sky_tool

#!/usr/bin/env python
# Copyright 2015 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.

import argparse
import atexit
import errno
import hashlib
import json
import logging
import multiprocessing
import os
import platform
import random
import re
import signal
import socket
import subprocess
import sys
import tempfile
import time
import urlparse

PACKAGES_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
SKY_ENGINE_DIR = os.path.join(PACKAGES_DIR, 'sky_engine')
APK_DIR = os.path.join(os.path.realpath(SKY_ENGINE_DIR), os.pardir, 'apks')

SKY_SERVER_PORT = 9888
OBSERVATORY_PORT = 8181
ADB_PATH = 'adb'
APK_NAME = 'SkyShell.apk'
ANDROID_PACKAGE = 'org.domokit.sky.shell'
ANDROID_COMPONENT = '%s/%s.SkyActivity' % (ANDROID_PACKAGE, ANDROID_PACKAGE)
SHA1_PATH = '/sdcard/%s/%s.sha1' % (ANDROID_PACKAGE, APK_NAME)

SKY_SHELL_APP_ID = 'com.google.SkyShell'
IOS_APP_NAME = 'SkyShell.app'

# FIXME: Do we need to look in $DART_SDK?
DART_PATH = 'dart'
PUB_PATH = 'pub'

PID_FILE_PATH = '/tmp/sky_tool.pids'
PID_FILE_KEYS = frozenset([
    'remote_sky_server_port',
    'sky_server_pid',
    'sky_server_port',
    'sky_server_root',
])

IOS_SIM_PATH = [
    os.path.join('/Applications', 'iOS Simulator.app', 'Contents', 'MacOS', 'iOS Simulator')
]

XCRUN_PATH = [
    os.path.join('/usr', 'bin', 'env'),
    'xcrun',
]

SIMCTL_PATH = XCRUN_PATH + [
    'simctl',
]

PLIST_BUDDY_PATH = XCRUN_PATH + [
    'PlistBuddy',
]


def _port_in_use(port):
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    return sock.connect_ex(('localhost', port)) == 0


def _start_http_server(port, root):
    server_command = [
        PUB_PATH, 'run', 'sky_tools:sky_server', str(port),
    ]
    logging.info(' '.join(server_command))
    return subprocess.Popen(server_command, cwd=root).pid


# This 'strict dictionary' approach is useful for catching typos.
class Pids(object):
    def __init__(self, known_keys, contents=None):
        self._known_keys = known_keys
        self._dict = contents if contents is not None else {}

    def __len__(self):
        return len(self._dict)

    def get(self, key, default=None):
        assert key in self._known_keys, '%s not in known_keys' % key
        return self._dict.get(key, default)

    def __getitem__(self, key):
        assert key in self._known_keys, '%s not in known_keys' % key
        return self._dict[key]

    def __setitem__(self, key, value):
        assert key in self._known_keys, '%s not in known_keys' % key
        self._dict[key] = value

    def __delitem__(self, key):
        assert key in self._known_keys, '%s not in known_keys' % key
        del self._dict[key]

    def __iter__(self):
        return iter(self._dict)

    def __contains__(self, key):
        assert key in self._known_keys, '%s not in allowed_keys' % key
        return key in self._dict

    def clear(self):
        self._dict = {}

    def pop(self, key, default=None):
        assert key in self._known_keys, '%s not in known_keys' % key
        return self._dict.pop(key, default)

    @classmethod
    def read_from(cls, path, known_keys):
        contents = {}
        try:
            with open(path, 'r') as pid_file:
                contents = json.load(pid_file)
        except:
            if os.path.exists(path):
                logging.warn('Failed to read pid file: %s' % path)
        return cls(known_keys, contents)

    def write_to(self, path):
        # These keys are required to write a valid file.
        if not self._dict.viewkeys() >= { 'sky_server_pid', 'sky_server_port' }:
            return

        try:
            with open(path, 'w') as pid_file:
                json.dump(self._dict, pid_file, indent=2, sort_keys=True)
        except:
            logging.warn('Failed to write pid file: %s' % path)


def _url_for_path(port, root, path):
    relative_path = os.path.relpath(path, root)
    return 'http://localhost:%s/%s' % (port, relative_path)


class SkyLogs(object):
    def add_subparser(self, subparsers):
        logs_parser = subparsers.add_parser('logs',
            help='Show logs for running Sky apps')
        logs_parser.add_argument('--clear', action='store_true', dest='clear_logs',
            help='Clear log history before reading from logs (currently only implemented for Android)')
        logs_parser.set_defaults(func=self.run)

    def run(self, args, pids):
        android_log_reader = None
        ios_dev_log_reader = None
        ios_sim_log_reader = None

        android = AndroidDevice()
        if android.is_connected():
            android_log_reader = android.logs(args.clear_logs)

        if IOSDevice.is_connected():
            ios_dev_log_reader = IOSDevice.logs(args.clear_logs)

        if IOSSimulator.is_connected():
            ios_sim_log_reader = IOSSimulator.logs(args.clear_logs)

        if android_log_reader is not None:
            try:
                android_log_reader.join()
            except KeyboardInterrupt:
                pass

        if ios_dev_log_reader is not None:
            try:
                ios_dev_log_reader.join()
            except KeyboardInterrupt:
                pass

        if ios_sim_log_reader is not None:
            try:
                ios_sim_log_reader.join()
            except KeyboardInterrupt:
                pass


class InstallSky(object):
    def add_subparser(self, subparsers):
        install_parser = subparsers.add_parser('install',
            help='install SkyShell on Android and iOS devices and simulators')
        install_parser.set_defaults(func=self.run)

    def run(self, args, pids):
        android = AndroidDevice()

        installed_somewhere = False
        # Install on connected Android device
        if android.is_connected() and args.android_build_available:
            installed_somewhere = installed_somewhere or android.install_apk(android.get_apk_path(args))

