from __future__ import unicode_literals

import subprocess
import sys

from pre_commit import color
from pre_commit import five


# TODO: smell: import side-effects
COLS = int(
    subprocess.Popen(
        ['tput', 'cols'], stdout=subprocess.PIPE
    ).communicate()[0] or
    # Default in the case of no terminal
    80
)


def get_hook_message(
        start,
        postfix='',
        end_msg=None,
        end_len=0,
        end_color=None,
        use_color=None,
        cols=COLS,
):
    """Prints a message for running a hook.

    This currently supports three approaches:

    # Print `start` followed by dots, leaving 6 characters at the end
    >>> print_hook_message('start', end_len=6)
    start...............................................................

    # Print `start` followed by dots with the end message colored if coloring
    # is specified and a newline afterwards
    >>> print_hook_message(
        'start',
        end_msg='end',
        end_color=color.RED,
        use_color=True,
    )
    start...................................................................end

    # Print `start` followed by dots, followed by the `postfix` message
    # uncolored, followed by the `end_msg` colored if specified and a newline
    # afterwards
    >>> print_hook_message(
        'start',
        postfix='postfix ',
        end_msg='end',
        end_color=color.RED,
        use_color=True,
    )
    start...........................................................postfix end
    """
    if bool(end_msg) == bool(end_len):
        raise ValueError('Expected one of (`end_msg`, `end_len`)')
    if end_msg is not None and (end_color is None or use_color is None):
        raise ValueError(
            '`end_color` and `use_color` are required with `end_msg`'
        )

    if end_len:
        return start + '.' * (cols - len(start) - end_len - 1)
    else:
        return '{0}{1}{2}{3}\n'.format(
            start,
            '.' * (cols - len(start) - len(postfix) - len(end_msg) - 1),
            postfix,
            color.format_color(end_msg, end_color, use_color),
        )


def sys_stdout_write_wrapper(s, stream=sys.stdout):
    """Python 2.6 chokes on unicode being passed to sys.stdout.write.

    This is an adapter because PY2 is ok with bytes and PY3 requires text.
    """
    assert type(s) is five.text
    if five.PY2:  # pragma: no cover (PY2)
        s = s.encode('UTF-8')
    stream.write(s)