#
#

# Copyright (C) 2007, 2011, 2012 Google Inc.
#
# 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., 51 Franklin Street, Fifth Floor, Boston, MA
# 02110-1301, USA.


"""Utilities for QA tests.

"""

import os
import re
import sys
import subprocess
import random
import tempfile

try:
  import functools
except ImportError, err:
  raise ImportError("Python 2.5 or higher is required: %s" % err)

from ganeti import utils
from ganeti import compat
from ganeti import constants
from ganeti import ht

import qa_config
import qa_error


_INFO_SEQ = None
_WARNING_SEQ = None
_ERROR_SEQ = None
_RESET_SEQ = None

_MULTIPLEXERS = {}

#: Unique ID per QA run
_RUN_UUID = utils.NewUUID()


(INST_DOWN,
 INST_UP) = range(500, 502)

(FIRST_ARG,
 RETURN_VALUE) = range(1000, 1002)


def _SetupColours():
  """Initializes the colour constants.

  """
  # pylint: disable=W0603
  # due to global usage
  global _INFO_SEQ, _WARNING_SEQ, _ERROR_SEQ, _RESET_SEQ

  # Don't use colours if stdout isn't a terminal
  if not sys.stdout.isatty():
    return

  try:
    import curses
  except ImportError:
    # Don't use colours if curses module can't be imported
    return

  curses.setupterm()

  _RESET_SEQ = curses.tigetstr("op")

  setaf = curses.tigetstr("setaf")
  _INFO_SEQ = curses.tparm(setaf, curses.COLOR_GREEN)
  _WARNING_SEQ = curses.tparm(setaf, curses.COLOR_YELLOW)
  _ERROR_SEQ = curses.tparm(setaf, curses.COLOR_RED)


_SetupColours()


def AssertIn(item, sequence):
  """Raises an error when item is not in sequence.

  """
  if item not in sequence:
    raise qa_error.Error("%r not in %r" % (item, sequence))


def AssertNotIn(item, sequence):
  """Raises an error when item is in sequence.

  """
  if item in sequence:
    raise qa_error.Error("%r in %r" % (item, sequence))


def AssertEqual(first, second):
  """Raises an error when values aren't equal.

  """
  if not first == second:
    raise qa_error.Error("%r == %r" % (first, second))


def AssertNotEqual(first, second):
  """Raises an error when values are equal.

  """
  if not first != second:
    raise qa_error.Error("%r != %r" % (first, second))


def AssertMatch(string, pattern):
  """Raises an error when string doesn't match regexp pattern.

  """
  if not re.match(pattern, string):
    raise qa_error.Error("%r doesn't match /%r/" % (string, pattern))


def _GetName(entity, key):
  """Tries to get name of an entity.

  @type entity: string or dict
  @type key: string
  @param key: Dictionary key containing name

  """
  if isinstance(entity, basestring):
    result = entity
  elif isinstance(entity, dict):
    result = entity[key]
  else:
    raise qa_error.Error("Expected string or dictionary, got %s: %s" %
                         (type(entity), entity))

  if not ht.TNonEmptyString(result):
    raise Exception("Invalid name '%s'" % result)

  return result


def AssertCommand(cmd, fail=False, node=None):
  """Checks that a remote command succeeds.

  @param cmd: either a string (the command to execute) or a list (to
      be converted using L{utils.ShellQuoteArgs} into a string)
  @type fail: boolean
  @param fail: if the command is expected to fail instead of succeeding
  @param node: if passed, it should be the node on which the command
      should be executed, instead of the master node (can be either a
      dict or a string)

  """
  if node is None:
    node = qa_config.GetMasterNode()

  nodename = _GetName(node, "primary")

  if isinstance(cmd, basestring):
    cmdstr = cmd
  else:
    cmdstr = utils.ShellQuoteArgs(cmd)

  rcode = StartSSH(nodename, cmdstr).wait()

  if fail:
    if rcode == 0:
      raise qa_error.Error("Command '%s' on node %s was expected to fail but"
                           " didn't" % (cmdstr, nodename))
  else:
    if rcode != 0:
      raise qa_error.Error("Command '%s' on node %s failed, exit code %s" %
                           (cmdstr, nodename, rcode))

  return rcode


def GetSSHCommand(node, cmd, strict=True, opts=None, tty=None):
  """Builds SSH command to be executed.

