#!/usr/bin/env python
from __future__ import print_function, unicode_literals
import argparse
import os
import subprocess
import sys


SNIPS_PATH = os.environ.get('SNIPS_PATH', os.path.expanduser('~/.snips'))


def list_snips(path):
    for dirpath, dirnames, filenames in os.walk(path):
        for dirname in dirnames:
            if dirname.startswith('.'):
                dirnames.remove(dirname)
        subdir = dirpath[len(path) + len(os.sep):]
        for filename in filenames:
            if filename.startswith('.'):
                continue
            try:
                os.stat(os.path.join(dirpath, filename))
            except OSError as e:
                sys.stderr.write('Error reading snip: {}\n'.format(e))
                continue
            yield os.path.join(subdir, filename)


def get_snip(path, key):
    try:
        f = open(os.path.join(path, key), 'rb')
    except IOError as e:
        sys.stderr.write('Error reading snip: {}\n'.format(e))
        raise SystemExit(1)
    with f:
        return f.read()


def xclip(data, selection='clipboard'):
    cmd = ['xclip', '-selection', selection]
    p = subprocess.Popen(cmd, stdin=subprocess.PIPE)
    with p.stdin:
        p.stdin.write(data)


def cmd_list(args):
    print('\n'.join(list_snips(args.path)))


def cmd_copy(args):
    if args.stdin:
        key = sys.stdin.readline().strip()
    else:
        key = args.snip
    xclip(get_snip(args.path, key), args.selection)


def parse_args():
    parser = argparse.ArgumentParser()
    sp = parser.add_subparsers(metavar='action')
    sp.required = True

    s_list = sp.add_parser('list')
    s_list.set_defaults(func=cmd_list)

    s_copy = sp.add_parser('copy')
    g_snip = s_copy.add_mutually_exclusive_group()
    g_snip.required = True
    g_snip.add_argument(
        '--stdin', '-I', action='store_true', default=False,
        help='Read the snip to copy from standard input'
    )
    g_snip.add_argument(
        'snip', nargs='?',
        help='Snip to copy',
    )
    s_copy.add_argument(
        '--selection', '-s', default='clipboard',
        help='X11 selection (clipboard) to use',
    )
    s_copy.set_defaults(func=cmd_copy)

    parser.add_argument(
        '--path', '-p', default=SNIPS_PATH,
        help='Path to snips directory',
    )
    return parser.parse_args()


def main():
    args = parse_args()
    args.func(args)


if __name__ == '__main__':
    main()