import asyncio
import smtplib
import ssl
from email.message import EmailMessage
from pathlib import Path
from typing import Literal

from jinja2 import Environment, FileSystemLoader, select_autoescape

EMAIL_TEMPLATE_FOLDER = Path(__file__).parent / "templates"


class SimpleEmailSender:
    def __init__(
        self,
        smtp_server: str,
        smtp_port: int,
        username: str,
        password: str,
        sender_email: str,
        connection_method: Literal["STARTTLS", "SSL", "PLAIN"] = "STARTTLS",
        validate_certs: bool = True,
    ) -> None:
        self.smtp_server = smtp_server
        self.smtp_port = smtp_port
        self.username = username
        self.password = password
        self.sender_email = sender_email
        self.connection_method = connection_method.upper()
        self.validate_certs = validate_certs

        self.env = Environment(
            loader=FileSystemLoader(EMAIL_TEMPLATE_FOLDER),
            autoescape=select_autoescape(["html", "xml"]),
        )

    async def send_password_reset_email(
        self,
        email: str,
        reset_url: str,
    ) -> None:
        subject = "[Phoenix] Password Reset Request"
        template_name = "password_reset.html"

        template = self.env.get_template(template_name)
        html_content = template.render(reset_url=reset_url)

        msg = EmailMessage()
        msg["Subject"] = subject
        msg["From"] = self.sender_email
        msg["To"] = email
        msg.set_content(html_content, subtype="html")

        def send_email() -> None:
            context: ssl.SSLContext
            if self.validate_certs:
                context = ssl.create_default_context()
            else:
                context = ssl._create_unverified_context()

            methods_to_try = [self.connection_method]
            # add secure method fallbacks
            if self.connection_method != "PLAIN":
                if self.connection_method != "STARTTLS":
                    methods_to_try.append("STARTTLS")
                elif self.connection_method != "SSL":
                    methods_to_try.append("SSL")

            for method in methods_to_try:
                try:
                    if method == "STARTTLS":
                        server = smtplib.SMTP(self.smtp_server, self.smtp_port)
                        server.ehlo()
                        server.starttls(context=context)
                        server.ehlo()
                    elif method == "SSL":
                        server = smtplib.SMTP_SSL(self.smtp_server, self.smtp_port, context=context)
                        server.ehlo()
                    elif method == "PLAIN":
                        server = smtplib.SMTP(self.smtp_server, self.smtp_port)
                        server.ehlo()
                    else:
                        continue  # Unsupported method

                    if self.username and self.password:
                        server.login(self.username, self.password)

                    server.send_message(msg)
                    server.quit()
                    break  # Success
                except Exception as e:
                    print(f"Failed to send email using {method}: {e}")
                    continue
            else:
                raise Exception("All connection methods failed")

        await asyncio.to_thread(send_email)