# Copyright (C) Ivan Kravets <me@ikravets.com>
# See LICENSE for details.

import platform
from time import sleep

from SCons.Script import Exit
from serial import Serial

from platformio.util import get_serialports


def FlushSerialBuffer(env, port):
    s = Serial(env.subst(port))
    s.flushInput()
    s.setDTR(False)
    s.setRTS(False)
    sleep(0.1)
    s.setDTR(True)
    s.setRTS(True)
    s.close()


def TouchSerialPort(env, port, baudrate):
    s = Serial(port=env.subst(port), baudrate=baudrate)
    s.close()
    if platform.system() != "Darwin":
        sleep(0.3)


def WaitForNewSerialPort(_, before):
    new_port = None
    elapsed = 0
    while elapsed < 10:
        now = [i['port'] for i in get_serialports()]
        diff = list(set(now) - set(before))
        if diff:
            new_port = diff[0]
            break

        before = now
        sleep(0.25)
        elapsed += 0.25

    if not new_port:
        Exit("Error: Couldn't find a board on the selected port. "
             "Check that you have the correct port selected. "
             "If it is correct, try pressing the board's reset "
             "button after initiating the upload.")

    return new_port


def AutodetectUploadPort(env):
    if "UPLOAD_PORT" not in env:
        for item in get_serialports():
            if "VID:PID" in item['hwid']:
                print "Auto-detected UPLOAD_PORT: %s" % item['port']
                env.Replace(UPLOAD_PORT=item['port'])
                break

    if "UPLOAD_PORT" not in env:
        Exit("Error: Please specify `upload_port` for environment or use "
             "global `--upload-port` option.\n")


def exists(_):
    return True


def generate(env):
    env.AddMethod(FlushSerialBuffer)
    env.AddMethod(TouchSerialPort)
    env.AddMethod(WaitForNewSerialPort)
    env.AddMethod(AutodetectUploadPort)
    return env