        # Install on connected iOS device
        if IOSDevice.is_connected() and args.ios_build_available:
            installed_somewhere = installed_somewhere or IOSDevice.install_app(IOSDevice.get_app_path(args))

        # Install on iOS simulator if it's running
        if IOSSimulator.is_booted() and args.ios_sim_build_available:
            installed_somewhere = installed_somewhere or IOSSimulator.fork_install_app(IOSSimulator.get_app_path(args))

        if installed_somewhere:
            return 0
        else:
            return 2

    # TODO(iansf): get rid of need for args
    def needs_install(self, args):
        return AndroidDevice().needs_install(args) or IOSDevice.needs_install(args) or IOSSimulator.needs_install(args)


class StartSky(object):
    def add_subparser(self, subparsers):
        start_parser = subparsers.add_parser('start',
            help='launch %s on the device' % APK_NAME)
        start_parser.add_argument('--poke', action='store_true')
        start_parser.add_argument('--checked', action='store_true')
        start_parser.add_argument('project_or_path', nargs='?', type=str,
            default='.')
        start_parser.set_defaults(func=self.run)

    def run(self, args, pids):
        started_sky_somewhere = False
        if not args.poke:
            StopSky().run(args, pids)

            # Only install if the user did not specify a poke
            installer = InstallSky()
            if installer.needs_install(args):
                started_sky_somewhere = (installer.run(args, pids) == 0)

        project_or_path = os.path.abspath(args.project_or_path)

        if os.path.isdir(project_or_path):
            sky_server_root = project_or_path
            main_dart = os.path.join(project_or_path, 'lib', 'main.dart')
            missing_msg = 'Missing lib/main.dart in project: %s' % project_or_path
        else:
            sky_server_root = os.getcwd()
            main_dart = project_or_path
            missing_msg = '%s does not exist.' % main_dart

        if not os.path.isfile(main_dart):
            logging.error(missing_msg)
            return 2

        package_root = os.path.join(sky_server_root, 'packages')
        if not os.path.isdir(package_root):
            logging.error('%s is not a valid packages path.' % package_root)
            return 2

        android = AndroidDevice()
        # TODO(iansf): fix this so that we don't have to pass sky_server_root, main_dart, pid, and args.
        started_sky_on_android = android.setup_servers(sky_server_root, main_dart, pids, args)

        if started_sky_somewhere or started_sky_on_android:
            return 0
        else:
            return 2


class StopSky(object):
    def add_subparser(self, subparsers):
        stop_parser = subparsers.add_parser('stop',
            help=('kill all running SkyShell.apk processes'))
        stop_parser.set_defaults(func=self.run)

    def _run(self, args):
        with open('/dev/null', 'w') as dev_null:
            logging.info(' '.join(args))
            subprocess.call(args, stdout=dev_null, stderr=dev_null)

    def run(self, args, pids):
        if 'remote_sky_server_port' in pids:
            port_string = 'tcp:%s' % pids['remote_sky_server_port']
            self._run([AndroidDevice().adb_path, 'reverse', '--remove', port_string])

        self._run([AndroidDevice().adb_path, 'shell', 'am', 'force-stop', ANDROID_PACKAGE])

        try:
            # Because the server gets forked by dart, pids.get(['sky_server_pid']) returns an invalid pid,
            # so just force things closed.
            if platform.system() == 'Darwin':
                cmd = ['lsof', '-i', ':%s' % SKY_SERVER_PORT, '-t']
                logging.info(' '.join(cmd))
                pid = subprocess.check_output(cmd)

                # Killing a pid with a shell command from within python is hard,
                # so use a library command, but it's still nice to give the
                # equivalent command when doing verbose logging.
                logging.info('kill %s' % pid)
                os.kill(int(pid), signal.SIGTERM)
            else:
                # This usage of fuser is not valid on OS X
                self._run(['fuser', '-k', '%s/tcp' % SKY_SERVER_PORT])
        except subprocess.CalledProcessError as e:
            pass

        pids.clear()

class AndroidDevice(object):
    # _state used in this manner gives a simple way to treat AndroidDevice
    # as a singleton while easily allowing subclassing for mocks.  All
    # AndroidDevices created in a given session will share the same state.
    _state = {}
    def __init__(self):
        self.__dict__ = AndroidDevice._state
        self._update_paths()

        # Checking for lollipop only needs to be done if we are starting an
        # app, but it has an important side effect, which is to discard any
        # progress messages if the adb server is restarted.
        self._check_for_adb()
        self._check_for_lollipop_or_later()

    def _update_paths(self):
        if 'adb_path' in self.__dict__:
            return
        if 'ANDROID_HOME' in os.environ:
            android_home_dir = os.environ['ANDROID_HOME']
            adb_location1 = os.path.join(android_home_dir, 'sdk', 'platform-tools', 'adb')
            adb_location2 = os.path.join(android_home_dir, 'platform-tools', 'adb')
            if os.path.exists(adb_location1):
                self.adb_path = adb_location1
            elif os.path.exists(adb_location2):
                self.adb_path = adb_location2
            else:
                logging.warning('"adb" not found at\n  "%s" or\n  "%s"\nusing default path "%s"' % (adb_location1, adb_location2, ADB_PATH))
                self.adb_path = ADB_PATH
        else:
            self.adb_path = ADB_PATH

