#!/usr/bin/python

# Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import hashlib
import image_chromeos
import lock_machine
import math
import os.path
import re
import sys
import threading
import time


from utils import command_executer
from utils import logger
from utils.file_utils import FileUtils

from image_checksummer import ImageChecksummer

CHECKSUM_FILE = "/usr/local/osimage_checksum_file"

class NonMatchingMachines(Exception):
  pass

class CrosMachine(object):
  def __init__(self, name, chromeos_root, log_level, cmd_exec=None):
    self.name = name
    self.image = None
    self.checksum = None
    self.locked = False
    self.released_time = time.time()
    self.test_run = None
    self.chromeos_root = chromeos_root
    self.log_level = log_level
    self.ce = cmd_exec or command_executer.GetCommandExecuter(
        log_level=self.log_level)
    self.SetUpChecksumInfo()

  def SetUpChecksumInfo(self):
    if not self.IsReachable():
      self.machine_checksum = None
      return
    self._GetMemoryInfo()
    self._GetCPUInfo()
    self._ComputeMachineChecksumString()
    self._GetMachineID()
    self.machine_checksum = self._GetMD5Checksum(self.checksum_string)
    self.machine_id_checksum = self._GetMD5Checksum(self.machine_id)

  def IsReachable(self):
    command = "ls"
    ret = self.ce.CrosRunCommand(command,
                                 machine=self.name,
                                 chromeos_root=self.chromeos_root)
    if ret:
      return False
    return True

  def _ParseMemoryInfo(self):
    line = self.meminfo.splitlines()[0]
    usable_kbytes = int(line.split()[1])
    # This code is from src/third_party/test/files/client/bin/base_utils.py
    # usable_kbytes is system's usable DRAM in kbytes,
    #   as reported by memtotal() from device /proc/meminfo memtotal
    #   after Linux deducts 1.5% to 9.5% for system table overhead
    # Undo the unknown actual deduction by rounding up
    #   to next small multiple of a big power-of-two
    #   eg  12GB - 5.1% gets rounded back up to 12GB
    mindeduct = 0.005  # 0.5 percent
    maxdeduct = 0.095  # 9.5 percent
    # deduction range 1.5% .. 9.5% supports physical mem sizes
    #    6GB .. 12GB in steps of .5GB
    #   12GB .. 24GB in steps of 1 GB
    #   24GB .. 48GB in steps of 2 GB ...
    # Finer granularity in physical mem sizes would require
    #   tighter spread between min and max possible deductions

    # increase mem size by at least min deduction, without rounding
    min_kbytes = int(usable_kbytes / (1.0 - mindeduct))
    # increase mem size further by 2**n rounding, by 0..roundKb or more
    round_kbytes = int(usable_kbytes / (1.0 - maxdeduct)) - min_kbytes
    # find least binary roundup 2**n that covers worst-cast roundKb
    mod2n = 1 << int(math.ceil(math.log(round_kbytes, 2)))
    # have round_kbytes <= mod2n < round_kbytes*2
    # round min_kbytes up to next multiple of mod2n
    phys_kbytes = min_kbytes + mod2n - 1
    phys_kbytes -= phys_kbytes % mod2n  # clear low bits
    self.phys_kbytes = phys_kbytes

  def _GetMemoryInfo(self):
    #TODO yunlian: when the machine in rebooting, it will not return
    #meminfo, the assert does not catch it either
    command = "cat /proc/meminfo"
    ret, self.meminfo, _ = self.ce.CrosRunCommand(command, return_output=True,
                                              machine=self.name,
                                              username="root",
                                              chromeos_root=self.chromeos_root)
    assert ret == 0, "Could not get meminfo from machine: %s" % self.name
    if ret == 0:
      self._ParseMemoryInfo()

  #cpuinfo format is different across architecture
  #need to find a better way to parse it.
  def _ParseCPUInfo(self, cpuinfo):
    return 0

  def _GetCPUInfo(self):
    command = "cat /proc/cpuinfo"
    ret, self.cpuinfo, _ = self.ce.CrosRunCommand(command, return_output=True,
                                              machine=self.name,
                                              username="root",
                                              chromeos_root=self.chromeos_root)
    assert ret == 0, "Could not get cpuinfo from machine: %s" % self.name
    if ret == 0:
      self._ParseCPUInfo(self.cpuinfo)

