"""
app/models/tenant_settings.py
------------------------------
Per-tenant branding / self-service settings (MT-7).

One row per tenant DB. Created on first save; reads fall back to defaults
when no row exists so tenant-zero needs zero data migration.
"""

import logging
import sqlalchemy.exc

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

logger = logging.getLogger(__name__)


class TenantSettings(db.Model):
    __tablename__ = 'tenant_settings'

    id            = db.Column(db.Integer, primary_key=True)
    company_name  = db.Column(db.String(150), nullable=True)
    logo_url      = db.Column(db.String(500), nullable=True)
    primary_color = db.Column(db.String(7),  nullable=False, default='#1a56db')
    accent_color  = db.Column(db.String(7),  nullable=False, default='#16a34a')
    support_email = db.Column(db.String(255), nullable=True)
    updated_at    = db.Column(db.DateTime,   nullable=False, default=now_eastern)
    updated_by    = db.Column(db.Integer, db.ForeignKey('users.id', ondelete='SET NULL'),
                              nullable=True)

    # ── Defaults ──────────────────────────────────────────────────────────────
    DEFAULTS = {
        'company_name':  'Janitorial QC',
        'logo_url':      None,
        'primary_color': '#1a56db',
        'accent_color':  '#16a34a',
        'support_email': None,
    }

    @classmethod
    def get_or_default(cls):
        """Return the settings row, a default-filled transient instance, or None.

        Returns None when the tenant_settings table does not yet exist (i.e.
        phase33 migration has not been run for this tenant DB). The caller
        must handle None — routes redirect to the dashboard with a migration
        prompt; the context processor silently returns no branding.
        """
        try:
            row = cls.query.first()
        except (sqlalchemy.exc.ProgrammingError, sqlalchemy.exc.OperationalError) as exc:
            # Table 'tenant_settings' doesn't exist — phase33 migration not yet applied.
            # Any other DB error (connection failure, permission error) is re-raised.
            logger.warning('TenantSettings.get_or_default: table missing — %s: %s',
                           type(exc).__name__, exc)
            return None
        if row is not None:
            return row
        # Return a transient default so templates always get a real object.
        obj = cls()
        for k, v in cls.DEFAULTS.items():
            setattr(obj, k, v)
        return obj

    @property
    def display_name(self):
        return self.company_name or self.DEFAULTS['company_name']

    def __repr__(self):
        return f'<TenantSettings company={self.company_name}>'