# -*- coding: utf-8 -*-
import os.path
import re
import sys
import tkinter as tk
import traceback
from logging import exception, getLogger
from tkinter import messagebox, simpledialog, ttk
from typing import Optional

from _tkinter import TclError

from thonny import get_runner, get_workbench, ui_utils
from thonny.base_file_browser import ask_backend_path, choose_node_for_file_operations
from thonny.codeview import BinaryFileException, CodeView, CodeViewText
from thonny.common import (
    REMOTE_PATH_MARKER,
    InlineCommand,
    TextRange,
    ToplevelResponse,
    is_local_path,
    is_remote_path,
    is_same_path,
    normpath_with_actual_case,
    universal_dirname,
)
from thonny.languages import tr
from thonny.misc_utils import running_on_mac_os, running_on_windows
from thonny.tktextext import rebind_control_a
from thonny.ui_utils import (
    askopenfilename,
    asksaveasfilename,
    get_beam_cursor,
    select_sequence,
    windows_known_extensions_are_hidden,
)

PYTHON_FILES_STR = tr("Python files")
_dialog_filetypes = [(PYTHON_FILES_STR, ".py .pyw .pyi .pyde .pyx"), (tr("all files"), ".*")]

PYTHON_EXTENSIONS = {"py", "pyw", "pyi", "pyde"}
PYTHONLIKE_EXTENSIONS = {"pyx", "pyde"}
DEBOUNCE_SECONDS = 0.5


logger = getLogger(__name__)


class EditorCodeViewText(CodeViewText):
    """Allows separate class binding for CodeViewTexts which are inside editors"""

    def __init__(self, master=None, cnf={}, **kw):
        super().__init__(
            master=master,
            cnf=cnf,
            **kw,
        )
        self.bindtags(self.bindtags() + ("EditorCodeViewText",))


class Editor(ttk.Frame):
    def __init__(self, master):
        ttk.Frame.__init__(self, master)
        assert isinstance(master, EditorNotebook)
        self.notebook = master  # type: EditorNotebook

        # parent of codeview will be workbench so that it can be maximized
        self._code_view = CodeView(
            get_workbench(),
            propose_remove_line_numbers=True,
            font="EditorFont",
            text_class=EditorCodeViewText,
            cursor=get_beam_cursor(),
        )
        get_workbench().event_generate(
            "EditorTextCreated", editor=self, text_widget=self.get_text_widget()
        )

        self._code_view.grid(row=0, column=0, sticky=tk.NSEW, in_=self)
        self._code_view.home_widget = self  # don't forget home
        self.maximizable_widget = self._code_view

        self.columnconfigure(0, weight=1)
        self.rowconfigure(0, weight=1)

        self._filename = None
        self._last_known_mtime = None

        self._code_view.text.bind("<<Modified>>", self._on_text_modified, True)
        self._code_view.text.bind("<<TextChange>>", self._on_text_change, True)
        self._code_view.text.bind("<Control-Tab>", self._control_tab, True)

        get_workbench().bind("DebuggerResponse", self._listen_debugger_progress, True)
        get_workbench().bind("ToplevelResponse", self._listen_for_toplevel_response, True)

        self.update_appearance()

    def get_text_widget(self):
        return self._code_view.text

    def get_code_view(self):
        # TODO: try to get rid of this
        return self._code_view

    def get_content(self) -> str:
        return self._code_view.get_content()

    def set_filename(self, path):
        self._filename = path

    def get_filename(self, try_hard=False):
        if self._filename is None and try_hard:
            self.save_file()

        return self._filename

    def get_identifier(self):
        if self._filename:
            return self._filename
        else:
            return str(self.winfo_id())

    def get_title(self):
        if self.get_filename() is None:
            result = tr("<untitled>")
        elif is_remote_path(self.get_filename()):
            path = extract_target_path(self.get_filename())
            name = path.split("/")[-1]
            result = "[ " + name + " ]"
        else:
            result = os.path.basename(self.get_filename())

        if self.is_modified():
            result += " *"

        return result

    def check_for_external_changes(self):
        if self._filename is None:
            return

        if is_remote_path(self._filename):
            return

        if self._last_known_mtime is None:
            return

        elif not os.path.exists(self._filename):
            self.master.select(self)

            if messagebox.askyesno(
                tr("File is gone"),
                tr("Looks like '%s' was deleted or moved.") % self._filename
                + "\n\n"
                + tr("Do you want to also close the editor?"),
                master=self,
            ):
                self.master.close_editor(self)
            else:
                self.get_text_widget().edit_modified(True)
                self._last_known_mtime = None