    def _is_valid_adb_version(self, adb_version):
        # Sample output: 'Android Debug Bridge version 1.0.31'
        version_fields = re.search('(\d+)\.(\d+)\.(\d+)', adb_version)
        if version_fields:
            major_version = int(version_fields.group(1))
            minor_version = int(version_fields.group(2))
            patch_version = int(version_fields.group(3))
            if major_version > 1:
                return True
            if major_version == 1 and minor_version > 0:
                return True
            if major_version == 1 and minor_version == 0 and patch_version >= 32:
                return True
            return False
        else:
            logging.warn('Unrecognized adb version string. Skipping version check.')
            return True

    def _check_for_adb(self):
        if 'has_valid_adb' in self.__dict__:
            return
        try:
            cmd = [self.adb_path, 'version']
            logging.info(' '.join(cmd))
            adb_version = subprocess.check_output(cmd)
            if self._is_valid_adb_version(adb_version):
                self.has_valid_adb = True
                return

            cmd = ['which', ADB_PATH]
            logging.info(' '.join(cmd))
            adb_path = subprocess.check_output(cmd).rstrip()
            logging.error('"%s" is too old. Need 1.0.32 or later. '
                'Try setting ANDROID_HOME to use Android builds. Android builds are unavailable.' % adb_path)
            self.has_valid_adb = False
        except OSError:
            logging.warning('"adb" (from the Android SDK) not in $PATH, Android builds are unavailable.')
            self.has_valid_adb = False

    def _check_for_lollipop_or_later(self):
        if 'has_valid_android' in self.__dict__:
            return
        try:
            # If the server is automatically restarted, then we get irrelevant
            # output lines like this, which we want to ignore:
            #   adb server is out of date.  killing..
            #   * daemon started successfully *
            cmd = [self.adb_path, 'start-server']
            logging.info(' '.join(cmd))
            subprocess.call(cmd)

            cmd = [self.adb_path, 'shell', 'getprop', 'ro.build.version.sdk']
            logging.info(' '.join(cmd))
            sdk_version = subprocess.check_output(cmd).rstrip()
            # Sample output: '22'
            if not sdk_version.isdigit():
                logging.error('Unexpected response from getprop: "%s".' % sdk_version)
                self.has_valid_android = False
                return

            if int(sdk_version) < 22:
                logging.error('Version "%s" of the Android SDK is too old. '
                              'Need Lollipop (22) or later. ' % sdk_version)
                self.has_valid_android = False
                return
        except subprocess.CalledProcessError as e:
            # adb printed the error, so we print nothing.
            self.has_valid_android = False
            return
        self.has_valid_android = True

    def is_package_installed(self, package_name):
        if not self.is_connected():
            return False
        pm_path_cmd = [self.adb_path, 'shell', 'pm', 'path', package_name]
        logging.info(' '.join(pm_path_cmd))
        return subprocess.check_output(pm_path_cmd).strip() != ''

    def get_device_apk_sha1(self, apk_path):
        # We might need to install a new APK, so check SHA1
        cmd = [self.adb_path, 'shell', 'cat', SHA1_PATH]
        logging.info(' '.join(cmd))
        return subprocess.check_output(cmd)

    def get_source_sha1(self, apk_path):
        return hashlib.sha1(open(apk_path, 'rb').read()).hexdigest()

    # TODO(iansf): get rid of need for args
    def get_apk_path(self, args):
        if args.android_build_available and args.use_release:
            return os.path.join(os.path.normpath(args.sky_src_path), args.android_release_build_path, 'apks', APK_NAME)
        elif args.android_build_available and args.local_build:
            return os.path.join(os.path.normpath(args.sky_src_path), args.android_debug_build_path, 'apks', APK_NAME)
        else:
            return os.path.join(APK_DIR, APK_NAME)

    def is_connected(self):
        return self.has_valid_android

    def needs_install(self, args):
        apk_path = self.get_apk_path(args)

        if not self.is_package_installed(ANDROID_PACKAGE):
            logging.info('%s is not on the device. Installing now...' % APK_NAME)
            return True
        elif self.get_device_apk_sha1(apk_path) != self.get_source_sha1(apk_path):
            logging.info('%s on the device is out of date. Installing now...' % APK_NAME)
            return True
        return False

    def install_apk(self, apk_path):
        if not os.path.exists(apk_path):
            logging.error('"%s" does not exist.' % apk_path)
            return False

        cmd = [self.adb_path, 'install', '-r', apk_path]
        logging.info(' '.join(cmd))
        subprocess.check_call(cmd)
        # record the SHA1 of the APK we just pushed
        with tempfile.NamedTemporaryFile() as fp:
            fp.write(self.get_source_sha1(apk_path))
            fp.seek(0)
            cmd = [self.adb_path, 'push', fp.name, SHA1_PATH]
            logging.info(' '.join(cmd))
            subprocess.check_call(cmd)

        return True


    # TODO(iansf): refactor setup_servers
    def setup_servers(self, sky_server_root, main_dart, pids, args):
        if not self.is_connected():
            return False

        # Set up port forwarding for observatory
        observatory_port_string = 'tcp:%s' % OBSERVATORY_PORT
        cmd = [
            self.adb_path,
            'forward',
            observatory_port_string,
            observatory_port_string
        ]
        logging.info(' '.join(cmd))
        subprocess.check_call(cmd)

        sky_server_port = SKY_SERVER_PORT
        pids['sky_server_port'] = sky_server_port
        if _port_in_use(sky_server_port):
            logging.info(('Port %s already in use. '
            ' Not starting server for %s') % (sky_server_port, sky_server_root))
        else:
            sky_server_pid = _start_http_server(sky_server_port, sky_server_root)
            pids['sky_server_pid'] = sky_server_pid
            pids['sky_server_root'] = sky_server_root

        port_string = 'tcp:%s' % sky_server_port
        cmd = [
            self.adb_path,
            'reverse',
            port_string,
            port_string
        ]
        logging.info(' '.join(cmd))
        subprocess.check_call(cmd)
        pids['remote_sky_server_port'] = sky_server_port

