import subprocess
import threading
import io
import json
import sys
import os
import pprint
import traceback
import time


def forward(config_dir, config):
    server_address = config['server_address']
    username = config['username']
    target_address = config['target_address']
    blank_endpoint = config['blank_endpoint']
    target_ports = config['target_ports']
    app_name = config['app_name']
    ssh_key = os.path.join(
        config_dir,
        config['ssh_key']
    )
    ssh_command = 'ssh -o "ExitOnForwardFailure yes" -o "StrictHostKeyChecking no"'

    ports = dict(
        target=r'''
          %s -i %s \
            %s@%s \
            %s \
            -N;
        ''' % (
            ssh_command,
            ssh_key,
            username,
            server_address,
            ' '.join([
                '-R 0.0.0.0:%d:%s:%d' % (
                    pair[0],
                    target_address,
                    pair[1],
                )
                for pair in target_ports
            ]),
        ),
        blank=r'''
          %s -i %s \
            %s@%s \
            %s \
            -N;
        ''' % (
            ssh_command,
            ssh_key,
            username,
            server_address,
            ' '.join([
                '-R 0.0.0.0:%d:%s' % (
                    pair[0],
                    blank_endpoint,
                )
                for pair in target_ports
            ]),
        )
    )

    has_server = lambda : subprocess.call([
        'ping','-c', '1', target_address,
    ], stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=subprocess.PIPE) == 0

    #notify = lambda msg : subprocess.check_output(['notify-send', '-t', '5000', app_name, msg])
    notify = lambda msg: subprocess.call(['echo', app_name, msg])

    while True:
        notify('started')
        if has_server():
            t6 = ports['target']
            notify('has_server')
        else:
            t6 = ports['blank']
            notify('blank_app')
        t2 = t6
        with subprocess.Popen(t2, shell=True) as p:
            try:
                while True:
                    time.sleep(10)
                    t3 = has_server()
                    t4 = None
                    if t6 == ports['target'] and not t3:
                        t4 = 'no server'
                    elif t6 == ports['blank'] and t3:
                        t4 = 'server found'
                    if not t4 is None:
                        notify(t4)
                        raise RuntimeError(t4)
                    assert p.poll() is None
            except KeyboardInterrupt:
                break
            except:
                pprint.pprint(traceback.format_exc())
                continue
            finally:
                p.terminate()
                notify('stopped')

config_path = sys.argv[1]
config_dir = os.path.split(
    config_path
)[0]

with io.open(config_path, 'r') as f:
    configs = json.load(f)

t1 = []
for config in configs:
    t2 = threading.Thread(
        target=forward,
        args=[config_dir, config],
    )
    t2.start()
    t1.append(t2)

for o in t1:
    o.join()