# Copyright 2018 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""Implements commands for running and interacting with Fuchsia on devices."""

import boot_data
import logging
import os
import subprocess
import sys
import target
import time
import uuid

from common import SDK_ROOT, EnsurePathExists

CONNECT_RETRY_COUNT = 20
CONNECT_RETRY_WAIT_SECS = 1

# Number of failed connection attempts before redirecting system logs to stdout.
CONNECT_RETRY_COUNT_BEFORE_LOGGING = 10

class DeviceTarget(target.Target):
  def __init__(self, output_dir, target_cpu, host=None, port=None,
               ssh_config=None, system_log_file=None):
    """output_dir: The directory which will contain the files that are
                   generated to support the deployment.
    target_cpu: The CPU architecture of the deployment target. Can be
                "x64" or "arm64".
    host: The address of the deployment target device.
    port: The port of the SSH service on the deployment target device.
    ssh_config: The path to SSH configuration data."""

    super(DeviceTarget, self).__init__(output_dir, target_cpu)

    self._port = 22
    self._auto = not host or not ssh_config
    self._new_instance = True
    self._system_log_file = system_log_file
    self._loglistener = None

    if self._auto:
      self._ssh_config_path = EnsurePathExists(
          boot_data.GetSSHConfigPath(output_dir))
    else:
      self._ssh_config_path = os.path.expanduser(ssh_config)
      self._host = host
      if port:
        self._port = port
      self._new_instance = False

  def __exit__(self, exc_type, exc_val, exc_tb):
    if self._loglistener:
      self._loglistener.kill()

  def __Discover(self, node_name):
    """Returns the IP address and port of a Fuchsia instance discovered on
    the local area network."""

    netaddr_path = os.path.join(SDK_ROOT, 'tools', 'netaddr')
    command = [netaddr_path, '--fuchsia', '--nowait', node_name]
    logging.debug(' '.join(command))
    proc = subprocess.Popen(command,
                            stdout=subprocess.PIPE,
                            stderr=open(os.devnull, 'w'))
    proc.wait()
    if proc.returncode == 0:
      return proc.stdout.readlines()[0].strip()
    return None

  def Start(self):
    if self._auto:
      logging.debug('Starting automatic device deployment.')
      node_name = boot_data.GetNodeName(self._output_dir)
      self._host = self.__Discover(node_name)
      if self._host and self._WaitUntilReady(retries=0):
        logging.info('Connected to an already booted device.')
        self._new_instance = False
        return

      logging.info('Netbooting Fuchsia. ' +
                   'Please ensure that your device is in bootloader mode.')
      bootserver_path = os.path.join(SDK_ROOT, 'tools', 'bootserver')
      bootserver_command = [
          bootserver_path,
          '-1',
          '--efi',
          EnsurePathExists(boot_data.GetTargetFile(self._GetTargetSdkArch(),
                                                   'local.esp.blk')),
          '--fvm',
          EnsurePathExists(boot_data.GetTargetFile(self._GetTargetSdkArch(),
                                                   'fvm.sparse.blk')),
          '--fvm',
          EnsurePathExists(
              boot_data.ConfigureDataFVM(self._output_dir,
                                         boot_data.FVM_TYPE_SPARSE)),
          EnsurePathExists(boot_data.GetTargetFile(self._GetTargetSdkArch(),
                                                   'zircon.bin')),
          EnsurePathExists(boot_data.GetTargetFile(self._GetTargetSdkArch(),
                                                   'bootdata-blob.bin')),
          '--'] + boot_data.GetKernelArgs(self._output_dir)
      logging.debug(' '.join(bootserver_command))
      subprocess.check_call(bootserver_command)

      # Start loglistener to save system logs.
      if self._system_log_file:
        loglistener_path = os.path.join(SDK_ROOT, 'tools', 'loglistener')
        self._loglistener = subprocess.Popen(
            [loglistener_path, node_name],
            stdout=self._system_log_file,
            stderr=subprocess.STDOUT, stdin=open(os.devnull))

      logging.debug('Waiting for device to join network.')
      for retry in xrange(CONNECT_RETRY_COUNT):
        self._host = self.__Discover(node_name)
        if self._host:
          break
        time.sleep(CONNECT_RETRY_WAIT_SECS)
      if not self._host:
        raise Exception('Couldn\'t connect to device.')

      logging.debug('host=%s, port=%d' % (self._host, self._port))

    self._WaitUntilReady();

  def IsNewInstance(self):
    return self._new_instance

  def _GetEndpoint(self):
    return (self._host, self._port)

  def _GetSshConfigPath(self):
    return self._ssh_config_path