import os
import re

from sqlalchemy import inspect, text

from app import db
from app.models import User, UserGroup


def ensure_schema():
    inspector = inspect(db.engine)
    tables = inspector.get_table_names()

    if "photos" in tables:
        columns = {col["name"] for col in inspector.get_columns("photos")}
        if "user_id" not in columns:
            db.session.execute(
                text("ALTER TABLE photos ADD COLUMN user_id INTEGER REFERENCES users(id)")
            )
            db.session.commit()

    if "users" in tables and "user_groups" in tables:
        columns = {col["name"] for col in inspector.get_columns("users")}
        if "group_id" not in columns:
            db.session.execute(
                text("ALTER TABLE users ADD COLUMN group_id INTEGER REFERENCES user_groups(id)")
            )
            db.session.commit()


def ensure_default_group(app):
    default_quota = int(os.getenv("DEFAULT_GROUP_QUOTA_MB", "100"))
    default_group = UserGroup.query.filter_by(is_default=True).first()

    if not default_group:
        default_group = UserGroup.query.filter_by(slug="users").first()
        if default_group:
            default_group.is_default = True
        else:
            default_group = UserGroup(
                name="Пользователи",
                slug="users",
                disk_quota_mb=default_quota,
                is_default=True,
            )
            db.session.add(default_group)
        db.session.commit()
        app.logger.info("Default user group 'users' created with %s MB quota", default_quota)

    User.query.filter(User.group_id.is_(None)).update({"group_id": default_group.id})
    db.session.commit()


def ensure_site_settings(app):
    from app.models import SiteSettings

    if SiteSettings.query.get(1) is None:
        db.session.add(SiteSettings(id=1))
        db.session.commit()
        app.logger.info("Site settings initialized")


def ensure_photo_storage_column():
    inspector = inspect(db.engine)
    if "photos" not in inspector.get_table_names():
        return
    columns = {col["name"] for col in inspector.get_columns("photos")}
    if "storage_backend" not in columns:
        db.session.execute(text("ALTER TABLE photos ADD COLUMN storage_backend VARCHAR(20) DEFAULT 'local'"))
        db.session.commit()


def slugify(name):
    slug = re.sub(r"[^a-z0-9]+", "-", name.lower().strip())
    slug = slug.strip("-") or "group"
    return slug[:80]


def create_first_admin(app):
    username = os.getenv("ADMIN_USERNAME", "").strip()
    email = os.getenv("ADMIN_EMAIL", "").strip()
    password = os.getenv("ADMIN_PASSWORD", "").strip()

    if not username or not email or not password:
        app.logger.info("ADMIN_* env vars not set — first admin was not created automatically")
        return None

    if User.query.filter_by(is_admin=True).first():
        return None

    default_group = UserGroup.query.filter_by(is_default=True).first()

    if User.query.filter_by(username=username).first():
        user = User.query.filter_by(username=username).first()
        user.is_admin = True
        user.set_password(password)
        if default_group and not user.group_id:
            user.group_id = default_group.id
        db.session.commit()
        app.logger.info("Existing user '%s' promoted to admin", username)
        return user

    user = User(
        username=username,
        email=email,
        is_admin=True,
        group_id=default_group.id if default_group else None,
    )
    user.set_password(password)
    db.session.add(user)
    db.session.commit()
    app.logger.info("First admin '%s' created", username)
    return user