# Copyright Jonathan Hartley 2013. BSD 3-Clause license, see LICENSE file.
import atexit
import contextlib
import sys

from .ansitowin32 import AnsiToWin32


def _wipe_internal_state_for_tests():
    global orig_stdout, orig_stderr
    orig_stdout = None
    orig_stderr = None

    global wrapped_stdout, wrapped_stderr
    wrapped_stdout = None
    wrapped_stderr = None

    global atexit_done
    atexit_done = False

    global fixed_windows_console
    fixed_windows_console = False

    try:
        # no-op if it wasn't registered
        atexit.unregister(reset_all)
    except AttributeError:
        # python 2: no atexit.unregister. Oh well, we did our best.
        pass


def reset_all():
    if AnsiToWin32 is not None:    # Issue #74: objects might become None at exit
        AnsiToWin32(orig_stdout).reset_all()


def init(autoreset=False, convert=None, strip=None, wrap=True):

    if not wrap and any([autoreset, convert, strip]):
        raise ValueError('wrap=False conflicts with any other arg=True')

    global wrapped_stdout, wrapped_stderr
    global orig_stdout, orig_stderr

    orig_stdout = sys.stdout
    orig_stderr = sys.stderr

    if sys.stdout is None:
        wrapped_stdout = None
    else:
        sys.stdout = wrapped_stdout = \
            wrap_stream(orig_stdout, convert, strip, autoreset, wrap)
    if sys.stderr is None:
        wrapped_stderr = None
    else:
        sys.stderr = wrapped_stderr = \
            wrap_stream(orig_stderr, convert, strip, autoreset, wrap)

    global atexit_done
    if not atexit_done:
        atexit.register(reset_all)
        atexit_done = True


def deinit():
    if orig_stdout is not None:
        sys.stdout = orig_stdout
    if orig_stderr is not None:
        sys.stderr = orig_stderr


def just_fix_windows_console():
    global fixed_windows_console

    if sys.platform != "win32":
        return
    if fixed_windows_console:
        return
    if wrapped_stdout is not None or wrapped_stderr is not None:
        # Someone already ran init() and it did stuff, so we won't second-guess them
        return

    # On newer versions of Windows, AnsiToWin32.__init__ will implicitly enable the
    # native ANSI support in the console as a side-effect. We only need to actually
    # replace sys.stdout/stderr if we're in the old-style conversion mode.
    new_stdout = AnsiToWin32(sys.stdout, convert=None, strip=None, autoreset=False)
    if new_stdout.convert:
        sys.stdout = new_stdout
    new_stderr = AnsiToWin32(sys.stderr, convert=None, strip=None, autoreset=False)
    if new_stderr.convert:
        sys.stderr = new_stderr

    fixed_windows_console = True

@contextlib.contextmanager
def colorama_text(*args, **kwargs):
    init(*args, **kwargs)
    try:
        yield
    finally:
        deinit()


def reinit():
    if wrapped_stdout is not None:
        sys.stdout = wrapped_stdout
    if wrapped_stderr is not None:
        sys.stderr = wrapped_stderr


def wrap_stream(stream, convert, strip, autoreset, wrap):
    if wrap:
        wrapper = AnsiToWin32(stream,
            convert=convert, strip=strip, autoreset=autoreset)
        if wrapper.should_wrap():
            stream = wrapper.stream
    return stream


# Use this for initial setup as well, to reduce code duplication
_wipe_internal_state_for_tests()