feat: Detect and display Teams meeting emails without ICS attachments

- Fix is_calendar_email() to decode base64 MIME content before checking
- Add extract_teams_meeting_info() to parse meeting details from email body
- Update parse_calendar_from_raw_message() to fall back to Teams extraction
- Show 'Join Meeting' button for TEAMS method events in CalendarInvitePanel
- Extract Teams URL, Meeting ID, and organizer from email content

src/mail/notification_detector.py

@@ -357,6 +357,43 @@ CALENDAR_SUBJECT_PATTERNS = [
 ]
 
 
+def _decode_mime_content(raw_content: str) -> str:
+    """Decode base64 parts from MIME content for text searching.
+
+    Args:
+        raw_content: Raw MIME message content
+
+    Returns:
+        Decoded text content for searching
+    """
+    import base64
+
+    decoded_parts = [raw_content]  # Include raw content for non-base64 parts
+
+    # Find and decode base64 text parts
+    b64_pattern = re.compile(
+        r"Content-Type:\s*text/(?:plain|html)[^\n]*\n"
+        r"(?:[^\n]+\n)*?"  # Other headers
+        r"Content-Transfer-Encoding:\s*base64[^\n]*\n"
+        r"(?:[^\n]+\n)*?"  # Other headers
+        r"\n"  # Empty line before content
+        r"([A-Za-z0-9+/=\s]+)",
+        re.IGNORECASE,
+    )
+
+    for match in b64_pattern.finditer(raw_content):
+        try:
+            b64_content = (
+                match.group(1).replace("\n", "").replace("\r", "").replace(" ", "")
+            )
+            decoded = base64.b64decode(b64_content).decode("utf-8", errors="replace")
+            decoded_parts.append(decoded)
+        except Exception:
+            pass
+
+    return " ".join(decoded_parts)
+
+
 def is_calendar_email(envelope: dict[str, Any], content: str | None = None) -> bool:
     """Check if an email is a calendar invite/update/cancellation.
 
@@ -388,12 +425,15 @@ def is_calendar_email(envelope: dict[str, Any], content: str | None = None) -> b
 
     # If content is provided, check for calendar indicators
     if content:
+        # Decode base64 parts for proper text searching
+        decoded_content = _decode_mime_content(content).lower()
+
         # Teams meeting indicators
-        if "microsoft teams meeting" in content.lower():
+        if "microsoft teams meeting" in decoded_content:
             return True
-        if "join the meeting" in content.lower():
+        if "join the meeting" in decoded_content:
             return True
-        # ICS content indicator
+        # ICS content indicator (check raw content for MIME headers)
         if "text/calendar" in content.lower():
             return True
         # VCALENDAR block

src/mail/utils/calendar_parser.py

@@ -233,19 +233,135 @@ def parse_ics_content(ics_content: str) -> Optional[ParsedCalendarEvent]:
         return None
 
 
+def _decode_mime_text(raw_message: str) -> str:
+    """Decode base64 text parts from MIME message.
+
+    Args:
+        raw_message: Raw MIME message
+
+    Returns:
+        Decoded text content
+    """
+    decoded_parts = []
+
+    # Find and decode base64 text parts
+    b64_pattern = re.compile(
+        r"Content-Type:\s*text/(?:plain|html)[^\n]*\n"
+        r"(?:[^\n]+\n)*?"
+        r"Content-Transfer-Encoding:\s*base64[^\n]*\n"
+        r"(?:[^\n]+\n)*?"
+        r"\n"
+        r"([A-Za-z0-9+/=\s]+)",
+        re.IGNORECASE,
+    )
+
+    for match in b64_pattern.finditer(raw_message):
+        try:
+            b64_content = (
+                match.group(1).replace("\n", "").replace("\r", "").replace(" ", "")
+            )
+            decoded = base64.b64decode(b64_content).decode("utf-8", errors="replace")
+            decoded_parts.append(decoded)
+        except Exception:
+            pass
+
+    return "\n".join(decoded_parts) if decoded_parts else raw_message
+
+
+def extract_teams_meeting_info(raw_message: str) -> Optional[ParsedCalendarEvent]:
+    """Extract Teams meeting info from email body when no ICS is present.
+
+    This handles emails that contain Teams meeting details in the body
+    but don't have an ICS calendar attachment.
+
+    Args:
+        raw_message: Full raw email in EML/MIME format
+
+    Returns:
+        ParsedCalendarEvent with Teams meeting info, or None if not a Teams meeting
+    """
+    # Decode the message content
+    content = _decode_mime_text(raw_message)
+    content_lower = content.lower()
+
+    # Check if this is a Teams meeting email
+    if (
+        "microsoft teams" not in content_lower
+        and "join the meeting" not in content_lower
+    ):
+        return None
+
+    # Extract Teams meeting URL
+    teams_url_pattern = re.compile(
+        r"https://teams\.microsoft\.com/l/meetup-join/[^\s<>\"']+",
+        re.IGNORECASE,
+    )
+    teams_url_match = teams_url_pattern.search(content)
+    teams_url = teams_url_match.group(0) if teams_url_match else None
+
+    # Extract meeting ID
+    meeting_id_pattern = re.compile(r"Meeting ID:\s*([\d\s]+)", re.IGNORECASE)
+    meeting_id_match = meeting_id_pattern.search(content)
+    meeting_id = meeting_id_match.group(1).strip() if meeting_id_match else None
+
+    # Extract subject from email headers
+    subject = None
+    subject_match = re.search(
+        r"^Subject:\s*(.+)$", raw_message, re.MULTILINE | re.IGNORECASE
+    )
+    if subject_match:
+        subject = subject_match.group(1).strip()
+
+    # Extract organizer from From header
+    organizer_email = None
+    organizer_name = None
+    from_match = re.search(r"^From:\s*(.+)$", raw_message, re.MULTILINE | re.IGNORECASE)
+    if from_match:
+        from_value = from_match.group(1).strip()
+        # Parse "Name <email>" format
+        email_match = re.search(r"<([^>]+)>", from_value)
+        if email_match:
+            organizer_email = email_match.group(1)
+            organizer_name = from_value.split("<")[0].strip().strip('"')
+        else:
+            organizer_email = from_value
+
+    # Create location string with Teams info
+    location = teams_url if teams_url else "Microsoft Teams Meeting"
+    if meeting_id:
+        location = f"Teams Meeting (ID: {meeting_id})"
+
+    return ParsedCalendarEvent(
+        summary=subject or "Teams Meeting",
+        location=location,
+        description=f"Join: {teams_url}" if teams_url else None,
+        method="TEAMS",  # Custom method to indicate this is extracted, not from ICS
+        organizer_name=organizer_name,
+        organizer_email=organizer_email,
+    )
+
+
 def parse_calendar_from_raw_message(raw_message: str) -> Optional[ParsedCalendarEvent]:
     """Extract and parse calendar event from raw email message.
 