  def _ComputeMachineChecksumString(self):
    self.checksum_string = ""
    exclude_lines_list = ["MHz", "BogoMIPS", "bogomips"]
    for line in self.cpuinfo.splitlines():
      if not any([e in line for e in exclude_lines_list]):
        self.checksum_string += line
    self.checksum_string += " " + str(self.phys_kbytes)

  def _GetMD5Checksum(self, ss):
    if ss:
      return hashlib.md5(ss).hexdigest()
    else:
      return ""

  def _GetMachineID(self):
    command = "dump_vpd_log --full --stdout"
    ret, if_out, _ = self.ce.CrosRunCommand(command, return_output=True,
                                            machine=self.name,
                                            chromeos_root=self.chromeos_root)
    b = if_out.splitlines()
    a = [l for l in b if "Product" in l]
    if len(a):
      self.machine_id = a[0]
      return
    command = "ifconfig"
    ret, if_out, _ = self.ce.CrosRunCommand(command, return_output=True,
                                            machine=self.name,
                                            chromeos_root=self.chromeos_root)
    b = if_out.splitlines()
    a = [l for l in b if "HWaddr" in l]
    if len(a):
      self.machine_id = "_".join(a)
      return
    a = [l for l in b if "ether" in l]
    if len(a):
      self.machine_id = "_".join(a)
      return
    assert 0, "Could not get machine_id from machine: %s" % self.name

  def __str__(self):
    l = []
    l.append(self.name)
    l.append(str(self.image))
    l.append(str(self.checksum))
    l.append(str(self.locked))
    l.append(str(self.released_time))
    return ", ".join(l)


class MachineManager(object):
  def __init__(self, chromeos_root, acquire_timeout, log_level, cmd_exec=None,
               lgr=None):
    self._lock = threading.RLock()
    self._all_machines = []
    self._machines = []
    self.image_lock = threading.Lock()
    self.num_reimages = 0
    self.chromeos_root = None
    self.machine_checksum = {}
    self.machine_checksum_string = {}
    self.acquire_timeout = acquire_timeout
    self.log_level = log_level
    self.ce = cmd_exec or command_executer.GetCommandExecuter(
        log_level=self.log_level)
    self.logger = lgr or logger.GetLogger()

    if os.path.isdir(lock_machine.Machine.LOCKS_DIR):
      self.no_lock = False
    else:
      self.no_lock = True
    self._initialized_machines = []
    self.chromeos_root = chromeos_root

  def ImageMachine(self, machine, label):
    if label.image_type == "local":
      checksum = ImageChecksummer().Checksum(label, self.log_level)
    elif label.image_type == "trybot":
      checksum = machine._GetMD5Checksum(label.chromeos_image)
    else:
      checksum = None

    if checksum and (machine.checksum == checksum):
      return
    chromeos_root = label.chromeos_root
    if not chromeos_root:
      chromeos_root = self.chromeos_root
    image_chromeos_args = [image_chromeos.__file__,
                           "--chromeos_root=%s" % chromeos_root,
                           "--image=%s" % label.chromeos_image,
                           "--image_args=%s" % label.image_args,
                           "--remote=%s" % machine.name,
                           "--logging_level=%s" % self.log_level]
    if label.board:
      image_chromeos_args.append("--board=%s" % label.board)

    # Currently can't image two machines at once.
    # So have to serialized on this lock.
    save_ce_log_level = self.ce.log_level
    if self.log_level != "verbose":
      self.ce.log_level = "average"

    with self.image_lock:
      if self.log_level != "verbose":
        self.logger.LogOutput("Pushing image onto machine.")
        self.logger.LogOutput("CMD : python %s "
                                 % " ".join(image_chromeos_args))
      retval = self.ce.RunCommand(" ".join(["python"] + image_chromeos_args))
      if retval:
        cmd = "reboot && exit"
        if self.log_level != "verbose":
          self.logger.LogOutput("reboot & exit.")
        self.ce.CrosRunCommand(cmd, machine=machine.name,
                               chromeos_root=self.chromeos_root)
        time.sleep(60)
        if self.log_level != "verbose":
          self.logger.LogOutput("Pushing image onto machine.")
          self.logger.LogOutput("CMD : python %s "
                                     % " ".join(image_chromeos_args))
        retval = self.ce.RunCommand(" ".join(["python"] + image_chromeos_args))
      if retval:
        raise Exception("Could not image machine: '%s'." % machine.name)
      else:
        self.num_reimages += 1
      machine.checksum = checksum
      machine.image = label.chromeos_image

