dotfiles/.scripts/lazygit_modify_commit_date.py

#!/usr/bin/env python3
from logging import NOTSET, basicConfig, debug
from subprocess import check_output
from sys import argv
from re import sub, MULTILINE


def run(args: list[str], env: dict):
    return check_output(args, env=env)


if __name__ == "__main__":
    basicConfig(level=NOTSET)
    debug(f"Called with parameters {argv}")
    if argv[1] == "commit":
        _, _, form_commit, form_following, form_timestamp = tuple(argv)
        if form_following == "following":
            is_form_root = not check_output(
                ["git", "log", "-1", "--format=%P", form_commit]
            ).strip()
            rev_list_args = ["git", "rev-list", "HEAD"] if is_form_root else ["git", "rev-list", form_commit + "^..HEAD"]
            commits = (
                commit
                for commit in check_output(rev_list_args)
                .decode("utf-8")
                .split("\n")
                if len(commit) > 1
            )
        else:
            commits = [form_commit]
        for commit in commits:
            previous_data = [
                run(["git", "log", "-1", f'--pretty="%{attribute}"', commit], {})
                for attribute in ["an", "ae", "cn", "ce"]
            ]
            author_name, author_email, committer_name, committer_email = tuple(
                previous_data
            )
            env = {
                "GIT_SEQUENCE_EDITOR": f"/usr/bin/env python3 {__file__}",
                "GIT_COMMITTER_DATE": form_timestamp,
                "GIT_AUTHOR_NAME": author_name,
                "GIT_AUTHOR_EMAIL": author_email,
                "GIT_COMMITTER_NAME": committer_name,
                "GIT_COMMITTER_EMAIL": committer_email,
            }
            is_root = not run(
                ["git", "log", "-1", "--format=%P", commit], {}
            ).strip()
            run(
                [
                    "git",
                    "rebase",
                    "--interactive",
                    "--autostash",
                    "--keep-empty",
                    "--no-autosquash",
                    "--rebase-merges",
                ]
                + (["--root"] if is_root else [f"{commit}~"]),
                env,
            )
            run(
                [
                    "git",
                    "commit",
                    "--allow-empty",
                    "--only",
                    "--no-edit",
                    "--amend",
                    "--no-verify",
                    f'--date="{form_timestamp}"',
                ],
                env,
            )
            run(
                [
                    "git",
                    "rebase",
                    "--continue",
                ],
                env,
            )
    else:
        path = argv[-1]
        file = open(path, "r")
        content = sub("^pick ", "edit ", file.read(), 1, flags=MULTILINE)
        file.close()
        file = open(path, "w")
        file.write(content)
        file.close()