        # The load happens on the remote device, use the remote port.
        url = _url_for_path(pids['remote_sky_server_port'], sky_server_root,
            main_dart)
        if args.poke:
            url += '?rand=%s' % random.random()

        cmd = [
            self.adb_path, 'shell',
            'am', 'start',
            '-a', 'android.intent.action.VIEW',
            '-d', url,
        ]

        if args.checked:
            cmd += ['--ez', 'enable-checked-mode', 'true']

        cmd += [ANDROID_COMPONENT]
        logging.info(' '.join(cmd))
        subprocess.check_output(cmd)

        return True

    def logs(self, clear=False):
        def do_logs():
            if clear:
                cmd = [
                    self.adb_path,
                    'logcat',
                    '-c'
                ]
                logging.info(' '.join(cmd))
                subprocess.check_call(cmd)

            cmd = [
                self.adb_path,
                'logcat',
                '-v',
                'tag', # Only log the tag and the message
                '-s',
                'sky',
                'chromium',
            ]
            logging.info(' '.join(cmd))
            log_process = subprocess.Popen(cmd, bufsize=1, stdout=subprocess.PIPE)
            while True:
                try:
                    log_line = log_process.stdout.readline()
                    if log_line == '':
                        if log_process.poll() != None:
                            logging.error('The Android logging process has quit unexpectedly. Please call the "logs" command again.')
                            break
                    sys.stdout.write('ANDROID: ' + log_line)
                    sys.stdout.flush()
                except KeyboardInterrupt:
                    break
        log_reader = multiprocessing.Process(target=do_logs)
        log_reader.daemon = True
        log_reader.start()
        return log_reader


class IOSDevice(object):
    _has_ios_deploy = None
    @classmethod
    def has_ios_deploy(cls):
        if cls._has_ios_deploy is not None:
            return cls._has_ios_deploy
        try:
            cmd = [
                'which',
                'ios-deploy'
            ]
            logging.info(' '.join(cmd))
            out = subprocess.check_output(cmd)
            match = re.search(r'ios-deploy', out)
            cls._has_ios_deploy = match is not None
        except subprocess.CalledProcessError:
            cls._has_ios_deploy = False
        return cls._has_ios_deploy

    _is_connected = False
    @classmethod
    def is_connected(cls):
        if not cls.has_ios_deploy():
            return False
        if cls._is_connected:
            return True
        try:
            cmd = [
                'ios-deploy',
                '--detect',
                '--timeout',
                '1'
            ]
            logging.info(' '.join(cmd))
            out = subprocess.check_output(cmd)
            match = re.search(r'\[\.\.\.\.\] Found [^\)]*\) connected', out)
            cls._is_connected = match is not None
        except subprocess.CalledProcessError:
            cls._is_connected = False
        return cls._is_connected

    @classmethod
    def get_app_path(cls, args):
        if args.use_release:
            return os.path.join(args.sky_src_path, args.ios_release_build_path, IOS_APP_NAME)
        else:
            return os.path.join(args.sky_src_path, args.ios_debug_build_path, IOS_APP_NAME)

    @classmethod
    def needs_install(cls, args):
        return cls.is_connected()

    @classmethod
    def install_app(cls, ios_app_path):
        if not cls.has_ios_deploy():
            return False
        try:
            cmd = [
                'ios-deploy',
                '--justlaunch',
                '--timeout',
                '10', # Smaller timeouts cause it to exit before having launched the app
                '--bundle',
                ios_app_path
            ]
            logging.info(' '.join(cmd))
            subprocess.check_call(cmd)
        except subprocess.CalledProcessError:
            return False
        return True

    @classmethod
    def copy_file(cls, bundle_id, local_path, device_path):
        if not cls.has_ios_deploy():
            return
        try:
            cmd = [
                'ios-deploy',
                '-t',
                '1',
                '--bundle_id',
                bundle_id,
                '--upload',
                local_path,
                '--to',
                device_path
            ]
            logging.info(' '.join(cmd))
            subprocess.check_call(cmd)
        except subprocess.CalledProcessError:
            pass

    @classmethod
    def logs(cls, clear=False):
        try:
            cmd = [
                'which',
                'idevicesyslog'
            ]
            logging.info(' '.join(cmd))
            subprocess.check_call(cmd)
        except subprocess.CalledProcessError:
            logging.error('"log" command only works with iOS devices if you have installed idevicesyslog. Run "brew install libimobiledevice" to install it with homebrew.')
            return None

        def do_logs():
            cmd = [
                'idevicesyslog',
            ]
            logging.info(' '.join(cmd))
            log_process = subprocess.Popen(cmd, stdout=subprocess.PIPE)
            while True:
                try:
                    log_line = log_process.stdout.readline()
                    if log_line == '':
                        if log_process.poll() != None:
                            logging.error('The iOS logging process has quit unexpectedly. Please call the "logs" command again.')
                            break
                    if re.match(r'.*SkyShell.*', log_line) is not None:
                        sys.stdout.write('IOS DEV: ' + log_line)
                        sys.stdout.flush()
                except KeyboardInterrupt:
                    break
        log_reader = multiprocessing.Process(target=do_logs)
        log_reader.daemon = True
        log_reader.start()
        return log_reader


class IOSSimulator(object):
    @classmethod
    def is_booted(cls):
        if platform.system() != 'Darwin':
            return False
        return cls.get_simulator_device_id() is not None

    @classmethod
    def is_connected(cls):
        return cls.is_booted()

