#!/usr/bin/env python
#
# This file is part of the MicroPython project, http://micropython.org/
#
# The MIT License (MIT)
#
# Copyright (c) 2014-2016 Damien P. George
# Copyright (c) 2017 Paul Sokolovsky
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.

"""
pyboard interface

This module provides the Pyboard class, used to communicate with and
control a MicroPython device over a communication channel. Both real
boards and emulated devices (e.g. running in QEMU) are supported.
Various communication channels are supported, including a serial
connection, telnet-style network connection, external process
connection.

Example usage:

 import pyboard
 pyb = pyboard.Pyboard('/dev/ttyACM0')

Or:

 pyb = pyboard.Pyboard('192.168.1.1')

Then:

 pyb.enter_raw_repl()
 pyb.exec('pyb.LED(1).on()')
 pyb.exit_raw_repl()

Note: if using Python2 then pyb.exec must be written as pyb.exec_.
To run a script from the local machine on the board and print out the results:

 import pyboard
 pyboard.execfile('test.py', device='/dev/ttyACM0')

This script can also be run directly. To execute a local script, use:

 ./pyboard.py test.py

Or:

 python pyboard.py test.py

"""

import sys
import time
import os

try:
 stdout = sys.stdout.buffer
except AttributeError:
 # Python2 doesn't have buffer attr
 stdout = sys.stdout

def stdout_write_bytes(b):
 b = b.replace(b"\x04", b"")
 stdout.write(b)
 stdout.flush()

class PyboardError(BaseException):
 pass

class TelnetToSerial:
 def __init__(self, ip, user, password, read_timeout=None):
 import telnetlib
 self.tn = telnetlib.Telnet(ip, timeout=15)
 self.read_timeout = read_timeout
 if b'Login as:' in self.tn.read_until(b'Login as:', timeout=read_timeout):
 self.tn.write(bytes(user, 'ascii') + b"\r\n")

 if b'Password:' in self.tn.read_until(b'Password:', timeout=read_timeout):
 # needed because of internal implementation details of the telnet server
 time.sleep(0.2)
 self.tn.write(bytes(password, 'ascii') + b"\r\n")

 if b'for more information.' in self.tn.read_until(b'Type "help()" for more information.', timeout=read_timeout):
 # login successful
 from collections import deque
 self.fifo = deque()
 return

 raise PyboardError('Failed to establish a telnet connection with the board')

 def __del__(self):
 self.close()

 def close(self):
 try:
 self.tn.close()
 except:
 # the telnet object might not exist yet, so ignore this one
 pass

 def read(self, size=1):
 while len(self.fifo) < size:
 timeout_count = 0
 data = self.tn.read_eager()
 if len(data):
 self.fifo.extend(data)
 timeout_count = 0
 else:
 time.sleep(0.25)
 if self.read_timeout is not None and timeout_count > 4 * self.read_timeout:
 break
 timeout_count += 1

 data = b''
 while len(data) < size and len(self.fifo) > 0:
 data += bytes([self.fifo.popleft()])
 return data

 def write(self, data):
 self.tn.write(data)
 return len(data)

 def inWaiting(self):
 n_waiting = len(self.fifo)
 if not n_waiting:
 data = self.tn.read_eager()
 self.fifo.extend(data)
 return len(data)
 else:
 return n_waiting


class ProcessToSerial:
 "Execute a process and emulate serial connection using its stdin/stdout."

 def __init__(self, cmd):
 import subprocess
 self.subp = subprocess.Popen(cmd.split(), bufsize=0, shell=True, preexec_fn=os.setsid,
 stdin=subprocess.PIPE, stdout=subprocess.PIPE)

 # Initially was implemented with selectors, but that adds Python3
 # dependency. However, there can be race conditions communicating
 # with a particular child process (like QEMU), and selectors may
 # still work better in that case, so left inplace for now.
 #
 #import selectors
 #self.sel = selectors.DefaultSelector()
 #self.sel.register(self.subp.stdout, selectors.EVENT_READ)

 import select
 self.poll = select.poll()
 self.poll.register(self.subp.stdout.fileno())

 def close(self):
 import signal
 os.killpg(os.getpgid(self.subp.pid), signal.SIGTERM)

 def read(self, size=1):
 data = b""
 while len(data) < size:
 data += self.subp.stdout.read(size - len(data))
 return data

 def write(self, data):
 self.subp.stdin.write(data)
 return len(data)

 def inWaiting(self):
 #res = self.sel.select(0)
 res = self.poll.poll(0)
 if res:
 return 1
 return 0


class ProcessPtyToTerminal:
 """Execute a process which creates a PTY and prints slave PTY as
 first line of its output, and emulate serial connection using
 this PTY."""

