SendGrid Inbound Parse Webhook: Receive & Process Incoming Email

# 1. Add MX record in DNS:
# Type: MX
# Name: inbound.yourdomain.com
# Value: mx.sendgrid.net
# Priority: 10

# 2. In SendGrid Dashboard:
# Settings > Inbound Parse
# Hostname: inbound.yourdomain.com
# URL: https://api.dodatech.com/sendgrid/inbound
# Spam check: On
# Send raw: Off

from flask import Flask, request, jsonify
import json

app = Flask(__name__)

@app.route("/sendgrid/inbound", methods=["POST"])
def handle_inbound():
    # Extract fields from multipart form data
    to_email = request.form.get("to")
    from_email = request.form.get("from")
    subject = request.form.get("subject")
    text_body = request.form.get("text")
    html_body = request.form.get("html")
    attachments_count = int(request.form.get("attachments", 0))

    print(f"Email received from {from_email}")
    print(f"Subject: {subject}")
    print(f"Body: {text_body[:200]}...")

    # Process attachments
    for i in range(attachments_count):
        attachment = request.files.get(f"attachment{i}")
        if attachment:
            filename = attachment.filename
            content_type = attachment.content_type
            print(f"  Attachment {i}: {filename} ({content_type})")

    # Store in database
    # db.incoming_emails.insert_one({
    #     "from": from_email,
    #     "subject": subject,
    #     "body": text_body,
    #     "received_at": datetime.utcnow()
    # })

    return jsonify({"status": "ok"}), 200

import re

def parse_reply(text_body):
    # Remove original message (common email clients)
    lines = text_body.split("\n")
    reply_lines = []

    for line in lines:
        # Stop at common reply markers
        if re.match(r"^On .+ wrote:", line.strip()):
            break
        if re.match(r"^_{10,}", line.strip()):
            break
        if line.strip().startswith("> "):
            continue
        reply_lines.append(line)

    reply_text = "\n".join(reply_lines).strip()
    return reply_text

@app.route("/sendgrid/inbound", methods=["POST"])
def handle_reply():
    from_email = request.form.get("from")
    text_body = request.form.get("text", "")
    subject = request.form.get("subject", "")
    references = request.form.get("references", "")

    reply_text = parse_reply(text_body)
    print(f"Parsed reply from {from_email}: {reply_text[:100]}...")

    # Extract incident ID from subject or references
    incident_id = extract_incident_id(subject, references)

    if incident_id:
        add_reply_to_incident(incident_id, from_email, reply_text)
        print(f"Reply added to incident: {incident_id}")
    else:
        create_new_ticket(from_email, reply_text, subject)
        print(f"New ticket created from email reply")

    return jsonify({"status": "ok"}), 200

def extract_incident_id(subject, references):
    match = re.search(r"\[INC-(\d+)\]", subject)
    if match:
        return match.group(1)
    # Fallback: check references header for message IDs
    return None

import os
from werkzeug.utils import secure_filename

UPLOAD_DIR = "/tmp/email_attachments"

def process_attachments(request, incident_id):
    attachments_count = int(request.form.get("attachments", 0))
    saved_files = []

    for i in range(attachments_count):
        attachment = request.files.get(f"attachment{i}")
        if attachment and attachment.filename:
            filename = secure_filename(f"{incident_id}_{int(time.time())}_{attachment.filename}")
            filepath = os.path.join(UPLOAD_DIR, filename)
            attachment.save(filepath)
            saved_files.append({
                "original_name": attachment.filename,
                "saved_as": filename,
                "content_type": attachment.content_type,
                "size": os.path.getsize(filepath)
            })
            print(f"Saved attachment: {filename} ({attachment.content_type})")

    return saved_files