maintainers/scripts/remove-old-aliases.py

   1 #!/usr/bin/env nix-shell
   2 #!nix-shell -i python3 -p "python3.withPackages(ps: with ps; [ ])" nix
   3 """
   4 A program to remove old aliases or convert old aliases to throws
   5 Example usage:
   6 ./maintainers/scripts/remove-old-aliases.py --year 2018 --file ./pkgs/top-level/aliases.nix
   7
   8 Check this file with mypy after every change!
   9 $ mypy --strict maintainers/scripts/remove-old-aliases.py
  10 """
  11 import argparse
  12 import shutil
  13 import subprocess
  14 from datetime import date as datetimedate
  15 from datetime import datetime
  16 from pathlib import Path
  17
  18
  19 def process_args() -> argparse.Namespace:
  20     """process args"""
  21     arg_parser = argparse.ArgumentParser()
  22     arg_parser.add_argument(
  23         "--year", required=True, type=int, help="operate on aliases older than $year"
  24     )
  25     arg_parser.add_argument(
  26         "--month",
  27         type=int,
  28         default=1,
  29         help="operate on aliases older than $year-$month",
  30     )
  31     arg_parser.add_argument(
  32         "--only-throws",
  33         action="store_true",
  34         help="only operate on throws. e.g remove throws older than $date",
  35     )
  36     arg_parser.add_argument("--file", required=True, type=Path, help="alias file")
  37     arg_parser.add_argument(
  38         "--dry-run", action="store_true", help="don't modify files, only print results"
  39     )
  40     return arg_parser.parse_args()
  41
  42
  43 def get_date_lists(
  44     txt: list[str], cutoffdate: datetimedate, only_throws: bool
  45 ) -> tuple[list[str], list[str], list[str]]:
  46     """get a list of lines in which the date is older than $cutoffdate"""
  47     date_older_list: list[str] = []
  48     date_older_throw_list: list[str] = []
  49     date_sep_line_list: list[str] = []
  50
  51     for lineno, line in enumerate(txt, start=1):
  52         line = line.rstrip()
  53         my_date = None
  54         for string in line.split():
  55             string = string.strip(":")
  56             try:
  57                 # strip ':' incase there is a string like 2019-11-01:
  58                 my_date = datetime.strptime(string, "%Y-%m-%d").date()
  59             except ValueError:
  60                 try:
  61                     my_date = datetime.strptime(string, "%Y-%m").date()
  62                 except ValueError:
  63                     continue
  64
  65         if (
  66             my_date is None
  67             or my_date > cutoffdate
  68             or "preserve, reason:" in line.lower()
  69         ):
  70             continue
  71
  72         if "=" not in line:
  73             date_sep_line_list.append(f"{lineno} {line}")
  74         # 'if' lines could be complicated
  75         elif "if " in line and "if =" not in line:
  76             print(f"RESOLVE MANUALLY {line}")
  77         elif "throw" in line:
  78             date_older_throw_list.append(line)
  79         elif not only_throws:
  80             date_older_list.append(line)
  81
  82     return (
  83         date_older_list,
  84         date_sep_line_list,
  85         date_older_throw_list,
  86     )
  87
  88
  89 def convert_to_throw(date_older_list: list[str]) -> list[tuple[str, str]]:
  90     """convert a list of lines to throws"""
  91     converted_list = []
  92     for line in date_older_list.copy():
  93         indent: str = " " * (len(line) - len(line.lstrip()))
  94         before_equal = ""
  95         after_equal = ""
  96         try:
  97             before_equal, after_equal = (x.strip() for x in line.split("=", maxsplit=2))
  98         except ValueError as err:
  99             print(err, line, "\n")
 100             date_older_list.remove(line)
 101             continue
 102
 103         alias = before_equal
 104         alias_unquoted = before_equal.strip('"')
 105         replacement = next(x.strip(";:") for x in after_equal.split())
 106         replacement = replacement.removeprefix("pkgs.")
