#!/usr/bin/python3
import os
import configparser
import sqlite3
import time
import json
import secrets
import datetime
from itertools import groupby
from werkzeug.utils import secure_filename
from werkzeug.security import generate_password_hash, check_password_hash
from flask import Flask, render_template, request, url_for, flash, redirect, session, make_response, send_from_directory, stream_with_context, Response, request
from flask_limiter import Limiter
from flask_limiter.util import get_remote_address

# read config file
config = configparser.ConfigParser()
config.read("config.ini")

HOST = config["config"]["HOST"]
PORT = config["config"]["PORT"]
SECRET_KEY = config["config"]["SECRET_KEY"]
UPLOAD_FOLDER = config["config"]["UPLOAD_FOLDER"]
UPLOAD_LIMIT = config["config"]["UPLOAD_LIMIT"]
PASSWORD_REQUIREMENT = config["config"]["PASSWORD_REQUIREMENT"]

app = Flask(__name__)
app.config["SECRET_KEY"] = SECRET_KEY
app.config["MAX_CONTENT_LENGTH"] = int(UPLOAD_LIMIT) * 1000 * 1000

limiter = Limiter(
    get_remote_address,
    app = app,
    default_limits = ["3 per second"],
    storage_uri = "memory://",
    strategy = "fixed-window"
)

if SECRET_KEY == "placeholder":
    print("[WARNING] Secret key is not set")

if not os.path.exists(UPLOAD_FOLDER):
    print("[WARNING] Upload folder doesn't exist, creating")
    os.mkdir(UPLOAD_FOLDER)

if not os.path.exists("database.db"):
    print("[ERROR] No database exists, please run init_db")
    exit()


def makeStrSafe(url):
    return str(urllib.parse.quote(url)).replace("%20", " ")


def get_db_connection():
    conn = sqlite3.connect("database.db")
    conn.row_factory = sqlite3.Row
    return conn


def get_user(id):
    conn = get_db_connection()
    post = conn.execute("SELECT * FROM users WHERE id = ?",
                        (id,)).fetchone()
    conn.close()
    if post is None:
        return "error"
    return post


def get_comments(id):
    conn = get_db_connection()
    post = conn.execute("SELECT * FROM comments WHERE post_id = ?",
                        (id,)).fetchall()
    conn.close()
    if post is None:
        return "error"
    return post


app.jinja_env.globals.update(getComments=get_comments)

def get_post(id):
    conn = get_db_connection()
    post = conn.execute("SELECT * FROM posts WHERE id = ?",
                        (id,)).fetchone()
    conn.close()
    if post is None:
        return "error"
    return post


app.jinja_env.globals.update(getUser=get_user)


def check_username_taken(username):
    conn = get_db_connection()
    post = conn.execute("SELECT * FROM users WHERE lower(username) = ?",
                        (username.lower(),)).fetchone()
    conn.close()
    if post is None:
        return "error"
    return post["id"]


def get_session(id):
    conn = get_db_connection()
    post = conn.execute("SELECT * FROM sessions WHERE session = ?",
                        (id,)).fetchone()
    conn.close()
    if post is None:
        return "error"
    return post


ALLOWED_EXTENSIONS = {"png", "apng", "jpg", "jpeg", "gif", "svg", "webp"}


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


@app.route("/", methods=("GET", "POST"))
def main():
    usersession = request.cookies.get("session_DO_NOT_SHARE")
    conn = get_db_connection()
    posts = conn.execute("SELECT * FROM posts ORDER BY created DESC;").fetchall()
    conn.close()

    if usersession:
        userCookie = get_session(usersession)
        user = get_user(userCookie["id"])
        return render_template("main.html", userdata=user, posts=posts)
    else:
        return render_template("main.html", posts=posts)

@app.route("/@<pageusername>", methods=("GET", "POST"))
def user(pageusername):
    usersession = request.cookies.get("session_DO_NOT_SHARE")

    checkusername = check_username_taken(pageusername)

    if not checkusername == "error":
        pageuser = get_user(checkusername)
        if usersession:
            userCookie = get_session(usersession)
            user = get_user(userCookie["id"])
            return render_template("user.html", userdata=user, createddate=datetime.datetime.utcfromtimestamp(int(str(pageuser["created"]).split(".")[0])).strftime("%Y-%m-%d"), pageuser=pageuser)
        else:
            return render_template("user.html", createddate=datetime.datetime.utcfromtimestamp(int(str(pageuser["created"]).split(".")[0])).strftime("%Y-%m-%d"), pageuser=pageuser)
    else:
        return """<img src="https://http.cat/images/404.jpg">""", 404

