app.py

from flask import Flask, render_template, request, redirect, session, flash
from models import db, User, Product
from sqlalchemy.exc import IntegrityError

app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///shop.db'
app.secret_key = "e*eh76t$%327!!626^5"

db.init_app(app)

# intialize the database and create all the tables
with app.app_context():
    db.create_all()

def login_required(f):
    from functools import wraps
    @wraps(f)
    def wrapper(*args, **kwargs):
        if "username" not in session or "user_id" not in session:
            return redirect("/login")
        return f(*args, **kwargs)
    return wrapper

@app.route("/")
@app.route("/products")
def products():
    query = request.args.get("q", "")
    category = request.args.get("category")

    products = Product.query

    if query:
        products = products.filter(Product.name.ilike(f"%{query}%"))

    if category:
        products = products.filter(Product.category == category)

    products = products.all()

    categories = db.session.query(Product.category).distinct()

    return render_template("products.html",
                           products=products,
                           categories=categories,
                           user_id = session.get("user_id"),
                           name=session.get("username"))

@app.route("/register", methods=["GET", "POST"])
def register():
    error = None
    # POST: the user has clicked on REGISTER button
    # ADD LOGIC for unique usernames here
    if request.method == "POST":
        
        # # fetch all usernames from the database
        # query = db.session.query(User.username)
        # usernames = query.all()

        # # check if the current user's username is unique
        # if request.form.get("username") not in usernames:
        try:
            user = User(
                username=request.form.get("username"),
                password=request.form.get("password")
            )
            # write the user's data to the User table (see models.py)
            db.session.add(user)
            db.session.commit()

        except IntegrityError as e:
            error = "Username already exists!"
            flash("Username already exists!")
            return render_template("register.html", error=error)
        
        else:
            return redirect("/login")

    # GET: the user is directed to register.html page
    return render_template("register.html")

# login logic
@app.route("/login", methods=["GET", "POST"])
def login():
    if request.method == "POST":
        # POST: the user has clicked on login button
        user = User.query.filter_by(
            username=request.form.get("username"),
            password=request.form.get("password")
        ).first()

        if user:
            # if the user is a valid user, 
            # store the user's id and the username
            # in the session as key-value pairs
            session["user_id"] = user.id
            session["username"] = user.username
            return redirect("/products")

    # GET operation: load the login.html page
    return render_template("login.html")

# logout logic
@app.route("/logout")
def logout():
    session.clear()
    return redirect("/products")

@app.route("/add_to_cart/<int:id>")
@login_required
def add_to_cart(id):
    if "cart" not in session:
        # if the user is shopping for the first time, 
        # initialize cart and add it to the session dict
        session["cart"] = []

    session["cart"].append(id)
    session.modified = True

    return redirect("/cart")
    # return redirect("/products")

@app.route("/add_to_wishlist/<int:id>")
@login_required
def add_to_wishlist(id):

    if "wishlist" not in session:
        # if the user is shopping for the first time, 
        # initialize wishlist and add it to the session dict
        session["wishlist"] = []

    session["wishlist"].append(id)
    session.modified = True

    return redirect("/")

@app.route("/wishlist")
@login_required
def wishlist():
    wishlisted_items = session.get("wishlist", [])

    products = Product.query.filter(Product.id.in_(wishlisted_items)).all()

    return render_template("wishlist.html", 
                    products=products,
                    name=session.get("username"),
                    user_id=session.get("user_id"))



@app.route("/remove_from_cart/<int:id>")
@login_required
def remove_from_cart(id):
    if "cart" in session:
        session["cart"] = [i for i in session["cart"] if i != id]
    return redirect("/cart")

@app.route("/cart")
@login_required
def cart():
    cart_ids = session.get("cart", [])

    products = Product.query.filter(Product.id.in_(cart_ids)).all()

    total = sum(p.price for p in products)

    return render_template("cart.html",
                           products=products,
                           total=total,
                           name=session.get("username"),
                           user_id=session.get("user_id"))

# go this route ONCE to fill your tables with items
@app.route("/seed")
def seed():
    if not Product.query.first():
        items = [
            Product(name="iPhone 14", category="Electronics", price=80000, image="https://via.placeholder.com/150"),
            Product(name="Nike Shoes", category="Footwear", price=5000, image="https://via.placeholder.com/150"),
            Product(name="Laptop", category="Electronics", price=60000, image="https://via.placeholder.com/150")
        ]
        db.session.add_all(items)
        db.session.commit()
    return "Data Seeded!"
    
if __name__ == "__main__":
    app.run()