eris/vigil

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

# Copyright (C) 2015 Andrew Hamilton. All rights reserved.
# Licensed under the Artistic License 2.0.

"""\
Produces a set of reports for every file in a directory tree.
The reports are produced by many existing command-line tools.

The state of each report is also summarised by a status indicator.
The possible states are listed below.

A report is viewed by selecting its status indicator with the cursor.

Reports are recalculated whenever files are changed, added, or deleted, and so
are kept up to date. (optional)

The reports are cached in a directory named ".vigil" under the target
directory.

Usage: vigil <root_path>

e.g. # vigil my_project

Keys:
  *h - Show the help screen. (toggle)
  *d, *c, *j, *k - Move the cursor up, down, left and right.
  *D, *C, *J, *K - Scroll the result pane up, down, left and right.
  *t - Turn the result pane to portrait or landscape orientation. (toggle)
  *l - Show the activity log. (toggle)
  *n - Move to the next issue.
  *N - Move to the next issue of the current tool.
  *o - Order files by type, or by directory location. (toggle)
  *w - Watch the filesystem for changes. (toggle)
  *s - Change the appearance of result statuses. (toggle)
  *q - Quit.
"""


import asyncio
import collections
import functools
import gc
import gzip
import importlib
import multiprocessing
import os
import pickle
import shutil
import signal
import subprocess
import sys
import threading
import time
import traceback

import pyinotify

import fill3
import terminal
import termstr
import tools


_LOG_PATH = os.path.join(os.getcwd(), "vigil.log")


def _log_error(message=None):
    message = traceback.format_exc() if message is None else message + "\n"
    with open(_LOG_PATH, "a") as log_file:
        log_file.write(message)


_CACHE_PATH = ".vigil"


def lru_cache_with_eviction(maxsize=128, typed=False):
    versions = {}
    make_key = functools._make_key

    def evict(*args, **kwds):
        key = make_key(args, kwds, typed)
        if key in versions:
            versions[key] += 1

    def decorating_function(user_function):

        def remove_version(*args, **kwds):
            return user_function(*args[1:], **kwds)
        new_func = functools.lru_cache(maxsize=maxsize, typed=typed)(
            remove_version)

        def add_version(*args, **kwds):
            key = make_key(args, kwds, typed)
            return new_func(*((versions.setdefault(key, 0),) + args), **kwds)
        add_version.versions = versions
        add_version.cache_info = new_func.cache_info
        add_version.evict = evict
        return functools.update_wrapper(add_version, user_function)
    return decorating_function


def dump_pickle_safe(object_, path, protocol=pickle.HIGHEST_PROTOCOL,
                     open=open):
    tmp_path = path + ".tmp"
    try:
        with open(tmp_path, "wb") as file_:
            pickle.dump(object_, file_, protocol=protocol)
    except OSError:
        os.remove(tmp_path)
    else:
        os.rename(tmp_path, path)


def multiprocessing_process(func, *args, **kwargs):
    def wrapper(child_conn, func, args, **kwargs):
        result = func(*args, **kwargs)
        child_conn.send(result)
        child_conn.close()
    parent_conn, child_conn = multiprocessing.Pipe()
    process = multiprocessing.Process(
        target=wrapper, args=(child_conn, func, args), kwargs=kwargs,
        daemon=True)
    process.start()
    process.result_conn = parent_conn
    return process


def status_to_str(status, is_status_simple):
    if isinstance(status, int):  # is a status enumeration
        dict_ = (tools._STATUS_TO_TERMSTR_SIMPLE if is_status_simple
                 else tools._STATUS_TO_TERMSTR)
        return dict_[status]
    else:
        return status


class Result:

    def __init__(self, path, tool, is_stored_compressed=True):
        self.path = path
        self.tool = tool
        self._open_func = gzip.open if is_stored_compressed else open
        self.pickle_path = os.path.join(_CACHE_PATH,
                                        path + "-" + tool.__name__)
        self.scroll_position = (0, 0)
        self.is_completed = False
        self.reset()

    def __del__(self):
        try:
            os.remove(self.pickle_path)
        except FileNotFoundError:
            pass