    _device_id = None
    @classmethod
    def get_simulator_device_id(cls):
        if cls._device_id is not None:
            return cls._device_id
        cmd = SIMCTL_PATH + [
            'list',
            'devices',
        ]
        logging.info(' '.join(cmd))
        out = subprocess.check_output(cmd)
        match = re.search(r'[^\(]+\(([^\)]+)\) \(Booted\)', out)
        if match is not None and match.group(1) is not None:
            cls._device_id = match.group(1)
            return cls._device_id
        else:
            logging.info('No running simulators found')
            # TODO: Maybe start the simulator?
            return None
        if err is not None:
            print(err)
            exit(-1)

    _simulator_path = None
    @classmethod
    def get_simulator_path(cls):
        if cls._simulator_path is not None:
            return cls._simulator_path
        home_dir = os.path.expanduser('~')
        device_id = cls.get_simulator_device_id()
        if device_id is None:
            # TODO: Maybe start the simulator?
            return None
        cls._simulator_path = os.path.join(home_dir, 'Library', 'Developer', 'CoreSimulator', 'Devices', device_id)
        return cls._simulator_path

    _simulator_app_id = None
    @classmethod
    def get_simulator_app_id(cls):
        if cls._simulator_app_id is not None:
            return cls._simulator_app_id
        simulator_path = cls.get_simulator_path()
        cmd = [
            'find',
            os.path.join(simulator_path, 'data', 'Containers', 'Data', 'Application'),
            '-name',
            SKY_SHELL_APP_ID
        ]
        logging.info(' '.join(cmd))
        out = subprocess.check_output(cmd)
        match = re.search(r'Data\/Application\/([^\/]+)\/Documents\/' + SKY_SHELL_APP_ID, out)
        if match is not None and match.group(1) is not None:
            cls._simulator_app_id = match.group(1)
            return cls._simulator_app_id
        else:
            logging.warning(SKY_SHELL_APP_ID + ' is not installed on the simulator')
            # TODO: Maybe install the app?
            return None
        if err is not None:
            print(err)
            exit(-1)

    _simulator_app_documents_dir = None
    @classmethod
    def get_simulator_app_documents_dir(cls):
        if cls._simulator_app_documents_dir is not None:
            return cls._simulator_app_documents_dir
        if not cls.is_booted():
            return None
        simulator_path = cls.get_simulator_path()
        simulator_app_id = cls.get_simulator_app_id()
        if simulator_app_id is None:
            return None
        cls._simulator_app_documents_dir = os.path.join(simulator_path, 'data', 'Containers', 'Data', 'Application', simulator_app_id, 'Documents')
        return cls._simulator_app_documents_dir

    @classmethod
    def get_app_path(cls, args):
        if args.use_release:
            return os.path.join(args.sky_src_path, args.ios_sim_release_build_path, IOS_APP_NAME)
        else:
            return os.path.join(args.sky_src_path, args.ios_sim_debug_build_path, IOS_APP_NAME)

    @classmethod
    def needs_install(cls, args):
        return cls.is_booted()

    @classmethod
    def logs(cls, clear=False):
        def do_logs():
            cmd = [
                'tail',
                '-f',
                os.path.expanduser('~/Library/Logs/CoreSimulator/' + cls.get_simulator_device_id() + '/system.log'),
            ]
            logging.info(' '.join(cmd))
            log_process = subprocess.Popen(cmd, stdout=subprocess.PIPE)
            while True:
                try:
                    log_line = log_process.stdout.readline()
                    if log_line == '':
                        if log_process.poll() != None:
                            logging.error('The iOS Simulator logging process has quit unexpectedly. Please call the "logs" command again.')
                            break
                    if re.match(r'.*SkyShell.*', log_line) is not None:
                        sys.stdout.write('IOS SIM: ' + log_line)
                        sys.stdout.flush()
                except KeyboardInterrupt:
                    break
        log_reader = multiprocessing.Process(target=do_logs)
        log_reader.daemon = True
        log_reader.start()
        return log_reader

    @classmethod
    def fork_install_app(cls, ios_app_path):
        try:
            cmd = [
                os.path.abspath(__file__),
                'ios_sim',
                '-p',
                ios_app_path,
                'launch'
            ]
            logging.info(' '.join(cmd))
            subprocess.check_call(cmd)
            return True
        except subprocess.CalledProcessError:
            return False

    def _process_args(self, args):
        if args.ios_sim_build_path is None:
            if args.ios_sim_build_available:
                if args.use_release:
                    args.ios_sim_build_path = os.path.join(args.sky_src_path, args.ios_sim_release_build_path, IOS_APP_NAME)
                elif args.local_build:
                    args.ios_sim_build_path = os.path.join(args.sky_src_path, args.ios_sim_debug_build_path, IOS_APP_NAME)
        if args.ios_sim_build_path is None:
            logging.error('ios_sim commands require a valid -p argument if not using the --release or --local-build global arguments')
            sys.exit(2)

    def get_application_identifier(self, path):
        cmd = PLIST_BUDDY_PATH + [
            '-c',
            'Print CFBundleIdentifier',
            os.path.join(path, 'Info.plist')
        ]
        logging.info(' '.join(cmd))
        identifier = subprocess.check_output(cmd)
        return identifier.strip()

    def is_simulator_booted(self):
        cmd = SIMCTL_PATH + [ 'list', 'devices' ]
        logging.info(' '.join(cmd))
        devices = subprocess.check_output(cmd).strip().split('\n')
        for device in devices:
            if re.search(r'\(Booted\)', device):
                return True
        return False