 def __init__(self, cmd):
 import subprocess
 import re
 import serial
 self.subp = subprocess.Popen(cmd.split(), bufsize=0, shell=False, preexec_fn=os.setsid,
 stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
 pty_line = self.subp.stderr.readline().decode("utf-8")
 m = re.search(r"/dev/pts/[0-9]+", pty_line)
 if not m:
 print("Error: unable to find PTY device in startup line:", pty_line)
 self.close()
 sys.exit(1)
 pty = m.group()
 # rtscts, dsrdtr params are to workaround pyserial bug:
 # http://stackoverflow.com/questions/34831131/pyserial-does-not-play-well-with-virtual-port
 self.ser = serial.Serial(pty, interCharTimeout=1, rtscts=True, dsrdtr=True)

 def close(self):
 import signal
 os.killpg(os.getpgid(self.subp.pid), signal.SIGTERM)

 def read(self, size=1):
 return self.ser.read(size)

 def write(self, data):
 return self.ser.write(data)

 def inWaiting(self):
 return self.ser.inWaiting()


class Pyboard:
 def __init__(self, device, baudrate=115200, user='micro', password='python', wait=0):
 if device.startswith("exec:"):
 self.serial = ProcessToSerial(device[len("exec:"):])
 elif device.startswith("execpty:"):
 self.serial = ProcessPtyToTerminal(device[len("qemupty:"):])
 elif device and device[0].isdigit() and device[-1].isdigit() and device.count('.') == 3:
 # device looks like an IP address
 self.serial = TelnetToSerial(device, user, password, read_timeout=10)
 else:
 import serial
 delayed = False
 for attempt in range(wait + 1):
 try:
 self.serial = serial.Serial(device, baudrate=baudrate, interCharTimeout=1)
 break
 except (OSError, IOError): # Py2 and Py3 have different errors
 if wait == 0:
 continue
 if attempt == 0:
 sys.stdout.write('Waiting {} seconds for pyboard '.format(wait))
 delayed = True
 time.sleep(1)
 sys.stdout.write('.')
 sys.stdout.flush()
 else:
 if delayed:
 print('')
 raise PyboardError('failed to access ' + device)
 if delayed:
 print('')

 def close(self):
 self.serial.close()

 def read_until(self, min_num_bytes, ending, timeout=10, data_consumer=None):
 data = self.serial.read(min_num_bytes)
 if data_consumer:
 data_consumer(data)
 timeout_count = 0
 while True:
 if data.endswith(ending):
 break
 elif self.serial.inWaiting() > 0:
 new_data = self.serial.read(1)
 data = data + new_data
 if data_consumer:
 data_consumer(new_data)
 timeout_count = 0
 else:
 timeout_count += 1
 if timeout is not None and timeout_count >= 100 * timeout:
 break
 time.sleep(0.01)
 return data

 def enter_raw_repl(self):
 self.serial.write(b'\r\x03\x03') # ctrl-C twice: interrupt any running program

 # flush input (without relying on serial.flushInput())
 n = self.serial.inWaiting()
 while n > 0:
 self.serial.read(n)
 n = self.serial.inWaiting()

 self.serial.write(b'\r\x01') # ctrl-A: enter raw REPL
 data = self.read_until(1, b'raw REPL; CTRL-B to exit\r\n>')
 if not data.endswith(b'raw REPL; CTRL-B to exit\r\n>'):
 print(data)
 raise PyboardError('could not enter raw repl')

 self.serial.write(b'\x04') # ctrl-D: soft reset
 data = self.read_until(1, b'soft reboot\r\n')
 if not data.endswith(b'soft reboot\r\n'):
 print(data)
 raise PyboardError('could not enter raw repl')
 # By splitting this into 2 reads, it allows boot.py to print stuff,
 # which will show up after the soft reboot and before the raw REPL.
 data = self.read_until(1, b'raw REPL; CTRL-B to exit\r\n')
 if not data.endswith(b'raw REPL; CTRL-B to exit\r\n'):
 print(data)
 raise PyboardError('could not enter raw repl')

 def exit_raw_repl(self):
 self.serial.write(b'\r\x02') # ctrl-B: enter friendly REPL

 def follow(self, timeout, data_consumer=None):
 # wait for normal output
 data = self.read_until(1, b'\x04', timeout=timeout, data_consumer=data_consumer)
 if not data.endswith(b'\x04'):
 raise PyboardError('timeout waiting for first EOF reception')
 data = data[:-1]

 # wait for error output
 data_err = self.read_until(1, b'\x04', timeout=timeout)
 if not data_err.endswith(b'\x04'):
 raise PyboardError('timeout waiting for second EOF reception')
 data_err = data_err[:-1]

