"""cliutil - Utilities for CLI tools"""

PKGNAME = 'conservancy_beancount'

LICENSE = """

Copyright © 2020  Brett Smith

This program is free software: you can redistribute it and/or modify

it under the terms of the GNU Affero General Public License as published by

the Free Software Foundation, either version 3 of the License, or

(at your option) any later version.

This program is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

GNU Affero General Public License for more details.

You should have received a copy of the GNU Affero General Public License

along with this program.  If not, see <https://www.gnu.org/licenses/>."""

import argparse

import enum

import logging

import operator

import os

import pkg_resources

import signal

import sys

import traceback

import types

from typing import (

    Any,

    Iterable,

    NoReturn,

    Optional,

    Sequence,

    TextIO,

    Type,

    Union,

)

VERSION = pkg_resources.require(PKGNAME)[0].version

class ExceptHook:

    def __init__(self,

                 logger: Optional[logging.Logger]=None,

                 default_exitcode: int=3,

    ) -> None:

        if logger is None:

            logger = logging.getLogger()

        self.logger = logger

        self.default_exitcode = default_exitcode

    def __call__(self,

                 exc_type: Type[BaseException],

                 exc_value: BaseException,

                 exc_tb: types.TracebackType,

    ) -> NoReturn:

        exitcode = self.default_exitcode

        if isinstance(exc_value, KeyboardInterrupt):

            signal.signal(signal.SIGINT, signal.SIG_DFL)

            os.kill(0, signal.SIGINT)

            signal.pause()

        elif isinstance(exc_value, OSError):

            exitcode += 1

            msg = "I/O error: {e.filename}: {e.strerror}".format(e=exc_value)

        else:

            parts = [type(exc_value).__name__, *exc_value.args]

            msg = "internal " + ": ".join(parts)

        self.logger.critical(msg)

        self.logger.debug(

            ''.join(traceback.format_exception(exc_type, exc_value, exc_tb)),

        )

        raise SystemExit(exitcode)

class InfoAction(argparse.Action):

    def __call__(self,

                 parser: argparse.ArgumentParser,

                 namespace: argparse.Namespace,

                 values: Union[Sequence[Any], str, None]=None,

                 option_string: Optional[str]=None,

    ) -> NoReturn:

        if isinstance(self.const, str):

            info = self.const

            exitcode = 0

        else:

            info, exitcode = self.const

        print(info)

        raise SystemExit(exitcode)

class LogLevel(enum.IntEnum):

    DEBUG = logging.DEBUG

    INFO = logging.INFO

    WARNING = logging.WARNING

    ERROR = logging.ERROR

    CRITICAL = logging.CRITICAL

    WARN = WARNING

    ERR = ERROR

    CRIT = CRITICAL

    @classmethod

    def from_arg(cls, arg: str) -> int:

        try:

            return cls[arg.upper()].value

        except KeyError:

            raise ValueError(f"unknown loglevel {arg!r}") from None

    @classmethod

    def choices(cls) -> Iterable[str]:

        for level in sorted(cls, key=operator.attrgetter('value')):

            yield level.name.lower()

def add_loglevel_argument(parser: argparse.ArgumentParser,

                          default: LogLevel=LogLevel.INFO) -> argparse.Action:

    return parser.add_argument(

        '--loglevel',

        metavar='LEVEL',

        default=default.value,

        type=LogLevel.from_arg,

        help="Show logs at this level and above."

        f" Specify one of {', '.join(LogLevel.choices())}."

        f" Default {default.name.lower()}.",

    )

def add_version_argument(parser: argparse.ArgumentParser) -> argparse.Action:

    progname = parser.prog or sys.argv[0]

    return parser.add_argument(

        '--version', '--copyright', '--license',

        action=InfoAction,

        nargs=0,

        const=f"{progname} version {VERSION}\n{LICENSE}",

        help="Show program version and license information",

    )

def setup_logger(logger: Union[str, logging.Logger]='',

                 loglevel: int=logging.INFO,

                 stream: TextIO=sys.stderr,

                 fmt: str='%(name)s: %(levelname)s: %(message)s',

) -> logging.Logger:

    if isinstance(logger, str):

        logger = logging.getLogger(logger)

    formatter = logging.Formatter(fmt)

    handler = logging.StreamHandler(stream)

    handler.setFormatter(formatter)

    logger.addHandler(handler)

    logger.setLevel(loglevel)

    return logger

"""Test CLI utilities"""

# Copyright © 2020  Brett Smith

#

# This program is free software: you can redistribute it and/or modify

# it under the terms of the GNU Affero General Public License as published by

# the Free Software Foundation, either version 3 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU Affero General Public License for more details.

