# This file is part of beets.
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.

from beets.dbcore import FieldQuery
from beets.plugins import BeetsPlugin
from beets.ui import Subcommand, decargs, print_
from collections import deque
from itertools import islice


def lslimit(lib, opts, args):
    """Query command with head/tail"""

    if (opts.head is not None) and (opts.tail is not None):
        raise ValueError("Only use one of --head and --tail")
    if (opts.head or opts.tail or 0) < 0:
        raise ValueError("Limit value must be non-negative")

    query = decargs(args)
    if opts.album:
        objs = lib.albums(query)
    else:
        objs = lib.items(query)

    if opts.head is not None:
        objs = islice(objs, opts.head)
    elif opts.tail is not None:
        objs = deque(objs, opts.tail)

    for obj in objs:
        print_(format(obj))


lslimit_cmd = Subcommand(
    "lslimit",
    help="query with optional head or tail"
)

lslimit_cmd.parser.add_option(
    '--head',
    action='store',
    type="int",
    default=None
)

lslimit_cmd.parser.add_option(
    '--tail',
    action='store',
    type="int",
    default=None
)

lslimit_cmd.parser.add_all_common_options()
lslimit_cmd.func = lslimit


class LimitPlugin(BeetsPlugin):
    """Query limit functionality via command and query prefix
    """

    def commands(self):
        return [lslimit_cmd]

    def queries(self):

        class HeadQuery(FieldQuery):
            """This inner class pattern allows the query to track state
            """
            n = 0
            N = None

            @classmethod
            def value_match(cls, pattern, value):

                if cls.N is None:
                    cls.N = int(pattern)
                    if cls.N < 0:
                        raise ValueError("Limit value must be non-negative")

                cls.n += 1
                return cls.n <= cls.N

        return {
            "<": HeadQuery
        }