#!/usr/bin/python3

#
# SPDX-License-Identifier: MIT
# Copyright (c) 2020 Daniel Thompson
#

import argparse
import random
import os.path
import pexpect
import time
import string
import sys

def sync(c):
    """Stop the watch and synchronize with the command prompt.

    Sending a random print ensure the final export (of the prompt)
    does not accidentally match a previously issued prompt.
    """
    tag = ''.join([random.choice(string.ascii_uppercase) for i in range(6)])

    c.send('\x03')
    c.expect('>>> ')
    c.sendline(f'print("{tag[:3]}""{tag[3:]}")')
    c.expect(tag)
    c.expect('>>> ')

def unsync(c):
    """Set the watch running again.

    There must be an expect (or a sleep) since if we kill the subordinate
    process too early then the sendline will not have completed.
    """
    c.sendline('wasp.system.run()')
    c.expect('Watch is running, use Ctrl-C to stop')
    c.send('\x18')

def paste(c, f, verbose=False):
    docstring = False
    for ln in f.readlines():
        ln = ln.rstrip()

        # This is a bit loose (definitely not PEP-257 compliant) but
        # is enough for most code.
        if ln.lstrip().startswith('"""'):
            docstring = True
        if docstring:
            if ln.rstrip().endswith('"""'):
                docstring = False
            continue

        if ln.lstrip().startswith('#'):
            continue


        c.sendline(ln)
        c.expect('=== ')

        if not verbose:
            print('.', end='', flush=True)

def handle_eval(c, cmd):
    verbose = bool(c.logfile)

    c.send('\x05')
    c.expect('=== ')
    c.sendline(cmd)
    c.expect('=== ')

    c.logfile = sys.stdout
    c.send('\x04')
    c.expect('>>> ')
    if not verbose:
        c.logfile = None

def handle_exec(c, fname):
    verbose = bool(c.logfile)

    with open(fname) as f:
        if not verbose:
            print(f'Preparing to run {fname} ...', end='', flush=True)

        c.send('\x05')
        c.expect('=== ')

        paste(c, f, verbose)

        print(' done')
        c.logfile = sys.stdout
        c.send('\x04')
        c.expect('>>> ')
        if not verbose:
            c.logfile = None

def handle_rtc(c):
    # Wait for the clock to tick over to the next second
    now = then = time.localtime()
    while now[5] == then[5]:
        now = time.localtime()

    # Set the time
    c.sendline(f'watch.rtc.set_localtime(({now[0]}, {now[1]}, {now[2]}, {now[3]}, {now[4]}, {now[5]}, {now[6]}, {now[7]}))')
    c.expect('>>> ')

def handle_upload(c, fname):
    verbose = bool(c.logfile)

    c.sendline('from shell import upload')
    c.expect('>>> ')

    with open(fname) as f:
        if not verbose:
            print(f'Uploading {fname} ...', end='', flush=True)

        c.sendline(f'upload("{os.path.basename(fname)}")')
        c.expect('=== ')
        paste(c, f, verbose)
        c.send('\x04')

        print(' done')
        c.expect('>>> ')

if __name__ == '__main__':
    parser = argparse.ArgumentParser(
            description='WASP command and control client')
    parser.add_argument('--console', action='store_true',
            help='Launch a REPL session')
    parser.add_argument('--device',
            help='Connect only to a specific named device')
    parser.add_argument('--exec',
            help='Execute the contents of a file')
    parser.add_argument('--eval',
            help='Execute the provided python string')
    parser.add_argument('--rtc', action='store_true',
            help='Set the time on the WASP device')
    parser.add_argument('--upload',
            help='Copy the specified file to the WASP device')
    parser.add_argument('--verbose', action='store_true',
            help='Log interaction with the WASP device')

    args = parser.parse_args()
    device_name = args.device

    pynus = os.path.dirname(sys.argv[0]) + '/pynus/pynus.py'
    console = pexpect.spawn(pynus, encoding='UTF-8')
    if args.verbose:
        console.logfile = sys.stdout

    console.expect('Connect')
    console.expect('Exit console using Ctrl-X')
    time.sleep(0.5)
    sync(console)

    if args.rtc:
        handle_rtc(console)

    if args.exec:
        handle_exec(console, args.exec)

    if args.eval:
        handle_eval(console, args.eval)

    if args.upload:
        handle_upload(console, args.upload)

    if args.console:
        console.close()
        os.execl(pynus, pynus)

    unsync(console)