    @property
    @lru_cache_with_eviction(maxsize=50)
    def result(self):
        unknown_label = fill3.Text("?")
        if self.is_placeholder:
            return unknown_label
        try:
            with self._open_func(self.pickle_path, "rb") as pickle_file:
                return pickle.load(pickle_file)
        except FileNotFoundError:
            return unknown_label

    @result.setter
    def result(self, value):
        os.makedirs(os.path.dirname(self.pickle_path), exist_ok=True)
        dump_pickle_safe(value, self.pickle_path, open=self._open_func)
        Result.result.fget.evict(self)

    def set_status(self, status, appearance_changed_event):
        self.status = status
        appearance_changed_event.set()
        self.entry.appearance_cache = None

    def run(self, log, appearance_changed_event):
        self.is_placeholder = False
        tool_name = tools._tool_name_colored(self.tool, self.path)
        path_colored = tools._path_colored(self.path)
        log.log_message(["Running ", tool_name, " on ", path_colored, "."])
        self.set_status(tools.Status.running, appearance_changed_event)
        start_time = time.time()
        self.process = multiprocessing_process(
            tools.run_tool_no_error, self.path, self.tool)
        new_status, result = self.process.result_conn.recv()
        self.status, self.result = new_status, result
        self.process = None
        end_time = time.time()
        self.set_status(new_status, appearance_changed_event)
        self.is_completed = True
        log.log_message(
            ["Finished running ", tool_name, " on ", path_colored, ". ",
             status_to_str(new_status, self.entry.summary.is_status_simple),
             " %s secs" % round(end_time - start_time, 2)])

    def reset(self):
        self.is_placeholder = True
        self.status = tools.Status.empty
        try:
            self.process.terminate()
        except AttributeError:
            pass
        self.process = None

    def appearance_min(self):
        return [status_to_str(self.status,
                              self.entry.summary.is_status_simple)]


def reverse_style(style):
    return termstr.CharStyle(style.bg_color, style.fg_color, style.is_bold,
                             style.is_underlined)


class Entry(collections.UserList):

    def __init__(self, path, results, summary, highlighted=None,
                 set_results=True):
        collections.UserList.__init__(self, results)
        self.path = path
        self.summary = summary
        self.highlighted = highlighted
        self.widgets = self.data
        if set_results:
            # FIX: this is missed for entries appended later
            for result in results:
                result.entry = self
        self.widget = fill3.Row(results)
        self.appearance_cache = None

    def appearance_min(self):
        # 'appearance' local variable exists because appearance_cache can
        # become None at any time.
        appearance = self.appearance_cache
        if appearance is None:
            if self.highlighted is not None:
                if self.summary.is_status_simple:
                    cursor = fill3.Text("●")
                else:
                    cursor = fill3.Style(self.widget[self.highlighted],
                                         reverse_style)
                self.widget[self.highlighted] = cursor
            new_appearance = self.widget.appearance_min()
            path = tools._path_colored(self.path)
            padding = " " * (self.summary._max_path_length - len(path) + 1)
            new_appearance[0] = path + padding + new_appearance[0]
            self.appearance_cache = appearance = new_appearance
        return appearance


def is_filename_excluded(filename):
    return filename.startswith(".")


def codebase_files(path, skip_hidden_directories=True):
    for (dirpath, dirnames, filenames) in os.walk(path):
        if skip_hidden_directories:
            filtered_dirnames = [dirname for dirname in dirnames
                                 if not is_filename_excluded(dirname)]
            dirnames[:] = filtered_dirnames
        for filename in filenames:
            if not is_filename_excluded(filename):
                yield os.path.join(dirpath, filename)


def fix_paths(root_path, paths):
    return [os.path.join(".", os.path.relpath(path, root_path))
            for path in paths]


def change_background(str_, new_background):

    def change_background_style(style):
        new_bg = (new_background if style.bg_color == termstr.Color.black
                  else style.bg_color)
        return termstr.CharStyle(style.fg_color, new_bg, style.is_bold,
                                 style.is_underlined)
    return termstr.TermStr(str_).transform_style(change_background_style)


class Summary:

    def __init__(self, root_path, jobs_added_event):
        self._root_path = root_path
        self._jobs_added_event = jobs_added_event
        self._view_widget = fill3.View.from_widget(self)
        self.__cursor_position = (0, 0)
        self.closest_placeholder_generator = None
        self._lock = threading.Lock()
        self._cache = {}
        self.is_status_simple = False
        self.is_directory_sort = True
        self._max_width = None
        self._max_path_length = None
        self.sync_with_filesystem()

