eris/vigil

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

# Copyright (C) 2015-2016 Andrew Hamilton. All rights reserved.
# Licensed under the Artistic License 2.0.

"""\
Vigil maintains a set of reports for each file in a directory tree.
Different types of reports are produced for different types of file.

The state of each report is summarised by a status indicator, and a report is
viewed by selecting this status indicator with the cursor. The types of status
are listed below.

Reports are recalculated whenever files are changed, so that they are always up
to date.

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


Usage:
  vigil [options] <directory>
  vigil -h | --help

Example:
  # vigil my_project

Options:
  -h, --help                       Show this screen and exit.
  -s on|off, --sandbox=on|off      Use a sandbox to prevent changes to the
                                   filesystem. The sandbox is on by default.
  -w COUNT, --workers=COUNT        The number of processes working in parallel.
                                   By default it is twice the number of cpus.
  -e "COMMAND", --editor="COMMAND" The command used to start the editor, in
                                   the *edit command. It may contain options.

Keys:
  *h - Show the help screen. (toggle)
  *q - Quit.
  *d, *c, *j, *k, *f, *v or arrow keys or mouse click - Move the cursor.
  *D, *C, *J, *K, *F, *V or page up, page down, home, end or the mouse wheel -
      Scroll the result pane.
  *t - Turn the result pane to portrait or landscape orientation. (toggle)
  *l - Show the activity log. (toggle)
  *e - Edit the current file with an editor defined by -e, $EDITOR or $VISUAL.
  *n - Move to the next issue.
  *N - Move to the next issue of the current tool.
  *p - Pause workers. (toggle)
  *o - Order files by type, or by directory location. (toggle)
  *r - Refresh the currently selected report.
  *s - Change the appearance of result statuses. (toggle)
"""


import asyncio
import collections
import contextlib
import functools
import gzip
import multiprocessing
import os
import pickle
import shutil
import signal
import subprocess
import sys
import tempfile
import threading
import time
import traceback

import docopt
import pyinotify
import urwid
import urwid.raw_display

import fill3
import sandbox_fs
import terminal
import termstr
import tools
import worker


_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)


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 _get_cursor(self):
        result_selected = self.widget[self.highlighted]
        if self.summary.is_status_simple:
            status_color = tools._STATUS_COLORS.get(
                result_selected.status, None)
            fg_color = (termstr.Color.white
                        if (status_color is None or
                            (sum(status_color) / 3) < (255 / 2))
                        else termstr.Color.black)
            return fill3.Text(termstr.TermStr("●", termstr.CharStyle(
                fg_color=fg_color, bg_color=status_color)))
        else:
            return fill3.Style(result_selected, _reverse_style)

    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:
                self.widget[self.highlighted] = self._get_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_path_excluded(path):
    return any(part.startswith(".") for part in path.split(os.path.sep))


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_path_excluded(dirname)]
            dirnames[:] = filtered_dirnames
        for filename in filenames:
            if not _is_path_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)


def _in_green(str_):
    return termstr.TermStr(str_, termstr.CharStyle(termstr.Color.green))


_UP, _DOWN, _LEFT, _RIGHT = (0, -1), (0, 1), (-1, 0), (1, 0)


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))


def _log_filesystem_changed(log, added, removed, modified):
    def part(stat, text, color):
        return termstr.TermStr("%2s %s." % (stat, text)).fg_color(
            termstr.Color.grey_100 if stat == 0 else color)
    parts = [part(added, "added", termstr.Color.green),
             part(removed, "removed", termstr.Color.red),
             part(modified, "modified", termstr.Color.light_blue)]
    log.log_message("Filesystem changed: " + fill3.join(" ", parts))


def _get_diff_stats(old_files, new_files):
    old_names = set(name for name, ctime in old_files)
    new_names = set(name for name, ctime in new_files)
    added_count = len(new_names - old_names)
    removed_count = len(old_names - new_names)
    same_count = len(new_names) - added_count
    modified_count = same_count - len(old_files.intersection(new_files))
    return added_count, removed_count, modified_count


