from flask import Flask, request, redirect, url_for, render_template
from plankapy import Planka, User, InvalidToken
from flask_wtf import FlaskForm
from wtforms import StringField, SubmitField, PasswordField
from wtforms.validators import DataRequired, Email, ValidationError

from configparser import ConfigParser
from random import SystemRandom

import sqlite3
import smtplib
import uuid
import string

app = Flask(__name__, static_folder="static", template_folder="templates")

app.config["SECRET_KEY"] = "".join(
    SystemRandom().choice("".join([string.ascii_letters, string.digits]))
    for _ in range(50)
)

config = ConfigParser()
config.read("settings.ini")


def initialize_database():
    conn = sqlite3.connect("db.sqlite3")

    conn.execute(
        """
        CREATE TABLE IF NOT EXISTS requests (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            email TEXT NOT NULL,
            token TEXT NOT NULL,
            ip TEXT NOT NULL,
            created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
        )
    """
    )

    conn.close()


def rate_limit(request):
    conn = sqlite3.connect("db.sqlite3")
    cursor = conn.cursor()

    cursor.execute(
        """
        SELECT COUNT(*)
        FROM requests
        WHERE ip = ? AND created_at > datetime('now', '-1 hour')
    """,
        (request.remote_addr,),
    )

    count = cursor.fetchone()[0]

    conn.close()

    return count >= config.getint("App", "rate_limit", fallback=5)


def get_mailserver():
    if config.getboolean("SMTP", "ssl", fallback=True):
        port = config.getint("SMTP", "port", fallback=465)
        mailserver = smtplib.SMTP_SSL(config["SMTP"]["host"], port)
    else:
        port = config.getint("SMTP", "port", fallback=587)
        mailserver = smtplib.SMTP(config["SMTP"]["host"], port)

        if config.getboolean("SMTP", "starttls", fallback=True):
            mailserver.starttls()

    mailserver.login(config["SMTP"]["username"], config["SMTP"]["password"])
    return mailserver


def send_email(email, token):
    mailserver = get_mailserver()
    sender = config.get("SMTP", "from", fallback=config["SMTP"]["username"])

    message = f"""
From: {sender}
To: {email}
Subject: {config['App']['name']} - Confirm your email address

Hi,

Thank you for registering with {config['App']['name']}! Please click the link below to confirm your email address:

https://{config['App']['host']}/confirm/{token}

If you did not register with {config['App']['name']}, please ignore this email.

Thanks,
The {config['App']['name']} Team
    """.strip()

    mailserver.sendmail(sender, email, message)

    mailserver.quit()


def process_request(request):
    email = request.form["email"]

    conn = sqlite3.connect("db.sqlite3")
    cursor = conn.cursor()

    # Check if the email address is already in the database
    cursor.execute(
        """
        SELECT COUNT(*)
        FROM requests
        WHERE email = ?
    """,
        (email,),
    )

    count = cursor.fetchone()[0]

    if count > 0:
        return render_template(
            "already_requested.html",
            app=config["App"]["name"],
            title="Already Requested",
            subtitle="You have already requested access with this email address.",
        )

    token = str(uuid.uuid4())

    cursor.execute(
        """
        INSERT INTO requests (email, token, ip)
        VALUES (?, ?, ?)
    """,
        (email, token, request.remote_addr),
    )

    conn.commit()
    conn.close()

    send_email(email, token)

    return redirect(url_for("post_request"))


class EmailForm(FlaskForm):
    email = StringField("Email", validators=[DataRequired(), Email()])
    submit = SubmitField("Submit")


@app.route("/", methods=["GET", "POST"])
def start_request():
    if rate_limit(request):
        return render_template("rate_limit.html")

    form = EmailForm()

    if form.validate_on_submit():
        return process_request(request)

    return render_template(
        "request.html",
        app=config["App"]["name"],
        title="Request Access",
        subtitle="Please enter your email address to request access.",
        form=form,
    )


@app.route("/post_request")
def post_request():
    return render_template(
        "post_request.html",
        app=config["App"]["name"],
        title="Request Received",
        subtitle="Your request has been received. Please check your email for further instructions.",
    )


class SignupForm(FlaskForm):
    email = StringField("Email")
    name = StringField("Your Name", validators=[DataRequired()])
    username = StringField("Username", validators=[DataRequired()])
    password = PasswordField("Password", validators=[DataRequired()])
    submit = SubmitField("Submit")

    email.render_kw = {"readonly": True}

    def validate_username(self, field):
        planka = Planka(
            url=config["Planka"]["url"],
            username=config["Planka"]["username"],
            password=config["Planka"]["password"],
        )

        users = User(planka)

        try:
            user = users.get(username=field.data)

            if user:
                raise ValidationError(f"User with username {field.data} already exists")

        except InvalidToken:
            # This error *should* be specific at this point, but I still don't trust it
            pass


@app.route("/confirm/<token>", methods=["GET", "POST"])
def confirm_request(token):
    conn = sqlite3.connect("db.sqlite3")
    cursor = conn.cursor()

    cursor.execute(
        """
        SELECT email
        FROM requests
        WHERE token = ?
    """,
        (token,),
    )

    row = cursor.fetchone()

    if row is None:
        return render_template(
            "unknown.html",
            app=config["App"]["name"],
            title="Invalid Token",
            subtitle="The token you provided is invalid.",
        )

    email = row[0]

    form = SignupForm()

    if form.validate_on_submit():
        planka = Planka(
            url=config["Planka"]["url"],
            username=config["Planka"]["username"],
            password=config["Planka"]["password"],
        )

        users = User(planka)
        new_user = users.build(
            username=form.username.data,
            name=form.name.data,
            password=form.password.data,
            email=email,
        )

        users.create(new_user)

        cursor.execute(
            """
            DELETE FROM requests
            WHERE token = ?
        """,
            (token,),
        )

        conn.commit()
        conn.close()

        return redirect(url_for("post_signup"))

    return render_template(
        "signup.html",
        app=config["App"]["name"],
        title="Complete Signup",
        subtitle="Please confirm your email address by filling out the form below.",
        email=email,
        form=form,
    )


@app.route("/post_signup")
def post_signup():
    return render_template(
        "post_signup.html",
        app=config["App"]["name"],
        title="Signup Complete",
        subtitle="Your account has been created. You may now log in.",
        planka=config["Planka"]["url"],
    )


initialize_database()