    self.ce.log_level = save_ce_log_level
    return retval

  def ComputeCommonCheckSum(self, label):
    for machine in self.GetMachines(label):
      if machine.machine_checksum:
        self.machine_checksum[label.name] = machine.machine_checksum
        break

  def ComputeCommonCheckSumString(self, label):
    for machine in self.GetMachines(label):
      if machine.checksum_string:
        self.machine_checksum_string[label.name] = machine.checksum_string
        break

  def _TryToLockMachine(self, cros_machine):
    with self._lock:
      assert cros_machine, "Machine can't be None"
      for m in self._machines:
        if m.name == cros_machine.name:
          return
      if self.no_lock:
        locked = True
      else:
        locked = lock_machine.Machine(cros_machine.name).Lock(True, sys.argv[0])
      if locked:
        self._machines.append(cros_machine)
        command = "cat %s" % CHECKSUM_FILE
        ret, out, _ = self.ce.CrosRunCommand(
            command, return_output=True, chromeos_root=self.chromeos_root,
            machine=cros_machine.name)
        if ret == 0:
          cros_machine.checksum = out.strip()
      else:
        self.logger.LogOutput("Couldn't lock: %s" % cros_machine.name)

  # This is called from single threaded mode.
  def AddMachine(self, machine_name):
    with self._lock:
      for m in self._all_machines:
        assert m.name != machine_name, "Tried to double-add %s" % machine_name
        if self.log_level != "verbose":
          self.logger.LogOutput("Setting up remote access to %s"
                              % machine_name)
          self.logger.LogOutput("Checking machine characteristics for %s"
                              % machine_name)
      cm = CrosMachine(machine_name, self.chromeos_root, self.log_level)
      if cm.machine_checksum:
        self._all_machines.append(cm)


  def AreAllMachineSame(self, label):
    checksums = [m.machine_checksum for m in self.GetMachines(label)]
    return len(set(checksums)) == 1


  def RemoveMachine(self, machine_name):
    with self._lock:
      self._machines = [m for m in self._machines
                        if m.name != machine_name]
      res = lock_machine.Machine(machine_name).Unlock(True)
      if not res:
        self.logger.LogError("Could not unlock machine: '%s'."
                             % m.name)

  def ForceSameImageToAllMachines(self, label):
    machines = self.GetMachines(label)
    for m in machines:
      self.ImageMachine(m, label)
      m.SetUpChecksumInfo()

  def AcquireMachine(self, chromeos_image, label, throw=False):
    if label.image_type == "local":
      image_checksum = ImageChecksummer().Checksum(label, self.log_level)
    elif label.image_type == "trybot":
      image_checksum = hashlib.md5(chromeos_image).hexdigest()
    else:
      image_checksum = None
    machines = self.GetMachines(label)
    check_interval_time = 120
    with self._lock:
      # Lazily external lock machines
      while self.acquire_timeout >= 0:
        for m in machines:
          new_machine = m not in self._all_machines
          self._TryToLockMachine(m)
          if new_machine:
            m.released_time = time.time()
        if not self.AreAllMachineSame(label):
          if not throw:
            # Log fatal message, which calls sys.exit.  Default behavior.
            self.logger.LogFatal("-- not all the machines are identical")
          else:
            # Raise an exception, which can be caught and handled by calling
            # function.
            raise NonMatchingMachines("Not all the machines are identical")
        if self.GetAvailableMachines(label):
          break
        else:
          sleep_time = max(1, min(self.acquire_timeout, check_interval_time))
          time.sleep(sleep_time)
          self.acquire_timeout -= sleep_time

      if self.acquire_timeout < 0:
        machine_names = []
        for machine in machines:
          machine_names.append(machine.name)
        self.logger.LogFatal("Could not acquire any of the "
                             "following machines: '%s'"
                             % ", ".join(machine_names))

###      for m in self._machines:
###        if (m.locked and time.time() - m.released_time < 10 and
###            m.checksum == image_checksum):
###          return None
      for m in [machine for machine in self.GetAvailableMachines(label)
                if not machine.locked]:
        if image_checksum and (m.checksum == image_checksum):
          m.locked = True
          m.test_run = threading.current_thread()
          return m
      for m in [machine for machine in self.GetAvailableMachines(label)
                if not machine.locked]:
        if not m.checksum:
          m.locked = True
          m.test_run = threading.current_thread()
          return m
      # This logic ensures that threads waiting on a machine will get a machine
      # with a checksum equal to their image over other threads. This saves time
      # when crosperf initially assigns the machines to threads by minimizing
      # the number of re-images.
      # TODO(asharif): If we centralize the thread-scheduler, we wont need this
      # code and can implement minimal reimaging code more cleanly.
      for m in [machine for machine in self.GetAvailableMachines(label)
                if not machine.locked]:
        if time.time() - m.released_time > 15:
          # The release time gap is too large, so it is probably in the start
          # stage, we need to reset the released_time.
          m.released_time = time.time()
        elif time.time() - m.released_time > 8:
          m.locked = True
          m.test_run = threading.current_thread()
          return m
    return None

