import secrets
from app import db
from app.utils.time_utils import now_eastern

class Facility(db.Model):
    __tablename__ = 'facilities'

    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(255), nullable=False)
    address = db.Column(db.Text)
    contact_person = db.Column(db.String(100))
    contact_phone = db.Column(db.String(20))
    active = db.Column(db.Boolean, default=True)
    created_at = db.Column(db.DateTime, default=now_eastern, nullable=True)

    # Phase 1: link facility to a project (nullable for backward compatibility)
    project_id = db.Column(db.Integer, db.ForeignKey('projects.id', ondelete='SET NULL'),
                           nullable=True, index=True)

    # Phase 34: unguessable token encoded in the facility's public QR code.
    # The QR points at /f/<public_token>, a login-free occupant summary page.
    # Backfilled for existing rows by phase34; set at creation for new rows.
    public_token = db.Column(db.String(48), nullable=True, unique=True, index=True)

    # Relationships
    areas = db.relationship('Area', backref='facility', lazy='dynamic')
    inspections = db.relationship('Inspection', backref='facility', lazy='dynamic')

    @staticmethod
    def generate_public_token() -> str:
        """Return a fresh URL-safe token for the public QR link."""
        return secrets.token_urlsafe(24)

    def ensure_public_token(self) -> str:
        """Return this facility's public_token, generating & persisting one
        if it is missing (e.g. a row created before phase34 ran). The caller
        is responsible for db.session.commit()."""
        if not self.public_token:
            self.public_token = self.generate_public_token()
        return self.public_token

    def __repr__(self):
        return f'<Facility {self.name}>'

class Area(db.Model):
    __tablename__ = 'areas'

    id = db.Column(db.Integer, primary_key=True)
    facility_id = db.Column(db.Integer, db.ForeignKey('facilities.id'), nullable=False)
    name = db.Column(db.String(255), nullable=False)
    area_type = db.Column(db.String(50))

    # Phase 39: unguessable token encoded in the area's public QR code.
    # The QR points at /f/area/<public_token>, a login-free occupant summary
    # page scoped to this area. Backfilled for existing rows by phase39.
    public_token = db.Column(db.String(48), nullable=True, unique=True, index=True)

    # Relationships
    inspections = db.relationship('Inspection', backref='area', lazy='dynamic')
    issues = db.relationship('Issue', backref='area', lazy='dynamic')

    @staticmethod
    def generate_public_token() -> str:
        """Return a fresh URL-safe token for the public QR link."""
        return secrets.token_urlsafe(24)

    def ensure_public_token(self) -> str:
        """Return this area's public_token, generating & persisting one if it
        is missing. The caller is responsible for db.session.commit()."""
        if not self.public_token:
            self.public_token = self.generate_public_token()
        return self.public_token

    def __repr__(self):
        return f'<Area {self.name}>'