 # return normal and error output
 return data, data_err

 def exec_raw_no_follow(self, command):
 if isinstance(command, bytes):
 command_bytes = command
 else:
 command_bytes = bytes(command, encoding='utf8')

 # check we have a prompt
 data = self.read_until(1, b'>')
 if not data.endswith(b'>'):
 raise PyboardError('could not enter raw repl')

 # write command
 for i in range(0, len(command_bytes), 256):
 self.serial.write(command_bytes[i:min(i + 256, len(command_bytes))])
 time.sleep(0.01)
 self.serial.write(b'\x04')

 # check if we could exec command
 data = self.serial.read(2)
 if data != b'OK':
 raise PyboardError('could not exec command (response: %r)' % data)

 def exec_raw(self, command, timeout=10, data_consumer=None):
 self.exec_raw_no_follow(command);
 return self.follow(timeout, data_consumer)

 def eval(self, expression):
 ret = self.exec_('print({})'.format(expression))
 ret = ret.strip()
 return ret

 def exec_(self, command):
 ret, ret_err = self.exec_raw(command)
 if ret_err:
 raise PyboardError('exception', ret, ret_err)
 return ret

 def execfile(self, filename):
 with open(filename, 'rb') as f:
 pyfile = f.read()
 return self.exec_(pyfile)

 def get_time(self):
 t = str(self.eval('pyb.RTC().datetime()'), encoding='utf8')[1:-1].split(', ')
 return int(t[4]) * 3600 + int(t[5]) * 60 + int(t[6])

# in Python2 exec is a keyword so one must use "exec_"
# but for Python3 we want to provide the nicer version "exec"
setattr(Pyboard, "exec", Pyboard.exec_)

def execfile(filename, device='/dev/ttyACM0', baudrate=115200, user='micro', password='python'):
 pyb = Pyboard(device, baudrate, user, password)
 pyb.enter_raw_repl()
 output = pyb.execfile(filename)
 stdout_write_bytes(output)
 pyb.exit_raw_repl()
 pyb.close()

def main():
 import argparse
 cmd_parser = argparse.ArgumentParser(description='Run scripts on the pyboard.')
 cmd_parser.add_argument('--device', default='/dev/ttyACM0', help='the serial device or the IP address of the pyboard')
 cmd_parser.add_argument('-b', '--baudrate', default=115200, help='the baud rate of the serial device')
 cmd_parser.add_argument('-u', '--user', default='micro', help='the telnet login username')
 cmd_parser.add_argument('-p', '--password', default='python', help='the telnet login password')
 cmd_parser.add_argument('-c', '--command', help='program passed in as string')
 cmd_parser.add_argument('-w', '--wait', default=0, type=int, help='seconds to wait for USB connected board to become available')
 cmd_parser.add_argument('--follow', action='store_true', help='follow the output after running the scripts [default if no scripts given]')
 cmd_parser.add_argument('files', nargs='*', help='input files')
 args = cmd_parser.parse_args()

 # open the connection to the pyboard
 try:
 pyb = Pyboard(args.device, args.baudrate, args.user, args.password, args.wait)
 except PyboardError as er:
 print(er)
 sys.exit(1)

 # run any command or file(s)
 if args.command is not None or len(args.files):
 # we must enter raw-REPL mode to execute commands
 # this will do a soft-reset of the board
 try:
 pyb.enter_raw_repl()
 except PyboardError as er:
 print(er)
 pyb.close()
 sys.exit(1)

 def execbuffer(buf):
 try:
 ret, ret_err = pyb.exec_raw(buf, timeout=None, data_consumer=stdout_write_bytes)
 except PyboardError as er:
 print(er)
 pyb.close()
 sys.exit(1)
 except KeyboardInterrupt:
 sys.exit(1)
 if ret_err:
 pyb.exit_raw_repl()
 pyb.close()
 stdout_write_bytes(ret_err)
 sys.exit(1)

 # run the command, if given
 if args.command is not None:
 execbuffer(args.command.encode('utf-8'))

 # run any files
 for filename in args.files:
 with open(filename, 'rb') as f:
 pyfile = f.read()
 execbuffer(pyfile)

 # exiting raw-REPL just drops to friendly-REPL mode
 pyb.exit_raw_repl()

 # if asked explicitly, or no files given, then follow the output
 if args.follow or (args.command is None and len(args.files) == 0):
 try:
 ret, ret_err = pyb.follow(timeout=None, data_consumer=stdout_write_bytes)
 except PyboardError as er:
 print(er)
 sys.exit(1)
 except KeyboardInterrupt:
 sys.exit(1)
 if ret_err:
 pyb.close()
 stdout_write_bytes(ret_err)
 sys.exit(1)

 # close the connection to the pyboard
 pyb.close()

if __name__ == "__main__":
 main()