    @property
    def _cursor_position(self):
        return self.__cursor_position

    @_cursor_position.setter
    def _cursor_position(self, new_position):
        if new_position != self.__cursor_position:
            self.__cursor_position = new_position
            self.closest_placeholder_generator = None

    def sync_with_filesystem(self, sync_tools=True, sync_paths=True):
        if sync_tools:
            importlib.reload(tools)
        x, y = self._cursor_position
        try:
            old_path = self.get_selection().path
        except AttributeError:
            old_path = None
        new_column = fill3.Column([])
        new_cache = {}
        if sync_paths:
            paths = fix_paths(self._root_path,
                              codebase_files(self._root_path))
            self._paths = paths
            self.sort(self.is_directory_sort)
        else:
            paths = self._paths
        jobs_added = False
        new_cursor_position = (0, 0)
        row_index = 0
        result_total, completed_total = 0, 0
        for path in paths:
            full_path = os.path.join(self._root_path, path)
            try:
                key = (path, os.stat(full_path).st_ctime)
            except FileNotFoundError:
                continue
            if path == old_path:
                new_cursor_position = (x, row_index)
            row = []
            for tool in tools.tools_for_path(path):
                cache_key = (key, tool.__name__, tool.__code__.co_code)
                if cache_key in self._cache:
                    result = self._cache[cache_key]
                    result.tool = tool
                else:
                    result = Result(path, tool)
                    jobs_added = True
                if result.is_completed:
                    completed_total += 1
                new_cache[cache_key] = result
                row.append(result)
            new_column.append(Entry(path, row, self))
            row_index += 1
            result_total += len(row)
        max_width = max(len(row) for row in new_column)
        max_path_length = max(len(path) for path in paths) - len("./")
        self._column, self._cache, self._cursor_position, self.result_total, \
            self.completed_total, self._max_width, self._max_path_length, \
            self.closest_placeholder_generator = (
                new_column, new_cache, new_cursor_position, result_total,
                completed_total, max_width, max_path_length, None)
        if jobs_added:
            self._jobs_added_event.set()
        # Delete the stale results from the disk now, to avoid accidently
        # deleting a future result with the same filename. See Result.__del__.
        gc.collect()

    def placeholder_spiral(self):
        x, y = self.cursor_position()
        result = self._column[y][x]
        if result.is_placeholder:
            yield result
        for lap in range(max(len(self._column), self._max_width)):
            y -= 1
            for dx, dy in [(1, 1), (-1, 1), (-1, -1), (1, -1)]:
                for move in range(lap + 1):
                    x += dx
                    y += dy
                    try:
                        result = self._column[y][x]
                    except IndexError:
                        continue
                    if result.is_placeholder:
                        yield result

    def get_closest_placeholder(self):
        with self._lock:
            try:
                return self.closest_placeholder_generator.send(None)
            except AttributeError:
                self.closest_placeholder_generator = self.placeholder_spiral()
                return self.closest_placeholder_generator.send(None)

    def appearance_dimensions(self):
        status_width = 1 if self.is_status_simple else 2
        width = self._max_path_length + 1 + status_width * self._max_width
        return width, len(self._column)

    def appearance_interval(self, interval):
        start_y, end_y = interval
        x, y = self.cursor_position()
        rows = fill3.Column(self._column.widgets)
        rows[y] = Entry(rows[y].path, rows[y].widgets, self, highlighted=x,
                        set_results=False)
        return rows.appearance_interval(interval)

