import os
import shutil
from hashlib import sha1

REMOTE_PATH=os.getenv("REMOTE_PATH", "/mnt/files/nginx")
LOCAL_PATH=os.getenv("LOCAL_PATH", "/etc/nginx")

ENV={}

def refresh_env():
  global ENV

  lines = [l.strip() for l in open('/etc/default/nman')]
  ENV = {k: v for k, v in [l.split('=') for l in lines]}

def apply_env(data):
  for k, v in ENV.items():
    data = data.replace(f'$({k})', v)
  return data

def restart():
    return os.system('systemctl restart nginx') == 0

def full_copy():
  shutil.rmtree(LOCAL_PATH)
  os.mkdir(LOCAL_PATH)
  shutil.copytree(REMOTE_PATH, LOCAL_PATH)

def tree(path):
  if not os.path.exists(path):
    raise FileNotFoundError()
  for root, dirs, files in os.walk(path):
    rl = len(path)
    pre = root[rl:]
    if pre.startswith('/'):
      pre = pre[1:]
    print(pre)

    for file in files:
      yield (0, os.path.join(pre, file))
    for dir in dirs:
      yield (1, os.path.join(pre, dir))

def compare(all=False):
  refresh_env()

  remote_tree = [i for i in tree(REMOTE_PATH)]
  local_tree = [i for i in tree(LOCAL_PATH)]
  remote_new = [i for i in remote_tree if not i in local_tree]
  local_new = [i for i in local_tree if not i in remote_tree]

  outdated = []

  for i in [i[1] for i in local_tree if i in remote_tree and i[0] == 0]:
    data = open(os.path.join(LOCAL_PATH, i), 'r').read()
    data = apply_env(data).encode()
    local_hash = sha1(data).digest()

    data = open(os.path.join(REMOTE_PATH, i), 'r').read()
    data = apply_env(data).encode()
    remote_hash = sha1(data).digest()

    if all or local_hash != remote_hash:
      outdated += [(0, i)]

  return {'create': remote_new, 'delete': local_new, 'sync': outdated}

def update(force=False):
  diff = compare(all=force)
  changes = len([i for i in [diff[k] for k in diff.keys()]])

  print(diff)

  print('changes: %d' % changes)

  for t, i in diff['create'] + diff['sync']:
    if t == 1:
      continue
    local = os.path.join(LOCAL_PATH, i)
    remote = os.path.join(REMOTE_PATH, i)

    print('syncing %s to %s' % (remote, local))

    os.makedirs(os.path.dirname(local), exist_ok=True)

    if local.endswith('.conf'):
      f = open(local, 'w')
      f.write(apply_env(open(remote, 'r').read()))
      f.close()
    else:
      shutil.copy(remote, local)

  for t, i in diff['delete']:
    path = os.path.join(LOCAL_PATH, i)
    print('deleting %s' % path)

    if t == 0:
      os.unlink(path)
    else:
      shutil.rmtree(path)

  if changes > 0:
    if not restart():
      print("error restartyi ng!")

  print('done update')