"""Player evolution — KPI measurement entries for objectives."""

from app.extensions import db
from app.time_utils import utc_now_naive


class ObjectiveEntry(db.Model):
    """A single KPI measurement recorded for an objective.

    Each entry records a value at a point in time so the evolution
    graph can plot historical data and compute a trend line.
    """

    __tablename__ = 'objective_entries'

    id = db.Column(db.Integer, primary_key=True)
    objective_id = db.Column(
        db.Integer,
        db.ForeignKey('objectives.id'),
        nullable=False,
    )
    value = db.Column(db.Numeric(10, 2), nullable=True)
    recorded_at = db.Column(db.DateTime, nullable=False, default=utc_now_naive)
    note = db.Column(db.Text, nullable=True)

    # Who recorded it
    recorded_by = db.Column(db.Integer, db.ForeignKey('users.id'), nullable=False)

    # Timestamps
    created_at = db.Column(db.DateTime, default=utc_now_naive)

    # -----------------------------------------------------------------------
    # Relationships
    # -----------------------------------------------------------------------
    objective = db.relationship(
        'Objective',
        backref=db.backref('entries', lazy='dynamic', order_by='ObjectiveEntry.recorded_at'),
    )
    recorder = db.relationship('User', foreign_keys=[recorded_by])