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._all_results = set()
        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, log=None):
        x, y = self._cursor_position
        try:
            old_path = self.get_selection().path
        except AttributeError:
            old_path = None
        new_column = fill3.Column([])
        new_cache = {}
        paths = _fix_paths(self._root_path,
                           _codebase_files(self._root_path))
        paths.sort(key=_directory_sort if self.is_directory_sort
                   else _type_sort)
        jobs_added = False
        new_cursor_position = (0, 0)
        row_index = 0
        result_total, completed_total = 0, 0
        all_results = set()
        for path in paths:
            full_path = os.path.join(self._root_path, path)
            try:
                file_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):
                tool_key = (tool.__name__, tool.__code__.co_code)
                if file_key in self._cache \
                   and tool_key in self._cache[file_key]:
                    result = self._cache[file_key][tool_key]
                    result.tool = tool
                else:
                    result = tools.Result(path, tool)
                    jobs_added = True
                all_results.add(result)
                if result.is_completed:
                    completed_total += 1
                file_entry = new_cache.setdefault(file_key, {})
                file_entry[tool_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("./")
        deleted_results = self._all_results - all_results
        if log is not None:
            stats = _get_diff_stats(
                set(self._cache.keys()), set(new_cache.keys()))
            if sum(stats) != 0:
                _log_filesystem_changed(log, *stats)
        self._column, self._cache, self._cursor_position, self.result_total, \
            self.completed_total, self._max_width, self._max_path_length, \
            self.closest_placeholder_generator, self._all_results = (
                new_column, new_cache, new_cursor_position, result_total,
                completed_total, max_width, max_path_length, None, all_results)
        if jobs_added:
            self._jobs_added_event.set()
        for result in deleted_results:
            with contextlib.suppress(FileNotFoundError):
                os.remove(result.pickle_path)

    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, vector):
        dx, dy = vector
        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(_RIGHT)

    def cursor_left(self):
        self._move_cursor(_LEFT)

    def cursor_up(self):
        self._move_cursor(_UP)

    def cursor_down(self):
        self._move_cursor(_DOWN)

    def cursor_page_up(self):
        view_width, view_height = self._view_widget.portal.last_dimensions
        x, y = self._cursor_position
        jump = view_height - 1
        self._cursor_position = (x, max(y - jump, 0))

    def cursor_page_down(self):
        view_width, view_height = self._view_widget.portal.last_dimensions
        x, y = self._cursor_position
        jump = view_height - 1
        self._cursor_position = (x, min(y + jump, len(self._column) - 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.problem 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):
        with contextlib.suppress(StopIteration):
            issue, self._cursor_position = self._issue_generator().send(None)

    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, log):
        self.is_status_simple = not self.is_status_simple
        self.sync_with_filesystem(log)

    def refresh(self, log):
        selection = self.get_selection()
        if selection.status not in {tools.Status.running, tools.Status.paused,
                                    tools.Status.pending}:
            tool_name = tools.tool_name_colored(
                selection.tool, selection.path)
            path_colored = tools.path_colored(selection.path)
            log.log_message([_in_green("Refreshing "), tool_name,
                             _in_green(" result of "), path_colored,
                             _in_green("...")])
            selection.reset()
            self.closest_placeholder_generator = None
            self._jobs_added_event.set()
            self.completed_total -= 1


class Log:

    _GREY_BOLD_STYLE = termstr.CharStyle(termstr.Color.grey_100, is_bold=True)
    _GREEN_STYLE = termstr.CharStyle(termstr.Color.green)
    _LOG_PATH = os.path.join(tools.CACHE_PATH, "log")

    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)
        line = termstr.TermStr(timestamp, Log._GREY_BOLD_STYLE) + " " + message
        self.widget.append(fill3.Text(line))
        with open(Log._LOG_PATH, "a") as log_file:
            print(line, file=log_file)
        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 delete_log_file(self):
        with contextlib.suppress(FileNotFoundError):
            os.remove(Log._LOG_PATH)

    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)


@functools.lru_cache()
def _get_help_text(is_status_simple=True):
    usage = _highlight_chars(__doc__, Log._GREEN_STYLE)
    return fill3.join(
        "\n", [usage, "Statuses:"] +
        ["  " + tools.status_to_str(status, is_status_simple) + " " + meaning
         for status, meaning in tools.STATUS_MEANINGS])


def _make_key_map(key_data):
    key_map = {}
    for keys, action in key_data:
        for key in keys:
            key_map[key] = action
    return key_map


