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.strip()
 104         after_equal_list = [x.strip(";:") for x in after_equal.split()]
 105
 106         converted = (
 107             f"{indent}{alias} = throw \"'{alias}' has been renamed to/replaced by"
 108             f" '{after_equal_list.pop(0)}'\";"
 109             f' # Converted to throw {datetime.today().strftime("%Y-%m-%d")}'
 110         )
 111         converted_list.append((line, converted))
 112
 113     return converted_list
 114
 115
 116 def generate_text_to_write(
 117     txt: list[str],
 118     date_older_list: list[str],
 119     converted_to_throw: list[tuple[str, str]],
 120     date_older_throw_list: list[str],
 121 ) -> list[str]:
 122     """generate a list of text to be written to the aliasfile"""
 123     text_to_write: list[str] = []
 124     for line in txt:
 125         text_to_append: str = ""
 126         if converted_to_throw:
 127             for tupl in converted_to_throw:
 128                 if line == tupl[0]:
 129                     text_to_append = f"{tupl[1]}\n"
 130         if line not in date_older_list and line not in date_older_throw_list:
 131             text_to_append = f"{line}\n"
 132         if text_to_append:
 133             text_to_write.append(text_to_append)
 134
 135     return text_to_write
 136
 137
 138 def write_file(
 139     aliasfile: Path,
 140     text_to_write: list[str],
 141 ) -> None:
 142     """write file"""
 143     temp_aliasfile = Path(f"{aliasfile}.raliases")
 144     with open(temp_aliasfile, "w", encoding="utf-8") as far:
 145         for line in text_to_write:
 146             far.write(line)
 147     print("\nChecking the syntax of the new aliasfile")
 148     try:
 149         subprocess.run(
 150             ["nix-instantiate", "--eval", temp_aliasfile],
 151             check=True,
 152             stdout=subprocess.DEVNULL,
 153         )
 154     except subprocess.CalledProcessError:
 155         print(
 156             "\nSyntax check failed,",
 157             "there may have been a line which only has\n"
 158             'aliasname = "reason why";\n'
 159             "when it should have been\n"
 160             'aliasname = throw "reason why";',
 161         )
 162         temp_aliasfile.unlink()
 163         return
 164     shutil.move(f"{aliasfile}.raliases", aliasfile)
 165     print(f"{aliasfile} modified! please verify with 'git diff'.")
 166
 167
 168 def main() -> None:
 169     """main"""
 170     args = process_args()
 171
 172     only_throws = args.only_throws
 173     aliasfile = Path(args.file).absolute()
 174     cutoffdate = (datetime.strptime(f"{args.year}-{args.month}-01", "%Y-%m-%d")).date()
 175
 176     txt: list[str] = (aliasfile.read_text(encoding="utf-8")).splitlines()
 177
 178     date_older_list: list[str] = []
 179     date_sep_line_list: list[str] = []
 180     date_older_throw_list: list[str] = []
 181
 182     date_older_list, date_sep_line_list, date_older_throw_list = get_date_lists(
 183         txt, cutoffdate, only_throws
 184     )
 185
 186     converted_to_throw: list[tuple[str, str]] = []
 187     if date_older_list:
 188         converted_to_throw = convert_to_throw(date_older_list)
 189         print(" Will be converted to throws. ".center(100, "-"))
 190         for l_n in date_older_list:
 191             print(l_n)
 192
 193     if date_older_throw_list:
 194         print(" Will be removed. ".center(100, "-"))
 195         for l_n in date_older_throw_list:
 196             print(l_n)
 197
 198     if date_sep_line_list:
 199         print(" On separate line, resolve manually. ".center(100, "-"))
 200         for l_n in date_sep_line_list:
 201             print(l_n)
 202
 203     if not args.dry_run:
 204         text_to_write = generate_text_to_write(
 205             txt, date_older_list, converted_to_throw, date_older_throw_list
 206         )
 207         write_file(aliasfile, text_to_write)
 208
 209
 210 if __name__ == "__main__":
 211     main()