  def GetAvailableMachines(self, label=None):
    if not label:
      return self._machines
    return [m for m in self._machines if m.name in label.remote]

  def GetMachines(self, label=None):
    if not label:
      return self._all_machines
    return [m for m in self._all_machines if m.name in label.remote]

  def ReleaseMachine(self, machine):
    with self._lock:
      for m in self._machines:
        if machine.name == m.name:
          assert m.locked == True, "Tried to double-release %s" % m.name
          m.released_time = time.time()
          m.locked = False
          m.status = "Available"
          break

  def Cleanup(self):
    with self._lock:
      # Unlock all machines.
      for m in self._machines:
        if not self.no_lock:
          res = lock_machine.Machine(m.name).Unlock(True)
          if not res:
            self.logger.LogError("Could not unlock machine: '%s'."
                                 % m.name)

  def __str__(self):
    with self._lock:
      l = ["MachineManager Status:"]
      for m in self._machines:
        l.append(str(m))
      return "\n".join(l)

  def AsString(self):
    with self._lock:
      stringify_fmt = "%-30s %-10s %-4s %-25s %-32s"
      header = stringify_fmt % ("Machine", "Thread", "Lock", "Status",
                                "Checksum")
      table = [header]
      for m in self._machines:
        if m.test_run:
          test_name = m.test_run.name
          test_status = m.test_run.timeline.GetLastEvent()
        else:
          test_name = ""
          test_status = ""

        try:
          machine_string = stringify_fmt % (m.name,
                                            test_name,
                                            m.locked,
                                            test_status,
                                            m.checksum)
        except Exception:
          machine_string = ""
        table.append(machine_string)
      return "Machine Status:\n%s" % "\n".join(table)

  def GetAllCPUInfo(self, labels):
    """Get cpuinfo for labels, merge them if their cpuinfo are the same."""
    dic = {}
    for label in labels:
      for machine in self._all_machines:
        if machine.name in label.remote:
          if machine.cpuinfo not in dic:
            dic[machine.cpuinfo] = [label.name]
          else:
            dic[machine.cpuinfo].append(label.name)
          break
    output = ""
    for key, v in dic.items():
      output += " ".join(v)
      output += "\n-------------------\n"
      output += key
      output += "\n\n\n"
    return output


class MockCrosMachine(CrosMachine):
  def __init__(self, name, chromeos_root, log_level):
    self.name = name
    self.image = None
    self.checksum = None
    self.locked = False
    self.released_time = time.time()
    self.test_run = None
    self.chromeos_root = chromeos_root
    self.checksum_string = re.sub("\d", "", name)
    #In test, we assume "lumpy1", "lumpy2" are the same machine.
    self.machine_checksum =  self._GetMD5Checksum(self.checksum_string)
    self.log_level = log_level

  def IsReachable(self):
    return True


class MockMachineManager(MachineManager):

  def __init__(self, chromeos_root, acquire_timeout, log_level):
    super(MockMachineManager, self).__init__(chromeos_root, acquire_timeout,
                                             log_level)

  def _TryToLockMachine(self, cros_machine):
    self._machines.append(cros_machine)
    cros_machine.checksum = ""

  def AddMachine(self, machine_name):
    with self._lock:
      for m in self._all_machines:
        assert m.name != machine_name, "Tried to double-add %s" % machine_name
      cm = MockCrosMachine(machine_name, self.chromeos_root, self.log_level)
      assert cm.machine_checksum, ("Could not find checksum for machine %s" %
                                   machine_name)
      self._all_machines.append(cm)

  def AcquireMachine(self, chromeos_image, label, throw=False):
    for machine in self._all_machines:
      if not machine.locked:
        machine.locked = True
        return machine
    return None

  def ImageMachine(self, machine_name, label):
    return 0

  def ReleaseMachine(self, machine):
    machine.locked = False

  def GetMachines(self, label):
    return self._all_machines

  def GetAvailableMachines(self, label):
    return self._all_machines