from flask_sqlalchemy import SQLAlchemy
from flask_login import UserMixin
from werkzeug.security import generate_password_hash, check_password_hash
from datetime import datetime
from sqlalchemy import func

db = SQLAlchemy() # Create the extension object

class User(UserMixin, db.Model):
    id = db.Column(db.Integer, primary_key=True)
    updated_at = db.Column(db.TIMESTAMP, default=datetime.now, onupdate=datetime.now, nullable=False)
    group_id = db.Column(db.Integer, default=0, nullable=False)
    name = db.Column(db.String(40), unique=True, nullable=False)
    password_hash = db.Column(db.String(256))
    is_admin = db.Column(db.Boolean, default=False)
    is_approved = db.Column(db.Boolean, default=False)
    is_private = db.Column(db.Boolean, default=False)
    is_guest = db.Column(db.Boolean, default=False)

    def as_dict(self):
        result = {}
        for p in ['id','name','is_admin','is_approved','is_private','is_guest']:
            result[p] = getattr(self, p)
        return result

    def set_password(self, password):
        self.password_hash = generate_password_hash(password)

    def check_password(self, password):
        return check_password_hash(self.password_hash, password)
    
    def my_owned_lists(self, with_inactive=False):
        if with_inactive:
            return ListOfItems.query.filter_by(owner_user_id=self.id).all()
        return ListOfItems.query.filter_by(owner_user_id=self.id, is_active=True).all()
    
    def all_my_lists(self):
        result = self.my_owned_lists()
        for s in Shared.query.filter_by(user_id=self.id).all():
            l = ListOfItems.query.filter_by(id=s.listofitem_id, is_active=True).first()
            if l:
                result.append(l)
        return result
    
    def all_my_lists_as_dict(self):
        result = []
        for l in self.all_my_lists():
            result.append(l.as_dict())
        return result

    def shares_in_list(self, listofitem_id):
        shared = Shared.query.filter_by(user_id=self.id, listofitem_id=listofitem_id).first()
        return True if shared else False

    def owns_list(self, listofitem_id):
        return ListOfItems.query.filter_by(id=listofitem_id, owner_user_id=self.id).first() is not None

    def can_access_list(self, listofitem_id):
        listofitem = ListOfItems.query.filter_by(id=listofitem_id, is_active=True).first()
        if not listofitem:
            return False
        return listofitem.owner_user_id == self.id or self.shares_in_list(listofitem_id)

    def can_access_item(self, item_id):
        item = Item.query.get(item_id)
        return item is not None and self.can_access_list(item.listofitems_id)

    def set_group_id(self, secret):
        group = Group.query.filter_by(secret=secret).first()
        if group:
            return group.id
        else:
            return 0

class ListOfItems(db.Model):
    __table_args__ = (
        db.UniqueConstraint("owner_user_id", "name", name="uq_list_owner_name"),
    )

    id = db.Column(db.Integer, primary_key=True)
    updated_at = db.Column(db.TIMESTAMP, default=datetime.now, onupdate=datetime.now, nullable=False)
    owner_user_id = db.Column(db.Integer, nullable=False)
    name = db.Column(db.String(40), nullable=False)
    is_active = db.Column(db.Boolean, default=False)

    @classmethod
    def name_exists_for_owner(cls, owner_user_id, name, exclude_id=None):
        query = cls.query.filter(
            cls.owner_user_id == owner_user_id,
            func.lower(cls.name) == name.strip().lower(),
        )
        if exclude_id is not None:
            query = query.filter(cls.id != exclude_id)
        return query.first() is not None

    def as_dict(self):
        result = {}
        for p in ['id','name','owner_user_id','is_active']:
            result[p] = getattr(self, p)
            result["pending"] = self.items_left()
            result["total"] = self.items_total()
        return result

    def items_left(self):
        return len(Item.query.filter_by(listofitems_id=self.id, is_checked=False, is_suggestion=False).all())

    def items_total(self):
        return len(Item.query.filter_by(listofitems_id=self.id, is_suggestion=False).all())

class Item(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    updated_at = db.Column(db.TIMESTAMP, default=datetime.now, onupdate=datetime.now, nullable=False)
    listofitems_id = db.Column(db.Integer, nullable=False)
    label = db.Column(db.String(40), nullable=False)
    quantity = db.Column(db.Integer, default=0)
    unit = db.Column(db.String(10))
    label_alt1 = db.Column(db.String(40))
    label_alt2 = db.Column(db.String(40))
    is_checked = db.Column(db.Boolean, default=False)
    is_suggestion = db.Column(db.Boolean, default=False)
    category = db.Column(db.String(20))

    def as_dict(self):
        result = {}
        for p in ['id','listofitems_id','label','quantity','unit','is_checked', 'is_suggestion', 'category']:
            result[p] = getattr(self, p)
        return result
    
class Shared(db.Model):
    user_id = db.Column(db.Integer, primary_key=True)
    listofitem_id = db.Column(db.Integer, primary_key=True)

class Group(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    updated_at = db.Column(db.TIMESTAMP, default=datetime.now, onupdate=datetime.now, nullable=False)
    secret = db.Column(db.String(128))