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")
        portal = self.view.portal
        self.key_map = _make_key_map([
            ({"h"}, self._exit_help), ({"d", "up"}, portal.scroll_up),
            ({"c", "down"}, portal.scroll_down),
            ({"j", "left"}, portal.scroll_left),
            ({"k", "right"}, portal.scroll_right), ({"q"}, self._exit_help)])

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

    def _on_mouse_event(self, event, appearance_changed_event):
        if event[1] == 4:  # Mouse wheel up
            self.view.portal.scroll_up()
            appearance_changed_event.set()
        elif event[1] == 5:  # Mouse wheel down
            self.view.portal.scroll_down()
            appearance_changed_event.set()

    def on_input_event(self, event, appearance_changed_event):
        if type(event) == tuple:
            self._on_mouse_event(event, appearance_changed_event)
            return
        try:
            action = self.key_map[event]
        except KeyError:
            pass
        else:
            action()
            appearance_changed_event.set()

    def appearance(self, dimensions):
        text = _get_help_text(self.summary.is_status_simple)
        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)


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_paused = False
        self._make_widgets()
        self._key_map = _make_key_map(Screen._KEY_DATA)

    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 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 cursor_page_up(self):
        self._summary.cursor_page_up()

    def cursor_page_down(self):
        self._summary.cursor_page_down()

    def _move_listing(self, vector):
        dx, dy = vector
        selected_widget = self._summary.get_selection()
        x, y = selected_widget.scroll_position
        if dy < 0 or dx < 0:  # up or left
            x, y = max(x + dx, 0), max(y + dy, 0)
        else:  # down or right
            widget_width, widget_height = fill3.appearance_dimensions(
                selected_widget.result.appearance_min())
            listing_width, listing_height = (self._listing.widget.
                                             last_dimensions)
            listing_width -= 1  # scrollbars
            listing_height -= 1
            x = min(x + dx, max(widget_width - listing_width, 0))
            y = min(y + dy, max(widget_height - listing_height, 0))
        selected_widget.scroll_position = x, y

    def _page_listing(self, vector):
        dx, dy = vector
        listing_width, listing_height = self._listing.widget.last_dimensions
        self._move_listing((dx * (listing_width // 2),
                            dy * (listing_height // 2)))

    def listing_up(self):
        self._move_listing(_UP)

    def listing_down(self):
        self._move_listing(_DOWN)

    def listing_right(self):
        self._page_listing(_RIGHT)

    def listing_left(self):
        self._page_listing(_LEFT)

    def listing_page_up(self):
        self._page_listing(_UP)

    def listing_page_down(self):
        self._page_listing(_DOWN)

    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):
        if self.editor_command is None:
            self._log.log_message("An editor has not been defined. "
                                  "See option -e.")
        else:
            path = self._summary.get_selection().path
            path_colored = tools.path_colored(path)
            self._log.log_message([_in_green("Editing "), path_colored,
                                   _in_green(' with command: "%s"...'
                                             % self.editor_command)])
            subprocess.Popen("%s %s" % (self.editor_command, path), shell=True,
                             stdout=subprocess.PIPE, stderr=subprocess.PIPE)

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

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

    def toggle_pause(self):
        self._is_paused = not self._is_paused
        self._log.log_command("Paused workers." if self._is_paused else
                              "Running workers...")
        if self._is_paused:
            for worker in self.workers:
                worker.pause()
        else:
            for worker in self.workers:
                worker.continue_()

    def quit_(self):
        os.kill(os.getpid(), signal.SIGINT)

    def refresh(self):
        self._summary.refresh(self._log)

    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_page_up()
            self._appearance_changed_event.set()
            return
        if event[1] == 5:  # Mouse wheel down
            self.listing_page_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_input_event(self, event):
        if self._is_help_visible:
            self._help_widget.on_input_event(
                event, self._appearance_changed_event)
            return
        if type(event) == tuple:
            self._on_mouse_event(event)
            return
        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,*f,*v:navigate *turn *log *edit *next *pause"
        " *order *refresh *statuses", Log._GREEN_STYLE)

