import logging
from typing import Optional

import resend
from flask import Flask


class Mail:
    def __init__(self):
        self._client = None
        self._default_send_from = None

    def is_inited(self) -> bool:
        return self._client is not None

    def init_app(self, app: Flask):
        if app.config.get("MAIL_TYPE"):
            if app.config.get("MAIL_DEFAULT_SEND_FROM"):
                self._default_send_from = app.config.get("MAIL_DEFAULT_SEND_FROM")

            if app.config.get("MAIL_TYPE") == "resend":
                api_key = app.config.get("RESEND_API_KEY")
                if not api_key:
                    raise ValueError("RESEND_API_KEY is not set")

                api_url = app.config.get("RESEND_API_URL")
                if api_url:
                    resend.api_url = api_url

                resend.api_key = api_key
                self._client = resend.Emails
            elif app.config.get("MAIL_TYPE") == "smtp":
                from libs.smtp import SMTPClient

                if not app.config.get("SMTP_SERVER") or not app.config.get("SMTP_PORT"):
                    raise ValueError("SMTP_SERVER and SMTP_PORT are required for smtp mail type")
                if not app.config.get("SMTP_USE_TLS") and app.config.get("SMTP_OPPORTUNISTIC_TLS"):
                    raise ValueError("SMTP_OPPORTUNISTIC_TLS is not supported without enabling SMTP_USE_TLS")
                self._client = SMTPClient(
                    server=app.config.get("SMTP_SERVER"),
                    port=app.config.get("SMTP_PORT"),
                    username=app.config.get("SMTP_USERNAME"),
                    password=app.config.get("SMTP_PASSWORD"),
                    _from=app.config.get("MAIL_DEFAULT_SEND_FROM"),
                    use_tls=app.config.get("SMTP_USE_TLS"),
                    opportunistic_tls=app.config.get("SMTP_OPPORTUNISTIC_TLS"),
                )
            else:
                raise ValueError("Unsupported mail type {}".format(app.config.get("MAIL_TYPE")))
        else:
            logging.warning("MAIL_TYPE is not set")

    def send(self, to: str, subject: str, html: str, from_: Optional[str] = None):
        if not self._client:
            raise ValueError("Mail client is not initialized")

        if not from_ and self._default_send_from:
            from_ = self._default_send_from

        if not from_:
            raise ValueError("mail from is not set")

        if not to:
            raise ValueError("mail to is not set")

        if not subject:
            raise ValueError("mail subject is not set")

        if not html:
            raise ValueError("mail html is not set")

        self._client.send(
            {
                "from": from_,
                "to": to,
                "subject": subject,
                "html": html,
            }
        )


def init_app(app: Flask):
    mail.init_app(app)


mail = Mail()