# This script is used to set up the system for sending triggers to the 
# EEG recording software (e.g., BrainVision Recorder). The code 
# automatically looks for an available serial port at the beginning 
# of the session. If there are any available ports, a connection is 
# established to the first port in the list. If there are no available 
# ports, no connection is established, and a warning is shown on 
# the screen, informing the user that no triggers will be sent to the 
# EEG recorder. In the latter case, the triggers are only printed in 
# the Python console of OpenSesame.
# 
# The code is in part based on a tutorial by Kate Stone, available at 
# https://stonekate.github.io/blog/opensesame, and on an answer 
# on StackOverflow by user 'quamrana', available at 
# https://stackoverflow.com/a/76829646/7050882. 
# The rest is based on pyserial:
# https://pyserial.readthedocs.io/en/latest/pyserial_api.html


# For development purposes, the test mode can be set to 'yes' 
# below, which will prevent attempting to connect to a port. 
# As a result, no triggers will be sent to the EEG recorder, 
# and instead, the triggers will be printed in the Python 
# console of OpenSesame.

var.test_mode = 'no' 


#_______________________________________________________________

import serial
import serial.tools.list_ports
import time

# If no serial ports are available, activate test mode
if serial.tools.list_ports.comports() == []:
    var.test_mode = 'yes' 

# Define `send_trigger` function, which should be used in inline 
# scripts as in the following example: `send_trigger(1)`

# If we are not in test mode...
if(var.test_mode == 'no'):

    # Open the first serial port available
    serialport = serial.Serial(serial.tools.list_ports.comports()[0].device)
    
    # Send triggers to the port
    def send_trigger(trigger):
        serialport.write(trigger.to_bytes(length = 1, byteorder = 'big'))
        time.sleep(0.01) # 10 ms separation from next trigger (see manual of BrainVision Recorder)
        serialport.write(int(0).to_bytes(length = 1, byteorder = 'big')) # reset port
        return;
    
# When in test mode, show warning at the beginning of the experiment. 
# To continue, the letter C must be pressed twice. 
else:
    test_canvas = Canvas(color = 'red', font_size = 38, font_family = 'sans');
    test_canvas.text('<div style="line-height:200%; margin-right:150px; margin-left:150px; text-align:left;">WARNING. Triggers cannot be sent to the EEG recorder, either because <tt>test_mode</tt> is activated in the trigger-setup script, or because no serial ports are available. Press <b>Esc</b> to quit the session, or press <b>C</b> twice to continue. If you continue, the triggers will only be printed in the Python console of OpenSesame.</div>');
    test_canvas.show();
    my_keyboard = Keyboard();
    key, end_time = my_keyboard.get_key(keylist=['c']);
    key, end_time = my_keyboard.get_key(keylist=['c']);
    
    # In the `send_trigger` function, only print the triggers
    def send_trigger(trigger):
        print(trigger)
        time.sleep(0.01) # 10 ms separation from next trigger
        print(0)
        return;
    
# Reset EEG port at the beginning of the session
send_trigger(0)