        elif os.path.getmtime(self._filename) != self._last_known_mtime:
            skip_confirmation = not self.is_modified() and get_workbench().get_option(
                "edit.auto_refresh_saved_files"
            )
            if not skip_confirmation:
                self.master.select(self)

            if skip_confirmation or messagebox.askyesno(
                tr("External modification"),
                tr("Looks like '%s' was modified outside of the editor.") % self._filename
                + "\n\n"
                + tr(
                    "Do you want to discard current editor content and reload the file from disk?"
                ),
                master=self,
            ):
                prev_location = self.get_text_widget().index("insert")
                self._load_file(self._filename, keep_undo=True)
                try:
                    self.get_text_widget().mark_set("insert", prev_location)
                    self.see_line(int(prev_location.split(".")[0]))
                except Exception:
                    logger.exception("Could not restore previous location")

            self._last_known_mtime = os.path.getmtime(self._filename)

    def get_long_description(self):
        if self._filename is None:
            result = tr("<untitled>")
        else:
            result = self._filename

        try:
            index = self._code_view.text.index("insert")
            if index and "." in index:
                line, col = index.split(".")
                result += "  @  {} : {}".format(line, int(col) + 1)
        except Exception:
            exception("Finding cursor location")

        return result

    def _load_file(self, filename, keep_undo=False):
        try:
            if is_remote_path(filename):
                result = self._load_remote_file(filename)
            else:
                result = self._load_local_file(filename, keep_undo)
                if not result:
                    return False
        except BinaryFileException:
            messagebox.showerror(
                tr("Problem"), tr("%s doesn't look like a text file") % (filename,), master=self
            )
            return False
        except SyntaxError as e:
            assert "encoding" in str(e).lower()
            messagebox.showerror(
                tr("Problem loading file"),
                tr(
                    "This file seems to have problems with encoding.\n\n"
                    "Make sure it is in UTF-8 or contains proper encoding hint."
                ),
                master=self,
            )
            return False

        self.update_appearance()
        return True

    def _load_local_file(self, filename, keep_undo=False):
        with open(filename, "rb") as fp:
            source = fp.read()

        # Make sure Windows filenames have proper format
        filename = normpath_with_actual_case(filename)
        self._filename = filename
        self.update_file_type()
        self._last_known_mtime = os.path.getmtime(self._filename)

        get_workbench().event_generate("Open", editor=self, filename=filename)
        if not self._code_view.set_content_as_bytes(source, keep_undo):
            return False
        self.get_text_widget().edit_modified(False)
        self._code_view.focus_set()
        self.master.remember_recent_file(filename)
        return True

    def _load_remote_file(self, filename):
        self._filename = filename
        self.update_file_type()
        self._code_view.set_content("")
        self._code_view.text.set_read_only(True)

        target_filename = extract_target_path(self._filename)

        self.update_title()
        response = get_runner().send_command_and_wait(
            InlineCommand(
                "read_file", path=target_filename, description=tr("Loading %s") % target_filename
            ),
            dialog_title=tr("Loading"),
        )

        if response.get("error"):
            # TODO: make it softer
            raise RuntimeError(response["error"])

        content = response["content_bytes"]
        self._code_view.text.set_read_only(False)
        if not self._code_view.set_content_as_bytes(content):
            return False
        self.get_text_widget().edit_modified(False)
        self.update_title()
        return True

    def is_modified(self):
        return bool(self._code_view.text.edit_modified())

    def save_file_enabled(self):
        return self.is_modified() or not self.get_filename()

    def save_file(self, ask_filename=False, save_copy=False, node=None) -> Optional[str]:
        if self._filename is not None and not ask_filename:
            save_filename = self._filename
            get_workbench().event_generate("Save", editor=self, filename=save_filename)
        else:
            save_filename = self.ask_new_path(node)

            if not save_filename:
                return None

            if self.notebook.get_editor(save_filename) is not None:
                messagebox.showerror(
                    tr("File is open"),
                    tr(
                        "This file is already open in Thonny.\n\n"
                        "If you want to save with this name,\n"
                        "close the existing editor first!"
                    ),
                    master=get_workbench(),
                )
                return None

            get_workbench().event_generate(
                "SaveAs", editor=self, filename=save_filename, save_copy=save_copy
            )

        content_bytes = self._code_view.get_content_as_bytes()

        if is_remote_path(save_filename):
            result = self.write_remote_file(save_filename, content_bytes, save_copy)
        else:
            result = self.write_local_file(save_filename, content_bytes, save_copy)

