"""
app/models/work_order.py
------------------------
Vendor work orders (phase36).

A work order dispatches an existing Issue to an external contractor by email.
The contractor opens a tokenized public link (no account required) to see the
scoped issue details and to Acknowledge and then mark the work Completed. Staff
see the work-order status on the issue and are notified on each vendor action.

Builds on the existing free-text `vendor_*` fields on Issue (phase26) — a work
order is the "send it and track it" layer on top of that.
"""

import secrets

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


class IssueWorkOrder(db.Model):
    __tablename__ = 'issue_work_orders'

    id           = db.Column(db.Integer, primary_key=True)
    issue_id     = db.Column(
        db.Integer, db.ForeignKey('issues.id', ondelete='CASCADE'),
        nullable=False, index=True
    )
    vendor_name  = db.Column(db.String(150), nullable=False)
    vendor_email = db.Column(db.String(255), nullable=False)

    # Unguessable public access token (URL path segment). Never exposed to
    # anyone but the vendor who receives the emailed link.
    token        = db.Column(db.String(64), nullable=False, unique=True, index=True)

    status       = db.Column(
        db.Enum('sent', 'acknowledged', 'completed'),
        nullable=False, default='sent'
    )
    message      = db.Column(db.Text, nullable=True)   # staff → vendor instructions
    vendor_note  = db.Column(db.Text, nullable=True)   # vendor → staff completion note

    sent_at         = db.Column(db.DateTime, nullable=False, default=now_eastern)
    acknowledged_at = db.Column(db.DateTime, nullable=True)
    completed_at    = db.Column(db.DateTime, nullable=True)

    created_by   = db.Column(
        db.Integer, db.ForeignKey('users.id', ondelete='SET NULL'), nullable=True
    )
    created_at   = db.Column(db.DateTime, nullable=False, default=now_eastern)

    # Relationships
    issue   = db.relationship('Issue', backref=db.backref(
        'work_orders', lazy='dynamic', cascade='all, delete-orphan',
        order_by='IssueWorkOrder.created_at.desc()'))
    creator = db.relationship('User', foreign_keys=[created_by])

    @staticmethod
    def new_token():
        """Return a fresh unguessable token (43 url-safe chars ≈ 256 bits)."""
        return secrets.token_urlsafe(32)

    @property
    def status_label(self):
        return {'sent': 'Sent', 'acknowledged': 'Acknowledged',
                'completed': 'Completed'}.get(self.status, self.status)

    def __repr__(self):
        return f'<IssueWorkOrder {self.id} issue={self.issue_id} {self.status}>'