"""
BreakPilot Email Service

Ermoeglicht den Versand von Emails via SMTP.
Verwendet Mailpit im Entwicklungsmodus.
"""

import os
import smtplib
import logging
from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart
from email.utils import formataddr
from typing import Optional, List
from dataclasses import dataclass
from datetime import datetime

logger = logging.getLogger(__name__)

# SMTP Konfiguration aus Umgebungsvariablen
SMTP_HOST = os.getenv("SMTP_HOST", "localhost")
SMTP_PORT = int(os.getenv("SMTP_PORT", "1025"))
SMTP_USERNAME = os.getenv("SMTP_USERNAME", "")
SMTP_PASSWORD = os.getenv("SMTP_PASSWORD", "")
SMTP_FROM_NAME = os.getenv("SMTP_FROM_NAME", "BreakPilot")
SMTP_FROM_ADDR = os.getenv("SMTP_FROM_ADDR", "noreply@breakpilot.app")
SMTP_USE_TLS = os.getenv("SMTP_USE_TLS", "false").lower() == "true"


@dataclass
class EmailResult:
    """Ergebnis eines Email-Versands."""
    success: bool
    message_id: Optional[str] = None
    error: Optional[str] = None
    recipient: Optional[str] = None
    sent_at: Optional[str] = None


class EmailService:
    """Service fuer den Email-Versand."""

    def __init__(
        self,
        host: str = SMTP_HOST,
        port: int = SMTP_PORT,
        username: str = SMTP_USERNAME,
        password: str = SMTP_PASSWORD,
        from_name: str = SMTP_FROM_NAME,
        from_addr: str = SMTP_FROM_ADDR,
        use_tls: bool = SMTP_USE_TLS
    ):
        self.host = host
        self.port = port
        self.username = username
        self.password = password
        self.from_name = from_name
        self.from_addr = from_addr
        self.use_tls = use_tls

    def _get_connection(self):
        """Erstellt eine SMTP-Verbindung."""
        if self.use_tls:
            smtp = smtplib.SMTP_SSL(self.host, self.port)
        else:
            smtp = smtplib.SMTP(self.host, self.port)

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

        return smtp

    def send_email(
        self,
        to_email: str,
        subject: str,
        body_text: str,
        body_html: Optional[str] = None,
        reply_to: Optional[str] = None,
        cc: Optional[List[str]] = None,
        bcc: Optional[List[str]] = None
    ) -> EmailResult:
        """
        Sendet eine Email.

        Args:
            to_email: Empfaenger-Email
            subject: Betreff
            body_text: Plaintext-Inhalt
            body_html: Optional HTML-Inhalt
            reply_to: Optional Reply-To Adresse
            cc: Optional CC-Empfaenger
            bcc: Optional BCC-Empfaenger

        Returns:
            EmailResult mit Erfolg/Fehler
        """
        try:
            # Message erstellen
            if body_html:
                msg = MIMEMultipart("alternative")
                msg.attach(MIMEText(body_text, "plain", "utf-8"))
                msg.attach(MIMEText(body_html, "html", "utf-8"))
            else:
                msg = MIMEText(body_text, "plain", "utf-8")

            msg["Subject"] = subject
            msg["From"] = formataddr((self.from_name, self.from_addr))
            msg["To"] = to_email

            if reply_to:
                msg["Reply-To"] = reply_to

            if cc:
                msg["Cc"] = ", ".join(cc)

            # Alle Empfaenger sammeln
            recipients = [to_email]
            if cc:
                recipients.extend(cc)
            if bcc:
                recipients.extend(bcc)

            # Senden
            with self._get_connection() as smtp:
                smtp.sendmail(self.from_addr, recipients, msg.as_string())

            logger.info(f"Email sent to {to_email}: {subject}")

            return EmailResult(
                success=True,
                recipient=to_email,
                sent_at=datetime.utcnow().isoformat()
            )

        except smtplib.SMTPException as e:
            logger.error(f"SMTP error sending to {to_email}: {e}")
            return EmailResult(
                success=False,
                error=f"SMTP Fehler: {str(e)}",
                recipient=to_email
            )
        except Exception as e:
            logger.error(f"Error sending email to {to_email}: {e}")
            return EmailResult(
                success=False,
                error=str(e),
                recipient=to_email
            )

    def send_messenger_notification(
        self,
        to_email: str,
        to_name: str,
        sender_name: str,
        message_content: str,
        reply_link: Optional[str] = None
    ) -> EmailResult:
        """
        Sendet eine Messenger-Benachrichtigung per Email.

