main.py

from datetime import date
from flask import Flask, abort, render_template, redirect, url_for, flash
from flask_bootstrap import Bootstrap5
from flask_ckeditor import CKEditor
from flask_gravatar import Gravatar
from flask_login import UserMixin, login_user, LoginManager, current_user, logout_user, login_required
from flask_sqlalchemy import SQLAlchemy
from sqlalchemy.orm import relationship, DeclarativeBase, Mapped, mapped_column
from sqlalchemy import Integer, String, Text, ForeignKey
from werkzeug.security import generate_password_hash, check_password_hash
from forms import CreatePostForm, RegisterForm, LoginForm, CommentForm
from typing import List
import os

# In the Procfile. file in this folder:
# This will tell our hosting provider to create a web worker that is able to receive HTTP requests.
# The Procfile also says to use gunicorn to serve your web app.
# And finally it specifies the Flask app object is the main.py file.
# That way the hosting provider knows about the entry point for the app and what our app is called.
# When uploading app to host provider like render, they'll automatically change the line from main:app to app:app
# You have to manually revert this

# App initialization
app = Flask(__name__)
app.config['SECRET_KEY'] = os.environ.get('FLASK_KEY')

ckeditor = CKEditor(app)
Bootstrap5(app)

# Gravatar Initialization (random profile pics)
gravatar = Gravatar(app,
                    size=80,
                    rating='g',
                    default='retro',
                    force_default=False,
                    force_lower=False,
                    use_ssl=False,
                    base_url=None)


# DATABASE Initialization
class Base(DeclarativeBase):
    pass


app.config['SQLALCHEMY_DATABASE_URI'] = os.environ.get('DB_URI', 'sqlite:///posts.db')

db = SQLAlchemy(model_class=Base)
db.init_app(app)

# LOGIN Manager
login_manager = LoginManager()
login_manager.init_app(app)


def make_login(email, password):
    user = User.query.filter_by(email=email).first()
    if user and check_password_hash(user.password, password):
        login_user(user)
        return redirect(url_for('get_all_posts'))
    else:
        flash('Invalid email or password')


@login_manager.user_loader
def load_user(user_id):
    return User.query.get(int(user_id))


# DECORATOR TO MAKE ADMIN REQUIRED
def admin_required(f):
    def wrap(*args, **kwargs):
        if current_user.id == 1:
            return f(*args, **kwargs)
        else:
            abort(403)

    wrap.__name__ = f.__name__  # Necessary to wrap more than one function with decorator,
    # otherwise: AssertionError: View function mapping is overwriting an existing endpoint function: wrap
    # it is caused by trying to register a few functions with the name wrap:
    return wrap


# CONFIGURE TABLES
class BlogPost(db.Model):
    __tablename__ = "blog_posts"
    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    title: Mapped[str] = mapped_column(String(250), unique=True, nullable=False)
    subtitle: Mapped[str] = mapped_column(String(250), nullable=False)
    date: Mapped[str] = mapped_column(String(250), nullable=False)
    body: Mapped[str] = mapped_column(Text, nullable=False)
    img_url: Mapped[str] = mapped_column(String(250), nullable=False)
    author: Mapped["User"] = relationship(back_populates="posts")
    author_id: Mapped[int] = mapped_column(ForeignKey('users.id'), nullable=False)
    comments: Mapped[List["Comment"]] = relationship(back_populates="parent_post")


class User(db.Model, UserMixin):
    __tablename__ = "users"
    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    name: Mapped[str] = mapped_column(String(250), nullable=False)
    email: Mapped[str] = mapped_column(String(250), unique=True, nullable=False)
    password: Mapped[str] = mapped_column(String(250), nullable=False)
    posts: Mapped[List["BlogPost"]] = relationship(back_populates="author")
    comments: Mapped[List["Comment"]] = relationship(back_populates="author")


class Comment(db.Model):
    __tablename__ = "comments"
    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    author_id: Mapped[int] = mapped_column(ForeignKey('users.id'), nullable=False)
    author: Mapped["User"] = relationship(back_populates="comments")
    post_id: Mapped[int] = mapped_column(ForeignKey('blog_posts.id'), nullable=False)
    parent_post: Mapped["BlogPost"] = relationship(back_populates="comments")
    body: Mapped[str] = mapped_column(Text, nullable=False)


with app.app_context():
    db.create_all()


