path: root/gamechest/gamemanager.py.backup

#!python3

import contextlib
import os
import queue
import re
import selectors
import shutil
import subprocess
import tarfile
import threading
from logging import debug, info, warning, critical
from enum import Enum, auto as enum_auto

import yaml


def strip_tar_ext(name):
    ext = '.tar.lzip'
    return name[:-len(ext)] if name.lower().endswith(ext) else name


class GameChestConfig:
    '''
    Stores configuration for whole program run time.

    Should be pretty unmuttable.
    '''

    def __init__(self, repository_host, repository_path, gamedir, game_data):
        self.repository_host = repository_host
        self.repository_path = repository_path
        self.gamedir = gamedir
        self.game_data = game_data



class LockedData:
    'every attribute access to this class is locked except lock and data'

    def __init__(self, data={}):
        super().__setattr__('lock', threading.Lock())
        super().__setattr__('data', dict())
        self.data.update(data)

    def __getattr__(self, name):
        with self.lock:
            return self.data[name]

    def __setattr__(self, name, value):
        with self.lock:
            self.data[name] = value


class Progress(LockedData):
    'hold a progression status'

    def __init__(self):
        super().__init__(self, {
            'global': 0,
            'steps_count': 1,
            'step': 0,
            'step_index': 0,
            'step_name': 'unknown',
        })

    @locked
    def set_step_index(self, index):
        self._step_index = index
        self._global = (index/self._steps_count)*100


class GameManagerBase:
    '''
    Manage a worker processing steps in background and allows polling its
    status (global steps progress, and current step progress).
    '''

    class State(Enum):
        IDLE = enum_auto()
        ONGOING = enum_auto()

    class Command(Enum):
        STOP = enum_auto()

    def __init__(self, conf):
        self.conf = conf
        self.state_holder = LockedData()
        self.state = self.State.IDLE
        self.thread = None
        self.lock = threading.Lock()
        self.queue = queue.Queue(maxsize=10)
        self.progress = Progress()

    @property
    def state(self):
        return self.state_holder.state

    @property.setter
    def set_state(self, value):
        self.state_holder.state = value

    def worker(self, *args):
        self.progress.steps_count = len(self.steps)
        try:
            for index, step in enumerate(self.steps):
                self.progress.step_index = index
                for step_progress in step():
                    self.progress.step = step_progress
        finally:
            self.state = self.State.IDLE

    def start(self, *, game_status=None):
        if self.steps is None:
            raise NotImplementedError
        if self.state == self.State.ONGOING:
            return
        self.progress.global = 0
        self.progress.step = 0
        with self.lock:
            self.game_status = game_status
            self.thread = threading.Thread(target=self.worker, daemon=True)
            self.thread.start()
        self.state = self.State.ONGOING

    def stop(self):
        if self.state != self.State.ONGOING:
            return
        self.state = self.State.IDLE
        self.queue.put(self.Command.STOP)

    def poll(self):
        return self.state, self.global_progress, self.step_progress


class GameInstaller(GameManagerBase):
    '''
    Defines how to install a game:
    - download it
    - unarchive it
    - remove the archive
    '''

    rsync_progress_re = re.compile(r'\s(\d+)%\s')

    def __init__(self, conf):
        super().__init__(conf)
        self.steps = (
                self._worker_rsync,
                self._worker_unarchive,
                self._worker_rmarchive,
        )

    def _worker_rsync_loop(self, proc, selector):
        while True:
            with contextlib.suppress(queue.Empty):
                if self.queue.get_nowait() == self.Command.STOP:
                    proc.terminate()
                    break

            if proc.poll() is not None:
                break

            if not any(key
                for key, mask in selector.select(timeout=0.250)
                if mask & selectors.EVENT_READ and key.fileobj == proc.stdout):
                continue