  @type node: string
  @param node: node the command should run on
  @type cmd: string
  @param cmd: command to be executed in the node; if None or empty
      string, no command will be executed
  @type strict: boolean
  @param strict: whether to enable strict host key checking
  @type opts: list
  @param opts: list of additional options
  @type tty: boolean or None
  @param tty: if we should use tty; if None, will be auto-detected

  """
  args = ["ssh", "-oEscapeChar=none", "-oBatchMode=yes", "-lroot"]

  if tty is None:
    tty = sys.stdout.isatty()

  if tty:
    args.append("-t")

  if strict:
    tmp = "yes"
  else:
    tmp = "no"
  args.append("-oStrictHostKeyChecking=%s" % tmp)
  args.append("-oClearAllForwardings=yes")
  args.append("-oForwardAgent=yes")
  if opts:
    args.extend(opts)
  if node in _MULTIPLEXERS:
    spath = _MULTIPLEXERS[node][0]
    args.append("-oControlPath=%s" % spath)
    args.append("-oControlMaster=no")
  args.append(node)
  if cmd:
    args.append(cmd)

  return args


def StartLocalCommand(cmd, _nolog_opts=False, **kwargs):
  """Starts a local command.

  """
  if _nolog_opts:
    pcmd = [i for i in cmd if not i.startswith("-")]
  else:
    pcmd = cmd
  print "Command: %s" % utils.ShellQuoteArgs(pcmd)
  return subprocess.Popen(cmd, shell=False, **kwargs)


def StartSSH(node, cmd, strict=True):
  """Starts SSH.

  """
  return StartLocalCommand(GetSSHCommand(node, cmd, strict=strict),
                           _nolog_opts=True)


def StartMultiplexer(node):
  """Starts a multiplexer command.

  @param node: the node for which to open the multiplexer

  """
  if node in _MULTIPLEXERS:
    return

  # Note: yes, we only need mktemp, since we'll remove the file anyway
  sname = tempfile.mktemp(prefix="ganeti-qa-multiplexer.")
  utils.RemoveFile(sname)
  opts = ["-N", "-oControlPath=%s" % sname, "-oControlMaster=yes"]
  print "Created socket at %s" % sname
  child = StartLocalCommand(GetSSHCommand(node, None, opts=opts))
  _MULTIPLEXERS[node] = (sname, child)


def CloseMultiplexers():
  """Closes all current multiplexers and cleans up.

  """
  for node in _MULTIPLEXERS.keys():
    (sname, child) = _MULTIPLEXERS.pop(node)
    utils.KillProcess(child.pid, timeout=10, waitpid=True)
    utils.RemoveFile(sname)


def GetCommandOutput(node, cmd, tty=None):
  """Returns the output of a command executed on the given node.

  """
  p = StartLocalCommand(GetSSHCommand(node, cmd, tty=tty),
                        stdout=subprocess.PIPE)
  AssertEqual(p.wait(), 0)
  return p.stdout.read()


def UploadFile(node, src):
  """Uploads a file to a node and returns the filename.

  Caller needs to remove the returned file on the node when it's not needed
  anymore.

  """
  # Make sure nobody else has access to it while preserving local permissions
  mode = os.stat(src).st_mode & 0700

  cmd = ('tmp=$(tempfile --mode %o --prefix gnt) && '
         '[[ -f "${tmp}" ]] && '
         'cat > "${tmp}" && '
         'echo "${tmp}"') % mode

  f = open(src, "r")
  try:
    p = subprocess.Popen(GetSSHCommand(node, cmd), shell=False, stdin=f,
                         stdout=subprocess.PIPE)
    AssertEqual(p.wait(), 0)

    # Return temporary filename
    return p.stdout.read().strip()
  finally:
    f.close()


def UploadData(node, data, mode=0600, filename=None):
  """Uploads data to a node and returns the filename.

  Caller needs to remove the returned file on the node when it's not needed
  anymore.

  """
  if filename:
    tmp = "tmp=%s" % utils.ShellQuote(filename)
  else:
    tmp = "tmp=$(tempfile --mode %o --prefix gnt)" % mode
  cmd = ("%s && "
         "[[ -f \"${tmp}\" ]] && "
         "cat > \"${tmp}\" && "
         "echo \"${tmp}\"") % tmp

  p = subprocess.Popen(GetSSHCommand(node, cmd), shell=False,
                       stdin=subprocess.PIPE, stdout=subprocess.PIPE)
  p.stdin.write(data)
  p.stdin.close()
  AssertEqual(p.wait(), 0)

  # Return temporary filename
  return p.stdout.read().strip()


def BackupFile(node, path):
  """Creates a backup of a file on the node and returns the filename.

  Caller needs to remove the returned file on the node when it's not needed
  anymore.