        if not result:
            return None

        if not save_copy:
            self._filename = save_filename
            self.update_file_type()

        self.update_title()
        return save_filename

    def write_local_file(self, save_filename, content_bytes, save_copy):
        process_shebang = content_bytes.startswith(b"#!/") and get_workbench().get_option(
            "file.make_saved_shebang_scripts_executable"
        )
        if process_shebang:
            content_bytes = content_bytes.replace(b"\r\n", b"\n")

        try:
            f = open(save_filename, mode="wb")
            f.write(content_bytes)
            f.flush()
            # Force writes on disk, see https://learn.adafruit.com/adafruit-circuit-playground-express/creating-and-editing-code#1-use-an-editor-that-writes-out-the-file-completely-when-you-save-it
            os.fsync(f)
            f.close()
            if process_shebang:
                os.chmod(save_filename, 0o755)
            if not save_copy or save_filename == self._filename:
                self._last_known_mtime = os.path.getmtime(save_filename)
            get_workbench().event_generate(
                "LocalFileOperation", path=save_filename, operation="save"
            )
        except PermissionError:
            messagebox.showerror(
                tr("Permission Error"),
                tr("Looks like this file or folder is not writable."),
                master=self,
            )
            return False

        if not save_copy or save_filename == self._filename:
            self.master.remember_recent_file(save_filename)

        if not save_copy or save_filename == self._filename:
            self._code_view.text.edit_modified(False)

        return True

    def update_file_type(self):
        if self._filename is None:
            self._code_view.set_file_type(None)
        else:
            ext = self._filename.split(".")[-1].lower()
            if ext in PYTHON_EXTENSIONS:
                file_type = "python"
            elif ext in PYTHONLIKE_EXTENSIONS:
                file_type = "pythonlike"
            else:
                file_type = None

            self._code_view.set_file_type(file_type)

        self.update_appearance()

    def write_remote_file(self, save_filename, content_bytes, save_copy):
        if get_runner().ready_for_remote_file_operations(show_message=True):
            target_filename = extract_target_path(save_filename)

            result = get_runner().send_command_and_wait(
                InlineCommand(
                    "write_file",
                    path=target_filename,
                    content_bytes=content_bytes,
                    editor_id=id(self),
                    blocking=True,
                    description=tr("Saving to %s") % target_filename,
                    make_shebang_scripts_executable=get_workbench().get_option(
                        "file.make_saved_shebang_scripts_executable"
                    ),
                ),
                dialog_title=tr("Saving"),
            )

            if "error" in result:
                messagebox.showerror(tr("Could not save"), str(result["error"]))
                return False

            if not save_copy:
                self._code_view.text.edit_modified(False)

            self.update_title()

            # NB! edit_modified is not falsed yet!
            get_workbench().event_generate(
                "RemoteFileOperation", path=target_filename, operation="save"
            )
            get_workbench().event_generate("RemoteFilesChanged")
            return True
        else:
            messagebox.showerror(tr("Could not save"), tr("Back-end is not ready"))
            return False

    def ask_new_path(self, node=None):
        if node is None:
            node = choose_node_for_file_operations(self.winfo_toplevel(), tr("Where to save to?"))
        if not node:
            return None

        if node == "local":
            return self.ask_new_local_path()
        else:
            assert node == "remote"
            return self.ask_new_remote_path()

    def ask_new_remote_path(self):
        target_path = ask_backend_path(self.winfo_toplevel(), "save")
        if target_path:
            target_path = self._check_add_py_extension(target_path)
            return make_remote_path(target_path)
        else:
            return None

    def ask_new_local_path(self):
        if self._filename is None:
            initialdir = get_workbench().get_local_cwd()
            initialfile = None
        else:
            initialdir = os.path.dirname(self._filename)
            initialfile = os.path.basename(self._filename)

        # https://tcl.tk/man/tcl8.6/TkCmd/getOpenFile.htm
        type_var = tk.StringVar(value="")
        new_filename = asksaveasfilename(
            filetypes=_dialog_filetypes,
            defaultextension=None,
            initialdir=initialdir,
            initialfile=initialfile,
            parent=get_workbench(),
            typevariable=type_var,
        )
        logger.info("Save dialog returned %r with typevariable %r", new_filename, type_var.get())

