#!/usr/bin/env python3
"""
Email rules processing (Auto-Reply/OOO and Forwarding)
"""

import smtplib
from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart
from email.utils import parseaddr, formatdate, make_msgid
from botocore.exceptions import ClientError

from logger import log
from config import config, is_internal_address
from aws.dynamodb_handler import DynamoDBHandler
from aws.ses_handler import SESHandler
from email_processing.parser import EmailParser


class RulesProcessor:
    """Processes email rules (OOO, Forwarding)"""
    
    def __init__(self, dynamodb: DynamoDBHandler, ses: SESHandler):
        self.dynamodb = dynamodb
        self.ses = ses
    
    def process_rules_for_recipient(
        self,
        recipient: str,
        parsed,
        domain: str,
        worker_name: str,
        metrics_callback=None
    ):
        """
        Process OOO and Forward rules for a recipient
        
        Args:
            recipient: Recipient email address
            parsed: Parsed email message object
            domain: Email domain
            worker_name: Worker name for logging
            metrics_callback: Optional callback to increment metrics
        """
        rule = self.dynamodb.get_email_rules(recipient)
        
        if not rule:
            return
        
        original_from = parsed.get('From', '')
        sender_name, sender_addr = parseaddr(original_from)
        if not sender_addr:
            sender_addr = original_from
        
        # ============================================
        # OOO / Auto-Reply handling
        # ============================================
        if rule.get('ooo_active', False):
            self._handle_ooo(
                recipient, 
                parsed, 
                sender_addr, 
                rule, 
                domain, 
                worker_name,
                metrics_callback
            )
        
        # ============================================
        # Forward handling
        # ============================================
        forwards = rule.get('forwards', [])
        if forwards:
            self._handle_forwards(
                recipient,
                parsed,
                original_from,
                forwards,
                domain,
                worker_name,
                metrics_callback,
                rule=rule
            )
    
    def _handle_ooo(
        self,
        recipient: str,
        parsed,
        sender_addr: str,
        rule: dict,
        domain: str,
        worker_name: str,
        metrics_callback=None
    ):
        """Handle Out-of-Office auto-reply"""
        # Don't reply to automatic messages
        auto_submitted = parsed.get('Auto-Submitted', '')
        precedence = (parsed.get('Precedence') or '').lower()
        
        if auto_submitted and auto_submitted != 'no':
            log(f"  ⏭ Skipping OOO for auto-submitted message", 'INFO', worker_name)
            return
        
        if precedence in ['bulk', 'junk', 'list']:
            log(f"  ⏭ Skipping OOO for {precedence} message", 'INFO', worker_name)
            return
        
        if any(x in sender_addr.lower() for x in ['noreply', 'no-reply', 'mailer-daemon']):
            log(f"  ⏭ Skipping OOO for noreply address", 'INFO', worker_name)
            return
        
        try:
            ooo_msg = rule.get('ooo_message', 'I am out of office.')
            content_type = rule.get('ooo_content_type', 'text')
            ooo_reply = self._create_ooo_reply(parsed, recipient, ooo_msg, content_type)
            ooo_bytes = ooo_reply.as_bytes()
            
            # Distinguish: Internal (Port 2525) vs External (SES)
            if is_internal_address(sender_addr):
                # Internal address → direct via Port 2525
                success = self._send_internal_email(recipient, sender_addr, ooo_bytes, worker_name)
                if success:
                    log(f"✓ Sent OOO reply internally to {sender_addr}", 'SUCCESS', worker_name)
                else:
                    log(f"⚠ Internal OOO reply failed to {sender_addr}", 'WARNING', worker_name)
            else:
                # External address → via SES
                success = self.ses.send_raw_email(recipient, sender_addr, ooo_bytes, worker_name)
                if success:
                    log(f"✓ Sent OOO reply externally to {sender_addr} via SES", 'SUCCESS', worker_name)
            
            if metrics_callback:
                metrics_callback('autoreply', domain)
        
        except Exception as e:
            log(f"⚠ OOO reply failed to {sender_addr}: {e}", 'ERROR', worker_name)
    
    def _handle_forwards(
        self,
        recipient: str,
        parsed,
        original_from: str,
        forwards: list,
        domain: str,
        worker_name: str,
        metrics_callback=None,
        rule: dict = None          # NEU
    ):
        """Handle email forwarding"""
        # NEU: SMTP Override aus Rule lesen
        smtp_override = None
        if rule:
            smtp_override = rule.get('forward_smtp_override')

        for forward_to in forwards:
            try:
                fwd_msg = self._create_forward_message(
                    parsed, recipient, forward_to, original_from
                )
                fwd_bytes = fwd_msg.as_bytes()

