##############################################################################
# Copyright (c) 2015 Ericsson AB and others.
#
# All rights reserved. This program and the accompanying materials
# are made available under the terms of the Apache License, Version 2.0
# which accompanies this distribution, and is available at
# http://www.apache.org/licenses/LICENSE-2.0
##############################################################################

"""
Command-line interface to yardstick
"""

from __future__ import absolute_import
import logging
import os
import sys

from pkg_resources import get_distribution
from argparse import RawDescriptionHelpFormatter
from oslo_config import cfg

from yardstick import _init_logging, _LOG_STREAM_HDLR
from yardstick.cmd.commands import task
from yardstick.cmd.commands import runner
from yardstick.cmd.commands import scenario
from yardstick.cmd.commands import testcase
from yardstick.cmd.commands import plugin
from yardstick.cmd.commands import env
from yardstick.cmd.commands import report
from yardstick.common import import_tools


CONF = cfg.CONF
cli_opts = [
    cfg.BoolOpt('debug',
                short='d',
                default=False,
                help='increase output verbosity to debug')
]
CONF.register_cli_opts(cli_opts)

CONFIG_SEARCH_PATHS = [sys.prefix + "/etc/yardstick",
                       "~/.yardstick",
                       "/etc/yardstick"]


def find_config_files(path_list):
    for path in path_list:
        abspath = os.path.abspath(os.path.expanduser(path))
        confname = abspath + "/yardstick.conf"
        if os.path.isfile(confname):
            return [confname]

    return None


@import_tools.decorator_banned_modules
class YardstickCLI(object):   # pragma: no cover
    """Command-line interface to yardstick"""

    # Command categories
    categories = {
        'task': task.TaskCommands,
        'runner': runner.RunnerCommands,
        'scenario': scenario.ScenarioCommands,
        'testcase': testcase.TestcaseCommands,
        'plugin': plugin.PluginCommands,
        'env': env.EnvCommand,
        'report': report.ReportCommands
    }

    def __init__(self):
        self.opts = []
        self._version = 'yardstick version %s ' % \
            get_distribution('yardstick').version

    def _find_actions(self, subparsers, actions_module):
        """find action methods"""
        # Find action methods inside actions_module and
        # add them to the command parser.
        # The 'actions_module' argument may be a class
        # or module. Action methods start with 'do_'
        for attr in (a for a in dir(actions_module) if a.startswith('do_')):
            command = attr[3:].replace('_', '-')
            callback = getattr(actions_module, attr)
            desc = callback.__doc__ or ''
            arguments = getattr(callback, 'arguments', [])
            subparser = subparsers.add_parser(
                command,
                description=desc
            )
            for (args, kwargs) in arguments:
                subparser.add_argument(*args, **kwargs)
            subparser.set_defaults(func=callback)

    def _add_command_parsers(self, categories, subparsers):
        """add commands to command-line parser"""
        for category in categories:
            command_object = categories[category]()
            desc = command_object.__doc__ or ''
            subparser = subparsers.add_parser(
                category, description=desc,
                formatter_class=RawDescriptionHelpFormatter
            )
            subparser.set_defaults(command_object=command_object)
            cmd_subparsers = subparser.add_subparsers(title='subcommands')
            self._find_actions(cmd_subparsers, command_object)

    def _register_cli_opt(self):

        # register subcommands to parse additional command line arguments
        def parser(subparsers):
            self._add_command_parsers(self.categories, subparsers)

        category_opt = cfg.SubCommandOpt("category",
                                         title="Command categories",
                                         help="Available categories",
                                         handler=parser)
        self._register_opt(category_opt)

    def _register_opt(self, opt):

        CONF.register_cli_opt(opt)
        self.opts.append(opt)

    def _load_cli_config(self, argv):

        # load CLI args and config files
        CONF(argv, project="yardstick", version=self._version,
             default_config_files=find_config_files(CONFIG_SEARCH_PATHS))

    def _handle_global_opts(self):

        _init_logging()
        if CONF.debug:
            _LOG_STREAM_HDLR.setLevel(logging.DEBUG)

    def _dispatch_func_notask(self):

        # dispatch to category parser
        func = CONF.category.func
        func(CONF.category)

    def _dispatch_func_task(self, task_id):

        # dispatch to category parser
        func = CONF.category.func
        func(CONF.category, task_id=task_id)

    def _clear_config_opts(self):

        CONF.clear()
        CONF.unregister_opts(self.opts)

    def main(self, argv):    # pragma: no cover
        """run the command line interface"""
        try:
            self._register_cli_opt()

            self._load_cli_config(argv)

            self._handle_global_opts()

            self._dispatch_func_notask()
        finally:
            self._clear_config_opts()

    def api(self, argv, task_id):    # pragma: no cover
        """run the api interface"""
        try:
            self._register_cli_opt()

            self._load_cli_config(argv)

            self._handle_global_opts()

            self._dispatch_func_task(task_id)
        finally:
            self._clear_config_opts()