#!/usr/bin/python
#
# This file is part of Ansible
#
# Ansible is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Ansible is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
#

ANSIBLE_METADATA = {'status': ['preview'],
                    'supported_by': 'community',
                    'version': '1.0'}

DOCUMENTATION = '''
---
module: nxos_ospf_vrf
version_added: "2.2"
short_description: Manages a VRF for an OSPF router.
description:
    - Manages a VRF for an OSPF router.
author: Gabriele Gerbino (@GGabriele)
extends_documentation_fragment: nxos
notes:
    - Value I(default) restores params default value, if any.
      Otherwise it removes the existing param configuration.
options:
    vrf:
        description:
            - Name of the resource instance. Valid value is a string.
              The name 'default' is a valid VRF representing the global OSPF.
        required: false
        default: default
    ospf:
        description:
            - Name of the OSPF instance.
        required: true
        default: null
    router_id:
        description:
            - Router Identifier (ID) of the OSPF router VRF instance.
        required: false
        default: null
    default_metric:
        description:
            - Specify the default Metric value. Valid values are an integer
              or the keyword 'default'.
        required: false
        default: null
    log_adjacency:
        description:
            - Controls the level of log messages generated whenever a
              neighbor changes state. Valid values are 'log', 'detail',
              and 'default'.
        required: false
        choices: ['log','detail','default']
        default: null
    timer_throttle_lsa_start:
        description:
            - Specify the start interval for rate-limiting Link-State
              Advertisement (LSA) generation. Valid values are an integer,
              in milliseconds, or the keyword 'default'.
        required: false
        default: null
    timer_throttle_lsa_hold:
        description:
            - Specify the hold interval for rate-limiting Link-State
              Advertisement (LSA) generation. Valid values are an integer,
              in milliseconds, or the keyword 'default'.
        required: false
        default: null
    timer_throttle_lsa_max:
        description:
            - Specify the max interval for rate-limiting Link-State
              Advertisement (LSA) generation. Valid values are an integer,
              in milliseconds, or the keyword 'default'.
        required: false
        default: null
    timer_throttle_spf_start:
        description:
            - Specify initial Shortest Path First (SPF) schedule delay.
              Valid values are an integer, in milliseconds, or
              the keyword 'default'.
        required: false
        default: null
    timer_throttle_spf_hold:
        description:
            - Specify minimum hold time between Shortest Path First (SPF)
              calculations. Valid values are an integer, in milliseconds,
              or the keyword 'default'.
        required: false
        default: null
    timer_throttle_spf_max:
        description:
            - Specify the maximum wait time between Shortest Path First (SPF)
              calculations. Valid values are an integer, in milliseconds,
              or the keyword 'default'.
        required: false
        default: null
    auto_cost:
        description:
            - Specifies the reference bandwidth used to assign OSPF cost.
              Valid values are an integer, in Mbps, or the keyword 'default'.
        required: false
        default: null
'''

EXAMPLES = '''
- nxos_ospf_vrf:
    ospf: 1
    timer_throttle_spf_start: 50
    timer_throttle_spf_hold: 1000
    timer_throttle_spf_max: 2000
    timer_throttle_lsa_start: 60
    timer_throttle_lsa_hold: 1100
    timer_throttle_lsa_max: 3000
    vrf: test
    state: present
    username: "{{ un }}"
    password: "{{ pwd }}"
    host: "{{ inventory_hostname }}"
'''

RETURN = '''
proposed:
    description: k/v pairs of parameters passed into module
    returned: verbose mode
    type: dict
    sample: {"ospf": "1", "timer_throttle_lsa_hold": "1100",
            "timer_throttle_lsa_max": "3000", "timer_throttle_lsa_start": "60",
            "timer_throttle_spf_hold": "1000",
            "timer_throttle_spf_max": "2000", "timer_throttle_spf_start": "50",
            "vrf": "test"}
existing:
    description: k/v pairs of existing configuration
    returned: verbose mode
    type: dict
    sample: {"auto_cost": "40000", "default_metric": "", "log_adjacency": "",
            "ospf": "1", "router_id": "", "timer_throttle_lsa_hold": "5000",
            "timer_throttle_lsa_max": "5000", "timer_throttle_lsa_start": "0",
            "timer_throttle_spf_hold": "1000",
            "timer_throttle_spf_max": "5000",
            "timer_throttle_spf_start": "200", "vrf": "test"}
end_state:
    description: k/v pairs of configuration after module execution
    returned: verbose mode
    type: dict
    sample: {"auto_cost": "40000", "default_metric": "", "log_adjacency": "",
            "ospf": "1", "router_id": "", "timer_throttle_lsa_hold": "1100",
            "timer_throttle_lsa_max": "3000", "timer_throttle_lsa_start": "60",
            "timer_throttle_spf_hold": "1000",
            "timer_throttle_spf_max": "2000", "timer_throttle_spf_start": "50",
            "vrf": "test"}
updates:
    description: commands sent to the device
    returned: always
    type: list
    sample: ["router ospf 1", "vrf test", "timers throttle lsa 60 1100 3000",
             "timers throttle spf 50 1000 2000"]
changed:
    description: check to see if a change was made on the device
    returned: always
    type: boolean
    sample: true
'''

