# Copyright 2014 - Mirantis, Inc.
# All Rights Reserved
#
#    Licensed under the Apache License, Version 2.0 (the "License"); you may
#    not use this file except in compliance with the License. You may obtain
#    a copy of the License at
#
#         http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
#    License for the specific language governing permissions and limitations
#    under the License.
#

import abc
import textwrap

from osc_lib.command import command
import six


DEFAULT_LIMIT = 100


@six.add_metaclass(abc.ABCMeta)
class MistralFormatter(object):
    COLUMNS = []

    @classmethod
    def fields(cls):
        return [c[0] for c in cls.COLUMNS]

    @classmethod
    def headings(cls):
        return [c[1] for c in cls.COLUMNS]

    @classmethod
    def format_list(cls, instance=None):
        return cls.format(instance, lister=True)

    @staticmethod
    def format(instance=None, lister=False):
        pass


@six.add_metaclass(abc.ABCMeta)
class MistralLister(command.Lister):
    @abc.abstractmethod
    def _get_format_function(self):
        raise NotImplementedError

    def get_parser(self, parsed_args):
        parser = super(MistralLister, self).get_parser(parsed_args)

        parser.add_argument(
            '--marker',
            type=str,
            help='The last execution uuid of the previous page, displays list '
                 'of executions after "marker".',
            default='',
            nargs='?'
        )
        parser.add_argument(
            '--limit',
            type=int,
            help='Maximum number of entries to return in a single result. ',
            nargs='?'
        )
        parser.add_argument(
            '--sort_keys',
            help='Comma-separated list of sort keys to sort results by. '
                 'Default: created_at. '
                 'Example: mistral execution-list --sort_keys=id,description',
            default='created_at',
            nargs='?'
        )
        parser.add_argument(
            '--sort_dirs',
            help='Comma-separated list of sort directions. Default: asc. '
                 'Example: mistral execution-list --sort_keys=id,description '
                 '--sort_dirs=asc,desc',
            default='asc',
            nargs='?'
        )
        parser.add_argument(
            '--filter',
            dest='filters',
            action='append',
            help='Filters. Can be repeated.'
        )

        return parser

    @abc.abstractmethod
    def _get_resources(self, parsed_args):
        """Gets a list of API resources (e.g. using client)."""
        raise NotImplementedError

    def _validate_parsed_args(self, parsed_args):
        # No-op by default.
        pass

    def take_action(self, parsed_args):
        self._validate_parsed_args(parsed_args)

        f = self._get_format_function()

        ret = self._get_resources(parsed_args)
        if not isinstance(ret, list):
            ret = [ret]

        data = [f(r)[1] for r in ret]

        if data:
            return f()[0], data
        else:
            return f()


@six.add_metaclass(abc.ABCMeta)
class MistralExecutionLister(MistralLister):
    def get_parser(self, parsed_args):
        parser = super(MistralExecutionLister, self).get_parser(parsed_args)
        parser.set_defaults(limit=DEFAULT_LIMIT)
        parser.add_argument(
            '--oldest',
            help='Display the executions starting from the oldest entries '
                 'instead of the newest',
            default=False,
            action='store_true'
        )

        return parser

    def take_action(self, parsed_args):
        self._validate_parsed_args(parsed_args)

        f = self._get_format_function()

        reverse_results = False
        if (parsed_args.marker == '' and parsed_args.sort_dirs == 'asc' and
            parsed_args.sort_keys == 'created_at' and
                not parsed_args.oldest):
            reverse_results = True
            parsed_args.sort_dirs = 'desc'

        ret = self._get_resources(parsed_args)
        if not isinstance(ret, list):
            ret = [ret]

        if reverse_results:
            ret.reverse()

        data = [f(r)[1] for r in ret]

        if data:
            return f()[0], data
        else:
            return f()


def cut(string, length=25):
    if string and len(string) > length:
        return "%s..." % string[:length]
    else:
        return string


def wrap(string, width=25):
    if string and len(string) > width:
        return textwrap.fill(string, width)
    else:
        return string


def get_filters(parsed_args):
    filters = {}

    if parsed_args.filters:
        for f in parsed_args.filters:
            arr = f.split('=')

            if len(arr) != 2:
                raise ValueError('Invalid filter: %s' % f)

            filters[arr[0]] = arr[1]

    return filters