import {HOME_FOLDER, SERVICE_WORKER_PATH} from './constants';

export enum MessageTag {

MATPLOTLIB_IMG = 'MATPLOTLIB_SHOW_IMG',

NEIGHBORHOOD_SIGNAL = '[NEIGHBORHOOD]',

INPUT_PROMPT = '[INPUT_PROMPT]',

INPUT_FAILED = '[INPUT_FAILED]',

}

export const TEARDOWN_CODE = `from pythonlab_setup import teardown_pythonlab

teardown_pythonlab('/${HOME_FOLDER}')

`;

export const SETUP_CODE = `from pythonlab_setup import setup_pythonlab

setup_pythonlab('${MessageTag.MATPLOTLIB_IMG}')

`;

// The two functions below are used to patch the input function in Python.

// When the user calls input() or readline from stdin in Python, we intercept

// the call and send a get request to our service worker, which in turn sends a

// message to the main thread that we are awaiting input. The main thread then

// sends a message back to the service worker, which becomes the result of the get request.

export const patchInputCode = (id: number) => `

import sys, builtins

import pythonlab_input

def get_input(prompt=""):

print(f'${MessageTag.INPUT_PROMPT}{prompt}')

return pythonlab_input.getInput("${id}", prompt)

builtins.input = get_input

sys.stdin.readline = lambda: pythonlab_input.getInput("${id}", "")

`;

export const pythonlabInputModule = {

getInput: (id: string, prompt: string) => {

const request = new XMLHttpRequest();

// Synchronous request to be intercepted by service worker

request.open(

'GET',

`${SERVICE_WORKER_PATH}?id=${id}&prompt=${encodeURIComponent(prompt)}`,

false

);

request.send(null);

if (request.status !== 200) {

throw new Error(MessageTag.INPUT_FAILED);

}

return request.responseText;

},

};