Source code for wxyz.dvcs.tools.tool_timetravel

"""baseline tools for working with time traveling"""

import ipywidgets as W
import jinja2
import traitlets as T
from tornado.ioloop import IOLoop

from ..repos.repo_base import Repo

CSS_PREFIX = "jp-wxyz-dvcs-tool-timetravel"

DEFAULT_OPTIONS = [("No History", 0)]

DEFAULT_OPTION_TMPL = """
[{{ commit[:7] }}] {{ message }} by {{ author.name }} {{ timestamp }}
""".strip()


class TimeTraveler(W.HBox):
    """Show a selection widget"""

    # pylint: disable=unused-argument
    repo = T.Instance(Repo)
    commits = T.Instance(W.DOMWidget)
    enabled = T.Bool(default_value=False)
    enable_chk = T.Instance(W.DOMWidget)
    _commits_cls = W.SelectionSlider
    _option_tmpl = jinja2.Template(DEFAULT_OPTION_TMPL)

    def __init__(self, *args, **kwargs):
        if "layout" not in kwargs:
            kwargs["layout"] = dict(
                flex="1",
                display="flex",
            )
        super().__init__(*args, **kwargs)
        T.dlink(
            (self.repo, "head_history"),
            (self.commits, "options"),
            self._update_history_options,
        )
        T.dlink(
            (self, "enabled"),
            (self.commits.layout, "display"),
            {True: "flex", False: "none"}.get,
        )
        T.link((self, "enabled"), (self.enable_chk, "value"))
        self._dom_classes += (f"{CSS_PREFIX}-box",)
        self.commits.observe(self._on_change_commit, "value")
        self.repo.observe(self._on_head_hash_change, "head_hash")
        self.children = [self.enable_chk, self.commits]

    def _on_change_commit(self, change):
        """revert to the selected commit"""
        if not self.enabled or change.new is None:
            return
        self.repo.revert(change.new)

    def _on_head_hash_change(self, _change=None):
        head_hash = str(self.repo.head_hash)

        if head_hash is None:
            return

        options = self._update_history_options(self.repo.head_history)

        if options:
            self.commits.options = options

        if head_hash not in dict(options).values():
            IOLoop.current().add_callback(self._on_head_hash_change)
            return

        self.commits.value = head_hash

    @T.default("commits")
    def _make_default_commits(self):
        """create a default commit selector"""
        return self._commits_cls(
            options=DEFAULT_OPTIONS, layout=dict(width="80%", flex="1"), rows=1
        )

    def _update_history_options(self, history):
        """nicely format the commit history"""
        return [(self._option_tmpl.render(**h), str(h["commit"])) for h in history][
            ::-1
        ] or DEFAULT_OPTIONS

    @T.default("enable_chk")
    def _default_enable_chk(self):
        checkbox = W.Checkbox(description="Time Travel", layout=dict(flex="0"))
        checkbox.add_class("jp-wxyz-dvcs-timetravel")
        return checkbox