#!@python@/bin/python

from os import environ
from os.path import expanduser
import socket
import ssl
import shlex
from sys import argv, stdin, stdout, exit
from multiprocessing import Process
from select import select
from io import BytesIO
import subprocess
from time import sleep

import logging


logger = logging.getLogger('notmuch-tcp-server')
logger.setLevel(logging.DEBUG)
lh = logging.StreamHandler()
lh.setLevel(logging.DEBUG)
lh.setFormatter(logging.Formatter( fmt = '{levelname} - {message}', style = '{' ))
logger.addHandler(lh)


port = environ.get('NOTMUCH_TCP')
host = environ.get('NOTMUCH_HOST')
hostname = socket.gethostname()

if port is None:
    port = 2010
if host is None:
    host = "odin.asgard.yggdrasil"

sslcontext = ssl.SSLContext(ssl.PROTOCOL_TLS_SERVER)
sslcontext.load_verify_locations(cafile = expanduser('~/.notmuch-tcp/ca.pem'))
sslcontext.load_cert_chain(certfile = expanduser(f"~/.notmuch-tcp/{hostname}.pem"), keyfile = expanduser(f"~/.notmuch-tcp/{hostname}.key"))

s = None
for res in socket.getaddrinfo(host, int(port), socket.AF_UNSPEC, socket.SOCK_STREAM, 0, socket.AI_PASSIVE):
    af, socktype, proto, canonname, sa = res
    try:
        s = socket.socket(af, socktype, proto)
    except OSError as msg:
        logger.error(f"Could not create socket: {msg}")
        s = None
        continue
    try:
        s.bind(sa)
        s.listen()
    except OSError as msg:
        logger.error(f"Could not bind socket: {msg}")
        s.close()
        s = None
        continue
    break
if s is None:
    logger.error('Could not open any sockets')
    exit(1)

with s as sock:
    with sslcontext.wrap_socket(sock, server_side = True) as ssock:
        while True:
            logger.debug('waiting...')
            conn = None
            try:
                conn, client_addr = ssock.accept()
                client_host, client_port = client_addr
                logger.info(f"Connected: {client_host}:{client_port}")

                with BytesIO() as buffer:
                    while True:
                        resp = conn.recv(256)
                        buffer.write(resp)
                        buffer.seek(0)
                        start_index = 0
                        for line in buffer:
                            if not line.find(b"\n"):
                                break
                            
                            start_index += len(line)
                            escaped_args = line[:-1].decode()
                            break
                        if start_index:
                            buffer.seek(start_index)
                            remaining = buffer.read()
                            buffer.truncate(0)
                            buffer.seek(0)
                            buffer.write(remaining)
                            break
                        else:
                            buffer.seek(0, 2)

                    logger.info(f"Arguments: {escaped_args}")

                    sproc = subprocess.Popen(["notmuch"] + shlex.split(escaped_args), shell = False, stdin = subprocess.PIPE, stdout = subprocess.PIPE)

                    def send_stdout():
                        while True:
                          to_send = sproc.stdout.read(256)
                          logger.debug(f"Sending: {to_send}")

                          if to_send:
                              conn.sendall(to_send)
                          else:
                              logger.debug(f"Done sending")
                              break

                    def recv_stdin():
                        remaining = buffer.read()
                        logger.debug(f"Received (buffered): {remaining}")
                        sproc.stdin.write(remaining)

                        while True:
                            logger.debug("Waiting on input...")
                            ready = select([conn], [], [], 5)
                            if ready[0]:
                                resp = conn.recv(256)
                                logger.debug(f"Received: {resp}")

                                if len(resp) <= 0:
                                    break

                                sproc.stdin.write(resp)
                            else:
                                break
                        logger.debug(f"Done receiving")
                        sproc.stdin.close()

                        sleep(5)

                        sproc.kill()

                    send = Process(target = send_stdout)
                    recv = Process(target = recv_stdin)
                    send.start()
                    recv.start()
                    sproc_res = sproc.wait()
                    logger.info(f"Subprocess result: {sproc_res}")
                    send.join()
                    recv.terminate()
                    logger.debug(f"Handled I/O")
            finally:
                if conn is not None:
                    conn.close()