from datetime import timedelta, timezone, datetime
from flask import Blueprint
from flask_login import UserMixin
from flask_sqlalchemy import SQLAlchemy
import pytz

db = SQLAlchemy()
profile = Blueprint('models', __name__)
EAT = timezone(timedelta(hours=3))



followers = db.Table(
    'followers',
    db.Column('follower_id', db.Integer, db.ForeignKey('user.id')),
    db.Column('followed_id', db.Integer, db.ForeignKey('user.id'))
)

class User(UserMixin, db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(80), unique=True, nullable=False, index=True)
    email = db.Column(db.String(120), unique=True, nullable=False, index=True)
    password_hash = db.Column(db.String(128), nullable=False)
    profile_picture = db.Column(db.String(120), default='default.jpg')
    bio = db.Column(db.Text)
    date_joined = db.Column(db.DateTime, default=lambda: datetime.now(pytz.timezone('Africa/Nairobi')))
    posts = db.relationship('Post', backref='author', lazy='dynamic', cascade="all, delete-orphan")
    comments = db.relationship('Comment', backref='author', lazy='dynamic', cascade="all, delete-orphan")
    
    followed = db.relationship(
        'User',
        secondary=followers,
        primaryjoin=(id == followers.c.follower_id),
        secondaryjoin=(id == followers.c.followed_id),
        backref=db.backref('followers', lazy='dynamic'),
        lazy='dynamic'
    )
    def get_id(self):
        return str(self.id)

    def follow(self, user):
        if not self.is_following(user):
            self.followed.append(user)
            db.session.commit()

    def unfollow(self, user):
        if self.is_following(user):
            self.followed.remove(user)
            db.session.commit()

    def is_following(self, user):
        return self.followed.filter(followers.c.followed_id == user.id).first() is not None

    def __repr__(self):
        return f'<User {self.username}>'

class Post(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    content = db.Column(db.Text, nullable=False)
    timestamp = db.Column(db.DateTime, default=lambda: datetime.now(EAT))
    user_id = db.Column(db.Integer, db.ForeignKey('user.id'), nullable=False, index=True)
    media_url = db.Column(db.String(120))
    likes = db.relationship('User', secondary='post_likes', backref='liked_posts')
    comments = db.relationship('Comment', backref='post', lazy='dynamic')
    post_likes = db.Table('post_likes',
    db.Column('user_id', db.Integer, db.ForeignKey('user.id'), primary_key=True),
    db.Column('post_id', db.Integer, db.ForeignKey('post.id'), primary_key=True)
)

    def __repr__(self):
        return f'<Post {self.id}>'

class Like(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    user_id = db.Column(db.Integer, db.ForeignKey('user.id'), nullable=False, index=True)
    post_id = db.Column(db.Integer, db.ForeignKey('post.id'), nullable=False, index=True)

    def __repr__(self):
        return f'<Like {self.id}>'

class Comment(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    content = db.Column(db.Text, nullable=False)
    timestamp = db.Column(db.DateTime, default=datetime.utcnow)
    author_id = db.Column(db.Integer, db.ForeignKey('user.id'), nullable=False)
    post_id = db.Column(db.Integer, db.ForeignKey('post.id'), nullable=False)

class Message(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    sender_id = db.Column(db.Integer, db.ForeignKey('user.id'), nullable=False)
    recipient_id = db.Column(db.Integer, db.ForeignKey('user.id'), nullable=False)
    content = db.Column(db.Text, nullable=False)
    media_url = db.Column(db.String, nullable=True)
    timestamp = db.Column(db.DateTime, default=datetime.utcnow)
    
    sender = db.relationship('User', foreign_keys=[sender_id], backref='sent_messages')
    recipient = db.relationship('User', foreign_keys=[recipient_id], backref='received_messages')


class Notification(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    user_id = db.Column(db.Integer, db.ForeignKey('user.id'), nullable=False, index=True)
    content = db.Column(db.Text, nullable=False)
    timestamp = db.Column(db.DateTime, default=lambda: datetime.now(EAT))
    read = db.Column(db.Boolean, default=False)

    def __repr__(self):
        return f'<Notification {self.id}>'

class Follow(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    follower_id = db.Column(db.Integer, db.ForeignKey('user.id'), nullable=False, index=True)
    followed_id = db.Column(db.Integer, db.ForeignKey('user.id'), nullable=False, index=True)
    timestamp = db.Column(db.DateTime, default=lambda: datetime.now(EAT))

    def __repr__(self):
        return f'<Follow {self.id}>'