# models.py
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 database import db

class User(UserMixin, db.Model):
    __tablename__ = 'users'
    
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(80), unique=True, nullable=False)
    password_hash = db.Column(db.String(200), nullable=False)
    is_admin = db.Column(db.Boolean, default=False)
    created_at = db.Column(db.DateTime, default=datetime.utcnow)
    
    photos = db.relationship('Photo', backref='uploader', lazy=True)
    likes = db.relationship('Like', backref='user', lazy=True)
    
    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)

class Photo(db.Model):
    __tablename__ = 'photos'
    
    id = db.Column(db.Integer, primary_key=True)
    filename = db.Column(db.String(200), nullable=False)
    caption = db.Column(db.String(500))
    upload_date = db.Column(db.DateTime, default=datetime.utcnow)
    uploader_id = db.Column(db.Integer, db.ForeignKey('users.id'), nullable=False)
    likes_count = db.Column(db.Integer, default=0)
    
    likes = db.relationship('Like', backref='photo', lazy=True, cascade='all, delete-orphan')

class Like(db.Model):
    __tablename__ = 'likes'
    
    id = db.Column(db.Integer, primary_key=True)
    user_id = db.Column(db.Integer, db.ForeignKey('users.id'), nullable=False)
    photo_id = db.Column(db.Integer, db.ForeignKey('photos.id'), nullable=False)
    created_at = db.Column(db.DateTime, default=datetime.utcnow)
    
    __table_args__ = (db.UniqueConstraint('user_id', 'photo_id', name='unique_user_photo_like'),)