            # stdout.readline is a blocking call if there is no endline in
            # stdout outputed by the subprocess.
            # normally rsync output should be line buffered thus at any read event
            # a call to readline should not block (or not long enough to be
            # able to process a queued command quick enough).
            line = proc.stdout.readline()
            if match := self.rsync_progress_re.search(line):
                progress = int(match.group(1))
                yield progress

    def _worker_rsync(self):
        package_name = self.conf.game_data['package_name']
        command = (
            'rsync',
            '-a',
            '--partial',
            '--info=progress2',
            f'{self.conf.repository_host}:{self.conf.repository_path}/{package_name}',
            f'{self.conf.gamedir}/.',
        )
        debug('running command %s', command)
        with contextlib.ExitStack() as stack:
            proc = stack.enter_context(subprocess.Popen(
                    command,
                    stdout=subprocess.PIPE,
                    encoding='utf8'))
            selector = stack.enter_context(selectors.DefaultSelector())
            selector.register(proc.stdout, selectors.EVENT_READ)
            yield from self._worker_rsync_loop(proc=proc, selector=selector)

    def _worker_unarchive(self):
        with contextlib.ExitStack() as stack:
            lzip_command = '/usr/bin/lzip'
            plzip_command = '/usr/bin/plzip'
            if os.path.exists(plzip_command):
                lzip_command = plzip_command
            lzip_proc = stack.enter_context(subprocess.Popen(
                    (lzip_command, '-d'),
                    stdin=subprocess.PIPE,
                    stdout=subprocess.PIPE,
            ))
            tar_proc = stack.enter_context(subprocess.Popen(
                    ('tar', '-C', self.output_dir, '-xvf', '-'),
                    stdin=lzip_proc.stdout,
                    stdout=subprocess.PIPE,
            ))
            filepath = f'{self.conf.gamedir}/{self.conf.game_data["package_name"]}'
            filepath_status = f'{self.conf.gamedir}/{self.conf.game_data["name"]}.yaml'
            fobj = stack.enter_context(open(filepath, 'rb'))
            selector = stack.enter_context(selectors.DefaultSelector())
            selector.register(tar_proc.stdout, selectors.EVENT_READ)
            filesize = os.stat(filepath).st_size
            def _itemscounter():
                while ready := selector.select(0.100):
                    data = tar_proc.stdout.read1()
                    if len(data) == 0:
                        break
                    itemscount += data.count(b'\n')
            itemscount = 0
            while True:
                with contextlib.suppress(queue.Empty):
                    if self.queue.get_nowait() == self.Command.STOP:
                        break
                data = fobj.read(131072) # 128kib chunks
                if len(data) == 0:
                    lzip_proc.stdin.close()
                    break
                lzip_proc.stdin.write(data)
                yield filesize / fobj.tell()
                _itemscounter()
            _itemscounter()
            with open(filepath_status, 'wb') as fobj:
                yaml.safe_dump({
                    'installed_count': itemscount,
                    'installed_version': self.conf.game_data['version'],
                    'installed_package_name': self.conf.game_data['package_name'],
                }, fobj)

    def _worker_rmarchive(self):
        os.unlink(f'{self.conf.gamedir}/{self.conf.game_data["package_name"]}')


class GameRemover(GameManagerBase):
    '''
    Defines how to remove a game. Basically removes a directory, with progress
    report.
    '''

    def __init__(self, conf):
        super().__init__(conf)
        self.steps = (self._worker_remove, self._worker_rm_data)

    def _worker_remove(self):
        if self.game_status is None:
            return
        extracted_path = '/'.join((
                self.conf.gamedir,
                strip_tar_ext(self.game_status['installed_package_name']),
        ))
        filepath_status = f'{self.conf.gamedir}/{self.conf.game_data["name"]}.yaml'
        with open(filepath_status) as stream:
            pkg_status = yaml.safe_load(stream)
        with contextlib.ExitStack() as stack:
            proc = stack.enter_context(subprocess.Popen(
                    ('rm', '-rvf', '--', extracted_path),
                    stdout=subprocess.PIPE,
            ))
            selector = stack.enter_context(selectors.DefaultSelector())
            selector.register(proc.stdout, selectors.EVENT_READ)
            itemscount = 0
            while True:
                with contextlib.suppress(queue.Empty):
                    if self.queue.get_nowait() == self.Command.STOP:
                        proc.terminate()
                        break
                if ready := selector.select(0.250):
                    data = proc.stdout.read1()
                    if len(data) == 0:
                        break
                    itemscount += data.count(b'\n')
                    yield itemscount*100/pkg_status['installed_count']

