suchwow/suchwow/app.py

from functools import wraps
import uuid
import os
import json
import requests
from flask import Flask, g, request, redirect, url_for, abort
from flask import jsonify, render_template, flash, session
from flask import send_from_directory, make_response
from flask_session import Session
from werkzeug.utils import secure_filename
from suchwow.models import Meme, db


app = Flask(__name__)
app.config.from_envvar("FLASK_SECRETS")
app.secret_key = app.config["SECRET_KEY"]
Session(app)

OPENID_URL = app.config["OIDC_URL"][0]
OPENID_CLIENT_ID = app.config["OIDC_CLIENT_ID"][0]
OPENID_CLIENT_SECRET = app.config["OIDC_CLIENT_SECRET"][0]
OPENID_REDIRECT_URI = "http://localhost:5000/auth"


def allowed_file(filename):
    return "." in filename and \
           filename.rsplit(".", 1)[1].lower() in app.config["ALLOWED_EXTENSIONS"]

def login_required(f):
    @wraps(f)
    def decorated_function(*args, **kwargs):
        if "auth" not in session or not session["auth"]:
            return redirect(url_for("login"))
        return f(*args, **kwargs)
    return decorated_function


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

@app.route("/meme/<id>")
def view(id):
    if Meme.filter(id=id):
        m = Meme.get(Meme.id == id)
        return render_template("view.html", meme=m)
    else:
        return "no meme there brah"

@app.route("/uploads/<path:filename>")
def uploaded_file(filename):
    return send_from_directory(app.config['UPLOAD_FOLDER'], filename)

@app.route("/submit", methods=["GET", "POST"])
@login_required
def submit():
    if request.method == "POST":
        # check if the post request has the file part
        if "file" not in request.files:
            flash("No file part")
            return redirect(request.url)
        file = request.files["file"]
        # if user does not select file, browser also
        # submit an empty part without filename
        if file.filename == "":
            flash("No selected file")
            return redirect(request.url)
        if file and allowed_file(file.filename):
            filename = secure_filename(file.filename)
            save_path = os.path.join(app.config["UPLOAD_FOLDER"], filename)
            file.save(save_path)
            meme = Meme(
                title=request.form.get('title'),
                submitter=session["auth"]["preferred_username"],
                image_name=filename,
            )
            meme.save()
            return redirect(url_for("view", id=meme.id))
    return render_template("submit.html")

@app.route("/login")
def login():
    state = uuid.uuid4().hex
    session["auth_state"] = state
    url = f"{OPENID_URL}/auth?" \
          f"client_id={OPENID_CLIENT_ID}&" \
          f"redirect_uri={OPENID_REDIRECT_URI}&" \
          f"response_type=code&" \
          f"state={state}"

    return redirect(url)


@app.route("/auth/")
def auth():
    # todo
    assert "state" in request.args
    assert "session_state" in request.args
    assert "code" in request.args

    # verify state
    if not session.get("auth_state"):
        return "session error", 500
    if request.args["state"] != session["auth_state"]:
        return "attack detected :)", 500

    # with this authorization code we can fetch an access token
    url = f"{OPENID_URL}/token"
    data = {
        "grant_type": "authorization_code",
        "code": request.args["code"],
        "redirect_uri": OPENID_REDIRECT_URI,
        "client_id": OPENID_CLIENT_ID,
        "client_secret": OPENID_CLIENT_SECRET,
        "state": request.args["state"]
    }
    try:
        resp = requests.post(url, data=data)
        resp.raise_for_status()
    except:
        return resp.content, 500

    data = resp.json()
    assert "access_token" in data
    assert data.get("token_type") == "bearer"
    access_token = data["access_token"]

    # fetch user information with the access token
    url = f"{OPENID_URL}/userinfo"

    try:
        resp = requests.post(url, headers={"Authorization": f"Bearer {access_token}"})
        resp.raise_for_status()
        user_profile = resp.json()
    except:
        return resp.content, 500

    # user can now visit /secret
    session["auth"] = user_profile
    return redirect(url_for("index"))


@app.route("/debug")
@login_required
def debug():
    return f"""
    <h3>We are logged in!</h3>
    <pre>{json.dumps(session["auth"], indent=4, sort_keys=True)}</pre><br>
    <a href="/logout">Logout</a>
    """

@app.route("/logout")
def logout():
    session["auth"] = None
    return redirect(url_for("index"))

@app.errorhandler(404)
def not_found(error):
    return make_response(jsonify({"error": "Page not found"}), 404)

@app.cli.command('dbinit')
def dbinit():
    db.create_tables([Meme])

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