#! /usr/bin/env python
#
#    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.

"""Generate list of cinder drivers"""

import os
import sys

from cinder.interface import util


class Output(object):

    def __init__(self, base_dir):
        # At this point we don't care what was passed in, just a trigger
        # to write this out to the doc tree for now
        self.driver_file = None
        if len(sys.argv) > 1:
            self.driver_file = open(
                '%s/doc/source/drivers.rst' % base_dir, 'w+')
            self.driver_file.write('===================\n')
            self.driver_file.write('Available Drivers\n')
            self.driver_file.write('===================\n\n')

    def __enter__(self):
        return self

    def __exit__(self, type, value, traceback):
        if self.driver_file:
            self.driver_file.close()

    def write(self, text):
        if self.driver_file:
            self.driver_file.write('%s\n' % text)
        else:
            print(text)


def format_description(desc, output):
    desc = desc or '<None>'
    lines = desc.rstrip('\n').split('\n')
    for line in lines:
        output.write('    %s' % line)


def print_drivers(drivers, config_name, output):
    for driver in sorted(drivers, key=lambda x: x.class_fqn):
        output.write(driver.class_name)
        output.write('-' * len(driver.class_name))
        if driver.version:
            output.write('* Version: %s' % driver.version)
        output.write('* %s=%s' % (config_name, driver.class_fqn))
        output.write('* Description:')
        format_description(driver.desc, output)
        output.write('')
    output.write('')


def main():
    tools_dir = os.path.dirname(os.path.abspath(__file__))
    cinder_root = os.path.dirname(tools_dir)
    cur_dir = os.getcwd()
    os.chdir(cinder_root)

    try:
        with Output(cinder_root) as output:
            output.write('Volume Drivers')
            output.write('==============')
            print_drivers(util.get_volume_drivers(), 'volume_driver', output)

            output.write('Backup Drivers')
            output.write('==============')
            print_drivers(util.get_backup_drivers(), 'backup_driver', output)

            output.write('FC Zone Manager Drivers')
            output.write('=======================')
            print_drivers(util.get_fczm_drivers(), 'zone_driver', output)
    finally:
        os.chdir(cur_dir)

if __name__ == '__main__':
    main()