# COMMON CODE FOR MIGRATION
import re

import ansible.module_utils.nxos
from ansible.module_utils.basic import get_exception
from ansible.module_utils.netcfg import NetworkConfig, ConfigLine
from ansible.module_utils.network import NetworkModule
from ansible.module_utils.shell import ShellError


def to_list(val):
     if isinstance(val, (list, tuple)):
         return list(val)
     elif val is not None:
         return [val]
     else:
         return list()


class CustomNetworkConfig(NetworkConfig):

    def expand_section(self, configobj, S=None):
        if S is None:
            S = list()
        S.append(configobj)
        for child in configobj.children:
            if child in S:
                continue
            self.expand_section(child, S)
        return S

    def get_object(self, path):
        for item in self.items:
            if item.text == path[-1]:
                parents = [p.text for p in item.parents]
                if parents == path[:-1]:
                    return item

    def to_block(self, section):
        return '\n'.join([item.raw for item in section])

    def get_section(self, path):
        try:
            section = self.get_section_objects(path)
            return self.to_block(section)
        except ValueError:
            return list()

    def get_section_objects(self, path):
        if not isinstance(path, list):
            path = [path]
        obj = self.get_object(path)
        if not obj:
            raise ValueError('path does not exist in config')
        return self.expand_section(obj)


    def add(self, lines, parents=None):
        """Adds one or lines of configuration
        """

        ancestors = list()
        offset = 0
        obj = None

        ## global config command
        if not parents:
            for line in to_list(lines):
                item = ConfigLine(line)
                item.raw = line
                if item not in self.items:
                    self.items.append(item)

        else:
            for index, p in enumerate(parents):
                try:
                    i = index + 1
                    obj = self.get_section_objects(parents[:i])[0]
                    ancestors.append(obj)

                except ValueError:
                    # add parent to config
                    offset = index * self.indent
                    obj = ConfigLine(p)
                    obj.raw = p.rjust(len(p) + offset)
                    if ancestors:
                        obj.parents = list(ancestors)
                        ancestors[-1].children.append(obj)
                    self.items.append(obj)
                    ancestors.append(obj)

            # add child objects
            for line in to_list(lines):
                # check if child already exists
                for child in ancestors[-1].children:
                    if child.text == line:
                        break
                else:
                    offset = len(parents) * self.indent
                    item = ConfigLine(line)
                    item.raw = line.rjust(len(line) + offset)
                    item.parents = ancestors
                    ancestors[-1].children.append(item)
                    self.items.append(item)


def get_network_module(**kwargs):
    try:
        return get_module(**kwargs)
    except NameError:
        return NetworkModule(**kwargs)

def get_config(module, include_defaults=False):
    config = module.params['config']
    if not config:
        try:
            config = module.get_config()
        except AttributeError:
            defaults = module.params['include_defaults']
            config = module.config.get_config(include_defaults=defaults)
    return CustomNetworkConfig(indent=2, contents=config)

def load_config(module, candidate):
    config = get_config(module)

    commands = candidate.difference(config)
    commands = [str(c).strip() for c in commands]

    save_config = module.params['save']

    result = dict(changed=False)

    if commands:
        if not module.check_mode:
            try:
                module.configure(commands)
            except AttributeError:
                module.config(commands)

            if save_config:
                try:
                    module.config.save_config()
                except AttributeError:
                    module.execute(['copy running-config startup-config'])