        # Different tkinter versions may return different values
        if new_filename in ["", (), None]:
            return None

        if running_on_windows():
            # may have /-s instead of \-s and wrong case
            new_filename = os.path.join(
                normpath_with_actual_case(os.path.dirname(new_filename)),
                os.path.basename(new_filename),
            )

        if type_var.get() == PYTHON_FILES_STR or type_var.get() == "":
            new_filename = self._check_add_py_extension(
                new_filename, without_asking=type_var.get() == PYTHON_FILES_STR
            )

        if new_filename.endswith(".py"):
            base = os.path.basename(new_filename)
            mod_name = base[:-3].lower()
            if running_on_windows():
                mod_name = mod_name.lower()

            if mod_name in [
                "math",
                "turtle",
                "random",
                "statistics",
                "pygame",
                "matplotlib",
                "numpy",
            ]:
                # More proper name analysis will be performed by ProgramNamingAnalyzer
                if not tk.messagebox.askyesno(
                    tr("Potential problem"),
                    tr(
                        "If you name your script '%s', "
                        "you won't be able to import the library module named '%s'"
                    )
                    % (base, mod_name)
                    + ".\n\n"
                    + tr("Do you still want to use this name for your script?"),
                    master=self,
                ):
                    return self.ask_new_local_path()

        return new_filename

    def show(self):
        self.master.select(self)

    def update_appearance(self):
        self._code_view.set_gutter_visibility(
            get_workbench().get_option("view.show_line_numbers") or get_workbench().in_simple_mode()
        )
        self._code_view.set_line_length_margin(
            get_workbench().get_option("view.recommended_line_length")
        )
        self._code_view.text.update_tabs()
        self._code_view.text.event_generate("<<UpdateAppearance>>")
        self._code_view.grid_main_widgets()

    def _listen_debugger_progress(self, event):
        # Go read-only
        # TODO: check whether this module is active?
        self._code_view.text.set_read_only(True)

    def _listen_for_toplevel_response(self, event: ToplevelResponse) -> None:
        self._code_view.text.set_read_only(False)

    def _control_tab(self, event):
        if event.state & 1:  # shift was pressed
            direction = -1
        else:
            direction = 1
        self.master.select_next_prev_editor(direction)
        return "break"

    def _shift_control_tab(self, event):
        self.master.select_next_prev_editor(-1)
        return "break"

    def select_range(self, text_range):
        self._code_view.select_range(text_range)

    def select_line(self, lineno, col_offset=None):
        self._code_view.select_range(TextRange(lineno, 0, lineno + 1, 0))
        self.see_line(lineno)

        if col_offset is None:
            col_offset = 0

        self.get_text_widget().mark_set("insert", "%d.%d" % (lineno, col_offset))

    def see_line(self, lineno):
        # first see an earlier line in order to push target line downwards
        self._code_view.text.see("%d.0" % max(lineno - 4, 1))
        self._code_view.text.see("%d.0" % lineno)

    def focus_set(self):
        self._code_view.focus_set()

    def is_focused(self):
        return self.focus_displayof() == self._code_view.text

    def _on_text_modified(self, event):
        self.update_title()

    def update_title(self):
        try:
            self.master.update_editor_title(self)
        except Exception as e:
            logger.exception("Could not update editor title", exc_info=e)

    def _on_text_change(self, event):
        self.update_title()

    def destroy(self):
        get_workbench().unbind("DebuggerResponse", self._listen_debugger_progress)
        get_workbench().unbind("ToplevelResponse", self._listen_for_toplevel_response)
        ttk.Frame.destroy(self)
        get_workbench().event_generate(
            "EditorTextDestroyed", editor=self, text_widget=self.get_text_widget()
        )

    def _check_add_py_extension(self, path: str, without_asking: bool = False) -> str:
        assert path
        parts = re.split(r"[/\\]", path)
        name = parts[-1]
        if "." not in name:
            if without_asking or messagebox.askyesno(
                title=tr("Confirmation"),
                message=tr("Python files usually have .py extension.")
                + "\n\n"
                + tr("Did you mean '%s'?" % (name + ".py")),
                parent=self.winfo_toplevel(),
            ):
                return path + ".py"
            else:
                return path

        return path


class EditorNotebook(ui_utils.ClosableNotebook):
    """
    Manages opened files / modules
    """

    def __init__(self, master):
        super().__init__(master, padding=0)

        get_workbench().set_default("file.reopen_all_files", False)
        get_workbench().set_default("file.open_files", [])
        get_workbench().set_default("file.current_file", None)
        get_workbench().set_default("file.recent_files", [])
        get_workbench().set_default("view.highlight_current_line", False)
        get_workbench().set_default("view.show_line_numbers", True)
        get_workbench().set_default("view.recommended_line_length", 0)
        get_workbench().set_default("edit.indent_with_tabs", False)
        get_workbench().set_default("edit.auto_refresh_saved_files", True)
        get_workbench().set_default("file.make_saved_shebang_scripts_executable", True)

        self._recent_menu = tk.Menu(
            get_workbench().get_menu("file"), postcommand=self._update_recent_menu
        )
        self._init_commands()
        self.enable_traversal()

