#!/usr/bin/python3

from flask import Flask, request
import threading
import serial
import time

app = Flask(__name__)

globals()['data'] = ""
globals()['lock'] = threading.Lock()

@app.route('/update', methods=['PUT'])
def update():
  grid = request.json['data']
  grid_string = prepare_grid(grid)

  with globals()['lock']:
    globals()['data'] = grid_string

  return grid_string

def prepare_grid(grid):
  # follow down up down down up down
  HEIGHT = 5
  WIDTH = 6

  out = ""
  for x in range(WIDTH):
    for y in (range(0,HEIGHT,1) if x%3 == 1 else range(HEIGHT-1,-1,-1)):
      for r in range(3):
        out += hex(grid[x][y][r])[2:] + 'n'
      out += 'l'
  out += 'q'
  return out

def serial_func():
  with serial.Serial('/dev/ttyACM0', 9600, timeout=1) as ser:
    while True:
      with globals()['lock']:
        if globals()['data'] != '':
          t1 = time.time()
          ser.write(bytes(globals()['data'], 'ascii'))
          t2 = time.time()
          print("time taken: " + str(t2-t1) + "s")
          globals()['data'] = ''
      time.sleep(0.1)

serial_thread = threading.Thread(target=serial_func)
serial_thread.start()

if __name__ == '__main__':
  app.run(host='0.0.0.0')