import json
import smtplib
import random
import string

from cryptography.fernet import Fernet
from pydantic import EmailStr


from app.config import settings
from app.tasks.celery import celery
from app.tasks.email_templates import create_registration_confirmation_template, \
    create_password_change_confirmation_template, create_password_recover_template


def generate_confirmation_code(length=6):
    characters = string.ascii_letters + string.digits
    confirmation_code = ''.join(random.choice(characters) for _ in range(length))
    return confirmation_code


@celery.task
def send_registration_confirmation_email(
        user_id: int,
        username: str,
        email_to: EmailStr,
        MODE: str
):
    confirmation_code = generate_confirmation_code()

    if MODE == 'TEST':
        return confirmation_code

    load = {"user_id": user_id, "username": username, "email": email_to, "confirmation_code": confirmation_code}
    str_load = json.dumps(load)
    cipher_suite = Fernet(settings.INVITATION_LINK_TOKEN_KEY)
    invitation_token = cipher_suite.encrypt(str_load.encode())

    confirmation_link = settings.INVITATION_LINK_HOST + '/api/users/email_verification/' + invitation_token.decode()

    msg_content = create_registration_confirmation_template(
        username=username, email_to=email_to, confirmation_link=confirmation_link
    )

    with smtplib.SMTP_SSL(settings.SMTP_HOST, settings.SMTP_PORT) as server:
        server.login(settings.SMTP_USER, settings.SMTP_PASS)
        server.send_message(msg_content)

    return confirmation_code


@celery.task
def send_password_change_email(
        username: str,
        email_to: EmailStr,
        MODE: str
):
    if MODE == 'TEST':
        return True
    msg_content = create_password_change_confirmation_template(
        username=username, email_to=email_to
    )

    with smtplib.SMTP_SSL(settings.SMTP_HOST, settings.SMTP_PORT) as server:
        server.login(settings.SMTP_USER, settings.SMTP_PASS)
        server.send_message(msg_content)

    return True


@celery.task
def send_password_recover_email(
        username: str,
        email_to: EmailStr,
        MODE: str
):
    confirmation_code = generate_confirmation_code()
    if MODE == 'TEST':
        return confirmation_code
    msg_content = create_password_recover_template(
        username=username, email_to=email_to, confirmation_code=confirmation_code
    )

    with smtplib.SMTP_SSL(settings.SMTP_HOST, settings.SMTP_PORT) as server:
        server.login(settings.SMTP_USER, settings.SMTP_PASS)
        server.send_message(msg_content)

    return confirmation_code