        # open files from last session
        """ TODO: they should go only to recent files
        for filename in prefs["open_files"].split(";"):
            if os.path.exists(filename):
                self._open_file(filename)
        """

        # should be in the end, so that it can be detected when
        # constructor hasn't completed yet
        self.preferred_size_in_pw = None
        self._checking_external_changes = False

        get_workbench().bind("WindowFocusIn", self.check_for_external_changes, True)
        get_workbench().bind("ToplevelResponse", self.check_for_external_changes, True)
        self.bind("<<NotebookTabChanged>>", self.on_tab_changed, True)

    def on_tab_changed(self, *args):
        if sys.platform == "darwin":
            # Since Tk 8.6.11, after closing an editor, the previous editor re-appeared with
            # widgets disappeared, at least on Aivar's machine.
            for child in self.get_all_editors():
                assert isinstance(child, Editor)
                child.get_code_view().grid_main_widgets()
            self.update_idletasks()

    def _init_commands(self):
        # TODO: do these commands have to be in EditorNotebook ??
        # Create a module level function install_editor_notebook ??
        # Maybe add them separately, when notebook has been installed ??

        get_workbench().add_command(
            "new_file",
            "file",
            tr("New"),
            self._cmd_new_file,
            caption=tr("New"),
            default_sequence=select_sequence("<Control-n>", "<Command-n>"),
            extra_sequences=["<Control-Greek_nu>"],
            group=10,
            image="new-file",
            include_in_toolbar=True,
        )

        get_workbench().add_command(
            "open_file",
            "file",
            tr("Open..."),
            self._cmd_open_file,
            caption=tr("Load"),
            default_sequence=select_sequence("<Control-o>", "<Command-o>"),
            extra_sequences=["<Control-Greek_omicron>"],
            group=10,
            image="open-file",
            include_in_toolbar=True,
        )

        get_workbench().add_command(
            "recents", "file", tr("Recent files"), group=10, submenu=self._recent_menu
        )

        # http://stackoverflow.com/questions/22907200/remap-default-keybinding-in-tkinter
        get_workbench().bind_class("Text", "<Control-o>", self._control_o)
        get_workbench().bind_class("Text", "<Control-Greek_omicron>", self._control_o)
        rebind_control_a(get_workbench())

        get_workbench().add_command(
            "close_file",
            "file",
            tr("Close"),
            self._cmd_close_file,
            default_sequence=select_sequence("<Control-w>", "<Command-w>"),
            extra_sequences=["<Control-Greek_finalsmallsigma>"],
            tester=lambda: self.get_current_editor() is not None,
            group=10,
        )

        get_workbench().add_command(
            "close_files",
            "file",
            tr("Close all"),
            self.close_tabs,
            tester=lambda: self.get_current_editor() is not None,
            default_sequence=select_sequence("<Control-W>", "<Command-Alt-w>"),
            group=10,
        )

        get_workbench().add_command(
            "save_file",
            "file",
            tr("Save"),
            self._cmd_save_file,
            caption=tr("Save"),
            default_sequence=select_sequence("<Control-s>", "<Command-s>"),
            extra_sequences=["<Control-Greek_sigma>"],
            tester=self._cmd_save_file_enabled,
            group=10,
            image="save-file",
            include_in_toolbar=True,
        )

        get_workbench().add_command(
            "save_all_files",
            "file",
            tr("Save All files"),
            self._cmd_save_all_files,
            caption=tr("Save All files"),
            default_sequence=select_sequence("<Control-Alt-s>", "<Command-Alt-s>"),
            tester=self._cmd_save_all_files_enabled,
            group=10,
        )

        get_workbench().add_command(
            "save_file_as",
            "file",
            tr("Save as..."),
            self._cmd_save_file_as,
            default_sequence=select_sequence("<Control-Shift-S>", "<Command-Shift-S>"),
            extra_sequences=["<Control-Greek_SIGMA>"],
            tester=lambda: self.get_current_editor() is not None,
            group=10,
        )

        get_workbench().add_command(
            "save_copy",
            "file",
            tr("Save copy..."),
            self._cmd_save_copy,
            tester=lambda: self.get_current_editor() is not None,
            group=10,
        )

