matekasse/main.py

import queue
from flask import Flask, render_template, request, make_response, session
from flask_socketio import SocketIO #https://pythonprogramminglanguage.com/python-flask-websocket/
import sqlite3
import time
import atexit
import sys
import uuid

db_path = 'mate.db'
conn = sqlite3.connect(db_path, check_same_thread=False)
c = conn.cursor()

app = Flask(__name__)
socketio = SocketIO(app)
app.debug = True

status = True
users = queue.Queue()
finished = None

def exit_handler():
    conn.close()
    sys.exit("Program sucsesfully exited")

#website
@app.route("/")
def index():
    return '<a href="/list">user and tag list</a> <p>The creator of this website accepts no liability for any linguistic or technical errors!</p>'

@app.route("/list")
def list():
    c.execute("SELECT * FROM users")   
    users = c.fetchall()
    text = ""
    for i in users:
        text = text + f'<p><a href="list/user?user={i[1]}">{i[1]}</a>: {i[2]} <form action="/change" method="get"><input name="id" type="hidden" value="{i[0]}"> Change balance: <input name="change"><input type="submit"></form></p> <br style="line-height: 50%;"></br>'
    return '<form action="/list/user" method="get"> Search for User: <input name="user"><input type="submit"></form> <form action="/adduser" method="get"><button type="submit">Add User</button></form> <br></br>' + text 

@app.route("/list/user", methods=['GET'])
def user_info():
    username = request.args.get("user")
    c.execute("SELECT * FROM users WHERE username = '%s'" % username)
    user = c.fetchall()
    if user != []:
        user = user[0]
        return f'<p>{user[1]}: {user[2]} <p><form action="/addtag" method="get"><input name="id" type="hidden" value="{user[0]}"><button type="submit">Add Tag</button></form><form action="/removetag" method="get"><input name="id" type="hidden" value="{user[0]}"><button type="submit">Remove Tag</button></form></p><form action="/change" method="get"><input name="id" type="hidden" value="{user[0]}"> Change balance: <input name="change"><input type="submit"></form></p>'
    else:
        return "User does not exists"

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

@app.route("/adduser/user", methods=['GET'])
def adduser():
    user = request.args.get("username")
    c.execute(f"SELECT * FROM users WHERE username='{str(user)}'") 
    if c.fetchall() == []:
        c.execute("INSERT or IGNORE INTO users (username, balance) VALUES ('%s', 0)" % user)
        conn.commit()
        return 'Added user <a href="/list">user and tag list</a> <p>The creator of this website accepts no liability for any linguistic or technical errors!</p>'
    else:
        return 'User already exists <a href="/list">user and tag list</a> <p>The creator of this website accepts no liability for any linguistic or technical errors!</p>'


@app.route("/change", methods=['GET'])
def change():
    user_id = int(request.args.get("id"))
    try: 
        change = int(request.args.get("change"))
    except ValueError:
        return '<p>Please enter a number!</p><a href="/list">tags and user list</a>'
    c.execute(f"UPDATE users SET balance = balance + {change} WHERE id={user_id}")
    conn.commit()
    if change < 0:
        text = "removed from"
        change_text = change * -1
    elif change > 0:
        text = "added to"
    elif change == 0:
        return "<p>Nothing was done!</p>"
    c.execute(f"SELECT * FROM users WHERE id={user_id}")
    user = c.fetchall()[0][1]
    return f'<p>{change_text} was {text} {user}</p> <a href="/list">back to the list</a>'

@app.route("/addtag", methods=['GET'])
def get_addtag_request():
    global users 
    try:
        user_id = int(request.args.get("id"))
    except:  #except im Normalen Code!
        return "Wrong user id!"
    session_id = uuid.uuid4()
    session[id] = session_id
    users.put([user_id, "add", session_id])
    return render_template("addtag.html", user=user_id)

@socketio.on('addtag')
def request_addtag(data):
    global finished
    if len(users.queue) > 0:
        user = users.queue[len(users.queue) - 1]
        if user == [data["data"], "add", session[id]]:
            socketio.emit("wait", "wait")
            i = 0
            while finished != [data["data"], "add", session[id]]:
                time.sleep(1)
                i += 1
                if i > 20:
                    socketio.emit("error", "timeout")
                    notimportant = users.get()
                    break
            else:
                finished = None
                c.execute(f"SELECT * FROM users WHERE id ={user}")
                username = c.fetchall()[0][1]
                c.execute(f"SELECT * FROM tags WHERE userid={user}")
                tag_id = c.fetchall()[0][0]
                socketio.emit("finished", f"Added {tag_id} to {username}")
        else:
            socketio.emit("busy", "busy")
    else:
        socketio.emit("error", "error")

@app.route("/removetag", methods=['GET'])
def get_removetag_request():
    global users 
    try:
        user_id = int(request.args.get("id"))
    except:  #except im Normalen Code!
        return "Wrong user id!"
    session_id = uuid.uuid4()
    session[id] = session_id
    users.put([user_id, "remove"])
    return render_template("removetag.html", user=user_id)

@socketio.on('removetag')
def request_removetag(data):
    global finished
    if len(users.queue) > 0:
        user = users.queue[len(users.queue) - 1]
        if user == [data["data"], "remove", session[id]]:
            socketio.emit("wait", "wait")
            i = 0
            while finished != [data["data"], "remove", session[id]]:
                time.sleep(1)
                i += 1
                if i > 20:
                    socketio.emit("error", "timeout")
                    notimportant = users.get()
                    break
            else:
                finished = None
                c.execute(f"SELECT * FROM users WHERE id ={user}")
                username = c.fetchall()[0][1]
                c.execute(f"SELECT * FROM tags WHERE userid={user}")
                tag_id = c.fetchall()[0][0]
                socketio.emit("finished", f"removed {tag_id} from {username}")
        else:
            socketio.emit("busy", "busy")
    else:
        socketio.emit("error", "error")

#api
@app.route("/api/tag_id", methods=['GET'])
def get_id():
    global finished
    tag_id = int(request.args.get("id"))
    c.execute(f"SELECT * FROM tags WHERE tagid ={tag_id}")
    tag_list = c.fetchall()
    print(tag_list)
    if tag_list != []:
        tag = tag_list[0]
        if users.qsize() == 0:
            c.execute(f"UPDATE users SET balance = balance - 1 WHERE id={tag[1]}")
            conn.commit() 
            return make_response("True")

    elif users.qsize() > 0:
        queue_item = users.get()
        user = queue_item[0]
        state = queue_item[1]
        if state == "add":
            c.execute(f"INSERT OR IGNORE INTO tags (tagid, userid) VALUES ({tag_id}, {user})")
        elif state == "remove":
            c.execute(f"DELETE FROM tags WHERE (tagid = {tag_id} AND userid = {user}) ")
        conn.commit()
        finished = queue_item
        return make_response("True")

    return make_response("False")  

def main():
    atexit.register(exit_handler)
    socketio.run(app, host='0.0.0.0', port=5000)