#!/usr/bin/env python3
# pylint: disable=invalid-name
# *****************************************************************************
# This program is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free Software
# Foundation; either version 2 of the License, or (at your option) any later
# version.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
# details.
#
# You should have received a copy of the GNU General Public License along with
# this program; if not, write to the Free Software Foundation, Inc.,
# 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
# Module authors:
#   Markus Zolliker <markus.zolliker@psi.ch>
# *****************************************************************************
"""server for a string communicator

Usage:

    bin/stringio-server <communciator> <server port>

open a server on <server port> to communicate with the string based <communicator> over TCP/IP.

Use cases, mainly for test purposes:
- as a T, if the hardware allows only one connection, and more than one is needed
- relay to a communicator not using TCP/IP, if Frappy should run on an other host
- relay to a hardware simulation written as a communicator
"""

import sys
import argparse
from os import path
import asyncore
import socket
import time

# Add import path for inplace usage
sys.path.insert(0, path.abspath(path.join(path.dirname(__file__), '..')))

from frappy.lib import get_class, formatException, mkthread


class LineHandler(asyncore.dispatcher_with_send):

    def __init__(self, sock):
        self.buffer = b""
        asyncore.dispatcher_with_send.__init__(self, sock)
        self.crlf = 0

    def handle_line(self, line):
        raise NotImplementedError

    def handle_read(self):
        data = self.recv(8192)
        if data:
            parts = data.split(b"\n")
            if len(parts) == 1:
                self.buffer += data
            else:
                self.handle_line((self.buffer + parts[0]).decode('latin_1'))
                for part in parts[1:-1]:
                    if part[-1] == b"\r":
                        self.crlf = True
                        part = part[:-1]
                    else:
                        self.crlf = False
                    self.handle_line(part.decode('latin_1'))
                self.buffer = parts[-1]

    def send_line(self, line):
        self.send((line + ("\r\n" if self.crlf else "\n")).encode('latin_1'))


class LineServer(asyncore.dispatcher):

    def __init__(self, port, line_handler_cls, handler_args):
        asyncore.dispatcher.__init__(self)
        self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
        self.set_reuse_addr()
        self.bind(('0.0.0.0', port))
        self.listen(5)
        print('accept connections at port', port)
        self.line_handler_cls = line_handler_cls
        self.handler_args = handler_args

    def handle_accept(self):
        pair = self.accept()
        if pair is not None:
            sock, addr = pair
            print("Incoming connection from %s" % repr(addr))
            self.line_handler_cls(sock, self.handler_args)

    def loop(self):
        asyncore.loop()


class Server(LineServer):

    class Dispatcher:
        def announce_update(self, *_):
            pass

        def announce_update_error(self, *_):
            pass

    def __init__(self, *args, **kwds):
        super().__init__(*args, **kwds)
        self.dispatcher = self.Dispatcher()


class Handler(LineHandler):
    def __init__(self, sock, handler_args):
        super().__init__(sock)
        self.module = handler_args['module']
        self.verbose = handler_args['verbose']

    def handle_line(self, line):
        try:
            reply = self.module.communicate(line.strip())
            if self.verbose:
                print('%-40s | %s' % (line, reply))
        except Exception:
            print(formatException(verbose=True))
            return
        self.send_line(reply)


class Logger:
    def debug(self, *args):
        pass

    def log(self, level, *args):
        pass

    def info(self, *args):
        print(*args)

    exception = error = warn = info


def parse_argv(argv):
    parser = argparse.ArgumentParser(description="Simulate HW with a serial interface")
    parser.add_argument("-v", "--verbose",
                        help="output full communication",
                        action='store_true', default=False)
    parser.add_argument("cls",
                        type=str,
                        help="simulator class.\n",)
    parser.add_argument('-p',
                        '--port',
                        action='store',
                        help='server port or uri',
                        default=2089)
    return parser.parse_args(argv)


def poller(pollfunc):
    while True:
        time.sleep(1.0)
        pollfunc()


def main(argv=None):
    if argv is None:
        argv = sys.argv

    args = parse_argv(argv[1:])

    opts = {'description': 'simulator'}

    handler_args = {'verbose': args.verbose}
    srv = Server(int(args.port), Handler, handler_args)
    module = get_class(args.cls)(args.cls, Logger(), opts, srv)
    handler_args['module'] = module
    module.earlyInit()
    mkthread(poller, module.doPoll)
    srv.loop()


if __name__ == '__main__':
    sys.exit(main(sys.argv))