import os
import smtplib
import ssl
from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart
from email.utils import formataddr
from threading import Thread
from flask import render_template_string, render_template
from dotenv import load_dotenv

load_dotenv()


class Mailer:
    def __init__(self):
        self.enabled = os.environ.get('MAIL_ENABLED', 'false').lower() == 'true'
        self.smtp_server = os.environ.get('MAIL_SERVER', 'smtp.gmail.com')
        self.smtp_port = int(os.environ.get('MAIL_PORT', 587))
        self.use_tls = os.environ.get('MAIL_USE_TLS', 'true').lower() == 'true'
        self.use_ssl = os.environ.get('MAIL_USE_SSL', 'false').lower() == 'true'
        self.username = os.environ.get('MAIL_USERNAME', '')
        self.password = os.environ.get('MAIL_PASSWORD', '')
        self.default_sender = os.environ.get('MAIL_DEFAULT_SENDER', self.username)

    def is_enabled(self) -> bool:
        if not self.enabled:
            return False
        if not self.username or not self.password:
            print("Mail: Отсутствуют логин или пароль")
            return False
        return True

    def _get_connection(self):
        if self.use_ssl:
            context = ssl.create_default_context()
            return smtplib.SMTP_SSL(self.smtp_server, self.smtp_port, context=context)
        else:
            server = smtplib.SMTP(self.smtp_server, self.smtp_port)
            if self.use_tls:
                server.starttls()
            return server

    def _send(self, to_emails, subject, body, html_body=None, from_email=None, from_name='SecretText'):
        if not self.is_enabled():
            print(f"Mail: Пропущено письмо (отключено)")
            return False

        if not to_emails:
            print("Mail: Не указаны получатели")
            return False

        if isinstance(to_emails, str):
            to_emails = [to_emails]

        from_email = from_email or self.default_sender

        try:
            msg = MIMEMultipart('alternative')
            msg['Subject'] = subject
            msg['From'] = formataddr((from_name, from_email))
            msg['To'] = ', '.join(to_emails)

            msg.attach(MIMEText(body, 'plain', 'utf-8'))

            if html_body:
                msg.attach(MIMEText(html_body, 'html', 'utf-8'))

            with self._get_connection() as server:
                if self.username and self.password:
                    server.login(self.username, self.password)
                server.send_message(msg)

            print(f"Mail: Письмо отправлено на {', '.join(to_emails)}")
            return True

        except Exception as e:
            print(f"Mail: Ошибка отправки: {e}")
            return False

    def send_email(self, to_emails, subject, body, html_body=None, from_email=None, from_name='SecretText'):
        if not self.is_enabled():
            print(f"Mail: Письмо не отправлено (отключено)")
            return None

        thread = Thread(
            target=self._send,
            args=(to_emails, subject, body, html_body, from_email, from_name),
            daemon=True
        )
        thread.start()
        return thread


    def send_email_with_template(self, to_emails, subject, template_name, context=None, from_email=None,
                                 from_name='SecretText'):
        from main import app
        context = context or {}

        with app.app_context():
            html_body = render_template(template_name, **context)

        body = f"Письмо от SecretText. Пожалуйста, используйте почтовый клиент с поддержкой HTML."

        return self.send_email(to_emails, subject, body, html_body, from_email, from_name)

    def send_user_created_email(self, to_email, username, view_url):
        subject = f"Ваш аккаунт в SecretText создан!"
        context = {
            'username': username,
            'view_url': view_url,
            'base_url': self._get_base_url()
        }
        return self.send_email_with_template(
            to_email,
            subject,
            'emails/user_created.html',
            context
        )

    def _get_base_url(self):
        from main import app
        return app.config.get('APP_URL', 'http://localhost:5000')

    def send_welcome_email(self, to_email, username):
        subject = f"Добро пожаловать в SecretText, {username}!"
        context = {
            'username': username,
            'base_url': self._get_base_url()
        }
        return self.send_email_with_template(
            to_email,
            subject,
            'emails/welcome.html',
            context
        )

    def send_secret_notification(self, to_email, username, secret_id=None):
        subject = f"Новый секрет для вас!"
        context = {
            'username': username,
            'base_url': self._get_base_url()
        }
        return self.send_email_with_template(
            to_email,
            subject,
            'emails/secret_notification.html',
            context
        )

    def send_secret_viewed_notification(self, to_email, username):
        subject = f"Ваш секрет просмотрен!"
        context = {
            'username': username,
            'base_url': self._get_base_url()
        }
        return self.send_email_with_template(
            to_email,
            subject,
            'emails/secret_viewed.html',
            context
        )

    # mailer.py

    def send_secret_received_email(self, to_email, username, note=None):
        subject = f"Вам отправили секрет по запросу!"
        context = {
            'username': username,
            'note': note,
            'base_url': self._get_base_url()
        }
        return self.send_email_with_template(
            to_email,
            subject,
            'emails/secret_received.html',
            context
        )



mailer = Mailer()



def send_mail(to_emails, subject, body, html_body=None):
    return mailer.send_email(to_emails, subject, body, html_body)


def send_mail_template(to_emails, subject, template_name, context=None):
    return mailer.send_email_with_template(to_emails, subject, template_name, context)


def send_user_created_email(to_email, username, view_url):
    return mailer.send_user_created_email(to_email, username, view_url)


def send_welcome_email(to_email, username):
    return mailer.send_welcome_email(to_email, username)


def send_secret_notification(to_email, username, secret_id=None):
    return mailer.send_secret_notification(to_email, username, secret_id)


def send_secret_viewed_notification(to_email, username):
    return mailer.send_secret_viewed_notification(to_email, username)


def send_secret_received_email(to_email, username, note=None):
    return mailer.send_secret_received_email(to_email, username, note)