  """
  cmd = ("tmp=$(tempfile --prefix .gnt --directory=$(dirname %s)) && "
         "[[ -f \"$tmp\" ]] && "
         "cp %s $tmp && "
         "echo $tmp") % (utils.ShellQuote(path), utils.ShellQuote(path))

  # Return temporary filename
  return GetCommandOutput(node, cmd).strip()


def _ResolveName(cmd, key):
  """Helper function.

  """
  master = qa_config.GetMasterNode()

  output = GetCommandOutput(master["primary"], utils.ShellQuoteArgs(cmd))
  for line in output.splitlines():
    (lkey, lvalue) = line.split(":", 1)
    if lkey == key:
      return lvalue.lstrip()
  raise KeyError("Key not found")


def ResolveInstanceName(instance):
  """Gets the full name of an instance.

  @type instance: string
  @param instance: Instance name

  """
  return _ResolveName(["gnt-instance", "info", instance],
                      "Instance name")


def ResolveNodeName(node):
  """Gets the full name of a node.

  """
  return _ResolveName(["gnt-node", "info", node["primary"]],
                      "Node name")


def GetNodeInstances(node, secondaries=False):
  """Gets a list of instances on a node.

  """
  master = qa_config.GetMasterNode()
  node_name = ResolveNodeName(node)

  # Get list of all instances
  cmd = ["gnt-instance", "list", "--separator=:", "--no-headers",
         "--output=name,pnode,snodes"]
  output = GetCommandOutput(master["primary"], utils.ShellQuoteArgs(cmd))

  instances = []
  for line in output.splitlines():
    (name, pnode, snodes) = line.split(":", 2)
    if ((not secondaries and pnode == node_name) or
        (secondaries and node_name in snodes.split(","))):
      instances.append(name)

  return instances


def _SelectQueryFields(rnd, fields):
  """Generates a list of fields for query tests.

  """
  # Create copy for shuffling
  fields = list(fields)
  rnd.shuffle(fields)

  # Check all fields
  yield fields
  yield sorted(fields)

  # Duplicate fields
  yield fields + fields

  # Check small groups of fields
  while fields:
    yield [fields.pop() for _ in range(rnd.randint(2, 10)) if fields]


def _List(listcmd, fields, names):
  """Runs a list command.

  """
  master = qa_config.GetMasterNode()

  cmd = [listcmd, "list", "--separator=|", "--no-headers",
         "--output", ",".join(fields)]

  if names:
    cmd.extend(names)

  return GetCommandOutput(master["primary"],
                          utils.ShellQuoteArgs(cmd)).splitlines()


def GenericQueryTest(cmd, fields, namefield="name", test_unknown=True):
  """Runs a number of tests on query commands.

  @param cmd: Command name
  @param fields: List of field names

  """
  rnd = random.Random(hash(cmd))

  fields = list(fields)
  rnd.shuffle(fields)

  # Test a number of field combinations
  for testfields in _SelectQueryFields(rnd, fields):
    AssertCommand([cmd, "list", "--output", ",".join(testfields)])

  if namefield is not None:
    namelist_fn = compat.partial(_List, cmd, [namefield])

    # When no names were requested, the list must be sorted
    names = namelist_fn(None)
    AssertEqual(names, utils.NiceSort(names))

    # When requesting specific names, the order must be kept
    revnames = list(reversed(names))
    AssertEqual(namelist_fn(revnames), revnames)

    randnames = list(names)
    rnd.shuffle(randnames)
    AssertEqual(namelist_fn(randnames), randnames)

  if test_unknown:
    # Listing unknown items must fail
    AssertCommand([cmd, "list", "this.name.certainly.does.not.exist"],
                  fail=True)

  # Check exit code for listing unknown field
  AssertEqual(AssertCommand([cmd, "list", "--output=field/does/not/exist"],
                            fail=True),
              constants.EXIT_UNKNOWN_FIELD)


def GenericQueryFieldsTest(cmd, fields):
  master = qa_config.GetMasterNode()

  # Listing fields
  AssertCommand([cmd, "list-fields"])
  AssertCommand([cmd, "list-fields"] + fields)

  # Check listed fields (all, must be sorted)
  realcmd = [cmd, "list-fields", "--separator=|", "--no-headers"]
  output = GetCommandOutput(master["primary"],
                            utils.ShellQuoteArgs(realcmd)).splitlines()
  AssertEqual([line.split("|", 1)[0] for line in output],
              utils.NiceSort(fields))

  # Check exit code for listing unknown field
  AssertEqual(AssertCommand([cmd, "list-fields", "field/does/not/exist"],
                            fail=True),
              constants.EXIT_UNKNOWN_FIELD)


def _FormatWithColor(text, seq):
  if not seq:
    return text
  return "%s%s%s" % (seq, text, _RESET_SEQ)


FormatWarning = lambda text: _FormatWithColor(text, _WARNING_SEQ)
FormatError = lambda text: _FormatWithColor(text, _ERROR_SEQ)
FormatInfo = lambda text: _FormatWithColor(text, _INFO_SEQ)


def AddToEtcHosts(hostnames):
  """Adds hostnames to /etc/hosts.