        get_workbench().add_command(
            "move_rename_file",
            "file",
            tr("Move / rename..."),
            self._cmd_move_rename_file,
            tester=self._cmd_move_rename_file_enabled,
            group=10,
        )

        get_workbench().add_command(
            "goto_source_line",
            "edit",
            tr("Go to line..."),
            self._cmd_goto_source_line,
            default_sequence=select_sequence("<Control-g>", "<Command-g>"),
            # tester=,
            # no global switch, or cross plugin switch?
            # todo use same as find and replace -> plugins/find_replace.py
            group=60,
        )

        get_workbench().createcommand("::tk::mac::OpenDocument", self._mac_open_document)

    def load_startup_files(self):
        """If no filename was sent from command line
        then load previous files (if setting allows)"""

        cmd_line_filenames = [
            os.path.abspath(name) for name in sys.argv[1:] if os.path.exists(name)
        ]

        if len(cmd_line_filenames) > 0:
            filenames = cmd_line_filenames
        elif get_workbench().get_option("file.reopen_all_files"):
            filenames = get_workbench().get_option("file.open_files")
        elif get_workbench().get_option("file.current_file"):
            filenames = [get_workbench().get_option("file.current_file")]
        else:
            filenames = []

        if len(filenames) > 0:
            for filename in filenames:
                if os.path.exists(filename):
                    self.show_file(filename)

            cur_file = get_workbench().get_option("file.current_file")
            # choose correct active file
            if len(cmd_line_filenames) > 0:
                self.show_file(cmd_line_filenames[0])
            elif cur_file and os.path.exists(cur_file):
                self.show_file(cur_file)
            else:
                self._cmd_new_file()
        else:
            self._cmd_new_file()

    def save_all_named_editors(self):
        all_saved = True
        for editor in self.winfo_children():
            if editor.get_filename() and editor.is_modified():
                success = editor.save_file()
                all_saved = all_saved and success

        return all_saved

    def remember_recent_file(self, filename):
        recents = get_workbench().get_option("file.recent_files")
        if filename in recents:
            recents.remove(filename)
        recents.insert(0, filename)
        relevant_recents = [name for name in recents if os.path.exists(name)][:15]
        get_workbench().set_option("file.recent_files", relevant_recents)
        self._update_recent_menu()

    def _update_recent_menu(self):
        recents = get_workbench().get_option("file.recent_files")
        relevant_recents = [
            path for path in recents if os.path.exists(path) and not self.file_is_opened(path)
        ]
        self._recent_menu.delete(0, "end")
        for path in relevant_recents:

            def load(path=path):
                self.show_file(path)

            self._recent_menu.insert_command("end", label=path, command=load)

    def remember_open_files(self):
        if (
            self.get_current_editor() is not None
            and self.get_current_editor().get_filename() is not None
        ):
            current_file = self.get_current_editor().get_filename()
        else:
            current_file = None

        get_workbench().set_option("file.current_file", current_file)

        open_files = [
            editor.get_filename() for editor in self.winfo_children() if editor.get_filename()
        ]
        get_workbench().set_option("file.open_files", open_files)

    def _cmd_new_file(self):
        self.open_new_file()

    def open_new_file(self, path=None, remote=False):
        new_editor = Editor(self)
        get_workbench().event_generate("NewFile", editor=new_editor)
        if path:
            if remote:
                new_editor.set_filename(make_remote_path(path))
            else:
                new_editor.set_filename(path)
        self.add(new_editor, text=new_editor.get_title())
        self.select(new_editor)
        new_editor.focus_set()

    def _cmd_open_file(self):
        node = choose_node_for_file_operations(self.winfo_toplevel(), "Where to open from?")
        if not node:
            return

        if node == "local":
            initialdir = get_workbench().get_local_cwd()
            if (
                self.get_current_editor() is not None
                and self.get_current_editor().get_filename() is not None
            ):
                initialdir = os.path.dirname(self.get_current_editor().get_filename())
            path = askopenfilename(
                filetypes=_dialog_filetypes, initialdir=initialdir, parent=get_workbench()
            )
        else:
            assert node == "remote"
            target_path = ask_backend_path(self.winfo_toplevel(), "open")
            if not target_path:
                return

            path = make_remote_path(target_path)

        if path:
            # self.close_single_untitled_unmodified_editor()
            self.show_file(path, propose_dialog=False)

    def _control_o(self, event):
        # http://stackoverflow.com/questions/22907200/remap-default-keybinding-in-tkinter
        self._cmd_open_file()
        return "break"