    def appearance(self, dimensions):
        width, height = dimensions
        x, y = self.cursor_position()
        status_width = 1 if self.is_status_simple else 2
        screen_x, screen_y = self._max_path_length + 1 + x * status_width, y
        width, height = width - 1, height - 1  # Minus one for the scrollbars
        scroll_y = (screen_y // height) * height
        self._view_widget.position = ((screen_x // width) * width, scroll_y)
        appearance = self._view_widget.appearance(dimensions)
        appearance[screen_y - scroll_y] = change_background(
            appearance[screen_y - scroll_y], termstr.Color.grey_50)
        return appearance

    def cursor_position(self):
        x, y = self._cursor_position
        return min(x, len(self._column[y])-1), y

    def get_selection(self):
        x, y = self.cursor_position()
        return self._column[y][x]

    def _move_cursor(self, dx, dy):
        if dy == 0:
            x, y = self.cursor_position()
            self._cursor_position = ((x + dx) % len(self._column[y]), y)
        elif dx == 0:
            x, y = self._cursor_position
            self._cursor_position = (x, (y + dy) % len(self._column))
        else:
            raise ValueError

    def cursor_right(self):
        self._move_cursor(1, 0)

    def cursor_left(self):
        self._move_cursor(-1, 0)

    def cursor_up(self):
        self._move_cursor(0, -1)

    def cursor_down(self):
        self._move_cursor(0, 1)

    def _issue_generator(self):
        x, y = self.cursor_position()
        for index in range(len(self._column) + 1):
            row_index = (index + y) % len(self._column)
            row = self._column[row_index]
            for index_x, result in enumerate(row):
                if (result.status == tools.Status.failure and
                    not (row_index == y and index_x <= x and
                         index != len(self._column))):
                    yield result, (index_x, row_index)

    def move_to_next_issue(self):
        try:
            issue, self._cursor_position = self._issue_generator().send(None)
        except StopIteration:
            pass

    def move_to_next_issue_of_tool(self):
        current_tool = self.get_selection().tool
        for issue, position in self._issue_generator():
            if issue.tool == current_tool:
                self._cursor_position = position
                return

    def toggle_status_style(self):
        self.is_status_simple = not self.is_status_simple
        self.sync_with_filesystem(sync_tools=False, sync_paths=False)

    def sort(self, is_directory_sort):
        def directory_sort(path):
            return (os.path.dirname(path), tools.splitext(path)[1],
                    os.path.basename(path))

        def type_sort(path):
            return (tools.splitext(path)[1], os.path.dirname(path),
                    os.path.basename(path))
        key_func = directory_sort if is_directory_sort else type_sort
        self._paths.sort(key=key_func)
        self.is_directory_sort = is_directory_sort
        self.sync_with_filesystem(sync_tools=False, sync_paths=False)


class Log:

    GREY_BOLD_STYLE = termstr.CharStyle(termstr.Color.grey_100, is_bold=True)
    GREEN_STYLE = termstr.CharStyle(termstr.Color.green)

    def __init__(self, appearance_changed_event):
        self._appearance_changed_event = appearance_changed_event
        self.widget = fill3.Column([])
        self.portal = fill3.Portal(self.widget)
        self._appearance_cache = None

    def log_message(self, message, timestamp=None, char_style=None):
        if isinstance(message, list):
            message = [part[1] if isinstance(part, tuple) else part
                       for part in message]
            message = fill3.join("", message)
        if char_style is not None:
            message = termstr.TermStr(message, char_style)
        timestamp = (time.strftime("%H:%M:%S", time.localtime())
                     if timestamp is None else timestamp)
        label = fill3.Text(termstr.TermStr(timestamp, Log.GREY_BOLD_STYLE) +
                           " " + message)
        self.widget.append(label)
        self.widget.widgets = self.widget[-200:]
        self._appearance_cache = None
        self._appearance_changed_event.set()

    def log_command(self, message, timestamp=None):
        self.log_message(message, char_style=Log.GREEN_STYLE)

    def appearance_min(self):
        appearance = self._appearance_cache
        if appearance is None:
            self._appearance_cache = appearance = self.widget.appearance_min()
        return appearance

