indent

#!/usr/bin/env python3
import sys
import os
import tempfile

import click


def get_terminal_size(fallback=(80, 24)):
    for i in range(0, 3):
        try:
            columns, rows = os.get_terminal_size(i)
        except OSError:
            continue
        break
    else:
        columns, rows = fallback
    return columns, rows


@click.command()
@click.argument('input', required=False, type=click.File('r'))
@click.argument('output', required=False, type=click.File('w'))
@click.option('-tmp', 'tmp', help='pipe to tmp file', is_flag=True)
def cli(input, output, tmp):
    """Simple, pipeable tool for indenting text"""
    columns, _ = get_terminal_size()
    source = input.readlines() if input else list(sys.stdin)
    max_line = len(sorted(source, key=len, reverse=True)[0])
    indent_size = int((columns - max_line) / 2)
    format_ = '{}{{}}\n'.format(indent_size * ' ')
    if tmp:
        filename = tempfile.mktemp()
        with open(filename, 'w') as f:
            f.write(''.join(format_.format(l.strip('\n')) for l in source))
            f.write(str(columns))
        sys.stdout.write(filename)
        return
    for line in source:
        text = format_.format(line.strip())
        if output:
            output.write(text)
        else:
            sys.stdout.write(text)


if __name__ == "__main__":
    cli()