    def _close_files(self, except_index=None):
        for tab_index in reversed(range(len(self.winfo_children()))):
            if except_index is not None and tab_index == except_index:
                continue
            else:
                editor = self.get_child_by_index(tab_index)
                if self.check_allow_closing(editor):
                    self.forget(editor)
                    editor.destroy()

    def _cmd_close_file(self):
        self.close_tab(self.index(self.select()))

    def close_tab(self, index):
        editor = self.get_child_by_index(index)

        if editor:
            self.close_editor(editor)

    def close_editor(self, editor, force=False):
        if not force and not self.check_allow_closing(editor):
            return
        self.forget(editor)
        editor.destroy()

    def _cmd_save_file(self):
        if self.get_current_editor():
            self.get_current_editor().save_file()
            self.update_editor_title(self.get_current_editor())

    def _cmd_save_file_enabled(self):
        return self.get_current_editor() and self.get_current_editor().save_file_enabled()

    def _cmd_save_all_files(self):
        for editor in self.get_all_editors():
            if editor.save_file_enabled() == True:
                editor.save_file()
                self.update_editor_title(editor)

    def _cmd_save_all_files_enabled(self):
        for editor in self.get_all_editors():
            if editor.save_file_enabled() == True:
                return True
        return False

    def _cmd_save_file_as(self, node=None):
        if not self.get_current_editor():
            return

        self.get_current_editor().save_file(ask_filename=True, node=node)
        self.update_editor_title(self.get_current_editor())
        get_workbench().update_title()

    def _cmd_save_copy(self):
        if not self.get_current_editor():
            return

        self.get_current_editor().save_file(ask_filename=True, save_copy=True)
        self.update_editor_title(self.get_current_editor())

    def _cmd_save_file_as_enabled(self):
        return self.get_current_editor() is not None

    def _cmd_move_rename_file(self):
        editor = self.get_current_editor()
        old_filename = editor.get_filename()
        assert old_filename is not None

        if is_remote_path(old_filename):
            node = "remote"
        else:
            node = "local"

        self._cmd_save_file_as(node=node)

        if editor.get_filename() != old_filename:
            if is_remote_path(old_filename):
                remote_path = extract_target_path(old_filename)
                get_runner().send_command_and_wait(
                    InlineCommand(
                        "delete", paths=[remote_path], description=tr("Deleting" + remote_path)
                    ),
                    dialog_title=tr("Deleting"),
                )
                get_workbench().event_generate(
                    "RemoteFileOperation", path=remote_path, operation="delete"
                )
            else:
                os.remove(old_filename)
                get_workbench().event_generate(
                    "LocalFileOperation", path=old_filename, operation="delete"
                )

    def _cmd_move_rename_file_enabled(self):
        return self.get_current_editor() and self.get_current_editor().get_filename() is not None

    def close_single_untitled_unmodified_editor(self):
        editors = self.winfo_children()
        if len(editors) == 1 and not editors[0].is_modified() and not editors[0].get_filename():
            self._cmd_close_file()

    def _cmd_goto_source_line(self):
        editor = self.get_current_editor()
        if editor:
            line_no = simpledialog.askinteger(tr("Go to line"), tr("Line number"))
            if line_no:
                editor.select_line(line_no)

    def _mac_open_document(self, *args):
        for arg in args:
            if isinstance(arg, str) and os.path.exists(arg):
                self.show_file(arg)
        get_workbench().become_active_window()

    def get_current_editor(self) -> Optional[Editor]:
        return self.get_current_child()

    def get_current_editor_content(self):
        editor = self.get_current_editor()
        if editor is None:
            return None
        else:
            return editor.get_content()

    def get_all_editors(self):
        # When workspace is closing, self.winfo_children()
        # may return an unexplainable tkinter.Frame
        return [child for child in self.winfo_children() if isinstance(child, Editor)]

    def select_next_prev_editor(self, direction):
        cur_index = self.index(self.select())
        next_index = (cur_index + direction) % len(self.tabs())
        self.select(self.get_child_by_index(next_index))

    def file_is_opened(self, path):
        for editor in self.get_all_editors():
            if editor.get_filename() and is_same_path(path, editor.get_filename()):
                return True

        return False

    def show_file(self, filename, text_range=None, set_focus=True, propose_dialog=True):
        # self.close_single_untitled_unmodified_editor()
        try:
            editor = self.get_editor(filename, True)
        except PermissionError:
            logger.exception("Loading " + filename)
            msg = tr("Got permission error when trying to load\n%s") % (filename,)
            if running_on_mac_os() and propose_dialog:
                msg += "\n\n" + tr("Try opening it with File => Open.")