    def appearance(self, dimensions):
        width, height = dimensions
        full_appearance = self.appearance_min()
        self.portal.position = (0, max(0, len(full_appearance) - height))
        return self.portal.appearance(dimensions)


def _highlight_chars(str_, style, marker="*"):
    parts = str_.split(marker)
    highlighted_parts = [termstr.TermStr(part[0], style) + part[1:]
                         for part in parts[1:] if part != ""]
    return fill3.join("", [parts[0]] + highlighted_parts)


class Help:

    def __init__(self, summary, screen):
        self.summary = summary
        self.screen = screen
        self.body = fill3.Placeholder()
        self.view = fill3.View.from_widget(self.body)
        self.widget = fill3.Border(self.view, title="Help")
        self.usage = _highlight_chars(__doc__, Log.GREEN_STYLE)
        portal = self.view.portal
        self.key_map = {"h": self.exit_help, "d": portal.scroll_up,
                        "c": portal.scroll_down, "j": portal.scroll_left,
                        "k": portal.scroll_right, "q": self.exit_help}

    def exit_help(self):
        self.screen._is_help_visible = False

    def on_keypressed(self):
        try:
            action = self.key_map[sys.stdin.read(1)]
        except KeyError:
            pass
        else:
            action()

    def appearance(self, dimensions):
        text = fill3.join(
            "\n", [self.usage, "Statuses:"] +
            ["  " + status_to_str(status, self.summary.is_status_simple) +
             " " + meaning for status, meaning in tools.STATUS_MEANINGS])
        self.body.widget = fill3.Text(text)
        return self.widget.appearance(dimensions)


class Listing:

    def __init__(self, view):
        self.view = view
        self.last_dimensions = None

    def appearance(self, dimensions):
        self.last_dimensions = dimensions
        return self.view.appearance(dimensions)


def add_watch_manager_to_mainloop(watch_manager, mainloop):
    notifier = pyinotify.Notifier(watch_manager)

    def on_inotify():
        notifier.read_events()
        notifier.process_events()
    mainloop.add_reader(watch_manager.get_fd(), on_inotify)


def is_path_excluded(path):
    return any(part.startswith(".") for part in path.split(os.path.sep))


class Screen:

    def __init__(self, summary, log, appearance_changed_event, main_loop):
        self._summary = summary
        self._log = log
        self._appearance_changed_event = appearance_changed_event
        self._main_loop = main_loop
        self._is_listing_portrait = True
        self._is_log_visible = True
        self._is_help_visible = False
        self._is_watching_filesystem = False
        self.toggle_watch_filesystem()
        self._make_widgets()
        self._make_keymap()

    def make_watch_manager(self):

        def on_filesystem_change(event):
            self._log.log_message("Filesystem changed.")
            self._summary.sync_with_filesystem(sync_tools=False)
            self._appearance_changed_event.set()

        def on_tools_change(event):
            self._log.log_message("Tools changed.")
            self._summary.sync_with_filesystem(sync_paths=False)
            self._appearance_changed_event.set()
        watch_manager = pyinotify.WatchManager()
        event_mask = (pyinotify.IN_CREATE | pyinotify.IN_DELETE |
                      pyinotify.IN_CLOSE_WRITE | pyinotify.IN_ATTRIB)
        watch_manager.add_watch(
            self._summary._root_path, event_mask, rec=True, auto_add=True,
            proc_fun=on_filesystem_change, exclude_filter=lambda path:
            is_path_excluded(path))
        watch_manager.add_watch(tools.__file__, event_mask,
                                proc_fun=on_tools_change)
        self._watch_manager = watch_manager
        add_watch_manager_to_mainloop(self._watch_manager, self._main_loop)

    def _partition(self, widgets, height):
        smaller_height = max(height // 4, 10)
        return [height - smaller_height, smaller_height]

    def _partition_2(self, widgets, height):
        smaller_height = max(height // 4, 10)
        return [smaller_height, height - smaller_height]