 107
 108         converted = (
 109             f"{indent}{alias} = throw \"'{alias_unquoted}' has been"
 110             f" renamed to/replaced by '{replacement}'\";"
 111             f" # Converted to throw {datetime.today().strftime('%Y-%m-%d')}"
 112         )
 113         converted_list.append((line, converted))
 114
 115     return converted_list
 116
 117
 118 def generate_text_to_write(
 119     txt: list[str],
 120     date_older_list: list[str],
 121     converted_to_throw: list[tuple[str, str]],
 122     date_older_throw_list: list[str],
 123 ) -> list[str]:
 124     """generate a list of text to be written to the aliasfile"""
 125     text_to_write: list[str] = []
 126     for line in txt:
 127         text_to_append: str = ""
 128         if converted_to_throw:
 129             for tupl in converted_to_throw:
 130                 if line == tupl[0]:
 131                     text_to_append = f"{tupl[1]}\n"
 132         if line not in date_older_list and line not in date_older_throw_list:
 133             text_to_append = f"{line}\n"
 134         if text_to_append:
 135             text_to_write.append(text_to_append)
 136
 137     return text_to_write
 138
 139
 140 def write_file(
 141     aliasfile: Path,
 142     text_to_write: list[str],
 143 ) -> None:
 144     """write file"""
 145     temp_aliasfile = Path(f"{aliasfile}.raliases")
 146     with open(temp_aliasfile, "w", encoding="utf-8") as far:
 147         for line in text_to_write:
 148             far.write(line)
 149     print("\nChecking the syntax of the new aliasfile")
 150     try:
 151         subprocess.run(
 152             ["nix-instantiate", "--eval", temp_aliasfile],
 153             check=True,
 154             stdout=subprocess.DEVNULL,
 155         )
 156     except subprocess.CalledProcessError:
 157         print(
 158             "\nSyntax check failed,",
 159             "there may have been a line which only has\n"
 160             'aliasname = "reason why";\n'
 161             "when it should have been\n"
 162             'aliasname = throw "reason why";',
 163         )
 164         temp_aliasfile.unlink()
 165         return
 166     shutil.move(f"{aliasfile}.raliases", aliasfile)
 167     print(f"{aliasfile} modified! please verify with 'git diff'.")
 168
 169
 170 def main() -> None:
 171     """main"""
 172     args = process_args()
 173
 174     only_throws = args.only_throws
 175     aliasfile = Path(args.file).absolute()
 176     cutoffdate = (datetime.strptime(f"{args.year}-{args.month}-01", "%Y-%m-%d")).date()
 177
 178     txt: list[str] = (aliasfile.read_text(encoding="utf-8")).splitlines()
 179
 180     date_older_list: list[str] = []
 181     date_sep_line_list: list[str] = []
 182     date_older_throw_list: list[str] = []
 183
 184     date_older_list, date_sep_line_list, date_older_throw_list = get_date_lists(
 185         txt, cutoffdate, only_throws
 186     )
 187
 188     converted_to_throw: list[tuple[str, str]] = []
 189     if date_older_list:
 190         converted_to_throw = convert_to_throw(date_older_list)
 191         print(" Will be converted to throws. ".center(100, "-"))
 192         for l_n in date_older_list:
 193             print(l_n)
 194
 195     if date_older_throw_list:
 196         print(" Will be removed. ".center(100, "-"))
 197         for l_n in date_older_throw_list:
 198             print(l_n)
 199
 200     if date_sep_line_list:
 201         print(" On separate line, resolve manually. ".center(100, "-"))
 202         for l_n in date_sep_line_list:
 203             print(l_n)
 204
 205     if not args.dry_run:
 206         text_to_write = generate_text_to_write(
 207             txt, date_older_list, converted_to_throw, date_older_throw_list
 208         )
 209         write_file(aliasfile, text_to_write)
 210
 211
 212 if __name__ == "__main__":
 213     main()