    # Launch whatever simulator the user last used, rather than try to guess which of their simulators they might want to use
    def boot_simulator(self, args, pids):
        # Guarantee that the args get processed, since all of the commands funnel through here.
        self._process_args(args)
        if self.is_simulator_booted():
            return
        # Use Popen here because launching the simulator from the command line in this manner doesn't return, so we can't check the result.
        if args.ios_sim_path:
            logging.info(args.ios_sim_path)
            subprocess.Popen(args.ios_sim_path)
        else:
            logging.info(IOS_SIM_PATH)
            subprocess.Popen(IOS_SIM_PATH)
        while not self.is_simulator_booted():
            print('Waiting for iOS Simulator to boot...')
            time.sleep(0.5)

    def install_app(self, args, pids):
        self.boot_simulator(args, pids)
        cmd = SIMCTL_PATH + [
            'install',
            'booted',
            args.ios_sim_build_path,
        ]
        logging.info(' '.join(cmd))
        return subprocess.check_call(cmd)

    def install_launch_and_wait(self, args, pids, wait):
        res = self.install_app(args, pids)
        if res != 0:
            return res
        identifier = self.get_application_identifier(args.ios_sim_build_path)
        launch_args = SIMCTL_PATH + ['launch']
        if wait:
            launch_args += [ '-w' ]
        launch_args += [
            'booted',
            identifier,
            '-target',
            args.target,
            '-server',
            args.server
        ]
        logging.info(' '.join(launch_args))
        return subprocess.check_output(launch_args).strip()

    def launch_app(self, args, pids):
        self.install_launch_and_wait(args, pids, False)

    def debug_app(self, args, pids):
        launch_res = self.install_launch_and_wait(args, pids, True)
        launch_pid = re.search('.*: (\d+)', launch_res).group(1)
        cmd = XCRUN_PATH + [
            'lldb',
            # TODO(iansf): get this working again
            # '-s',
            # os.path.join(os.path.dirname(__file__), 'lldb_start_commands.txt'),
            '-p',
            launch_pid,
        ]
        logging.info(' '.join(cmd))
        return subprocess.call(cmd)

    def add_subparser(self, subparsers):
        simulator_parser = subparsers.add_parser('ios_sim',
            help='A script that launches an'
                 ' application in the simulator and attaches'
                 ' the debugger to it.')
        simulator_parser.add_argument('-p', dest='ios_sim_build_path', required=False,
            help='Path to the simulator app build. Defaults to values specified by '
                 'the sky_src_path and ios_sim_[debug|release]_build_path parameters, '
                 'which are normally specified by using the local-build or release '
                 'parameters. Not normally required.')
        simulator_parser.add_argument('-t', dest='target', required=False,
            default='examples/demo_launcher/lib/main.dart',
            help='Sky server-relative path to the Sky app to run. Not normally required.')
        simulator_parser.add_argument('-s', dest='server', required=False,
            default='localhost:8080',
            help='Sky server address. Not normally required.')
        simulator_parser.add_argument('--ios_sim_path', dest='ios_sim_path',
            help='Path to your iOS Simulator executable. '
                 'Not normally required.')

        subparsers = simulator_parser.add_subparsers()
        install_parser = subparsers.add_parser('install', help='Install app')
        install_parser.set_defaults(func=self.install_app)
        launch_parser = subparsers.add_parser('launch', help='Launch app. Automatically installs.')
        launch_parser.set_defaults(func=self.launch_app)
        debug_parser = subparsers.add_parser('debug', help='Debug app. Automatically installs and launches.')
        debug_parser.set_defaults(func=self.debug_app)


class StartListening(object):
    def __init__(self):
        self.watch_cmd = None

    def add_subparser(self, subparsers):
        listen_parser = subparsers.add_parser('listen',
            help=('Listen for changes to files and reload the running app on all connected devices'))
        listen_parser.set_defaults(func=self.run)

    def watch_dir(self, directory):
        if self.watch_cmd is None:
            name = platform.system()
            if name == 'Linux':
                try:
                    cmd = [
                        'which',
                        'inotifywait'
                    ]
                    logging.info(' '.join(cmd))
                    out = subprocess.check_output(cmd)
                except subprocess.CalledProcessError:
                    logging.error('"listen" command is only useful if you have installed inotifywait on Linux.  Run "apt-get install inotify-tools" or equivalent to install it.')
                    return False

                self.watch_cmd = [
                    'inotifywait',
                    '-r',
                    '-e',
                    'modify,close_write,move,create,delete', # Only listen for events that matter, to avoid triggering constantly from the editor watching files
                    directory
                ]
            elif name == 'Darwin':
                try:
                    cmd = [
                        'which',
                        'fswatch'
                    ]
                    logging.info(' '.join(cmd))
                    out = subprocess.check_output(cmd)
                except subprocess.CalledProcessError:
                    logging.error('"listen" command is only useful if you have installed fswatch on Mac.  Run "brew install fswatch" to install it with homebrew.')
                    return False

                self.watch_cmd = [
                    'fswatch',
                    '-r',
                    '-v',
                    '-1',
                    directory
                ]
            else:
                logging.error('"listen" command is only available on Mac and Linux.')
                return False

        logging.info(' '.join(self.watch_cmd))
        subprocess.check_call(self.watch_cmd)
        return True

    def run(self, args, pids):
        if args.use_release:
            logging.info('Note that the listen command is not compatible with the '
                         'release flag for iOS and iOS simulator builds. If you have '
                         'installed iOS release builds, your Sky app will fail to '
                         'reload while using listen.')
        tempdir = tempfile.mkdtemp()
        currdir = os.getcwd()
        while True:
            logging.info('Updating running Sky apps...')

            # Restart the app on Android.  Android does not currently restart using skyx files.
            cmd = [
                sys.executable,
                os.path.abspath(__file__),
                'start',
                '--poke'
            ]
            logging.info(' '.join(cmd))
            subprocess.check_call(cmd)

            if args.local_build:
                # Currently sending to iOS only works if you are building Sky locally
                # since we aren't shipping the sky_snapshot binary yet.

