from datetime import datetime, timezone

from app.extensions import db


class TaskList(db.Model):
    __tablename__ = 'task_lists'

    id = db.Column(db.Integer, primary_key=True)
    owner_id = db.Column(db.Integer, db.ForeignKey('users.id'), nullable=False, index=True)
    name = db.Column(db.String(255), nullable=False)
    color = db.Column(db.String(7), default='#10b981')
    description = db.Column(db.Text, nullable=True)
    created_at = db.Column(db.DateTime, default=lambda: datetime.now(timezone.utc))
    updated_at = db.Column(db.DateTime, default=lambda: datetime.now(timezone.utc),
                           onupdate=lambda: datetime.now(timezone.utc))

    tasks = db.relationship('Task', backref='task_list', lazy='dynamic',
                            cascade='all, delete-orphan')
    shares = db.relationship('TaskListShare', backref='task_list', lazy='dynamic',
                             cascade='all, delete-orphan')

    def to_dict(self):
        return {
            'id': self.id,
            'owner_id': self.owner_id,
            'name': self.name,
            'color': self.color,
            'description': self.description,
            'created_at': self.created_at.isoformat() if self.created_at else None,
        }


class Task(db.Model):
    __tablename__ = 'tasks'

    id = db.Column(db.Integer, primary_key=True)
    task_list_id = db.Column(db.Integer, db.ForeignKey('task_lists.id'), nullable=False, index=True)
    uid = db.Column(db.String(255), unique=True, nullable=False)
    ical_data = db.Column(db.Text, nullable=False, default='')  # Full VTODO block
    summary = db.Column(db.String(500), nullable=True)
    description = db.Column(db.Text, nullable=True)
    status = db.Column(db.String(32), nullable=True)  # NEEDS-ACTION | IN-PROCESS | COMPLETED | CANCELLED
    priority = db.Column(db.Integer, nullable=True)  # 0 (keine) - 9
    percent_complete = db.Column(db.Integer, nullable=True)  # 0..100
    due = db.Column(db.DateTime, nullable=True, index=True)
    dtstart = db.Column(db.DateTime, nullable=True)
    completed_at = db.Column(db.DateTime, nullable=True)
    categories = db.Column(db.Text, nullable=True)  # kommagetrennt
    created_at = db.Column(db.DateTime, default=lambda: datetime.now(timezone.utc))
    updated_at = db.Column(db.DateTime, default=lambda: datetime.now(timezone.utc),
                           onupdate=lambda: datetime.now(timezone.utc))

    def to_dict(self):
        return {
            'id': self.id,
            'task_list_id': self.task_list_id,
            'uid': self.uid,
            'summary': self.summary,
            'description': self.description,
            'status': self.status or 'NEEDS-ACTION',
            'priority': self.priority,
            'percent_complete': self.percent_complete,
            'due': self.due.isoformat() if self.due else None,
            'dtstart': self.dtstart.isoformat() if self.dtstart else None,
            'completed_at': self.completed_at.isoformat() if self.completed_at else None,
            'categories': self.categories.split(',') if self.categories else [],
            'created_at': self.created_at.isoformat() if self.created_at else None,
            'updated_at': self.updated_at.isoformat() if self.updated_at else None,
        }


class TaskListShare(db.Model):
    __tablename__ = 'task_list_shares'

    id = db.Column(db.Integer, primary_key=True)
    task_list_id = db.Column(db.Integer, db.ForeignKey('task_lists.id'), nullable=False, index=True)
    shared_with_id = db.Column(db.Integer, db.ForeignKey('users.id'), nullable=False, index=True)
    permission = db.Column(db.String(20), nullable=False, default='read')
    color = db.Column(db.String(7), nullable=True)

    shared_with = db.relationship('User', backref='shared_task_lists')

    __table_args__ = (
        db.UniqueConstraint('task_list_id', 'shared_with_id', name='uq_task_list_share'),
    )