            messagebox.showerror(tr("Permission error"), msg, master=self)
            return None

        if editor is None:
            return

        self.select(editor)
        if set_focus:
            editor.focus_set()

        if text_range is not None:
            editor.select_range(text_range)

        return editor

    def show_remote_file(self, target_filename):
        if not get_runner().ready_for_remote_file_operations(show_message=True):
            return None
        else:
            return self.show_file(make_remote_path(target_filename))

    def show_file_at_line(self, filename, lineno, col_offset=None):
        editor = self.show_file(filename)
        editor.select_line(lineno, col_offset)

    def update_appearance(self):
        for editor in self.winfo_children():
            editor.update_appearance()

    def update_editor_title(self, editor, title=None):
        if title is None:
            title = editor.get_title()
        try:
            self.tab(editor, text=title)
        except TclError:
            pass

        try:
            self.indicate_modification()
        except Exception:
            logger.exception("Could not update modification indication")

    def indicate_modification(self):
        if not running_on_mac_os():
            return

        atts = self.winfo_toplevel().wm_attributes()
        if "-modified" in atts:
            i = atts.index("-modified")
            mod = atts[i : i + 2]
            rest = atts[:i] + atts[i + 2 :]
        else:
            mod = ()
            rest = atts

        for editor in self.get_all_editors():
            if editor.is_modified():
                if mod != ("-modified", 1):
                    self.winfo_toplevel().wm_attributes(*(rest + ("-modified", 1)))
                break
        else:
            if mod == ("-modified", 1):
                self.winfo_toplevel().wm_attributes(*(rest + ("-modified", 0)))

    def _open_file(self, filename):
        editor = Editor(self)
        if editor._load_file(filename):
            self.add(editor, text=editor.get_title())
            return editor
        else:
            editor.destroy()
            return None

    def get_editor(self, filename_or_id, open_when_necessary=False):
        if os.path.isfile(filename_or_id):
            filename_or_id = normpath_with_actual_case(os.path.abspath(filename_or_id))

        for child in self.winfo_children():
            assert isinstance(child, Editor)
            child_identifier = child.get_identifier()
            if child_identifier == filename_or_id:
                return child

        if open_when_necessary:
            return self._open_file(filename_or_id)
        else:
            return None

    def check_allow_closing(self, editor=None):
        if not editor:
            modified_editors = [e for e in self.winfo_children() if e.is_modified()]
        else:
            if not editor.is_modified():
                return True
            else:
                modified_editors = [editor]
        if len(modified_editors) == 0:
            return True

        message = tr("Do you want to save files before closing?")
        if editor:
            message = tr("Do you want to save file before closing?")

        confirm = messagebox.askyesnocancel(
            title=tr("Save On Close"), message=message, default=messagebox.YES, master=self
        )

        if confirm:
            for editor_ in modified_editors:
                assert isinstance(editor_, Editor)
                if editor_.get_filename(True):
                    if not editor_.save_file():
                        return False
                else:
                    return False
            return True

        elif confirm is None:
            return False
        else:
            return True

    def check_for_external_changes(self, event=None):
        if self._checking_external_changes:
            # otherwise the method will be re-entered when focus
            # changes because of a confirmation message box
            return

        self._checking_external_changes = True
        try:
            for editor in self.get_all_editors():
                editor.check_for_external_changes()
        finally:
            self._checking_external_changes = False


def get_current_breakpoints():
    result = {}

    for editor in get_workbench().get_editor_notebook().get_all_editors():
        filename = editor.get_filename()
        if filename:
            linenos = editor.get_code_view().get_breakpoint_line_numbers()
            if linenos:
                result[filename] = linenos

    return result


def get_saved_current_script_filename(force=True):
    editor = get_workbench().get_editor_notebook().get_current_editor()
    if not editor:
        return None

    filename = editor.get_filename(force)
    if not filename:
        return None

    if editor.is_modified():
        filename = editor.save_file()

    return filename


def get_target_dirname_from_editor_filename(s):
    if is_local_path(s):
        return os.path.dirname(s)
    else:
        return universal_dirname(extract_target_path(s))


def extract_target_path(s):
    assert is_remote_path(s)
    return s[s.find(REMOTE_PATH_MARKER) + len(REMOTE_PATH_MARKER) :]


def make_remote_path(target_path):
    return get_runner().get_node_label() + REMOTE_PATH_MARKER + target_path