    def _make_widgets(self):
        self._help_widget = Help(self._summary, self)
        root_path = os.path.basename(self._summary._root_path)
        summary = fill3.Border(self._summary, title="Summary of " + root_path)
        selected_widget = self._summary.get_selection()
        self._view = fill3.View.from_widget(selected_widget.result)
        self._listing = fill3.Border(Listing(self._view))
        log = fill3.Border(self._log, title="Log")
        port_log = fill3.Row([fill3.Column([summary, log], self._partition),
                              self._listing])
        land_log = fill3.Column([fill3.Row([summary, log]), self._listing],
                                self._partition_2)
        port_no_log = fill3.Row([summary, self._listing])
        land_no_log = fill3.Column([summary, self._listing], self._partition_2)
        self._layouts = [[land_no_log, port_no_log], [land_log, port_log]]

    def _make_keymap(self):
        key_map = {}
        for keys, action in self._KEY_DATA:
            for key in keys:
                key_map[key] = action
        self._key_map = key_map

    def toggle_help(self):
        self._is_help_visible = not self._is_help_visible

    def toggle_log(self):
        self._is_log_visible = not self._is_log_visible

    def toggle_window_orientation(self):
        self._is_listing_portrait = not self._is_listing_portrait

    def cursor_up(self):
        self._summary.cursor_up()

    def cursor_down(self):
        self._summary.cursor_down()

    def cursor_right(self):
        self._summary.cursor_right()

    def cursor_left(self):
        self._summary.cursor_left()

    def _move_listing(self, dx, dy):
        listing_width, listing_height = self._listing.widget.last_dimensions
        selected_widget = self._summary.get_selection()
        x, y = selected_widget.scroll_position
        selected_widget.scroll_position = \
            (max(x + dx * (listing_width // 2), 0),
             max(y + dy * (listing_height // 2), 0))

    def listing_up(self):
        self._move_listing(0, -1)

    def listing_down(self):
        self._move_listing(0, 1)

    def listing_right(self):
        self._move_listing(1, 0)

    def listing_left(self):
        self._move_listing(-1, 0)

    def move_to_next_issue(self):
        self._summary.move_to_next_issue()

    def move_to_next_issue_of_tool(self):
        self._summary.move_to_next_issue_of_tool()

    def edit_file(self):
        path = self._summary.get_selection().path
        path_colored = tools._path_colored(path)
        self._log.log_message("Editing " + path_colored + " in emacs.")
        subprocess.Popen(["emacsclient", path],
                         stdout=subprocess.PIPE, stderr=subprocess.PIPE)

    def toggle_status_style(self):
        self._summary.toggle_status_style()

    def toggle_sort(self):
        new_sort = not self._summary.is_directory_sort
        sort_order = ("directory then type" if new_sort
                      else "type then directory")
        self._log.log_command("Ordering files by %s." % sort_order)
        self._summary.sort(new_sort)

    def toggle_watch_filesystem(self):
        self._is_watching_filesystem = not self._is_watching_filesystem
        self._log.log_command("Watching the filesystem for changes."
                              if self._is_watching_filesystem else
                              "Stopped watching the filesystem.")
        if self._is_watching_filesystem:
            self._summary.sync_with_filesystem()
            self.make_watch_manager()
        else:
            self._main_loop.remove_reader(self._watch_manager.get_fd())
            self._watch_manager = None

    def quit_(self):
        raise KeyboardInterrupt

    def on_mouse_event(self, event):
        if event[0] not in ["mouse press", "mouse drag"]:
            return
        if event[1] == 4:  # Mouse wheel up
            self.listing_up()
            self._appearance_changed_event.set()
            return
        if event[1] == 5:  # Mouse wheel down
            self.listing_down()
            self._appearance_changed_event.set()
            return
        x, y = event[2:4]
        border_width = 1
        view_width, view_height = \
            self._summary._view_widget.portal.last_dimensions
        if x < border_width or y < border_width or x > view_width or \
           y > view_height:
            return
        status_width = 1 if self._summary.is_status_simple else 2
        view_x, view_y = self._summary._view_widget.portal.position
        spacer = 1
        column_index = (x - self._summary._max_path_length - spacer -
                        border_width + view_x) // status_width
        row_index = y - border_width + view_y
        if row_index >= len(self._summary._column):
            return
        row = self._summary._column[row_index]
        if column_index < 0 or column_index >= len(row):
            return
        new_position = column_index, row_index
        if new_position != self._summary._cursor_position:
            self._summary._cursor_position = new_position
            self._appearance_changed_event.set()

