pferd/PFERD/cli/parser.py
2021-05-25 14:23:38 +02:00

219 lines
6.4 KiB
Python

import argparse
import configparser
from argparse import ArgumentTypeError
from pathlib import Path
from typing import Any, Callable, List, Optional, Sequence, Union
from ..output_dir import OnConflict, Redownload
from ..version import NAME, VERSION
# TODO Replace with argparse version when updating to 3.9?
class BooleanOptionalAction(argparse.Action):
def __init__(
self,
option_strings: List[str],
dest: Any,
default: Any = None,
type: Any = None,
choices: Any = None,
required: Any = False,
help: Any = None,
metavar: Any = None,
):
if len(option_strings) != 1:
raise ValueError("There must be exactly one option string")
[self.name] = option_strings
if not self.name.startswith("--"):
raise ValueError(f"{self.name!r} doesn't start with '--'")
if self.name.startswith("--no-"):
raise ValueError(f"{self.name!r} starts with '--no-'")
options = [self.name, "--no-" + self.name[2:]]
super().__init__(
options,
dest,
nargs=0,
default=default,
type=type,
choices=choices,
required=required,
help=help,
metavar=metavar,
)
def __call__(
self,
parser: argparse.ArgumentParser,
namespace: argparse.Namespace,
values: Union[str, Sequence[Any], None],
option_string: Optional[str] = None,
) -> None:
if option_string and option_string in self.option_strings:
value = not option_string.startswith("--no-")
setattr(namespace, self.dest, value)
def format_usage(self) -> str:
return "--[no-]" + self.name[2:]
def show_value_error(inner: Callable[[str], Any]) -> Callable[[str], Any]:
"""
Some validation functions (like the from_string in our enums) raise a ValueError.
Argparse only pretty-prints ArgumentTypeErrors though, so we need to wrap our ValueErrors.
"""
def wrapper(input: str) -> Any:
try:
return inner(input)
except ValueError as e:
raise ArgumentTypeError(e)
return wrapper
CRAWLER_PARSER = argparse.ArgumentParser(add_help=False)
CRAWLER_PARSER_GROUP = CRAWLER_PARSER.add_argument_group(
title="general crawler arguments",
description="arguments common to all crawlers",
)
CRAWLER_PARSER_GROUP.add_argument(
"--redownload", "-r",
type=show_value_error(Redownload.from_string),
metavar="OPTION",
help="when to download a file that's already present locally"
)
CRAWLER_PARSER_GROUP.add_argument(
"--on-conflict",
type=show_value_error(OnConflict.from_string),
metavar="OPTION",
help="what to do when local and remote files or directories differ"
)
CRAWLER_PARSER_GROUP.add_argument(
"--transform", "-T",
action="append",
type=str,
metavar="RULE",
help="add a single transformation rule. Can be specified multiple times"
)
CRAWLER_PARSER_GROUP.add_argument(
"--tasks", "-n",
type=int,
metavar="N",
help="maximum number of concurrent tasks (crawling, downloading)"
)
CRAWLER_PARSER_GROUP.add_argument(
"--downloads", "-N",
type=int,
metavar="N",
help="maximum number of tasks that may download data at the same time"
)
CRAWLER_PARSER_GROUP.add_argument(
"--task-delay", "-d",
type=float,
metavar="SECONDS",
help="time the crawler should wait between subsequent tasks"
)
CRAWLER_PARSER_GROUP.add_argument(
"--windows-paths",
action=BooleanOptionalAction,
help="whether to repair invalid paths on windows"
)
def load_crawler(
args: argparse.Namespace,
section: configparser.SectionProxy,
) -> None:
if args.redownload is not None:
section["redownload"] = args.redownload.value
if args.on_conflict is not None:
section["on_conflict"] = args.on_conflict.value
if args.transform is not None:
section["transform"] = "\n" + "\n".join(args.transform)
if args.tasks is not None:
section["tasks"] = str(args.tasks)
if args.downloads is not None:
section["downloads"] = str(args.downloads)
if args.task_delay is not None:
section["task_delay"] = str(args.task_delay)
if args.windows_paths is not None:
section["windows_paths"] = "yes" if args.windows_paths else "no"
PARSER = argparse.ArgumentParser()
PARSER.set_defaults(command=None)
PARSER.add_argument(
"--version",
action="version",
version=f"{NAME} {VERSION}",
)
PARSER.add_argument(
"--config", "-c",
type=Path,
metavar="PATH",
help="custom config file"
)
PARSER.add_argument(
"--dump-config",
nargs="?",
const=True,
metavar="PATH",
help="dump current configuration to a file and exit."
" Uses default config file path if no path is specified"
)
PARSER.add_argument(
"--crawler", "-C",
action="append",
type=str,
metavar="NAME",
help="only execute a single crawler."
" Can be specified multiple times to execute multiple crawlers"
)
PARSER.add_argument(
"--working-dir",
type=Path,
metavar="PATH",
help="custom working directory"
)
PARSER.add_argument(
"--explain",
action=BooleanOptionalAction,
help="log and explain in detail what PFERD is doing"
)
PARSER.add_argument(
"--status",
action=BooleanOptionalAction,
help="print status updates while PFERD is crawling"
)
PARSER.add_argument(
"--report",
action=BooleanOptionalAction,
help="print a report of all local changes before exiting"
)
PARSER.add_argument(
"--share-cookies",
action=BooleanOptionalAction,
help="whether crawlers should share cookies where applicable"
)
def load_default_section(
args: argparse.Namespace,
parser: configparser.ConfigParser,
) -> None:
section = parser[parser.default_section]
if args.working_dir is not None:
section["working_dir"] = str(args.working_dir)
if args.explain is not None:
section["explain"] = "yes" if args.explain else "no"
if args.status is not None:
section["status"] = "yes" if args.status else "no"
if args.report is not None:
section["report"] = "yes" if args.report else "no"
if args.share_cookies is not None:
section["share_cookies"] = "yes" if args.share_cookies else "no"
SUBPARSERS = PARSER.add_subparsers(title="crawlers")