import logging

from dataclasses import dataclass

from datetime import datetime, timedelta, timezone

from pathlib import Path

from typing import Any

import emails  # type: ignore[import-untyped]

import jwt

from jinja2 import Template

from jwt.exceptions import InvalidTokenError

from app.core import security

from app.core.config import settings

logging.basicConfig(level=logging.INFO)

logger = logging.getLogger(__name__)

@dataclass

class EmailData:

    html_content: str

    subject: str

def render_email_template(*, template_name: str, context: dict[str, Any]) -> str:

    template_str = (

        Path(__file__).parent / "email-templates" / "build" / template_name

    ).read_text()

    html_content = Template(template_str).render(context)

    return html_content

def send_email(

    *,

    email_to: str,

    subject: str = "",

    html_content: str = "",

) -> None:

    assert settings.emails_enabled, "no provided configuration for email variables"

    message = emails.Message(

        subject=subject,

        html=html_content,

        mail_from=(settings.EMAILS_FROM_NAME, settings.EMAILS_FROM_EMAIL),

    )

    smtp_options = {"host": settings.SMTP_HOST, "port": settings.SMTP_PORT}

    if settings.SMTP_TLS:

        smtp_options["tls"] = True

    elif settings.SMTP_SSL:

        smtp_options["ssl"] = True

    if settings.SMTP_USER:

        smtp_options["user"] = settings.SMTP_USER

    if settings.SMTP_PASSWORD:

        smtp_options["password"] = settings.SMTP_PASSWORD

    response = message.send(to=email_to, smtp=smtp_options)

    logger.info(f"send email result: {response}")

def generate_test_email(email_to: str) -> EmailData:

    project_name = settings.PROJECT_NAME

    subject = f"{project_name} - Test email"

    html_content = render_email_template(

        template_name="test_email.html",

        context={"project_name": settings.PROJECT_NAME, "email": email_to},

    )

    return EmailData(html_content=html_content, subject=subject)

def generate_reset_password_email(email_to: str, email: str, token: str) -> EmailData:

    project_name = settings.PROJECT_NAME

    subject = f"{project_name} - Password recovery for user {email}"

    link = f"{settings.FRONTEND_HOST}/reset-password?token={token}"

    html_content = render_email_template(

        template_name="reset_password.html",

        context={

            "project_name": settings.PROJECT_NAME,

            "username": email,

            "email": email_to,

            "valid_hours": settings.EMAIL_RESET_TOKEN_EXPIRE_HOURS,

            "link": link,

        },

    )

    return EmailData(html_content=html_content, subject=subject)

    email_to: str, username: str, password: str

) -> EmailData:

    project_name = settings.PROJECT_NAME

    subject = f"{project_name} - New account for user {username}"

    html_content = render_email_template(

        template_name="new_account.html",

        context={

            "project_name": settings.PROJECT_NAME,

            "username": username,

            "password": password,

            "email": email_to,

            "link": settings.FRONTEND_HOST,

        },

    )

    return EmailData(html_content=html_content, subject=subject)

def generate_password_reset_token(email: str) -> str:

    delta = timedelta(hours=settings.EMAIL_RESET_TOKEN_EXPIRE_HOURS)

    now = datetime.now(timezone.utc)

    expires = now + delta

    exp = expires.timestamp()

    encoded_jwt = jwt.encode(

        {"exp": exp, "nbf": now, "sub": email},

        settings.SECRET_KEY,

        algorithm=security.ALGORITHM,

    )

    return encoded_jwt

def verify_password_reset_token(token: str) -> str | None:

    try:

        decoded_token = jwt.decode(

            token, settings.SECRET_KEY, algorithms=[security.ALGORITHM]

        )

        return str(decoded_token["sub"])

    except InvalidTokenError:

        return None