+    First tries to extract ICS content from the message. If no ICS is found,
+    falls back to extracting Teams meeting info from the email body.
+
     Args:
         raw_message: Full raw email in EML/MIME format
 
     Returns:
         ParsedCalendarEvent if found and parsed, None otherwise
     """
+    # First try to extract ICS content
     ics_content = extract_ics_from_mime(raw_message)
     if ics_content:
-        return parse_ics_content(ics_content)
+        event = parse_ics_content(ics_content)
-    return None
+        if event:
+            return event
+
+    # Fall back to extracting Teams meeting info from body
+    return extract_teams_meeting_info(raw_message)
 
 
 # Legacy function names for compatibility

src/mail/widgets/CalendarInvitePanel.py

@@ -132,7 +132,7 @@ class CalendarInvitePanel(Vertical):
                 classes="event-detail",
             )
 
-        # Action buttons (only for REQUEST method, not for CANCEL)
+        # Action buttons (only for REQUEST method, not for CANCEL or TEAMS)
         if is_event_request(self.event):
             with Horizontal(classes="action-buttons"):
                 yield Button(
@@ -150,6 +150,20 @@ class CalendarInvitePanel(Vertical):
                     id="btn-decline",
                     variant="error",
                 )
+        elif self.event.method == "TEAMS":
+            # Teams meeting extracted from email body (no ICS)
+            # Show join button if we have a URL in the description
+            if self.event.description and "Join:" in self.event.description:
+                with Horizontal(classes="action-buttons"):
+                    yield Button(
+                        "\uf0c1 Join Meeting",  # nf-fa-link
+                        id="btn-join",
+                        variant="primary",
+                    )
+            yield Static(
+                "[dim]Teams meeting - no calendar invite attached[/dim]",
+                classes="event-detail",
+            )
         elif is_cancelled_event(self.event):
             yield Static(
                 "[dim]This meeting has been cancelled[/dim]",
@@ -164,6 +178,8 @@ class CalendarInvitePanel(Vertical):
             return "CANCELLED", "cancelled"
         elif method == "REQUEST":
             return "INVITE", "request"
+        elif method == "TEAMS":
+            return "TEAMS", "request"
         elif method == "REPLY":
             return "REPLY", "reply"
         elif method == "COUNTER":
@@ -188,3 +204,16 @@ class CalendarInvitePanel(Vertical):
             self.post_message(self.InviteAction("tentative", self.event))
         elif button_id == "btn-decline":
             self.post_message(self.InviteAction("decline", self.event))
+        elif button_id == "btn-join":
+            # Open Teams meeting URL
+            if self.event.description and "Join:" in self.event.description:
+                import re
+                import subprocess
+
+                url_match = re.search(
+                    r"Join:\s*(https://[^\s]+)", self.event.description
+                )
+                if url_match:
+                    url = url_match.group(1)
+                    subprocess.run(["open", url], capture_output=True)
+                    self.app.notify("Opening Teams meeting...", severity="information")