        result['changed'] = True
        result['updates'] = commands

    return result
# END OF COMMON CODE


PARAM_TO_COMMAND_KEYMAP = {
    'router_id': 'router-id',
    'default_metric': 'default-metric',
    'log_adjacency': 'log-adjacency-changes',
    'timer_throttle_lsa_start': 'timers throttle lsa',
    'timer_throttle_lsa_max': 'timers throttle lsa',
    'timer_throttle_lsa_hold': 'timers throttle lsa',
    'timer_throttle_spf_max': 'timers throttle spf',
    'timer_throttle_spf_start': 'timers throttle spf',
    'timer_throttle_spf_hold': 'timers throttle spf',
    'auto_cost': 'auto-cost reference-bandwidth'
}
PARAM_TO_DEFAULT_KEYMAP = {
    'timer_throttle_lsa_start': '0',
    'timer_throttle_lsa_max': '5000',
    'timer_throttle_lsa_hold': '5000',
    'timer_throttle_spf_start': '200',
    'timer_throttle_spf_max': '5000',
    'timer_throttle_spf_hold': '1000',
    'auto_cost': '40000'
}


def invoke(name, *args, **kwargs):
    func = globals().get(name)
    if func:
        return func(*args, **kwargs)


def get_value(arg, config, module):
    REGEX = re.compile(r'(?:{0}\s)(?P<value>.*)$'.format(PARAM_TO_COMMAND_KEYMAP[arg]), re.M)
    value = ''

    if PARAM_TO_COMMAND_KEYMAP[arg] in config:
        if arg == 'log_adjacency':
            if 'log-adjacency-changes detail' in config:
                value = 'detail'
            else:
                value = 'log'
        else:
            value_list = REGEX.search(config).group('value').split()
            if 'hold' in arg:
                value = value_list[1]
            elif 'max' in arg:
                value = value_list[2]
            elif 'auto' in arg:
                if 'Gbps' in value_list:
                    value = str(int(value_list[0]) * 1000)
                else:
                    value = value_list[0]
            else:
                value = value_list[0]
    return value


def get_existing(module, args):
    existing = {}
    netcfg = get_config(module)
    parents = ['router ospf {0}'.format(module.params['ospf'])]

    if module.params['vrf'] != 'default':
        parents.append('vrf {0}'.format(module.params['vrf']))

    config = netcfg.get_section(parents)
    if config:
        if module.params['vrf'] == 'default':
            splitted_config = config.splitlines()
            vrf_index = False
            for index in range(0, len(splitted_config) - 1):
                if 'vrf' in splitted_config[index].strip():
                        vrf_index = index
                        break
            if vrf_index:
                config = '\n'.join(splitted_config[0:vrf_index])

        for arg in args:
            if arg not in ['ospf', 'vrf']:
                existing[arg] = get_value(arg, config, module)

        existing['vrf'] = module.params['vrf']
        existing['ospf'] = module.params['ospf']

    return existing


def apply_key_map(key_map, table):
    new_dict = {}
    for key, value in table.items():
        new_key = key_map.get(key)
        if new_key:
            value = table.get(key)
            if value:
                new_dict[new_key] = value
            else:
                new_dict[new_key] = value
    return new_dict


def state_present(module, existing, proposed, candidate):
    commands = list()
    proposed_commands = apply_key_map(PARAM_TO_COMMAND_KEYMAP, proposed)
    existing_commands = apply_key_map(PARAM_TO_COMMAND_KEYMAP, existing)

    for key, value in proposed_commands.iteritems():
        if value is True:
            commands.append(key)

        elif value is False:
            commands.append('no {0}'.format(key))

        elif value == 'default':
            if existing_commands.get(key):
                existing_value = existing_commands.get(key)
                commands.append('no {0} {1}'.format(key, existing_value))
        else:
            if key == 'timers throttle lsa':
                command = '{0} {1} {2} {3}'.format(
                                        key,
                                        proposed['timer_throttle_lsa_start'],
                                        proposed['timer_throttle_lsa_hold'],
                                        proposed['timer_throttle_lsa_max'])
            elif key == 'timers throttle spf':
                command = '{0} {1} {2} {3}'.format(
                                        key,
                                        proposed['timer_throttle_spf_start'],
                                        proposed['timer_throttle_spf_hold'],
                                        proposed['timer_throttle_spf_max'])
            elif key == 'log-adjacency-changes':
                if value == 'log':
                    command = key
                elif value == 'detail':
                    command = '{0} {1}'.format(key, value)
            elif key == 'auto-cost reference-bandwidth':
                if len(value) < 5:
                    command = '{0} {1} Mbps'.format(key, value)
                else:
                    value = str(int(value) / 1000)
                    command = '{0} {1} Gbps'.format(key, value)
            else:
                command = '{0} {1}'.format(key, value.lower())

