'''
Copyright 2019 Google LLC

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    https://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
'''


import os
import sys
import time

from mdt import command
from mdt import config
from mdt import console
from mdt import discoverer
from mdt import sshclient


PROGRESS_WIDTH = 45
FILENAME_WIDTH = 30


def MakeProgressFunc(full_filename, width, char='>'):
    def closure(bytes_xferred, total_bytes):
        filename = full_filename
        if len(filename) > FILENAME_WIDTH:
            filename = filename[0:FILENAME_WIDTH - 3] + '...'

        pcnt = bytes_xferred / total_bytes
        left = char * round(pcnt * width)
        right = ' ' * round((1 - pcnt) * width)
        pcnt = '%3d' % (int(pcnt * 100))
        sys.stdout.write('\r{0}% |{1}{2}| {3}'.format(
            pcnt, left, right, filename))
        sys.stdout.flush()

    return closure


class InstallCommand(command.NetworkCommand):
    '''Usage: mdt install <deb-package>

Installs a given Debian package file to the connected device via
mdt-install-package.

Variables used:
    preferred-device    - set this to your preferred device name to connect
                          to by default if no <devicename> is provided on the
                          command line. Can be set to an IPv4 address to bypass
                          the mDNS lookup.
    username            - set this to the username that should be used to
                          connect to a device with. Defaults to 'mendel'.
    password            - set this to the password to use to login to a new
                          device with. Defaults to 'mendel'. Only used
                          during the initial setup phase of pushing an SSH
                          key to the board.

Note: if the package provided has dependencies that are not already installed on
the device, this will require internet connectivity to fetch and install those
dependencies.
'''

    def preConnectRun(self, args):
        if len(args) < 2:
            print("Usage: mdt install [<package-filename...>]")
            return False

        return True

    def runWithClient(self, client, args):
        package_to_install = args[1]
        package_filename = os.path.basename(package_to_install)
        remote_filename = os.path.join('/tmp', package_filename)

        sftp_callback = MakeProgressFunc(package_filename, PROGRESS_WIDTH)
        sftp = client.openSftp()
        sftp.put(package_to_install, remote_filename, callback=sftp_callback)
        sftp.close()
        client.close()
        print()

        channel = client.shellExec("sudo /usr/sbin/mdt-install-package {0}; "
                                   "rm -f {0}".format(remote_filename),
                                   allocPty=True)
        cons = console.Console(channel, sys.stdin)
        return cons.run()


class PushCommand(command.NetworkCommand):
    '''Usage: mdt push <filename...> <remote-path>

Variables used:
    preferred-device    - set this to your preferred device name to connect
                          to by default if no <devicename> is provided on the
                          command line. Can be set to an IPv4 address to bypass
                          the mDNS lookup.
    username            - set this to the username that should be used to
                          connect to a device with. Defaults to 'mendel'.
    password            - set this to the password to use to login to a new
                          device with. Defaults to 'mendel'. Only used
                          during the initial setup phase of pushing an SSH
                          key to the board.

Pushes (copies) a local file or set of files to the remote device.
'''

    def preConnectRun(self, args):
        if len(args) < 3:
            print("Usage: mdt push <filename...> <remote-path>")
            return False

        for file in args[1:-1]:
            if not os.path.isfile(file):
                print("{0}: Is a directory -- cannot push".format(file))
                return False

        return True

    def runWithClient(self, client, args):
        files_to_push = args[1:-1]
        destination = args[-1]

        try:
            sftp = client.openSftp()
            for file in files_to_push:
                base_filename = os.path.basename(file)
                sftp_callback = MakeProgressFunc(file, PROGRESS_WIDTH)
                remote_filename = os.path.join(destination, base_filename)

                sftp_callback(0, 1)
                sftp.put(file, remote_filename, callback=sftp_callback)
                sftp_callback(1, 1)
                print()
        finally:
            print()
            sftp.close()

        return 0


class PullCommand(command.NetworkCommand):
    '''Usage: mdt pull <filename...> <local-destination-path>

Variables used:
    preferred-device    - set this to your preferred device name to connect
                          to by default if no <devicename> is provided on the
                          command line. Can be set to an IPv4 address to bypass
                          the mDNS lookup.
    username            - set this to the username that should be used to
                          connect to a device with. Defaults to 'mendel'.
    password            - set this to the password to use to login to a new
                          device with. Defaults to 'mendel'. Only used
                          during the initial setup phase of pushing an SSH
                          key to the board.

Pulls (copies) a set of files from the remote device to a local path.
'''

    def preConnectRun(self, args):
        if len(args) < 3:
            print("Usage: mdt pull <filename...> <local-destination-path>")
            return False

        return True

    def runWithClient(self, client, args):
        files_to_pull = args[1:-1]
        destination = args[-1]

        try:
            sftp = client.openSftp()
            for file in files_to_pull:
                base_filename = os.path.basename(file)
                sftp_callback = MakeProgressFunc(file,
                                                 PROGRESS_WIDTH,
                                                 char='<')
                destination_filename = os.path.join(destination, base_filename)

                sftp_callback(0, 1)
                sftp.get(file, destination_filename, callback=sftp_callback)
                sftp_callback(1, 1)
                print()
        finally:
            print()
            sftp.close()

        return 0