        Args:
            to_email: Empfaenger-Email
            to_name: Name des Empfaengers
            sender_name: Name des Absenders
            message_content: Nachrichteninhalt
            reply_link: Optional Link zum Antworten

        Returns:
            EmailResult
        """
        subject = f"Neue Nachricht von {sender_name} - BreakPilot"

        # Plaintext Version
        body_text = f"""Hallo {to_name},

Sie haben eine neue Nachricht von {sender_name} erhalten:

---
{message_content}
---

"""
        if reply_link:
            body_text += f"Um zu antworten, klicken Sie hier: {reply_link}\n\n"

        body_text += """Mit freundlichen Gruessen
Ihr BreakPilot Team

---
Diese E-Mail wurde automatisch versendet.
Bitte antworten Sie nicht direkt auf diese E-Mail.
"""

        # HTML Version
        body_html = f"""<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <style>
        body {{ font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif; }}
        .container {{ max-width: 600px; margin: 0 auto; padding: 20px; }}
        .header {{ background: #1a2b4e; color: white; padding: 20px; border-radius: 8px 8px 0 0; }}
        .content {{ background: #f8f9fa; padding: 20px; border: 1px solid #e0e0e0; }}
        .message-box {{ background: white; padding: 15px; border-radius: 8px; border-left: 4px solid #ffb800; margin: 15px 0; }}
        .button {{ display: inline-block; background: #ffb800; color: #1a2b4e; padding: 12px 24px; text-decoration: none; border-radius: 6px; font-weight: bold; }}
        .footer {{ padding: 15px; font-size: 12px; color: #666; text-align: center; }}
    </style>
</head>
<body>
    <div class="container">
        <div class="header">
            <h2 style="margin: 0;">Neue Nachricht</h2>
        </div>
        <div class="content">
            <p>Hallo <strong>{to_name}</strong>,</p>
            <p>Sie haben eine neue Nachricht von <strong>{sender_name}</strong> erhalten:</p>

            <div class="message-box">
                {message_content.replace(chr(10), '<br>')}
            </div>

"""
        if reply_link:
            body_html += f'<p><a href="{reply_link}" class="button">Nachricht beantworten</a></p>'

        body_html += """
        </div>
        <div class="footer">
            <p>Mit freundlichen Gruessen<br>Ihr BreakPilot Team</p>
            <p style="font-size: 11px; color: #999;">
                Diese E-Mail wurde automatisch versendet.<br>
                Bitte antworten Sie nicht direkt auf diese E-Mail.
            </p>
        </div>
    </div>
</body>
</html>
"""

        return self.send_email(
            to_email=to_email,
            subject=subject,
            body_text=body_text,
            body_html=body_html
        )

    def send_jitsi_invitation(
        self,
        to_email: str,
        to_name: str,
        organizer_name: str,
        meeting_title: str,
        meeting_date: str,
        meeting_time: str,
        jitsi_url: str,
        additional_info: Optional[str] = None
    ) -> EmailResult:
        """
        Sendet eine Jitsi-Meeting-Einladung per Email.

        Args:
            to_email: Empfaenger-Email
            to_name: Name des Empfaengers
            organizer_name: Name des Organisators
            meeting_title: Titel des Meetings
            meeting_date: Datum des Meetings (z.B. "20. Dezember 2024")
            meeting_time: Uhrzeit des Meetings (z.B. "14:00 Uhr")
            jitsi_url: Der Jitsi-Meeting-Link
            additional_info: Optional zusaetzliche Informationen

        Returns:
            EmailResult
        """
        subject = f"Einladung: {meeting_title} - {meeting_date}"

        # Plaintext Version
        body_text = f"""Hallo {to_name},

{organizer_name} laedt Sie zu einem Videogespraech ein.