            if command not in commands:
                commands.append(command)

    if commands:
        parents = ['router ospf {0}'.format(module.params['ospf'])]
        if module.params['vrf'] != 'default':
            parents.append('vrf {0}'.format(module.params['vrf']))

        candidate.add(commands, parents=parents)


def state_absent(module, existing, proposed, candidate):
    commands = []
    parents = ['router ospf {0}'.format(module.params['ospf'])]
    if module.params['vrf'] == 'default':
        existing_commands = apply_key_map(PARAM_TO_COMMAND_KEYMAP, existing)
        for key, value in existing_commands.iteritems():
            if value:
                if key == 'timers throttle lsa':
                    command = 'no {0} {1} {2} {3}'.format(
                                        key,
                                        existing['timer_throttle_lsa_start'],
                                        existing['timer_throttle_lsa_hold'],
                                        existing['timer_throttle_lsa_max'])
                elif key == 'timers throttle spf':
                    command = 'no {0} {1} {2} {3}'.format(
                                        key,
                                        existing['timer_throttle_spf_start'],
                                        existing['timer_throttle_spf_hold'],
                                        existing['timer_throttle_spf_max'])
                else:
                    existing_value = existing_commands.get(key)
                    command = 'no {0} {1}'.format(key, existing_value)

                if command not in commands:
                    commands.append(command)
    else:
        commands = ['no vrf {0}'.format(module.params['vrf'])]
    candidate.add(commands, parents=parents)


def main():
    argument_spec = dict(
            vrf=dict(required=False, type='str', default='default'),
            ospf=dict(required=True, type='str'),
            router_id=dict(required=False, type='str'),
            default_metric=dict(required=False, type='str'),
            log_adjacency=dict(required=False, type='str',
                               choices=['log', 'detail', 'default']),
            timer_throttle_lsa_start=dict(required=False, type='str'),
            timer_throttle_lsa_hold=dict(required=False, type='str'),
            timer_throttle_lsa_max=dict(required=False, type='str'),
            timer_throttle_spf_start=dict(required=False, type='str'),
            timer_throttle_spf_hold=dict(required=False, type='str'),
            timer_throttle_spf_max=dict(required=False, type='str'),
            auto_cost=dict(required=False, type='str'),
            state=dict(choices=['present', 'absent'], default='present',
                       required=False),
            include_defaults=dict(default=True),
            config=dict(),
            save=dict(type='bool', default=False)
    )
    module = get_network_module(argument_spec=argument_spec,
                        supports_check_mode=True)

    state = module.params['state']
    args =  [
            'vrf',
            'ospf',
            'router_id',
            'default_metric',
            'log_adjacency',
            'timer_throttle_lsa_start',
            'timer_throttle_lsa_hold',
            'timer_throttle_lsa_max',
            'timer_throttle_spf_start',
            'timer_throttle_spf_hold',
            'timer_throttle_spf_max',
            'auto_cost'
        ]

    existing = invoke('get_existing', module, args)
    end_state = existing
    proposed_args = dict((k, v) for k, v in module.params.iteritems()
                    if v is not None and k in args)

    proposed = {}
    for key, value in proposed_args.iteritems():
        if key != 'interface':
            if str(value).lower() == 'true':
                value = True
            elif str(value).lower() == 'false':
                value = False
            elif str(value).lower() == 'default':
                value = PARAM_TO_DEFAULT_KEYMAP.get(key)
                if value is None:
                    value = 'default'
            if existing.get(key) or (not existing.get(key) and value):
                proposed[key] = value

    result = {}
    if state == 'present' or (state == 'absent' and existing):
        candidate = CustomNetworkConfig(indent=3)
        invoke('state_%s' % state, module, existing, proposed, candidate)

        try:
            response = load_config(module, candidate)
            result.update(response)
        except ShellError:
            exc = get_exception()
            module.fail_json(msg=str(exc))
    else:
        result['updates'] = []

    result['connected'] = module.connected
    if module._verbosity > 0:
        end_state = invoke('get_existing', module, args)
        result['end_state'] = end_state
        result['existing'] = existing
        result['proposed'] = proposed_args

    module.exit_json(**result)


if __name__ == '__main__':
    main()