  @param hostnames: List of hostnames first used A records, all other CNAMEs

  """
  master = qa_config.GetMasterNode()
  tmp_hosts = UploadData(master["primary"], "", mode=0644)

  quoted_tmp_hosts = utils.ShellQuote(tmp_hosts)
  data = []
  for localhost in ("::1", "127.0.0.1"):
    data.append("%s %s" % (localhost, " ".join(hostnames)))

  try:
    AssertCommand(("cat /etc/hosts > %s && echo -e '%s' >> %s && mv %s"
                   " /etc/hosts") % (quoted_tmp_hosts, "\\n".join(data),
                                     quoted_tmp_hosts, quoted_tmp_hosts))
  except qa_error.Error:
    AssertCommand(["rm", tmp_hosts])


def RemoveFromEtcHosts(hostnames):
  """Remove hostnames from /etc/hosts.

  @param hostnames: List of hostnames first used A records, all other CNAMEs

  """
  master = qa_config.GetMasterNode()
  tmp_hosts = UploadData(master["primary"], "", mode=0644)
  quoted_tmp_hosts = utils.ShellQuote(tmp_hosts)

  sed_data = " ".join(hostnames)
  try:
    AssertCommand(("sed -e '/^\(::1\|127\.0\.0\.1\)\s\+%s/d' /etc/hosts > %s"
                   " && mv %s /etc/hosts") % (sed_data, quoted_tmp_hosts,
                                              quoted_tmp_hosts))
  except qa_error.Error:
    AssertCommand(["rm", tmp_hosts])


def RunInstanceCheck(instance, running):
  """Check if instance is running or not.

  """
  instance_name = _GetName(instance, "name")

  script = qa_config.GetInstanceCheckScript()
  if not script:
    return

  master_node = qa_config.GetMasterNode()

  # Build command to connect to master node
  master_ssh = GetSSHCommand(master_node["primary"], "--")

  if running:
    running_shellval = "1"
    running_text = ""
  else:
    running_shellval = ""
    running_text = "not "

  print FormatInfo("Checking if instance '%s' is %srunning" %
                   (instance_name, running_text))

  args = [script, instance_name]
  env = {
    "PATH": constants.HOOKS_PATH,
    "RUN_UUID": _RUN_UUID,
    "MASTER_SSH": utils.ShellQuoteArgs(master_ssh),
    "INSTANCE_NAME": instance_name,
    "INSTANCE_RUNNING": running_shellval,
    }

  result = os.spawnve(os.P_WAIT, script, args, env)
  if result != 0:
    raise qa_error.Error("Instance check failed with result %s" % result)


def _InstanceCheckInner(expected, instarg, args, result):
  """Helper function used by L{InstanceCheck}.

  """
  if instarg == FIRST_ARG:
    instance = args[0]
  elif instarg == RETURN_VALUE:
    instance = result
  else:
    raise Exception("Invalid value '%s' for instance argument" % instarg)

  if expected in (INST_DOWN, INST_UP):
    RunInstanceCheck(instance, (expected == INST_UP))
  elif expected is not None:
    raise Exception("Invalid value '%s'" % expected)


def InstanceCheck(before, after, instarg):
  """Decorator to check instance status before and after test.

  @param before: L{INST_DOWN} if instance must be stopped before test,
    L{INST_UP} if instance must be running before test, L{None} to not check.
  @param after: L{INST_DOWN} if instance must be stopped after test,
    L{INST_UP} if instance must be running after test, L{None} to not check.
  @param instarg: L{FIRST_ARG} to use first argument to test as instance (a
    dictionary), L{RETURN_VALUE} to use return value (disallows pre-checks)

  """
  def decorator(fn):
    @functools.wraps(fn)
    def wrapper(*args, **kwargs):
      _InstanceCheckInner(before, instarg, args, NotImplemented)

      result = fn(*args, **kwargs)

      _InstanceCheckInner(after, instarg, args, result)

      return result
    return wrapper
  return decorator