from flask import Flask, request, jsonify
from flask_cors import CORS
import smtplib
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.mime.base import MIMEBase
from email import encoders
import base64
import os

app = Flask(__name__)
CORS(app) # Allows requests from your frontend

# Environment variables for SMTP configuration (MUST BE SET before running)
SMTP_SERVER_HOST = os.environ.get("SMTP_SERVER_HOST")
SMTP_SERVER_PORT = os.environ.get("SMTP_SERVER_PORT")
SMTP_SENDER_EMAIL = os.environ.get("SMTP_SENDER_EMAIL")
SMTP_SENDER_PASSWORD = os.environ.get("SMTP_SENDER_PASSWORD")

@app.route('/send-report-via-email', methods=['POST']) # Changed endpoint name for clarity
def handle_send_email():
    print("EMAIL_SENDER_API: Received request at /send-report-via-email") # Log request
    if not all([SMTP_SERVER_HOST, SMTP_SERVER_PORT, SMTP_SENDER_EMAIL, SMTP_SENDER_PASSWORD]):
        error_msg = "EMAIL_SENDER_API: ERROR - SMTP environment variables not fully set."
        print(error_msg)
        return jsonify({"status": "error", "message": "Email server configuration incomplete on the API."}), 500
    
    try:
        SMTP_PORT_INT = int(SMTP_SERVER_PORT)
    except ValueError:
        error_msg = "EMAIL_SENDER_API: ERROR - Invalid SMTP_SERVER_PORT configured."
        print(error_msg)
        return jsonify({"status": "error", "message": "Invalid email server port configured on the API."}), 500

    data = request.json
    if not data:
        print("EMAIL_SENDER_API: No JSON data received.")
        return jsonify({"status": "error", "message": "No data received by email API."}), 400

    recipient_email = data.get('recipient_email')
    pdf_base64_data = data.get('pdf_base64_data')
    pdf_filename = data.get('pdf_filename')
    print(f"EMAIL_SENDER_API: Attempting to send to: {recipient_email}, Filename: {pdf_filename}")


    if not all([recipient_email, pdf_base64_data, pdf_filename]):
        print("EMAIL_SENDER_API: Missing required data in JSON payload.")
        return jsonify({"status": "error", "message": "Missing required data: recipient_email, pdf_base64_data, or pdf_filename."}), 400

    try:
        msg = MIMEMultipart()
        msg['From'] = SMTP_SENDER_EMAIL
        msg['To'] = recipient_email
        msg['Subject'] = f"EPIC-AMP Analysis Report: {pdf_filename}" # Updated subject
        body = f"""Dear User,\n\nPlease find your EPIC-AMP analysis report attached.\n\nFilename: {pdf_filename}\n\nThis report includes details on your sequence analysis.\n\nThank you for using EPIC-AMP!\n\nBest regards,\nThe EPIC-AMP Team\nBioinformatics and Computational Biology Unit, Zewail City\nFor inquiries: epicamp.sup@gmail.com"""
        msg.attach(MIMEText(body, 'plain'))

        pdf_data_bytes = base64.b64decode(pdf_base64_data)
        part = MIMEBase('application', 'octet-stream')
        part.set_payload(pdf_data_bytes)
        encoders.encode_base64(part)
        part.add_header('Content-Disposition', f"attachment; filename=\"{pdf_filename}\"")
        msg.attach(part)

        print(f"EMAIL_SENDER_API: Connecting to SMTP server {SMTP_SERVER_HOST}:{SMTP_PORT_INT}")
        with smtplib.SMTP(SMTP_SERVER_HOST, SMTP_PORT_INT) as server:
            server.set_debuglevel(1) # More verbose SMTP logs
            server.ehlo()
            if SMTP_PORT_INT == 587: # TLS
                print("EMAIL_SENDER_API: Starting TLS...")
                server.starttls()
                server.ehlo()
            print("EMAIL_SENDER_API: Logging in...")
            server.login(SMTP_SENDER_EMAIL, SMTP_SENDER_PASSWORD)
            print("EMAIL_SENDER_API: Sending mail...")
            server.sendmail(SMTP_SENDER_EMAIL, recipient_email, msg.as_string())
            print("EMAIL_SENDER_API: Mail sent.")
        
        success_msg = f"Report successfully sent to {recipient_email}."
        print(f"EMAIL_SENDER_API: {success_msg}")
        return jsonify({"status": "success", "message": success_msg}), 200

    except smtplib.SMTPAuthenticationError as e:
        error_msg = f"EMAIL_SENDER_API: SMTP Authentication Error - {e}"
        print(error_msg)
        return jsonify({"status": "error", "message": "Email server authentication failed on the API."}), 500
    except Exception as e:
        import traceback
        error_msg = f"EMAIL_SENDER_API: Error sending email to {recipient_email} - {e}"
        print(error_msg)
        print(traceback.format_exc())
        return jsonify({"status": "error", "message": f"Failed to send email via API: {e}"}), 500

if __name__ == '__main__':
    # IMPORTANT: Run this on a DIFFERENT port than your main Gradio app (usually 7860)
    api_port = 5002 # Using port 5002 here for the email API
    print(f"Starting Email Sender API Service on port {api_port}...")
    print(f"SMTP Config Loaded: Server={SMTP_SERVER_HOST}, Port={SMTP_SERVER_PORT}, User Email Set={SMTP_SENDER_EMAIL is not None}")
    if not all([SMTP_SERVER_HOST, SMTP_SERVER_PORT, SMTP_SENDER_EMAIL, SMTP_SENDER_PASSWORD]):
        print("WARNING: EMAIL_SENDER_API - SMTP environment variables are not fully set. Email sending will likely fail.")
    app.run(host='0.0.0.0', port=api_port, debug=True) # debug=True for development feedback