                # NEU: Legacy SMTP Override (Migration)
                if smtp_override:
                    success = self._send_via_legacy_smtp(
                        recipient, forward_to, fwd_bytes,
                        smtp_override, worker_name
                    )
                    if success:
                        log(f"✓ Forwarded via legacy SMTP to {forward_to} "
                            f"({smtp_override.get('host', '?')})",
                            'SUCCESS', worker_name)
                    else:
                        log(f"⚠ Legacy SMTP forward failed to {forward_to}",
                            'WARNING', worker_name)

                elif is_internal_address(forward_to):
                    success = self._send_internal_email(
                        recipient, forward_to, fwd_bytes, worker_name
                    )
                    if success:
                        log(f"✓ Forwarded internally to {forward_to}",
                            'SUCCESS', worker_name)
                    else:
                        log(f"⚠ Internal forward failed to {forward_to}",
                            'WARNING', worker_name)
                else:
                    success = self.ses.send_raw_email(
                        recipient, forward_to, fwd_bytes, worker_name
                    )
                    if success:
                        log(f"✓ Forwarded externally to {forward_to} via SES",
                            'SUCCESS', worker_name)

                if metrics_callback:
                    metrics_callback('forward', domain)

            except Exception as e:
                log(f"⚠ Forward failed to {forward_to}: {e}",
                    'ERROR', worker_name)

    @staticmethod
    def _send_via_legacy_smtp(
        from_addr: str,
        to_addr: str,
        raw_message: bytes,
        smtp_config: dict,
        worker_name: str
    ) -> bool:
        """
        Send email directly to a legacy SMTP server (for migration).
        Bypasses SES completely to avoid mail loops.
        """
        try:
            host = smtp_config.get('host', '')

            # DynamoDB speichert Zahlen als Decimal, daher int()
            port = int(smtp_config.get('port', 25))
            use_tls = smtp_config.get('tls', False)
            username = smtp_config.get('username')
            password = smtp_config.get('password')

            if not host:
                log(f"  ✗ Legacy SMTP: no host configured", 'ERROR', worker_name)
                return False

            with smtplib.SMTP(host, port, timeout=30) as conn:
                conn.ehlo()
                if use_tls:
                    conn.starttls()
                    conn.ehlo()
                if username and password:
                    conn.login(username, password)
                conn.sendmail(from_addr, [to_addr], raw_message)
                return True

        except Exception as e:
            log(
                f"  ✗ Legacy SMTP failed ({smtp_config.get('host', '?')}:"
                f"{smtp_config.get('port', '?')}): {e}",
                'ERROR', worker_name
            )
            return False

    @staticmethod
    def _send_internal_email(from_addr: str, to_addr: str, raw_message: bytes, worker_name: str) -> bool:
        """
        Send email via internal SMTP port (bypasses transport_maps)
        
        Args:
            from_addr: From address
            to_addr: To address
            raw_message: Raw MIME message bytes
            worker_name: Worker name for logging
            
        Returns:
            True on success, False on failure
        """
        try:
            with smtplib.SMTP(config.smtp_host, config.internal_smtp_port, timeout=30) as conn:
                conn.ehlo()
                conn.sendmail(from_addr, [to_addr], raw_message)
                return True
        except Exception as e:
            log(f"  ✗ Internal delivery failed to {to_addr}: {e}", 'ERROR', worker_name)
            return False
    