    @functools.lru_cache(maxsize=2)
    def _get_status_bar_appearance(self, width, is_directory_sort, is_paused,
                                   progress_bar_size):
        ordering_text = "directory" if is_directory_sort else "type     "
        paused_indicator = (termstr.TermStr("paused ").fg_color(
            termstr.Color.yellow) if is_paused else termstr.TermStr("running").
                            fg_color(termstr.Color.light_blue))
        indicators = " " + paused_indicator + "  order:%s " % 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 = max(dimensions[0], 10), max(dimensions[1], 20)
        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 + " " +
            tools.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_paused,
            progress_bar_size)
        result = (self._layouts[self._is_log_visible]
                  [self._is_listing_portrait] .appearance(
                      (width, height-len(status_bar_appearance))) +
                  status_bar_appearance)
        return (result if (width, height) == dimensions
                else fill3.appearance_resize(result, dimensions))

    _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), ({"v"}, cursor_page_down),
        ({"f"}, cursor_page_up), ({"F", "page up"}, listing_page_up),
        ({"V", "page down"}, listing_page_down), ({"D"}, listing_up),
        ({"C"}, listing_down), ({"J", "home"}, listing_left),
        ({"K", "end"}, listing_right), ({"o"}, toggle_order),
        ({"n"}, move_to_next_issue), ({"N"}, move_to_next_issue_of_tool),
        ({"e"}, edit_file), ({"s"}, toggle_status_style), ({"q"}, quit_),
        ({"p"}, toggle_pause), ({"r"}, refresh)]


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...")


def _add_watch_manager_to_mainloop(root_path, mainloop, on_filesystem_change,
                                   exclude_filter):
    watch_manager = pyinotify.WatchManager()
    event_mask = (pyinotify.IN_CREATE | pyinotify.IN_DELETE |
                  pyinotify.IN_CLOSE_WRITE | pyinotify.IN_ATTRIB |
                  pyinotify.IN_MOVED_FROM | pyinotify.IN_MOVED_TO)
    watch_manager.add_watch(root_path, event_mask, rec=True, auto_add=True,
                            proc_fun=lambda event: None,
                            exclude_filter=exclude_filter)
    notifier = pyinotify.Notifier(watch_manager)

    def on_inotify():
        time.sleep(0.1)  # A little time for more events
        notifier.read_events()
        notifier.process_events()
        on_filesystem_change()
    watch_manager_fd = watch_manager.get_fd()
    mainloop.add_reader(watch_manager_fd, on_inotify)
    return watch_manager_fd


@contextlib.contextmanager
def _urwid_screen():
    screen = urwid.raw_display.Screen()
    screen.set_mouse_tracking(True)
    screen.start()
    try:
        yield screen
    finally:
        screen.stop()


_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 make_sandbox(mount_point):
    sandbox = sandbox_fs.SandboxFs(mount_point)
    sandbox.mount()
    cache_path = os.path.join(os.getcwd(), tools.CACHE_PATH)
    subprocess.check_call(["sudo", "mount", "--bind", cache_path,
                           mount_point + cache_path])
    return sandbox


def main(root_path, loop, worker_count=None, is_sandboxed=True,
         editor_command=None, is_being_tested=False):
    if worker_count is None:
        worker_count = multiprocessing.cpu_count()*2
    global _UPDATE_THREAD_STOPPED
    jobs_added_event = asyncio.Event()
    appearance_changed_event = threading.Event()
    is_first_run = True
    try:
        pickle_path = os.path.join(tools.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:
        is_first_run = False
        screen._appearance_changed_event = appearance_changed_event
        screen._main_loop = loop
        summary = screen._summary
        summary._lock = threading.Lock()
        summary._jobs_added_event = jobs_added_event
        summary._root_path = root_path
        log = screen._log
        log._appearance_changed_event = appearance_changed_event
    screen.editor_command = editor_command
    log.delete_log_file()
    log.log_message("Program started.")
    jobs_added_event.set()
    if not is_first_run:
        summary.sync_with_filesystem(log)

    def on_filesystem_change():
        summary.sync_with_filesystem(log)
        appearance_changed_event.set()
    watch_manager_fd = _add_watch_manager_to_mainloop(
        root_path, loop, on_filesystem_change, _is_path_excluded)
    screen.workers = workers = []
    if is_sandboxed:
        log.log_message("Making filesystem sandbox...")
        sandbox_temp_dir = tempfile.mkdtemp()
        sandbox = make_sandbox(sandbox_temp_dir)
        log.log_message("Sandbox made.")
    else:
        log.log_message("Running without the filesystem sandbox...")
        sandbox = None
    try:
        log.log_message("Starting workers (%s) ..." % worker_count)
        for index in range(worker_count):
            worker_ = worker.Worker(sandbox, screen._is_paused, is_being_tested)
            workers.append(worker_)
            future = worker_.job_runner(
                summary, log, jobs_added_event, appearance_changed_event)
            worker_.future = asyncio.ensure_future(future, loop=loop)

