import smtplib
import logging
from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart
from typing import Optional, List
from app.core.config import settings

logger = logging.getLogger(__name__)

class EmailService:
    """
    Email Service mirroring Spring Boot's JavaMailSender / EmailService.
    Supports SMTP (Gmail, SendGrid, AWS SES, etc.).
    If SMTP is not configured, logs the message to console (Dev Mode) so flows never crash.
    """

    def __init__(self):
        self.host = getattr(settings, "SMTP_HOST", "")
        self.port = getattr(settings, "SMTP_PORT", 587)
        self.user = getattr(settings, "SMTP_USER", "")
        self.password = getattr(settings, "SMTP_PASSWORD", "")
        self.tls = getattr(settings, "SMTP_TLS", True)
        self.from_email = getattr(settings, "EMAILS_FROM_EMAIL", "noreply@authsec.com")

    def is_configured(self) -> bool:
        """Returns True if valid SMTP credentials are provided."""
        return bool(self.host and self.user and self.password)

    def send_simple_message(self, to: str, subject: str, text: str, from_email: Optional[str] = None) -> bool:
        """Sends a plain text email (mirrors Spring Boot EmailService.sendSimpleMessage)."""
        sender = from_email or self.from_email

        if not self.is_configured():
            print(f"\n==================== [DEV EMAIL SERVICE] ====================")
            print(f"To:      {to}")
            print(f"From:    {sender}")
            print(f"Subject: {subject}")
            print(f"Body:\n{text}")
            print(f"=============================================================\n")
            logger.info(f"[DEV EMAIL] Sent simulated email to {to}: {subject}")
            return True

        try:
            msg = MIMEMultipart()
            msg["From"] = sender
            msg["To"] = to
            msg["Subject"] = subject
            msg.attach(MIMEText(text, "plain"))

            with smtplib.SMTP(self.host, self.port) as server:
                if self.tls:
                    server.starttls()
                server.login(self.user, self.password)
                server.send_message(msg)

            logger.info(f"Email successfully sent to {to}")
            return True
        except Exception as e:
            logger.error(f"Failed to send email to {to}: {e}")
            print(f"❌ Email sending error: {e}")
            return False

    def send_html_message(self, to: str, subject: str, html_content: str, from_email: Optional[str] = None) -> bool:
        """Sends an HTML formatted email."""
        sender = from_email or self.from_email

        if not self.is_configured():
            print(f"\n==================== [DEV EMAIL SERVICE (HTML)] ====================")
            print(f"To:      {to}")
            print(f"Subject: {subject}")
            print(f"HTML Body:\n{html_content}")
            print(f"===================================================================\n")
            return True

        try:
            msg = MIMEMultipart("alternative")
            msg["From"] = sender
            msg["To"] = to
            msg["Subject"] = subject
            msg.attach(MIMEText(html_content, "html"))

            with smtplib.SMTP(self.host, self.port) as server:
                if self.tls:
                    server.starttls()
                server.login(self.user, self.password)
                server.send_message(msg)

            return True
        except Exception as e:
            logger.error(f"Failed to send HTML email to {to}: {e}")
            return False

    def adduserviaadmin(self, to: str, subject: str, otp_or_url: str):
        """Mirrors Spring Boot EmailService.adduserviaadmin."""
        body = f"Your verification code is: {otp_or_url}"
        return self.send_simple_message(to, subject, body)

email_service = EmailService()