    def _worker_rm_data(self):
        if self.game_status is None:
            return
        os.unlink(f'{self.conf.gamedir}/{self.conf.game_data["name"]}.yaml')


class GameUpdater(GameManagerBase):
    '''
    Combine GameRemover and GameInstaller to form a consistent updating unit.
    '''

    def __init__(self, conf):
        super().__init__(conf)
        self._remover = GameRemover(conf)
        self._installer = GameInstaller(conf)
        self.steps = self._remover.steps + self._installer.steps


    def _worker(self):


#class GameData:
#
#    class 


class GameManager:

    class State(Enum):
        IDLE = enum_auto()
        INSTALLING = enum_auto()
        REMOVING = enum_auto()
        UPDATING_REMOVING = enum_auto()
        UPDATING_INSTALLING = enum_auto()

    def __init__(self, games_data_yaml_path, games_dir):
        self.games_data_yaml_path = games_data_yaml_path
        self.games_dir = games_dir
        self.state = self.State.IDLE
        self.update_state = self.State.IDLE
        self.current_game_name = None
        self.current_game_item = None
        self.current_game_status = {}

        with open(games_data_yaml_path) as stream:
            self.games_data = yaml.safe_load(stream)

        self.game_installer = GameInstaller(
                self.games_data['repository']['host'],
                self.games_data['repository']['path'],
                self.games_dir,
        )
        self.game_remover = GameRemover(
                self.games_data['repository']['host'],
                self.games_data['repository']['path'],
                self.games_dir,
        )

    def get_game_item(self, name):
        self.current_game_item = next(
                item
                for item in self.games_data['games']
                if item['name'] == name
        )
        return self.current_game_item

    def get_game_status(self, name):
        self.current_game_status = {}
        with contextlib.suppress(FileNotFoundError):
            with open(f'{self.conf.gamedir}/{name}.yaml') as stream:
                self.current_game_status = yaml.safe_load(stream)
        return self.current_game_status

    def is_game_updatable(self, name):
        #self. ### FIXME: Stopped here ?
        if not self.current_game_name:
            return False
        ivers = self.current_game_status.get('installed_version', None)
        # only call "updatable" if there was at least a version installed
        # else, this is just an "installable" package.
        if ivers is not None and ivers < self.current_game_item['version']:
            return True
        return False

    def set_current_game(self, name):
        if self.current_game_name == name:
            return
        self.current_game_name = name
        self.get_game_item(name)
        self.get_game_status(name)

    def start_install(self, name):
        if self.state != self.State.IDLE:
            return
        self.status = self.State.INSTALLING
        self.set_current_game(name)
        self.game_installer.start(
                self.current_game_item,
                game_status=self.current_game_status,
        )

    def start_remove(self, name):
        if self.state != self.State.IDLE:
            return
        self.status = self.State.REMOVING
        self.set_current_game(name)
        self.game_remover.start(
                self.current_game_item,
                game_status=self.current_game_status,
        )

    def start_update(self, name):
        if self.state != self.State.IDLE:
            return
        self.status = self.State.UPDATING_REMOVING
        self.set_current_game(name)
        self.game_remover.start(
                self.current_game_item,
                game_status=self.current_game_status,
        )

    def stop(self):
        self.state = self.State.IDLE
        self.game_remover.stop()
        self.game_installer.stop()

    def poll(self):
        entry_state = self.state
        return_value = {
                self.State.IDLE: (lambda: GameManagerBase.State.IDLE, 0, 0),
                self.State.INSTALLING: self.game_installer.poll,
                self.State.REMOVING: self.game_remover.poll,
                self.State.UPDATING_REMOVING: self.game_remover.poll,
                self.State.UPDATING_INSTALLING: self.game_installer.poll,
        }[entry_state]()
        if return_value[0] == GameManagerBase.Sate.IDLE:
            self.state = self.State.IDLE
            if entry_state == self.State.UPDATING_REMOVING:
                self.start_install(self.current_game_name)
                return_value = self.poll()
        return self.state, return_value[1], return_value[2]