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


class SupportTicket(db.Model):
    __tablename__ = 'support_tickets'

    id          = db.Column(db.Integer, primary_key=True)
    customer_id = db.Column(db.Integer, db.ForeignKey('users.id', ondelete='SET NULL'), nullable=True)
    facility_id = db.Column(db.Integer, db.ForeignKey('facilities.id', ondelete='SET NULL'), nullable=True)
    subject     = db.Column(db.String(200), nullable=False)
    body        = db.Column(db.Text, nullable=False)
    status      = db.Column(db.String(20), nullable=False, default='open')  # open / answered / closed
    created_at  = db.Column(db.DateTime, default=now_eastern, nullable=False)

    customer = db.relationship('User',     foreign_keys=[customer_id], backref='support_tickets')
    facility = db.relationship('Facility', foreign_keys=[facility_id], backref='support_tickets')
    replies  = db.relationship(
        'SupportTicketReply', backref='ticket',
        cascade='all, delete-orphan',
        order_by='SupportTicketReply.created_at',
        lazy='dynamic',
    )

    def __repr__(self):
        return f'<SupportTicket {self.id} [{self.status}]>'


class SupportTicketReply(db.Model):
    __tablename__ = 'support_ticket_replies'

    id         = db.Column(db.Integer, primary_key=True)
    ticket_id  = db.Column(db.Integer, db.ForeignKey('support_tickets.id', ondelete='CASCADE'), nullable=False)
    user_id    = db.Column(db.Integer, db.ForeignKey('users.id', ondelete='SET NULL'), nullable=True)
    body       = db.Column(db.Text, nullable=False)
    created_at = db.Column(db.DateTime, default=now_eastern, nullable=False)

    author = db.relationship('User', foreign_keys=[user_id])

    def __repr__(self):
        return f'<SupportTicketReply {self.id} ticket={self.ticket_id}>'


# ── AI support-chat persistence (phase37) ─────────────────────────────────────

class SupportChatSession(db.Model):
    """One saved AI-chat conversation for a customer. Persisted so both the
    customer and staff can reference past conversations and maintain continuity
    (prior messages are reloaded into the chat window on return)."""
    __tablename__ = 'support_chat_sessions'

    id          = db.Column(db.Integer, primary_key=True)
    customer_id = db.Column(db.Integer, db.ForeignKey('users.id', ondelete='CASCADE'),
                            nullable=False, index=True)
    created_at  = db.Column(db.DateTime, default=now_eastern, nullable=False)
    updated_at  = db.Column(db.DateTime, default=now_eastern, nullable=False, index=True)

    customer = db.relationship('User', foreign_keys=[customer_id])
    messages = db.relationship(
        'SupportChatMessage', backref='session',
        cascade='all, delete-orphan',
        order_by='SupportChatMessage.created_at',
        lazy='dynamic',
    )

    @property
    def message_count(self):
        return self.messages.count()

    @property
    def preview(self):
        """First user message, for list views."""
        first = self.messages.filter_by(role='user').first()
        return first.content if first else '(no messages)'

    def __repr__(self):
        return f'<SupportChatSession {self.id} customer={self.customer_id}>'


class SupportChatMessage(db.Model):
    """A single turn in a SupportChatSession. role = 'user' | 'assistant'."""
    __tablename__ = 'support_chat_messages'

    id         = db.Column(db.Integer, primary_key=True)
    session_id = db.Column(db.Integer, db.ForeignKey('support_chat_sessions.id', ondelete='CASCADE'),
                           nullable=False, index=True)
    role       = db.Column(db.String(16), nullable=False)   # 'user' | 'assistant'
    content    = db.Column(db.Text, nullable=False)
    created_at = db.Column(db.DateTime, default=now_eastern, nullable=False)

    def __repr__(self):
        return f'<SupportChatMessage {self.id} session={self.session_id} role={self.role}>'