                # Check if we can make a snapshot
                sky_snapshot_path = None
                if args.ios_sim_build_available:
                    sky_snapshot_path = os.path.join(args.sky_src_path, args.ios_sim_debug_build_path, 'clang_x64', 'sky_snapshot')
                elif args.ios_build_available:
                    sky_snapshot_path = os.path.join(args.sky_src_path, args.ios_debug_build_path, 'clang_x64', 'sky_snapshot')

                if sky_snapshot_path is not None:
                    # If we can make a snapshot, do so and then send it to running iOS instances
                    cmd = [
                        sky_snapshot_path,
                        '--package-root=packages',
                        '--snapshot=' + os.path.join(tempdir, 'snapshot_blob.bin'),
                        os.path.join('lib', 'main.dart')
                    ]
                    logging.info(' '.join(cmd))
                    subprocess.check_call(cmd)

                    os.chdir(tempdir)
                    # Turn the snapshot into an app.skyx file
                    cmd = [
                        'zip',
                        '-r',
                        'app.skyx',
                        'snapshot_blob.bin',
                        'action',
                        'content',
                        'navigation'
                    ]
                    logging.info(' '.join(cmd))
                    subprocess.check_call(cmd)
                    os.chdir(currdir)

                    # Copy the app.skyx to the running simulator
                    simulator_app_documents_dir = IOSSimulator.get_simulator_app_documents_dir()
                    if simulator_app_documents_dir is not None:
                        cmd = [
                            'cp',
                            os.path.join(tempdir, 'app.skyx'),
                            simulator_app_documents_dir
                        ]
                        logging.info(' '.join(cmd))
                        subprocess.check_call(cmd)

                    # Copy the app.skyx to the attached iOS device
                    if IOSDevice.is_connected():
                        IOSDevice.copy_file(SKY_SHELL_APP_ID, os.path.join(tempdir, 'app.skyx'), 'Documents/app.skyx')

            # Watch filesystem for changes
            if not self.watch_dir(currdir):
                return


class StartTracing(object):
    def add_subparser(self, subparsers):
        start_tracing_parser = subparsers.add_parser('start_tracing',
            help=('start tracing a running sky instance'))
        start_tracing_parser.set_defaults(func=self.run)

    def run(self, args, pids):
        cmd = [
            ADB_PATH,
            'shell',
            'am',
            'broadcast',
            '-a',
            'org.domokit.sky.shell.TRACING_START'
        ]
        logging.info(' '.join(cmd))
        subprocess.check_output(cmd)


TRACE_COMPLETE_REGEXP = re.compile('Trace complete')
TRACE_FILE_REGEXP = re.compile(r'Saving trace to (?P<path>\S+)')


class StopTracing(object):
    def add_subparser(self, subparsers):
        stop_tracing_parser = subparsers.add_parser('stop_tracing',
            help=('stop tracing a running sky instance'))
        stop_tracing_parser.set_defaults(func=self.run)

    def run(self, args, pids):
        cmd = [ADB_PATH, 'logcat', '-c']
        logging.info(' '.join(cmd))
        subprocess.check_output(cmd)

        cmd = [
            ADB_PATH,
            'shell',
            'am',
            'broadcast',
            '-a',
            'org.domokit.sky.shell.TRACING_STOP'
        ]
        logging.info(' '.join(cmd))
        subprocess.check_output(cmd)

        device_path = None
        is_complete = False
        while not is_complete:
            time.sleep(0.2)
            cmd = [ADB_PATH, 'logcat', '-d']
            logging.info(' '.join(cmd))
            log = subprocess.check_output(cmd)
            if device_path is None:
                result = TRACE_FILE_REGEXP.search(log)
                if result:
                    device_path = result.group('path')
            is_complete = TRACE_COMPLETE_REGEXP.search(log) is not None

        logging.info('Downloading trace %s ...' % os.path.basename(device_path))

        if device_path:
            cmd = [ADB_PATH, 'root']
            logging.info(' '.join(cmd))
            output = subprocess.check_output(cmd)
            match = re.match(r'.*cannot run as root.*', output)
            if match is not None:
                logging.error('Unable to download trace file %s\n'
                              'You need to be able to run adb as root '
                              'on your android device' % device_path)
                return 2

            cmd = [ADB_PATH, 'pull', device_path]
            logging.info(' '.join(cmd))
            subprocess.check_output(cmd)

            cmd = [ADB_PATH, 'shell', 'rm', device_path]
            logging.info(' '.join(cmd))
            subprocess.check_output(cmd)


class SkyShellRunner(object):
    def _check_for_dart(self):
        try:
            cmd = [DART_PATH, '--version']
            logging.info(' '.join(cmd))
            subprocess.check_output(cmd, stderr=subprocess.STDOUT)
        except OSError:
            logging.error('"dart" (from the Dart SDK) not in $PATH, cannot continue.')
            return False
        return True

    def main(self):
        logging.basicConfig(format='%(levelname)s: %(message)s', level=logging.WARNING)
        real_path = os.path.realpath(__file__)
        if re.match(r'.*src\/sky\/packages\/sky\/', real_path) is not None:
            logging.warning('Using overridden sky package located at ' + os.path.dirname(os.path.dirname(real_path)))