    def on_keypressed(self, urwid_screen):
        if self._is_help_visible:
            self._help_widget.on_keypressed()
            self._appearance_changed_event.set()
            return
        events = urwid_screen.get_input()
        for event in events:
            if type(event) == tuple:
                self.on_mouse_event(event)
                continue
            try:
                action = self._key_map[event]
            except KeyError:
                pass
            else:
                action(self)
                self._appearance_changed_event.set()

    _STATUS_BAR = _highlight_chars(" *help *quit *d,*c,*j,*k:navigate *turn"
                                   " *log *edit *next *watch *order *statuses",
                                   Log.GREEN_STYLE)

    @functools.lru_cache(maxsize=2)
    def _get_status_bar_appearance(self, width, is_directory_sort,
                                   is_watching_filesystem, progress_bar_size):
        ordering_text = "directory" if is_directory_sort else "type     "
        watching_text = "watching" if is_watching_filesystem else "--------"
        indicators = " %s   order:%s " % (watching_text, ordering_text)
        spacing = " " * (width - len(self._STATUS_BAR) - len(indicators))
        bar = (self._STATUS_BAR[:width - len(indicators)] + spacing +
               indicators)[:width]
        return [bar[:progress_bar_size].underline() + bar[progress_bar_size:]]

    def appearance(self, dimensions):
        width, height = dimensions
        if self._is_help_visible:
            return self._help_widget.appearance(dimensions)
        widget = self._summary.get_selection()
        view = self._listing.widget.view
        view.position = widget.scroll_position
        view.widget = widget.result
        tool_name = tools._tool_name_colored(widget.tool, widget.path)
        self._listing.title = (
            tools._path_colored(widget.path) + " ─── " + tool_name + " " +
            status_to_str(widget.status, self._summary.is_status_simple))
        incomplete = self._summary.result_total - self._summary.completed_total
        progress_bar_size = max(0, width * incomplete //
                                self._summary.result_total)
        status_bar_appearance = self._get_status_bar_appearance(
            width, self._summary.is_directory_sort,
            self._is_watching_filesystem, progress_bar_size)
        return (self._layouts[self._is_log_visible][self._is_listing_portrait]
                .appearance((width, height-len(status_bar_appearance))) +
                status_bar_appearance)

    _KEY_DATA = [
        ({"t"}, toggle_window_orientation), ({"l"}, toggle_log),
        ({"h"}, toggle_help), ({"d", "up"}, cursor_up),
        ({"c", "down"}, cursor_down), ({"j", "left"}, cursor_left),
        ({"k", "right"}, cursor_right), ({"D", "page up"}, listing_up),
        ({"C", "page down"}, listing_down), ({"J", "home"}, listing_left),
        ({"K", "end"}, listing_right), ({"o"}, toggle_sort),
        ({"n"}, move_to_next_issue), ({"N"}, move_to_next_issue_of_tool),
        ({"e"}, edit_file), ({"s"}, toggle_status_style),
        ({"w"}, toggle_watch_filesystem), ({"q"}, quit_)]


def get_cpu_temperature():
    with open("/sys/class/thermal/thermal_zone0/temp", "r") as temp_file:
        return int(temp_file.read()[:-4])


def regulate_temperature(log):
    if get_cpu_temperature() >= 72:
        log.log_message("The computer is too hot. Waiting to cool down...")
        while get_cpu_temperature() > 66:
            time.sleep(1)
        log.log_message("The computer has cooled down. Continuing...")


class Runner:

    def __init__(self):
        self.result = None
        self.is_running = True

    def job_runner(self, summary, log, jobs_added_event,
                   appearance_changed_event):
        while True:
            jobs_added_event.wait()
            while self.is_running:
                # regulate_temperature(log)  # My fan is broken
                try:
                    self.result = summary.get_closest_placeholder()
                except StopIteration:
                    log.log_message("All results are up to date.")
                    break
                try:
                    self.result.run(log, appearance_changed_event)
                    summary.completed_total += 1
                except EOFError:  # Occurs if the process is terminated
                    pass
            jobs_added_event.clear()