        def on_window_resize():
            appearance_changed_event.set()
        appearance_changed_event.set()
        update_display_thread = threading.Thread(
            target=_update_screen, args=(screen, appearance_changed_event),
            daemon=True)

        def exit_loop():
            log.log_command("Exiting...")
            time.sleep(0.05)
            for worker in workers:
                worker.pause()
                worker.future.cancel()
                if worker.result is not None:
                    worker.result.reset()
            loop.stop()
        loop.add_signal_handler(signal.SIGWINCH, on_window_resize)
        loop.add_signal_handler(signal.SIGINT, exit_loop)
        loop.add_signal_handler(signal.SIGTERM, exit_loop)
        with terminal.hidden_cursor():
            with _urwid_screen() as urwid_screen:

                def on_input(urwid_screen):
                    for event in urwid_screen.get_input():
                        screen.on_input_event(event)
                loop.add_reader(sys.stdin, on_input, urwid_screen)
                update_display_thread.start()
                try:
                    loop.run_forever()
                finally:
                    _UPDATE_THREAD_STOPPED = True
                    appearance_changed_event.set()
                    update_display_thread.join()
        log.log_message("Program stopped.")
        # Cannot pickle generators, locks, sockets or events.
        (summary.closest_placeholder_generator, summary._lock,
         summary._jobs_added_event, screen._appearance_changed_event,
         screen._main_loop, screen.workers,
         log._appearance_changed_event) = [None] * 7
        open_compressed = functools.partial(gzip.open, compresslevel=1)
        tools.dump_pickle_safe(screen, pickle_path, open=open_compressed)
    finally:
        if is_sandboxed:
            cache_path = os.path.join(os.getcwd(), tools.CACHE_PATH)
            subprocess.check_call(["sudo", "umount",
                                   sandbox.mount_point + cache_path])
            sandbox.umount()
            os.rmdir(sandbox_temp_dir)
        loop.remove_reader(watch_manager_fd)


@contextlib.contextmanager
def _chdir(path):
    old_cwd = os.getcwd()
    os.chdir(path)
    try:
        yield
    finally:
        os.chdir(old_cwd)


def _manage_cache(root_path):
    cache_path = os.path.join(root_path, tools.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()


def _check_arguments():
    arguments = docopt.docopt(__doc__.replace("*", ""), help=False)
    if arguments["--help"]:
        print(_get_help_text())
        sys.exit(0)
    worker_count = None
    try:
        if arguments["--workers"] is not None:
            worker_count = int(arguments["--workers"])
            if worker_count == 0:
                print("There must be at least one worker.")
                sys.exit(1)
    except ValueError:
        print("--workers requires a number.")
        sys.exit(1)
    root_path = os.path.abspath(arguments["<directory>"])
    if not os.path.exists(root_path):
        print("File does not exist:", root_path)
        sys.exit(1)
    if not os.path.isdir(root_path):
        print("File is not a directory:", root_path)
        sys.exit(1)
    if arguments["--sandbox"] not in ["on", "off", None]:
        print("--sandbox argument must be 'on' or 'off'")
        sys.exit(1)
    is_sandboxed = arguments["--sandbox"] in ["on", None]
    editor_command = arguments["--editor"] or os.environ.get("EDITOR", None)\
        or os.environ.get("VISUAL", None)
    return root_path, worker_count, is_sandboxed, editor_command


if __name__ == "__main__":
    root_path, worker_count, is_sandboxed, editor_command = _check_arguments()
    subprocess.call(["sudo", "-p", "Vigil uses sudo...  "
                     "[sudo] password for %u: ", "true"])
    with terminal.console_title("vigil: " + os.path.basename(root_path)):
        _manage_cache(root_path)
        with _chdir(root_path):  # FIX: Don't change directory if possible.
            loop = asyncio.get_event_loop()
            main(root_path, loop, worker_count, is_sandboxed, editor_command)
            loop.close()