@app.route('/register', methods=['GET', 'POST'])
def register():
    form = RegisterForm()
    if form.validate_on_submit():
        name = form.name.data
        email = form.email.data
        password = form.password.data
        hashed_password = generate_password_hash(password, method='scrypt', salt_length=8)
        try:
            db.session.add(User(name=name, email=email, password=hashed_password))
            db.session.commit()
        except Exception as e:
            db.session.rollback()
            flash(f'This account has already been registered, log in here instead')
            return redirect(url_for('login'))
        else:
            if make_login(email=email, password=password):
                # flash(f'You are now registered with {name}')
                return redirect(url_for('get_all_posts'))
    return render_template("register.html", form=form)


@app.route('/login', methods=['GET', 'POST'])
def login():
    form = LoginForm()
    if form.validate_on_submit():
        email = form.email.data
        password = form.password.data
        make_login(email, password)
        return redirect(url_for('get_all_posts'))

    return render_template("login.html", form=form)


@app.route('/logout')
@login_required
def logout():
    logout_user()
    return redirect(url_for('get_all_posts'))


@app.route('/')
def get_all_posts():
    result = db.session.execute(db.select(BlogPost))
    posts = result.scalars().all()
    return render_template("index.html", all_posts=posts)


@app.route("/post/<int:post_id>", methods=['GET', 'POST'])
def show_post(post_id):
    form = CommentForm()
    requested_post = db.get_or_404(BlogPost, post_id)
    comments = requested_post.comments
    if form.validate_on_submit():
        if current_user.is_anonymous:
            return redirect(url_for('login'))
        else:
            new_comment = Comment(
                author=current_user,
                body=form.body.data,
                parent_post=requested_post,
            )
            db.session.add(new_comment)
            db.session.commit()
            return redirect(url_for('show_post', post_id=post_id))

    return render_template("post.html", post=requested_post, form=form)


@app.route("/new-post", methods=["GET", "POST"])
@admin_required
def add_new_post():
    form = CreatePostForm()
    if form.validate_on_submit():
        new_post = BlogPost(
            title=form.title.data,
            subtitle=form.subtitle.data,
            body=form.body.data,
            img_url=form.img_url.data,
            author=current_user,
            date=date.today().strftime("%B %d, %Y")
        )
        db.session.add(new_post)
        db.session.commit()
        return redirect(url_for("get_all_posts"))
    return render_template("make-post.html", form=form)


# TODO: Use a decorator so only an admin user can edit a post
@app.route("/edit-post/<int:post_id>", methods=["GET", "POST"])
@admin_required
def edit_post(post_id):
    post = db.get_or_404(BlogPost, post_id)
    edit_form = CreatePostForm(
        title=post.title,
        subtitle=post.subtitle,
        img_url=post.img_url,
        author=post.author,
        body=post.body
    )
    if edit_form.validate_on_submit():
        post.title = edit_form.title.data
        post.subtitle = edit_form.subtitle.data
        post.img_url = edit_form.img_url.data
        post.author = current_user
        post.body = edit_form.body.data
        db.session.commit()
        return redirect(url_for("show_post", post_id=post.id))
    return render_template("make-post.html", form=edit_form, is_edit=True)


# TODO: Use a decorator so only an admin user can delete a post
@app.route("/delete/<int:post_id>")
@admin_required
def delete_post(post_id):
    post_to_delete = db.get_or_404(BlogPost, post_id)
    db.session.delete(post_to_delete)
    db.session.commit()
    return redirect(url_for('get_all_posts'))


@app.route("/about")
def about():
    return render_template("about.html")


@app.route("/contact")
def contact():
    return render_template("contact.html")


if __name__ == "__main__":
    app.run(debug=False, port=5002)