#! /usr/bin/python

import logging
import optparse
import os
import sys

import libdelete

logger = logging.getLogger('lsdel')
whoami = os.path.basename(sys.argv[0])

def debug_callback(option, opt_str, value, parser):
    """
    An OptionParser callback that enables debugging.
    """
    all_loggers = [logger.name, 'libdelete']
    loggers = [x.strip() for x in value.split(',')]
    if value.lower() == 'all':
        loggers = all_loggers
    else:
        if not set(loggers) == set(all_loggers):
            parser.error('Valid debug targets: {0}'.format(
                    ", ".join(all_loggers)))
    for l in loggers:
        logging.getLogger(l).setLevel(logging.DEBUG)

def perror(message, **kwargs):
    """
    Format an error message, log it in the debug log
    and maybe also print it to stderr.
    """
    should_print = not kwargs.pop('_maybe', False)
    msg = "{0}: {1}".format(whoami, message.format(**kwargs))
    logger.debug("Error: %s", msg)
    if should_print:
        print >>sys.stderr, msg

def parse_options():
    parser = optparse.OptionParser(usage="%prog [options] filename ...")
    parser.add_option(
        "-1", dest="singlecolumn", action="store_true", default=False,
        help="Force single-column output")
    parser.add_option(
        "-C", dest="multicolumn", action="store_true", default=False,
        help="Force multicolumn output (default when stdout is a tty)")
    parser.add_option(
        "-d", dest="dirsonly", action="store_true", default=False,
        help="List directory names, not contents")
    parser.add_option(
        "-r", dest="recursive", action="store_true", default=False,
        help="recursive")
    parser.add_option(
        "-t", dest="timev", action="store", type="int", default=0,
        help="Only list n-day-or-older files", metavar="n")
    parser.add_option(
        "-y", dest="yieldsize", action="store_true", default=False,
        help="Report total space taken up by files")
    parser.add_option(
        "-s", dest="f_links", action="store_true", default=False,
        help="Follow symlinks to directories")
    parser.add_option(
        "-m", dest="f_mounts", action="store_true", default=False,
        help="Follow mount points")
    parser.add_option(
        "--debug", action="callback", type='string', help="Enable debugging (logger target or 'all')",
        callback=debug_callback, metavar='target')
    (options, args) = parser.parse_args()
    if options.singlecolumn and options.multicolumn:
        parser.error("-C and -1 are mutually exclusive")
    if not options.singlecolumn and not options.multicolumn:
        options.singlecolumn = not sys.stdout.isatty()
    # We really only need to this for mutual exclusivity
    delattr(options, 'multicolumn')
    return (options, args)

def main():
    rv = 0
    (options, args) = parse_options()
    if len(args) < 1:
        args.append('.')
    deleted_files = []
    for filename in args:
        try:
            deleted_files += libdelete.find_deleted_files(
                filename,
                follow_links=options.f_links,
                follow_mounts=options.f_mounts,
                recurse_undeleted_subdirs=options.recursive or None,
                recurse_deleted_subdirs= not options.dirsonly,
                n_days=options.timev)
        except libdelete.DeleteError as e:
            perror(e.message)
            rv = 1

    print libdelete.format_columns(sorted(
            [libdelete.relpath(
                    libdelete.undeleted_name(x)) for x in deleted_files]),
                                   options.singlecolumn)
    if options.yieldsize:
        total = None
        try:
            total = sum([os.path.getsize(x) for x in deleted_files])
        except OSError as e:
            perror('{filename}: {error} while getting size',
                   filename=e.filename, error=e.strerror)
            rv = 1

        if total is None:
            perror('Unable to display total size: errors occurred during calculation.')
        else:
            print "\nTotal space taken up by files: %dKB" % round((float(total) / 1024))
    return rv

if __name__ == "__main__":
    logging.basicConfig(level=logging.WARNING)
    sys.exit(main())