models.py

"""SQLAlchemy models for Warbler."""

from datetime import datetime

from flask_bcrypt import Bcrypt
from flask_sqlalchemy import SQLAlchemy

bcrypt = Bcrypt()
db = SQLAlchemy()

DEFAULT_IMAGE_URL = "/static/images/default-pic.png"
DEFAULT_HEADER_IMAGE_URL = "/static/images/warbler-hero.jpg"


class Follows(db.Model):
    """Connection of a follower <-> followed_user."""

    __tablename__ = 'follows'

    user_being_followed_id = db.Column(
        db.Integer,
        db.ForeignKey('users.id', ondelete="cascade"),
        primary_key=True,
    )

    user_following_id = db.Column(
        db.Integer,
        db.ForeignKey('users.id', ondelete="cascade"),
        primary_key=True,
    )

class Likes(db.Model):
    """Connection of a user <-> liked message."""

    __tablename__ = 'likes'

    user_id = db.Column(
        db.Integer,
        db.ForeignKey('users.id', ondelete="cascade"),
        primary_key=True,
    )

    message_id = db.Column(
        db.Integer,
        db.ForeignKey('messages.id', ondelete="cascade"),
        primary_key=True,
    )

class User(db.Model):
    """User in the system."""

    __tablename__ = 'users'

    id = db.Column(
        db.Integer,
        primary_key=True,
    )

    email = db.Column(
        db.Text,
        nullable=False,
        unique=True,
    )

    username = db.Column(
        db.Text,
        nullable=False,
        unique=True,
    )

    image_url = db.Column(
        db.Text,
        default=DEFAULT_IMAGE_URL,
    )

    header_image_url = db.Column(
        db.Text,
        default=DEFAULT_HEADER_IMAGE_URL,
    )

    bio = db.Column(
        db.Text,
    )

    location = db.Column(
        db.Text,
    )

    password = db.Column(
        db.Text,
        nullable=False,
    )

    messages = db.relationship('Message', backref="user")

    followers = db.relationship(
        "User",
        secondary="follows",
        primaryjoin=(Follows.user_being_followed_id == id),
        secondaryjoin=(Follows.user_following_id == id),
        backref="following",
    )

    liked_messages = db.relationship(
        'Message',
        secondary="likes",
        backref="users_liked"
    )

    def __repr__(self):
        return f"<User #{self.id}: {self.username}, {self.email}>"

    @classmethod
    def signup(cls, username, email, password, image_url=DEFAULT_IMAGE_URL):
        """Sign up user.

        Hashes password and adds user to system.
        """

        hashed_pwd = bcrypt.generate_password_hash(password).decode('UTF-8')

        user = User(
            username=username,
            email=email,
            password=hashed_pwd,
            image_url=image_url,
        )

        db.session.add(user)
        return user

    @classmethod
    def authenticate(cls, username, password):
        """Find user with `username` and `password`.

        This is a class method (call it on the class, not an individual user.)
        It searches for a user whose password hash matches this password
        and, if it finds such a user, returns that user object.

        If this can't find matching user (or if password is wrong), returns
        False.
        """

        user = cls.query.filter_by(username=username).first()

        if user:
            is_auth = bcrypt.check_password_hash(user.password, password)
            if is_auth:
                return user

        return False

    def is_followed_by(self, other_user):
        """Is this user followed by `other_user`?"""

        found_user_list = [
            user for user in self.followers if user == other_user]
        return len(found_user_list) == 1

    def is_following(self, other_user):
        """Is this user following `other_user`?"""

        found_user_list = [
            user for user in self.following if user == other_user]
        return len(found_user_list) == 1

    # DEPRECATED: used SQLAlchemy .append() and .remove()
    # def add_new_like(self, message_id):
    #     """Adds liked message to this user
    #     Function returns new Likes instance.
    #     """

    #     return Likes(user_id=self.id, message_id=message_id)

    # def remove_like(self, message_id):
    #     """Remove like from user's liked messages
    #     Function returns the number of messages the user has now liked.
    #     """

    #     liked = Likes.query.get_or_404((self.id, message_id))
    #     db.session.delete(liked)
    #     db.session.commit()

    #     return len(Likes.query.filter(Likes.user_id==self.id).all())
    #     # a lot of work to ignore entire NOTE:
    #     # would use .count instead.

    # def toggle_liked(self, message_id):
    #     """Toggles liked status of message"""

    #     if self.is_liked(message_id):
    #         self.remove_like(message_id)
    #     else:
    #         self.add_new_like(message_id)

    def is_liked(self, message_id):
        """Check if message_id is liked by current user. Returns boolean"""

        liked = Likes.query.filter(
                    Likes.user_id==self.id,
                    Likes.message_id==message_id
                ).one_or_none()

        return bool(liked)



    def get_my_likes(self):
        """Return list of message instances that this user has liked"""

        message_list = self.liked_messages
        return message_list

    def get_my_karma(self):
        """Returns list of likes this user's messages have gotten"""

        messages_id_list = [message.id for message in self.messages]
        messages_id_set = set(messages_id_list)
        likes = Likes.query.filter(Likes.message_id.in_(messages_id_set)).all()

        return likes


class Message(db.Model):
    """An individual message ("warble")."""

    __tablename__ = 'messages'

    id = db.Column(
        db.Integer,
        primary_key=True,
    )

    text = db.Column(
        db.String(140),
        nullable=False,
    )

    timestamp = db.Column(
        db.DateTime,
        nullable=False,
        default=datetime.utcnow,
    )

    user_id = db.Column(
        db.Integer,
        db.ForeignKey('users.id', ondelete='CASCADE'),
        nullable=False,
    )


def connect_db(app):
    """
    Connect this database to provided Flask app.
    You should call this in your Flask app.
    """

    app.app_context().push()
    db.app = app
    db.init_app(app)