execute(text("ALTER TABLE devices ADD COLUMN app_id TEXT"))
            db.session.commit()
            app.logger.info("Added app_id column to devices table")
        except Exception:
            db.session.rollback()  # Column already exists — safe to ignore

        # Backfill any rows that have no app_id yet
        from app.models.device import Device
        unset = Device.query.filter(Device.app_id.is_(None)).all()
        for d in unset:
            d.app_id = Device.generate_app_id(d.name, exclude_id=d.id)
        if unset:
            db.session.commit()
            app.logger.info("Backfilled app_id for %d device(s)", len(unset))


def _add_device_hardware_id_column(app: Flask) -> None:
    """Add hardware_device_id column and backfill from existing entity_num bindings."""
    from sqlalchemy import text
    with app.app_context():
        try:
            db.session.execute(text("ALTER TABLE devices ADD COLUMN hardware_device_id TEXT"))
            db.session.commit()
            app.logger.info("Added hardware_device_id column to devices table")
        except Exception:
            db.session.rollback()  # Column already exists — safe to ignore

        # Backfill: resolve entity_num → actual hardware device_id string
        from app.models.device import Device
        from app.models.sonoff_device import SonoffDevice
        from app.models.tuya_device import TuyaDevice
        unset = Device.query.filter(
            Device.hardware_device_id.is_(None),
            Device.entity_num.isnot(None),
            Device.entity_type.in_(["sonoff", "tuya"]),
        ).all()
        for d in unset:
            hw_id = None
            sd_or_td_id = d.entity_num // 100
            if d.entity_type == "sonoff":
                obj = db.session.get(SonoffDevice, sd_or_td_id)
                if obj:
                    hw_id = obj.device_id
            elif d.entity_type == "tuya":
                obj = db.session.get(TuyaDevice, sd_or_td_id)
                if obj:
                    hw_id = obj.device_id
            if hw_id:
                d.hardware_device_id = hw_id
        if unset:
            db.session.commit()
            app.logger.info("Backfilled hardware_device_id for %d device(s)", len(unset))