@app.route("/@<pageusername>/edit", methods=("GET", "POST"))
def edituser(pageusername):
    usersession = request.cookies.get("session_DO_NOT_SHARE")

    checkusername = check_username_taken(pageusername)

    if not checkusername == "error":
        pageuser = get_user(checkusername)
        if usersession:
            userCookie = get_session(usersession)
            user = get_user(userCookie["id"])
            if pageuser["username"] == user["username"]:
                if request.method == "POST":
                    code = request.form["code"].replace("Content-Security-Policy", "")
                    conn = get_db_connection()
                    conn.execute("UPDATE users SET htmldescription = ? WHERE id = ?",
                        (code, user["id"]))
                    conn.commit()
                    conn.close()
                    return redirect("/@" + user["username"])
                else:
                    return render_template("edituser.html", userdata=user, pageuser=pageuser)
            else:
                return """<img src="https://http.cat/images/403.jpg">""", 403
        else:
            return """<img src="https://http.cat/images/403.jpg">""", 403
    else:
        return """<img src="https://http.cat/images/404.jpg">""", 404


@app.route("/api/frontpage", methods=("GET", "POST"))
def apifrontpage():
    conn = get_db_connection()
    posts = conn.execute("SELECT * FROM posts ORDER BY created DESC;").fetchall()
    conn.close()

    result = []

    for post in posts:
        comments = []

        for comment in get_comments(post["id"]):
            commentthing = {
                "title": comment["textstr"],
                "created": comment["created"],
                "creator": {
                    "id": comment["creator"],
                    "username": get_user(comment["creator"])["username"]
                }
            }
            comments.append(commentthing)


        mainthing = {
            "id": post["id"],
            "created": post["created"],
            "title": post["textstr"],
            "imgurl": post["imageurl"],
            "creator": {
                "id": post["creator"],
                "username": get_user(post["creator"])["username"]
            },
            "comments": comments
        }
        
        result.append(mainthing)

    return result

@app.route("/api/userinfo", methods=("GET", "POST"))
def apiuserinfo():
    usersession = request.cookies.get("session_DO_NOT_SHARE")
    if usersession:
        userCookie = get_session(usersession)
        user = get_user(userCookie["id"])
        datatemplate = {
            "username": user["username"],
            "id": user["id"],
            "created": user["created"]
        }
        return datatemplate
    else:
        return {
                    "error": "no authentication"
                }, 403

@app.route("/api/login", methods=("GET", "POST"))
def apilogin():
    usersession = request.cookies.get("session_DO_NOT_SHARE")
    if request.method == "POST":
        data = request.get_json()
        username = data["username"]
        password = data["password"]

        userID = check_username_taken(username)
        user = get_user(userID)

        if user == "error":
            return {
                    "error": "wrong username or password"
                }, 401

        if not check_password_hash(user["password"], (password)):
            return {
                    "error": "wrong username or password"
                }, 401

        randomCharacters = secrets.token_hex(512)

        conn = get_db_connection()
        conn.execute("INSERT INTO sessions (session, id) VALUES (?, ?)",
                     (randomCharacters, userID))
        conn.commit()
        conn.close()

        return {
                    "key": randomCharacters
                }, 100

@app.route("/api/post", methods=("GET", "POST"))
def apipost():
    usersession = request.cookies.get("session_DO_NOT_SHARE")
    if usersession:
        if request.method == "POST":

            data = request.get_json()
            title = data["id"]

            if title == "":
                return {
                    "error": "no title"
                }, 403

            if "file" not in request.files:
                return {
                    "error": "no file"
                }, 403

            file = request.files["file"]
            if file.filename == "":
                return {
                    "error": "no file"
                }, 403

            if not allowed_file(file.filename):
                return {
                    "error": "invalid file format"
                }, 403
            
            filename = secure_filename(file.filename)
            finalfilename = secrets.token_hex(64) + filename