TERMIN: {meeting_title}
DATUM: {meeting_date}
UHRZEIT: {meeting_time}

Treten Sie dem Meeting bei:
{jitsi_url}

"""
        if additional_info:
            body_text += f"HINWEISE:\n{additional_info}\n\n"

        body_text += """TECHNISCHE VORAUSSETZUNGEN:
- Aktueller Webbrowser (Chrome, Firefox, Safari oder Edge)
- Keine Installation erforderlich
- Optional: Kopfhoerer fuer bessere Audioqualitaet

Bei technischen Problemen wenden Sie sich bitte an den Organisator.

Mit freundlichen Gruessen
Ihr BreakPilot Team
"""

        # HTML Version
        body_html = f"""<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <style>
        body {{ font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif; }}
        .container {{ max-width: 600px; margin: 0 auto; padding: 20px; }}
        .header {{ background: linear-gradient(135deg, #8b5cf6, #6366f1); color: white; padding: 30px; border-radius: 12px 12px 0 0; text-align: center; }}
        .header h2 {{ margin: 0 0 10px 0; font-size: 24px; }}
        .content {{ background: #f8f9fa; padding: 25px; border: 1px solid #e0e0e0; }}
        .meeting-info {{ background: white; padding: 20px; border-radius: 12px; margin: 20px 0; box-shadow: 0 2px 8px rgba(0,0,0,0.1); }}
        .info-row {{ display: flex; padding: 10px 0; border-bottom: 1px solid #eee; }}
        .info-row:last-child {{ border-bottom: none; }}
        .info-label {{ font-weight: 600; color: #666; width: 100px; }}
        .info-value {{ color: #333; }}
        .join-button {{ display: block; background: linear-gradient(135deg, #8b5cf6, #6366f1); color: white; padding: 16px 32px; text-decoration: none; border-radius: 8px; font-weight: bold; font-size: 18px; text-align: center; margin: 25px 0; }}
        .join-button:hover {{ opacity: 0.9; }}
        .requirements {{ background: #e8f5e9; padding: 15px; border-radius: 8px; margin: 20px 0; }}
        .requirements h4 {{ margin: 0 0 10px 0; color: #2e7d32; }}
        .requirements ul {{ margin: 0; padding-left: 20px; }}
        .footer {{ padding: 20px; font-size: 12px; color: #666; text-align: center; }}
    </style>
</head>
<body>
    <div class="container">
        <div class="header">
            <h2>Einladung zum Videogespraech</h2>
            <p style="margin: 0; opacity: 0.9;">{meeting_title}</p>
        </div>
        <div class="content">
            <p>Hallo <strong>{to_name}</strong>,</p>
            <p><strong>{organizer_name}</strong> laedt Sie zu einem Videogespraech ein.</p>

            <div class="meeting-info">
                <div class="info-row">
                    <span class="info-label">Termin:</span>
                    <span class="info-value">{meeting_title}</span>
                </div>
                <div class="info-row">
                    <span class="info-label">Datum:</span>
                    <span class="info-value">{meeting_date}</span>
                </div>
                <div class="info-row">
                    <span class="info-label">Uhrzeit:</span>
                    <span class="info-value">{meeting_time}</span>
                </div>
            </div>

            <a href="{jitsi_url}" class="join-button">Meeting beitreten</a>

"""
        if additional_info:
            body_html += f"""
            <div style="background: #fff3e0; padding: 15px; border-radius: 8px; margin: 20px 0;">
                <h4 style="margin: 0 0 10px 0; color: #e65100;">Hinweise:</h4>
                <p style="margin: 0;">{additional_info}</p>
            </div>
"""

        body_html += """
            <div class="requirements">
                <h4>Technische Voraussetzungen:</h4>
                <ul>
                    <li>Aktueller Webbrowser (Chrome, Firefox, Safari oder Edge)</li>
                    <li>Keine Installation erforderlich</li>
                    <li>Optional: Kopfhoerer fuer bessere Audioqualitaet</li>
                </ul>
            </div>

            <p style="font-size: 14px; color: #666;">
                Bei technischen Problemen wenden Sie sich bitte an den Organisator.
            </p>
        </div>
        <div class="footer">
            <p>Mit freundlichen Gruessen<br>Ihr BreakPilot Team</p>
        </div>
    </div>
</body>
</html>
"""

        return self.send_email(
            to_email=to_email,
            subject=subject,
            body_text=body_text,
            body_html=body_html
        )


# Globale Instanz
email_service = EmailService()