#

# You should have received a copy of the GNU Affero General Public License

# along with this program.  If not, see <https://www.gnu.org/licenses/>.

import argparse

import errno

import io

import inspect

import logging

import os

import re

import traceback

import pytest

from conservancy_beancount import cliutil

class MockTraceback:

    def __init__(self, stack=None, index=0):

        if stack is None:

            stack = inspect.stack(context=False)

        self._stack = stack

        self._index = index

        frame_record = self._stack[self._index]

        self.tb_frame = frame_record.frame

        self.tb_lineno = frame_record.lineno

    @property

    def tb_next(self):

        try:

            return type(self)(self._stack, self._index + 1)

        except IndexError:

            return None

@pytest.fixture(scope='module')

def argparser():

    parser = argparse.ArgumentParser(prog='test_cliutil')

    cliutil.add_loglevel_argument(parser)

    cliutil.add_version_argument(parser)

    return parser

@pytest.mark.parametrize('errnum', [

    errno.EACCES,

    errno.EPERM,

    errno.ENOENT,

])

def test_excepthook_oserror(errnum, caplog):

    error = OSError(errnum, os.strerror(errnum), 'TestFilename')

    with pytest.raises(SystemExit) as exc_check:

        cliutil.ExceptHook()(type(error), error, None)

    assert exc_check.value.args[0] == 4

    assert caplog.records

    for log in caplog.records:

        assert log.levelname == 'CRITICAL'

        assert log.message == f"I/O error: {error.filename}: {error.strerror}"

@pytest.mark.parametrize('exc_type', [

    AttributeError,

    RuntimeError,

    ValueError,

])

def test_excepthook_bug(exc_type, caplog):

    error = exc_type("test message")

    with pytest.raises(SystemExit) as exc_check:

        cliutil.ExceptHook()(exc_type, error, None)

    assert exc_check.value.args[0] == 3

    assert caplog.records

    for log in caplog.records:

        assert log.levelname == 'CRITICAL'

        assert log.message == f"internal {exc_type.__name__}: {error.args[0]}"

def test_excepthook_traceback(caplog):

    error = KeyError('test')

    args = (type(error), error, MockTraceback())

    caplog.set_level(logging.DEBUG)

    with pytest.raises(SystemExit) as exc_check:

        cliutil.ExceptHook()(*args)

    assert caplog.records

    assert caplog.records[-1].message == ''.join(traceback.format_exception(*args))

@pytest.mark.parametrize('arg,expected', [

    ('debug', logging.DEBUG),

    ('info', logging.INFO),

    ('warning', logging.WARNING),

    ('warn', logging.WARNING),

    ('error', logging.ERROR),

    ('err', logging.ERROR),

    ('critical', logging.CRITICAL),

    ('crit', logging.CRITICAL),

])

def test_loglevel_argument(argparser, arg, expected):

    for method in ['lower', 'title', 'upper']:

        args = argparser.parse_args(['--loglevel', getattr(arg, method)()])

        assert args.loglevel is expected

def test_setup_logger():

    stream = io.StringIO()

    logger = cliutil.setup_logger(

        'test_cliutil', logging.INFO, stream, '%(name)s %(levelname)s: %(message)s',

    )

    logger.debug("test debug")

    logger.info("test info")

    assert stream.getvalue() == "test_cliutil INFO: test info\n"

@pytest.mark.parametrize('arg', [

    '--license',

    '--version',

    '--copyright',

])

def test_version_argument(argparser, capsys, arg):

    with pytest.raises(SystemExit) as exc_check:

        args = argparser.parse_args(['--version'])

    assert exc_check.value.args[0] == 0

    stdout, _ = capsys.readouterr()

    lines = iter(stdout.splitlines())

    assert re.match(r'^test_cliutil version \d+\.\d+\.\d+', next(lines, "<EOF>"))