from flask import Flask, request, Response
import xml.etree.ElementTree as ET
import html

# Initialize the Flask application
app = Flask(__name__)

# This is the endpoint TeleCloud will send requests to.
# Make sure it's unique and secure.
@app.route('/your_module_endpoint', methods=['POST'])
def telecloud_module():
    """
    Handles incoming POST requests from TeleCloud.
    """
    
    # --- 1. Read Incoming Data ---
    # Flask's request.form object contains the POST data.
    # Note: Arrays may be flattened by web servers for Python frameworks. The key might look like 'Customer[first_name]'.
    # Adjust the keys if your server configuration handles them differently.
    
    service = request.form.get('SERVICE', '')
    customer_first_name = request.form.get('Customer[first_name]', 'Guest')
    var1_value = request.form.get('VAR1', '')  # Example: This could be an IMEI
    var2_value = request.form.get('VAR2', '')  # Example: This could be a SIM
    carrier_product_id = request.form.get('CARRIER_PRODUCT_ID', '')

    # --- 2. Handle the Module Test Request ---
    # When you configure the module in TeleCloud, it sends a test request.
    # Your module MUST respond correctly to be saved.
    if service == 'TEST':
        xml_response = '<MODULE><SUCCESS>Y</SUCCESS></MODULE>'
        return Response(xml_response, mimetype='text/xml')

    # --- 3. Your Business & Carrier Logic ---
    # This is where you'll add your custom code to interact with your carrier's API.
    # Use the variables from Step 1 to build your request to the carrier.
    
    # For this example, we'll simulate a carrier interaction.
    carrier_provisioned_successfully = True  # Change to False to test error handling
    carrier_error_message = 'Carrier API Error: Invalid SIM and IMEI combination.'
    new_phone_number_from_carrier = '5559876543'  # A value returned by the carrier

    # --- 4. Construct the XML Response for TeleCloud ---
    # Using a library like xml.etree.ElementTree is safer than building XML with strings.
    
    module_root = ET.Element('MODULE')

    if carrier_provisioned_successfully:
        # The operation was a success.
        success_element = ET.SubElement(module_root, 'SUCCESS')
        success_element.text = 'Y'
        
        # Example: The carrier assigned a new phone number during activation.
        # We want to store this in VAR3 on the TeleCloud order.
        # Your Product Group must have VAR3 configured for this to be saved.
        var3_element = ET.SubElement(module_root, 'VAR3')
        # Use html.escape to prevent XML injection, similar to htmlspecialchars in PHP.
        var3_element.text = html.escape(new_phone_number_from_carrier)
        
        # Optional: If provisioning takes a long time, you can tell TeleCloud to wait.
        # status_element = ET.SubElement(module_root, 'STATUS')
        # status_element.text = 'PENDING'

    else:
        # The operation failed.
        success_element = ET.SubElement(module_root, 'SUCCESS')
        success_element.text = 'N'
        
        error_element = ET.SubElement(module_root, 'ERROR')
        error_element.text = html.escape(carrier_error_message)

    # --- 5. Send the Response ---
    # Convert the XML ElementTree to a string and return it with the correct mimetype.
    xml_response_string = ET.tostring(module_root, encoding='unicode')
    
    return Response(xml_response_string, mimetype='text/xml')

# --- How to Run This Script ---
# To run for development:
# 1. Open your terminal in the same directory as this file.
# 2. Run the command: flask --app this_module_file_name.py run
#
# For production, use a proper WSGI server like Gunicorn or uWSGI.
# Example with Gunicorn: gunicorn --workers 4 --bind 0.0.0.0:8000 app:app
if __name__ == '__main__':
    # This allows running the script directly for simple testing.
    # The debug=True flag provides helpful error pages but should be
    # turned OFF in a production environment.
    app.run(host='0.0.0.0', port=5000, debug=True)