            file.save(os.path.join(UPLOAD_FOLDER, finalfilename))
            imgurl = "/cdn/" + finalfilename

            userCookie = get_session(usersession)
            user = get_user(userCookie["id"])

            if not user["banned"] == "0":
                return {
                    "error": "banned",
                    "reason": user["banned"]
                }, 403

            conn = get_db_connection()
            conn.execute("INSERT INTO posts (textstr, imageurl, creator, created) VALUES (?, ?, ?, ?)",
                         (title, imgurl, userCookie["id"], str(time.time())))
            conn.commit()
            conn.close()

            return "success", 100

@app.route("/apidocs", methods=("GET", "POST"))
def apidocs():
    usersession = request.cookies.get("session_DO_NOT_SHARE")

    if usersession:
        userCookie = get_session(usersession)
        user = get_user(userCookie["id"])
        return render_template("apidocs.html", userdata=user)
    else:
        return render_template("apidocs.html")

@app.route("/post", methods=("GET", "POST"))
def post():
    usersession = request.cookies.get("session_DO_NOT_SHARE")
    if usersession:
        if request.method == "POST":
            title = request.form["title"]
            if title == "":
                flash("Text required :3")
                return redirect(url_for("post"))

            if "file" not in request.files:
                flash("No file selected :3")
                return redirect(url_for("post"))

            file = request.files["file"]
            if file.filename == "":
                flash("No file selected :3")
                return redirect(url_for("post"))

            if not allowed_file(file.filename):
                flash("File is not an image!")
                return redirect(url_for("post"))

            filename = secure_filename(file.filename)
            finalfilename = secrets.token_hex(64) + filename

            file.save(os.path.join(UPLOAD_FOLDER, finalfilename))
            imgurl = "/cdn/" + finalfilename

            userCookie = get_session(usersession)
            user = get_user(userCookie["id"])

            if not user["banned"] == "0":
                flash("Your account has been banned. Reason: " +
                      user["banned"])
                return redirect(url_for("post"))

            conn = get_db_connection()
            conn.execute("INSERT INTO posts (textstr, imageurl, creator, created) VALUES (?, ?, ?, ?)",
                         (title, imgurl, userCookie["id"], str(time.time())))
            conn.commit()
            conn.close()
            return redirect(url_for("main"))

        else:
            userCookie = get_session(usersession)
            user = get_user(userCookie["id"])
            return render_template("post.html", userdata=user)
    else:
        flash("A burgercat account is required to post :3")
        return redirect(url_for("login"))


@app.route("/api/comment", methods=("GET", "POST"))
@limiter.limit("1/second", override_defaults=False)
def comment():
    usersession = request.cookies.get("session_DO_NOT_SHARE")
    if usersession:
        if request.method == "POST":

            data = request.get_json()
            uid = data["id"]
            title = data["title"]
            
            userCookie = get_session(usersession)
            user = get_user(userCookie["id"])

            if not user["banned"] == "0":
                return {
                    "error": "banned",
                    "reason": user["banned"]
                }, 403

            conn = get_db_connection()
            conn.execute("INSERT INTO comments (textstr, post_id, creator, created) VALUES (?, ?, ?, ?)",
                         (title, uid, userCookie["id"], str(time.time())))
            conn.commit()
            conn.close()

            return "success", 100

        else:
            return {
                    "error": "https://http.cat/images/400.jpg"
                }, 400
    else:
        return {
                    "error": "https://http.cat/images/401.jpg"
                }, 401


@app.route("/cdn/<filename>", methods=("GET", "POST"))
def cdn(filename):
    if os.path.exists(os.path.join(UPLOAD_FOLDER, filename)):
        return send_from_directory(UPLOAD_FOLDER, filename)
    else:
        return "file doesn't exist!!"


