#!/usr/bin/env nix-shell
#!nix-shell -i python3 -p "python3.withPackages(ps: with ps; [ ])" nix
"""
A program to remove old aliases or convert old aliases to throws
Example usage:
./maintainers/scripts/remove-old-aliases.py --year 2018 --file ./pkgs/top-level/aliases.nix
Check this file with mypy after every change!
$ mypy --strict maintainers/scripts/remove-old-aliases.py
"""
import argparse
import shutil
import subprocess
from datetime import date as datetimedate
from datetime import datetime
from pathlib import Path
def process_args() -> argparse.Namespace:
"""process args"""
arg_parser = argparse.ArgumentParser()
arg_parser.add_argument(
"--year", required=True, type=int, help="operate on aliases older than $year"
)
arg_parser.add_argument(
"--month",
type=int,
default=1,
help="operate on aliases older than $year-$month",
)
arg_parser.add_argument(
"--only-throws",
action="store_true",
help="only operate on throws. e.g remove throws older than $date",
)
arg_parser.add_argument("--file", required=True, type=Path, help="alias file")
arg_parser.add_argument(
"--dry-run", action="store_true", help="don't modify files, only print results"
)
return arg_parser.parse_args()
def get_date_lists(
txt: list[str], cutoffdate: datetimedate, only_throws: bool
) -> tuple[list[str], list[str], list[str]]:
"""get a list of lines in which the date is older than $cutoffdate"""
date_older_list: list[str] = []
date_older_throw_list: list[str] = []
date_sep_line_list: list[str] = []
for lineno, line in enumerate(txt, start=1):
line = line.rstrip()
my_date = None
for string in line.split():
string = string.strip(":")
try:
# strip ':' incase there is a string like 2019-11-01:
my_date = datetime.strptime(string, "%Y-%m-%d").date()
except ValueError:
try:
my_date = datetime.strptime(string, "%Y-%m").date()
except ValueError:
continue
if (
my_date is None
or my_date > cutoffdate
or "preserve, reason:" in line.lower()
):
continue
if "=" not in line:
date_sep_line_list.append(f"{lineno} {line}")
# 'if' lines could be complicated
elif "if " in line and "if =" not in line:
print(f"RESOLVE MANUALLY {line}")
elif "throw" in line:
date_older_throw_list.append(line)
elif not only_throws:
date_older_list.append(line)
return (
date_older_list,
date_sep_line_list,
date_older_throw_list,
)
def convert_to_throw(date_older_list: list[str]) -> list[tuple[str, str]]:
"""convert a list of lines to throws"""
converted_list = []
for line in date_older_list.copy():
indent: str = " " * (len(line) - len(line.lstrip()))
before_equal = ""
after_equal = ""
try:
before_equal, after_equal = (x.strip() for x in line.split("=", maxsplit=2))
except ValueError as err:
print(err, line, "\n")
date_older_list.remove(line)
continue
alias = before_equal.strip()
after_equal_list = [x.strip(";:") for x in after_equal.split()]
converted = (
f"{indent}{alias} = throw \"'{alias}' has been renamed to/replaced by"
f" '{after_equal_list.pop(0)}'\";"
f' # Converted to throw {datetime.today().strftime("%Y-%m-%d")}'
)
converted_list.append((line, converted))
return converted_list
def generate_text_to_write(
txt: list[str],
date_older_list: list[str],
converted_to_throw: list[tuple[str, str]],
date_older_throw_list: list[str],
) -> list[str]:
"""generate a list of text to be written to the aliasfile"""
text_to_write: list[str] = []
for line in txt:
text_to_append: str = ""
if converted_to_throw:
for tupl in converted_to_throw:
if line == tupl[0]:
text_to_append = f"{tupl[1]}\n"
if line not in date_older_list and line not in date_older_throw_list:
text_to_append = f"{line}\n"
if text_to_append:
text_to_write.append(text_to_append)
return text_to_write
def write_file(
aliasfile: Path,
text_to_write: list[str],
) -> None:
"""write file"""
temp_aliasfile = Path(f"{aliasfile}.raliases")
with open(temp_aliasfile, "w", encoding="utf-8") as far:
for line in text_to_write:
far.write(line)
print("\nChecking the syntax of the new aliasfile")
try:
subprocess.run(
["nix-instantiate", "--eval", temp_aliasfile],
check=True,
stdout=subprocess.DEVNULL,
)
except subprocess.CalledProcessError:
print(
"\nSyntax check failed,",
"there may have been a line which only has\n"
'aliasname = "reason why";\n'
"when it should have been\n"
'aliasname = throw "reason why";',
)
temp_aliasfile.unlink()
return
shutil.move(f"{aliasfile}.raliases", aliasfile)
print(f"{aliasfile} modified! please verify with 'git diff'.")
def main() -> None:
"""main"""
args = process_args()
only_throws = args.only_throws
aliasfile = Path(args.file).absolute()
cutoffdate = (datetime.strptime(f"{args.year}-{args.month}-01", "%Y-%m-%d")).date()
txt: list[str] = (aliasfile.read_text(encoding="utf-8")).splitlines()
date_older_list: list[str] = []
date_sep_line_list: list[str] = []
date_older_throw_list: list[str] = []
date_older_list, date_sep_line_list, date_older_throw_list = get_date_lists(
txt, cutoffdate, only_throws
)
converted_to_throw: list[tuple[str, str]] = []
if date_older_list:
converted_to_throw = convert_to_throw(date_older_list)
print(" Will be converted to throws. ".center(100, "-"))
for l_n in date_older_list:
print(l_n)
if date_older_throw_list:
print(" Will be removed. ".center(100, "-"))
for l_n in date_older_throw_list:
print(l_n)
if date_sep_line_list:
print(" On separate line, resolve manually. ".center(100, "-"))
for l_n in date_sep_line_list:
print(l_n)
if not args.dry_run:
text_to_write = generate_text_to_write(
txt, date_older_list, converted_to_throw, date_older_throw_list
)
write_file(aliasfile, text_to_write)
if __name__ == "__main__":
main()