_UPDATE_THREAD_STOPPED = False


def update_screen(main_widget, appearance_changed_event):
    while True:
        appearance_changed_event.wait()
        appearance_changed_event.clear()
        if _UPDATE_THREAD_STOPPED:
            break
        fill3.patch_screen(main_widget)


def main(root_path, urwid_screen):
    global _UPDATE_THREAD_STOPPED
    os.chdir(root_path)  # FIX: Don't change directory if possible.
    loop = asyncio.get_event_loop()
    jobs_added_event = threading.Event()
    appearance_changed_event = threading.Event()
    try:
        pickle_path = os.path.join(_CACHE_PATH, ".summary.pickle")
        with gzip.open(pickle_path, "rb") as file_:
            screen = pickle.load(file_)
    except FileNotFoundError:
        summary = Summary(root_path, jobs_added_event)
        log = Log(appearance_changed_event)
        screen = Screen(summary, log, appearance_changed_event, loop)
    else:
        screen._appearance_changed_event = appearance_changed_event
        screen._main_loop = loop
        if screen._is_watching_filesystem:
            screen.make_watch_manager()
        summary = screen._summary
        summary._lock = threading.Lock()
        summary._jobs_added_event = jobs_added_event
        log = screen._log
        log._appearance_changed_event = appearance_changed_event
        if screen._is_watching_filesystem:
            summary.sync_with_filesystem()
    log.log_message("Program started.")
    jobs_added_event.set()
    update_display_thread = threading.Thread(
        target=update_screen, args=(screen, appearance_changed_event),
        daemon=True)
    update_display_thread.start()
    loop.add_reader(sys.stdin, screen.on_keypressed, urwid_screen)
    runners = [Runner() for index in range(multiprocessing.cpu_count() * 2)]
    screen.runners = runners
    for runner in runners:
        args = (summary, log, jobs_added_event, appearance_changed_event)
        threading.Thread(target=runner.job_runner, args=args,
                         daemon=True).start()

    def on_window_resize(n, frame):
        appearance_changed_event.set()
    signal.signal(signal.SIGWINCH, on_window_resize)
    appearance_changed_event.set()
    try:
        loop.run_forever()
    except KeyboardInterrupt:
        log.log_message("Program stopped.")
        _UPDATE_THREAD_STOPPED = True
        appearance_changed_event.set()
        update_display_thread.join()
        for runner in runners:
            runner.is_running = False
            runner.result.reset()
        # Cannot pickle generators, locks, sockets or events.
        summary.closest_placeholder_generator = None
        summary._lock = None
        summary._jobs_added_event = None
        screen._appearance_changed_event = None
        screen._main_loop = None
        screen._watch_manager = None
        log._appearance_changed_event = None
        open_compressed = functools.partial(gzip.open, compresslevel=1)
        dump_pickle_safe(screen, pickle_path, open=open_compressed)


def manage_cache(root_path):
    cache_path = os.path.join(root_path, _CACHE_PATH)
    timestamp_path = os.path.join(cache_path, ".creation-time")
    if os.path.exists(cache_path) and \
       os.stat(__file__).st_mtime > os.stat(timestamp_path).st_mtime:
        print("Vigil has been updated, so clearing the cache and"
              " recalculating all results...")
        shutil.rmtree(cache_path)
    if not os.path.exists(cache_path):
        os.mkdir(cache_path)
        open(timestamp_path, "w").close()


if __name__ == "__main__":
    if len(sys.argv) == 2:
        root_path = os.path.abspath(sys.argv[1])
        with terminal.console_title("vigil: " + os.path.basename(root_path)):
            manage_cache(root_path)
            with terminal.hidden_cursor():
                with terminal.urwid_screen() as urwid_screen:
                    main(root_path, urwid_screen)
    else:
        usage = __doc__.replace("*", "")
        print(usage)