    @staticmethod
    def _create_ooo_reply(original_parsed, recipient: str, ooo_msg: str, content_type: str = 'text'):
        """Create Out-of-Office reply as complete MIME message"""
        text_body, html_body = EmailParser.extract_body_parts(original_parsed)
        original_subject = original_parsed.get('Subject', '(no subject)')
        original_from = original_parsed.get('From', 'unknown')

        msg = MIMEMultipart('mixed')
        msg['From'] = recipient
        msg['To'] = original_from
        msg['Subject'] = f"Out of Office: {original_subject}"
        msg['Date'] = formatdate(localtime=True)
        msg['Message-ID'] = make_msgid(domain=recipient.split('@')[1])
        msg['In-Reply-To'] = original_parsed.get('Message-ID', '')
        msg['References'] = original_parsed.get('Message-ID', '')
        msg['Auto-Submitted'] = 'auto-replied'
        msg['X-SES-Worker-Processed'] = 'ooo-reply'

        body_part = MIMEMultipart('alternative')
        
        # Text version
        text_content = f"{ooo_msg}\n\n--- Original Message ---\n"
        text_content += f"From: {original_from}\n"
        text_content += f"Subject: {original_subject}\n\n"
        text_content += text_body
        body_part.attach(MIMEText(text_content, 'plain', 'utf-8'))

        # HTML version (if desired and original available)
        if content_type == 'html' or html_body:
            html_content = f"<div>{ooo_msg}</div><br><hr><br>"
            html_content += "<strong>Original Message</strong><br>"
            html_content += f"<strong>From:</strong> {original_from}<br>"
            html_content += f"<strong>Subject:</strong> {original_subject}<br><br>"
            html_content += (html_body if html_body else text_body.replace('\n', '<br>'))
            body_part.attach(MIMEText(html_content, 'html', 'utf-8'))

        msg.attach(body_part)
        return msg
    
    @staticmethod
    def _create_forward_message(original_parsed, recipient: str, forward_to: str, original_from: str):
        """Create Forward message as complete MIME message"""
        original_subject = original_parsed.get('Subject', '(no subject)')
        original_date = original_parsed.get('Date', 'unknown')

        msg = MIMEMultipart('mixed')
        msg['From'] = recipient
        msg['To'] = forward_to
        msg['Subject'] = f"FWD: {original_subject}"
        msg['Date'] = formatdate(localtime=True)
        msg['Message-ID'] = make_msgid(domain=recipient.split('@')[1])
        msg['Reply-To'] = original_from
        msg['X-SES-Worker-Processed'] = 'forwarded'

        text_body, html_body = EmailParser.extract_body_parts(original_parsed)
        body_part = MIMEMultipart('alternative')
        
        # Text version
        fwd_text = "---------- Forwarded message ---------\n"
        fwd_text += f"From: {original_from}\n"
        fwd_text += f"Date: {original_date}\n"
        fwd_text += f"Subject: {original_subject}\n"
        fwd_text += f"To: {recipient}\n\n"
        fwd_text += text_body
        body_part.attach(MIMEText(fwd_text, 'plain', 'utf-8'))

        # HTML version
        if html_body:
            fwd_html = "<div style='border-left:3px solid #ccc;padding-left:10px;'>"
            fwd_html += "<strong>---------- Forwarded message ---------</strong><br>"
            fwd_html += f"<strong>From:</strong> {original_from}<br>"
            fwd_html += f"<strong>Date:</strong> {original_date}<br>"
            fwd_html += f"<strong>Subject:</strong> {original_subject}<br>"
            fwd_html += f"<strong>To:</strong> {recipient}<br><br>"
            fwd_html += html_body
            fwd_html += "</div>"
            body_part.attach(MIMEText(fwd_html, 'html', 'utf-8'))

        msg.attach(body_part)

        # Copy attachments - FIX FILENAMES
        if original_parsed.is_multipart():
            for part in original_parsed.walk():
                if part.get_content_maintype() == 'multipart':
                    continue
                if part.get_content_type() in ['text/plain', 'text/html']:
                    continue
                
                # Fix malformed filename in Content-Disposition
                content_disp = part.get('Content-Disposition', '')
                if 'filename=' in content_disp and '"' not in content_disp:
                    # Add quotes around filename with spaces
                    import re
                    fixed_disp = re.sub(r'filename=([^;"\s]+(?:\s+[^;"\s]+)*)', r'filename="\1"', content_disp)
                    part.replace_header('Content-Disposition', fixed_disp)
                
                msg.attach(part)

        return msg