main.py

import os
from flask import Flask, render_template, redirect, url_for, flash, abort
from flask_bootstrap import Bootstrap
from flask_ckeditor import CKEditor
from datetime import date
from sqlalchemy import ForeignKey
from werkzeug.security import generate_password_hash, check_password_hash
from flask_sqlalchemy import SQLAlchemy
from sqlalchemy.orm import relationship
from flask_login import UserMixin, login_user, LoginManager, login_required, current_user, logout_user
from forms import CreatePostForm, RegisterForm, LoginForm, CommentForm
from flask_gravatar import Gravatar
from functools import wraps

app = Flask(__name__)
app.config['SECRET_KEY'] = os.environ.get('SECRET_KEY')
ckeditor = CKEditor(app)
Bootstrap(app)

login_manager = LoginManager()
login_manager.init_app(app)

gravatar = Gravatar(app,
                    size=100,
                    rating='g',
                    default='retro',
                    force_default=False,
                    force_lower=False,
                    use_ssl=False,
                    base_url=None)

##CONNECT TO DB
# Connect to the remote database, but if unavailable, then connect locally to sqlite:///blog.db"
app.config['SQLALCHEMY_DATABASE_URI'] = os.environ.get("DATABASE_URL",  "sqlite:///blog.db") 
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
db = SQLAlchemy(app)


##CONFIGURE TABLES

class BlogPost(db.Model):
    __tablename__ = "blog_posts"
    id = db.Column(db.Integer, primary_key=True)
    
    #Create Foreign Key, "users.id" the users refers to the tablename of User.
    author_id = db.Column(db.Integer, db.ForeignKey("users.id"))
    #Create reference to the User object, the "posts" refers to the posts protperty in the User class.    
    author = relationship("User", back_populates="posts")
    
    title = db.Column(db.String(250), unique=True, nullable=False)
    subtitle = db.Column(db.String(250), nullable=False)
    date = db.Column(db.String(250), nullable=False)
    body = db.Column(db.Text, nullable=False)
    img_url = db.Column(db.String(250), nullable=False)
    
    comments = relationship("Comment", back_populates="parent_post")
    
    
class User(UserMixin, db.Model):
    __tablename__ = "users"
    id = db.Column(db.Integer, primary_key=True)
    email = db.Column(db.String(100), unique=True)
    password = db.Column(db.String(100))
    name = db.Column(db.String(1000))
    
    #This will act like a List of BlogPost objects attached to each User. 
    #The "author" refers to the author property in the BlogPost class.
    posts = relationship("BlogPost", back_populates="author")
    comments = relationship("Comment", back_populates="comment_author")
    
    
class Comment(db.Model):
    __tablename__ = "comments"
    id = db.Column(db.Integer, primary_key=True)
    text = db.Column(db.Text, nullable=False)
    
    #*******Add child relationship*******#
    #"users.id" The users refers to the tablename of the Users class.
    #"comments" refers to the comments property in the User class.
    author_id = db.Column(db.Integer, db.ForeignKey("users.id"))
    comment_author = relationship("User", back_populates="comments")
    post_id = db.Column(db.Integer, db.ForeignKey("blog_posts.id")) # Foreign Key for the blog post
    parent_post = relationship("BlogPost", back_populates="comments")
    
with app.app_context():
    db.create_all()

# ==================== DECORATORS ===============================

#Create admin-only decorator
def admin_only(f):
    @wraps(f)
    def decorated_function(*args, **kwargs):
        #If id is not 1 then return abort with 403 error
        if current_user.id != 1:
            return abort(403)
        #Otherwise continue with the route function
        return f(*args, **kwargs)        
    return decorated_function

# ====================== ROUTING FUNCTIONS ===========================

@app.route('/')
def get_all_posts():
    posts = BlogPost.query.all()
    return render_template("index.html", all_posts=posts, current_user=current_user)


@app.route('/register', methods = ['GET','POST'])
def register():
    register_form = RegisterForm()
    if register_form.validate_on_submit():

        print_debug(register_form.email)
        # check for an existing user
        user = User.query.filter_by(email=register_form.email.data).first()
        
        if not user:            
            new_user = User(
                email = register_form.email.data,
                password = generate_password_hash(password=register_form.password.data, method="pbkdf2:sha256", salt_length=8),
                name = register_form.name.data
            )
            db.session.add(new_user)
            db.session.commit()
                        
            #Log in and authenticate user after adding details to database.
            login_user(new_user)            
            return redirect(url_for('get_all_posts'))
        else:
            # User already exists so go to login page
            flash("You already have an account with that email. Please log in.")
            return redirect(url_for('login'))
        
    return render_template("register.html", form=register_form, current_user=current_user)


@app.route('/login', methods = ['GET','POST'])
def login():
    login_form = LoginForm()    
    if login_form.validate_on_submit():
        
        # Log the user in if password matches
        user = User.query.filter_by(email=login_form.email.data).first()
        
        #Email doesn't exist
        if not user:
            flash("That email does not exist, please try again.")
            return redirect(url_for('login'))
        #Password incorrect
        elif not check_password_hash(user.password, login_form.password.data):
            flash('Password incorrect, please try again.')
            return redirect(url_for('login'))
        #Email exists and password correct
        else:
            login_user(user)
            return redirect(url_for('get_all_posts'))
        
    return render_template("login.html", form=login_form, current_user=current_user)


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


@app.route("/post/<int:post_id>", methods = ['GET','POST'])
def show_post(post_id):
    comment_form = CommentForm()
    requested_post = BlogPost.query.get(post_id)
    
    if comment_form.validate_on_submit():
        
        if not current_user.is_authenticated:
            flash("You need to login or register to comment.")
            return redirect(url_for("login"))        
        
        # Save the comment to the database
        new_comment = Comment(
            text = comment_form.comment.data,
            comment_author = current_user,
            parent_post = requested_post
        )
        db.session.add(new_comment)
        db.session.commit()

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


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


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


@app.route("/new-post", methods = ['GET','POST'])
@login_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, current_user=current_user)


@app.route("/edit-post/<int:post_id>", methods = ['GET','POST'])
@login_required
@admin_only
def edit_post(post_id):
    post = BlogPost.query.get(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.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, current_user=current_user)


@app.route("/delete/<int:post_id>")
@login_required
def delete_post(post_id):
    post_to_delete = BlogPost.query.get(post_id)
    db.session.delete(post_to_delete)
    db.session.commit()
    return redirect(url_for('get_all_posts'))

@app.route("/delete_comment/<int:comment_id>")
@login_required
def delete_comment(comment_id):    
    comment_to_delete = Comment.query.get(comment_id)
    post_id = comment_to_delete.post_id
    db.session.delete(comment_to_delete)
    db.session.commit()
    return redirect(url_for('show_post', post_id=post_id))

# ------------------------------ user management -------------------------------
@login_manager.user_loader
def load_user(user_id):
    if User.query.get(user_id):
        return User.query.get(user_id)
    return None

def print_debug(*args):
    print("\n=====================================================")
    for a in args:
        print(a)
    print("=====================================================\n")

if __name__ == "__main__":
    app.run(debug=True)