        parser = argparse.ArgumentParser(description='Sky App Runner')
        parser.add_argument('--verbose', dest='verbose', action='store_true',
            help='Noisy logging, including all shell commands executed')
        parser.add_argument('--release', dest='use_release', action='store_true',
            help='Set this if you are building Sky locally and want to use the release build products. '
                 'When set, attempts to automaticaly determine sky-src-path if sky-src-path is '
                 'not set. Using this flag automatically turns on local-build as well, so you do not '
                 'need to specify both. Note that --release is not compatible with the listen command '
                 'on iOS devices and simulators. Not normally required.')
        parser.add_argument('--local-build', dest='local_build', action='store_true',
            help='Set this if you are building Sky locally and want to use those build products. '
                 'When set, attempts to automaticaly determine sky-src-path if sky-src-path is '
                 'not set. Not normally required.')
        parser.add_argument('--sky-src-path', dest='sky_src_path',
            help='Path to your Sky src directory, if you are building Sky locally. '
                 'Ignored if local-build is not set. Not normally required.')
        parser.add_argument('--android-debug-build-path', dest='android_debug_build_path',
            help='Path to your Android Debug out directory, if you are building Sky locally. '
                 'This path is relative to sky-src-path. Not normally required.',
            default='out/android_Debug/')
        parser.add_argument('--android-release-build-path', dest='android_release_build_path',
            help='Path to your Android Release out directory, if you are building Sky locally. '
                 'This path is relative to sky-src-path. Not normally required.',
            default='out/android_Release/')
        parser.add_argument('--ios-debug-build-path', dest='ios_debug_build_path',
            help='Path to your iOS Debug out directory, if you are building Sky locally. '
                 'This path is relative to sky-src-path. Not normally required.',
            default='out/ios_Debug/')
        parser.add_argument('--ios-release-build-path', dest='ios_release_build_path',
            help='Path to your iOS Release out directory, if you are building Sky locally. '
                 'This path is relative to sky-src-path. Not normally required.',
            default='out/ios_Release/')
        parser.add_argument('--ios-sim-debug-build-path', dest='ios_sim_debug_build_path',
            help='Path to your iOS Simulator Debug out directory, if you are building Sky locally. '
                 'This path is relative to sky-src-path. Not normally required.',
            default='out/ios_sim_Debug/')
        parser.add_argument('--ios-sim-release-build-path', dest='ios_sim_release_build_path',
            help='Path to your iOS Simulator Release out directory, if you are building Sky locally. '
                 'This path is relative to sky-src-path. Not normally required.',
            default='out/ios_sim_Release/')

        subparsers = parser.add_subparsers(help='sub-command help')

        for command in [SkyLogs(), InstallSky(), StartSky(), StopSky(), StartListening(), StartTracing(), StopTracing(), IOSSimulator()]:
            command.add_subparser(subparsers)

        args = parser.parse_args()
        if args.verbose:
            logging.getLogger().setLevel(logging.INFO)

        if args.use_release:
            args.local_build = True

        # TODO(iansf): args is unfortunately just a global context variable.  For now, add some additional context to it.
        args.android_build_available = False
        args.ios_build_available = False
        args.ios_sim_build_available = False

        # Also make sure that args is consistent with machine state for local builds
        if args.local_build and args.sky_src_path is None:
            real_sky_path = os.path.realpath(os.path.join(PACKAGES_DIR, 'sky'))
            match = re.match(r'pub.dartlang.org/sky', real_sky_path)
            if match is not None:
                args.local_build = False
            else:
                sky_src_path = os.path.dirname(
                    os.path.dirname(
                        os.path.dirname(
                            os.path.dirname(real_sky_path))))
                if sky_src_path == '/' or sky_src_path == '':
                    args.local_build = False
                else:
                    args.sky_src_path = sky_src_path

            if not args.local_build:
                logging.warning('Unable to detect a valid sky install. Disabling local-build flag.\n'
                                'The recommended way to use a local build of Sky is to add the following\n'
                                'to your pubspec.yaml file and then run pub get again:\n'
                                'dependency_overrides:\n'
                                '  material_design_icons:\n'
                                '    path: /path/to/sky_engine/src/sky/packages/material_design_icons\n'
                                '  sky:\n'
                                '    path: /path/to/sky_engine/src/sky/packages/sky\n')
        if args.local_build:
            if not os.path.isdir(args.sky_src_path):
                logging.warning('The selected sky-src-path (' + args.sky_src_path + ') does not exist.'
                                'Disabling local-build flag.')
                args.local_build = False
        if args.local_build and args.use_release:
            if os.path.isdir(os.path.join(args.sky_src_path, args.android_release_build_path)):
                args.android_build_available = True
            if os.path.isdir(os.path.join(args.sky_src_path, args.ios_release_build_path)):
                args.ios_build_available = True
            if os.path.isdir(os.path.join(args.sky_src_path, args.ios_sim_release_build_path)):
                args.ios_sim_build_available = True
        elif args.local_build:
            if os.path.isdir(os.path.join(args.sky_src_path, args.android_debug_build_path)):
                args.android_build_available = True
            if os.path.isdir(os.path.join(args.sky_src_path, args.ios_debug_build_path)):
                args.ios_build_available = True
            if os.path.isdir(os.path.join(args.sky_src_path, args.ios_sim_debug_build_path)):
                args.ios_sim_build_available = True
        else:
            if os.path.isdir(APK_DIR):
                args.android_build_available = True

        if not self._check_for_dart():
            sys.exit(2)

        pids = Pids.read_from(PID_FILE_PATH, PID_FILE_KEYS)
        atexit.register(pids.write_to, PID_FILE_PATH)
        exit_code = 0
        try:
            exit_code = args.func(args, pids)
        except subprocess.CalledProcessError as e:
            # Don't print a stack trace if the adb command fails.
            logging.error(e)
            exit_code = 2
        sys.exit(exit_code)


if __name__ == '__main__':
    sys.exit(SkyShellRunner().main())