@app.route("/signup", methods=("GET", "POST"))
@limiter.limit("5/minute", override_defaults=False)
def signup():
    usersession = request.cookies.get("session_DO_NOT_SHARE")
    if usersession:
        return redirect(url_for("main"))
    if request.method == "POST":
        if not check_username_taken(request.form["username"]) == "error":
            flash("Username already taken :3")
            return redirect(url_for("signup"))

        if not request.form["username"].isalnum():
            flash("Username must be alphanumeric :3")
            return redirect(url_for("signup"))

        if not len(request.form["password"]) > int(PASSWORD_REQUIREMENT):
            flash("Password must contain at least " + PASSWORD_REQUIREMENT + " characters")
            return redirect(url_for("signup"))

        hashedpassword = generate_password_hash(request.form["password"])

        conn = get_db_connection()
        conn.execute("INSERT INTO users (username, password, created, htmldescription) VALUES (?, ?, ?, ?)",
                     (request.form["username"], hashedpassword, str(time.time()), ""))
        conn.commit()
        conn.close()

        return redirect(url_for("login"))
    else:
        return render_template("signup.html")


@app.route("/login", methods=("GET", "POST"))
@limiter.limit("10/minute", override_defaults=False)
def login():
    usersession = request.cookies.get("session_DO_NOT_SHARE")
    if usersession:
        redirect(url_for("main"))
    if request.method == "POST":
        userID = check_username_taken(request.form["username"])
        user = get_user(userID)

        if user == "error":
            flash("Wrong username or password :3")
            return redirect(url_for("login"))

        if not check_password_hash(user["password"], (request.form["password"])):
            flash("Wrong username or password :3")
            return redirect(url_for("login"))

        randomCharacters = secrets.token_hex(512)

        conn = get_db_connection()
        conn.execute("INSERT INTO sessions (session, id) VALUES (?, ?)",
                     (randomCharacters, userID))
        conn.commit()
        conn.close()

        resp = make_response(redirect("/"))
        resp.set_cookie("session_DO_NOT_SHARE", randomCharacters, expires=datetime.datetime.now() + datetime.timedelta(days=float(180)))

        return resp
    else:
        return render_template("login.html")


@app.route("/settings", methods=("GET", "POST"))
def settings():
    usersession = request.cookies.get("session_DO_NOT_SHARE")
    if usersession:
        userCookie = get_session(usersession)
        user = get_user(userCookie["id"])

        return render_template("settings.html", userdata=user)
    else:
        return redirect("/")


@app.route("/remove/<postid>", methods=("GET", "POST"))
def remove(postid):
    usersession = request.cookies.get("session_DO_NOT_SHARE")
    if usersession:
        userCookie = get_session(usersession)
        user = get_user(userCookie["id"])
        if str(user["administrator"]) == "1":
            post = get_post(postid)
            conn = get_db_connection()
            conn.execute("DELETE FROM posts WHERE id = ?", (postid,))
            conn.commit()
            conn.close()
            return "Deleted post!"
        else:
            return "nice try"
    else:
        return redirect(url_for("login"))

@app.route("/listusers", methods=("GET", "POST"))
def listusers():
    usersession = request.cookies.get("session_DO_NOT_SHARE")
    if usersession:
        userCookie = get_session(usersession)
        user = get_user(userCookie["id"])
        if str(user["administrator"]) == "1":
            thing = ""

            conn = get_db_connection()
            users = conn.execute("SELECT * FROM users").fetchall()
            conn.close()
            for x in users:
                thing = str(x["id"]) + " - " + x["username"] + "<br>" + thing

            return thing
        else:
            return """<img src="https://http.cat/images/403.jpg">"""
    else:
        return redirect(url_for("login"))


@app.route("/settings/logout", methods=("GET", "POST"))
def logout():
    resp = redirect(url_for("main"))
    session = request.cookies.get("session_DO_NOT_SHARE")
    resp.delete_cookie("session_DO_NOT_SHARE")

    return resp

@app.errorhandler(500)
def page_not_found(e):
    return """<img src="https://http.cat/images/500.jpg">""", 500

@app.errorhandler(400)
def page_not_found(e):
    return """<img src="https://http.cat/images/400.jpg">""", 400

@app.errorhandler(429)
def page_not_found(e):
    return """<img src="https://http.cat/images/429.jpg">""", 429

@app.errorhandler(404)
def page_not_found(e):
    return """<img src="https://http.cat/images/404.jpg">""", 404

@app.errorhandler(413)
def page_not_found(e):
    return "Images can't be larger than " + str(UPLOAD_LIMIT) + "MB", 413


if __name__ == "__main__":
    from waitress import serve
    print("[INFO] Server started")
    serve(app, host=HOST, port=PORT)
    #app.run(host=HOST, port=PORT, debug=True)
    print("[INFO] Server stopped")