from flask import Flask, request, jsonify
from flask_cors import CORS
import base64
import os
import traceback

# For SendGrid
from sendgrid import SendGridAPIClient
from sendgrid.helpers.mail import (Mail, Attachment, FileContent, FileName, FileType, Disposition)

app = Flask(__name__)
CORS(app)

# Environment variable for the Email API Key (set as a Secret in HF Space)
SENDGRID_API_KEY = os.environ.get("SENDGRID_API_KEY")
# Your sender email address - should be verified with SendGrid for best results
SENDER_EMAIL_ADDRESS = os.environ.get("SENDER_EMAIL_ADDRESS") # e.g., epicamp.response@gmail.com or a domain email

@app.route('/send-report-via-email', methods=['POST'])
def handle_send_email_http_api():
    request_id = base64.b64encode(os.urandom(6)).decode('utf-8')
    print(f"EMAIL_SENDER_API (HTTP - SendGrid) [{request_id}]: Received request")

    if not SENDGRID_API_KEY:
        error_msg = f"EMAIL_SENDER_API (HTTP - SendGrid) [{request_id}]: ERROR - SENDGRID_API_KEY (Secret) not set."
        print(error_msg)
        return jsonify({"status": "error", "message": "Email API key configuration incomplete."}), 500
    
    if not SENDER_EMAIL_ADDRESS:
        error_msg = f"EMAIL_SENDER_API (HTTP - SendGrid) [{request_id}]: ERROR - SENDER_EMAIL_ADDRESS (Secret) not set."
        print(error_msg)
        return jsonify({"status": "error", "message": "Sender email address configuration incomplete."}), 500

    data = request.json
    if not data:
        print(f"EMAIL_SENDER_API (HTTP - SendGrid) [{request_id}]: 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 (HTTP - SendGrid) [{request_id}]: Attempting to send to: {recipient_email}, Filename: {pdf_filename}")

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

    message = Mail(
        from_email=SENDER_EMAIL_ADDRESS,
        to_emails=recipient_email,
        subject=f"EPIC-AMP Analysis Report: {pdf_filename}",
        html_content=f"""
        <p>Dear User,</p>
        <p>Please find your EPIC-AMP analysis report attached.</p>
        <p>Filename: {pdf_filename}</p>
        <p>This report includes details on your sequence analysis.</p>
        <p>Thank you for using EPIC-AMP!</p>
        <p>Best regards,<br>The EPIC-AMP Team<br>
        Bioinformatics and Computational Biology Unit, Zewail City<br>
        For inquiries: epicamp.sup@gmail.com</p>
        """
    )

    try:
        # The PDF data is already base64 encoded from the frontend
        attachment = Attachment()
        attachment.file_content = FileContent(pdf_base64_data) # SendGrid library expects base64 string
        attachment.file_name = FileName(pdf_filename)
        attachment.file_type = FileType('application/pdf')
        attachment.disposition = Disposition('attachment')
        # attachment.content_id = ContentId('MyId') # Optional
        message.attachment = attachment
    except Exception as e:
        error_msg = f"EMAIL_SENDER_API (HTTP - SendGrid) [{request_id}]: Error preparing attachment: {e}"
        print(error_msg); traceback.print_exc()
        return jsonify({"status": "error", "message": "Error preparing PDF attachment."}), 500

    try:
        sg = SendGridAPIClient(SENDGRID_API_KEY)
        response = sg.send(message)
        print(f"EMAIL_SENDER_API (HTTP - SendGrid) [{request_id}]: SendGrid Response Status Code: {response.status_code}")
        # print(f"EMAIL_SENDER_API (HTTP - SendGrid) [{request_id}]: SendGrid Response Body: {response.body}")
        # print(f"EMAIL_SENDER_API (HTTP - SendGrid) [{request_id}]: SendGrid Response Headers: {response.headers}")

        if 200 <= response.status_code < 300: # Check for successful status codes
            success_msg = f"Report successfully sent to {recipient_email} via SendGrid."
            print(f"EMAIL_SENDER_API (HTTP - SendGrid) [{request_id}]: {success_msg}")
            return jsonify({"status": "success", "message": success_msg}), 200
        else:
            error_msg = f"EMAIL_SENDER_API (HTTP - SendGrid) [{request_id}]: SendGrid API Error (Status {response.status_code}): {response.body}"
            print(error_msg)
            return jsonify({"status": "error", "message": f"Email service provider API error (Status {response.status_code})."}), 502 # Bad Gateway / Upstream error
    
    except Exception as e:
        error_msg = f"EMAIL_SENDER_API (HTTP - SendGrid) [{request_id}]: An unexpected error occurred while sending email via SendGrid: {e}"
        print(error_msg)
        traceback.print_exc()
        return jsonify({"status": "error", "message": f"An unexpected error occurred on the email API: {type(e).__name__}"}), 500

# if __name__ == '__main__':
#     # For local testing, set ENV VARS for SENDGRID_API_KEY and SENDER_EMAIL_ADDRESS
#     api_port = int(os.environ.get("PORT", 5003)) # Different port for this version locally
#     print(f"Starting HTTP Email Sender API Service (SendGrid) locally on port {api_port}...")
#     # ... local startup messages ...
#     app.run(host='0.0.0.0', port=api_port, debug=True)