#!/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/>.
#

DOCUMENTATION = '''
---
module: nxos_acl
version_added: "2.2"
short_description: Manages access list entries for ACLs.
description:
    - Manages access list entries for ACLs.
extends_documentation_fragment: nxos
author:
    - Jason Edelman (@jedelman8)
    - Gabriele Gerbino (@GGabriele)
notes:
    - C(state=absent) removes the ACE if it exists.
    - C(state=delete_acl) deleted the ACL if it exists.
    - For idempotency, use port numbers for the src/dest port
      params like I(src_port1) and names for the well defined protocols
      for the I(proto) param.
    - Although this module is idempotent in that if the ace as presented in
      the task is identical to the one on the switch, no changes will be made.
      If there is any difference, what is in Ansible will be pushed (configured
      options will be overridden).  This is to improve security, but at the
      same time remember an ACE is removed, then re-added, so if there is a
      change, the new ACE will be exactly what paramaters you are sending to
      the module.
options:
    seq:
        description:
            - Sequence number of the entry (ACE).
        required: false
        default: null
    name:
        description:
            - Case sensitive name of the access list (ACL).
        required: true
    action:
        description:
            - Action of the ACE.
        required: false
        default: null
        choices: ['permit', 'deny', 'remark']
    remark:
        description:
            - If action is set to remark, this is the description.
        required: false
        default: null
    proto:
        description:
            - Port number or protocol (as supported by the switch).
        required: false
        default: null
    src:
        description:
            - Source ip and mask using IP/MASK notation and
              supports keyword 'any'.
        required: false
        default: null
    src_port_op:
        description:
            - Source port operands such as eq, neq, gt, lt, range.
        required: false
        default: null
        choices: ['any', 'eq', 'gt', 'lt', 'neq', 'range']
    src_port1:
        description:
            - Port/protocol and also first (lower) port when using range
              operand.
        required: false
        default: null
    src_port2:
        description:
            - Second (end) port when using range operand.
        required: false
        default: null
    dest:
        description:
            - Destination ip and mask using IP/MASK notation and supports the
              keyword 'any'.
        required: false
        default: null
        default: null
    dest_port_op:
        description:
            - Destination port operands such as eq, neq, gt, lt, range.
        required: false
        default: null
        choices: ['any', 'eq', 'gt', 'lt', 'neq', 'range']
    dest_port1:
        description:
            - Port/protocol and also first (lower) port when using range
              operand.
        required: false
        default: null
    dest_port2:
        description:
            - Second (end) port when using range operand.
        required: false
        default: null
    log:
        description:
            - Log matches against this entry.
        required: false
        default: null
        choices: ['enable']
    urg:
        description:
            - Match on the URG bit.
        required: false
        default: null
        choices: ['enable']
    ack:
        description:
            - Match on the ACK bit.
        required: false
        default: null
        choices: ['enable']
    psh:
        description:
            - Match on the PSH bit.
        required: false
        default: null
        choices: ['enable']
    rst:
        description:
            - Match on the RST bit.
        required: false
        default: null
        choices: ['enable']
    syn:
        description:
            - Match on the SYN bit.
        required: false
        default: null
        choices: ['enable']
    fin:
        description:
            - Match on the FIN bit.
        required: false
        default: null
        choices: ['enable']
    established:
        description:
            - Match established connections.
        required: false
        default: null
        choices: ['enable']
    fragments:
        description:
            - Check non-initial fragments.
        required: false
        default: null
        choices: ['enable']
    time-range:
        description:
            - Name of time-range to apply.
        required: false
        default: null
    precedence:
        description:
            - Match packets with given precedence.
        required: false
        default: null
        choices: ['critical', 'flash', 'flash-override', 'immediate',
                  'internet', 'network', 'priority', 'routine']
    dscp:
        description:
            - Match packets with given dscp value.
        required: false
        default: null
        choices: ['af11', 'af12', 'af13', 'af21', 'af22', 'af23','af31','af32',
                  'af33', 'af41', 'af42', 'af43', 'cs1', 'cs2', 'cs3', 'cs4',
                  'cs5', 'cs6', 'cs7', 'default', 'ef']
    state:
        description:
            - Specify desired state of the resource.
        required: false
        default: present
        choices: ['present','absent','delete_acl']
'''

EXAMPLES = '''

# configure ACL ANSIBLE
- nxos_acl:
    name: ANSIBLE
    seq: 10
    action: permit
    proto: tcp
    src: 1.1.1.1/24
    dest: any
    state: present
    provider: "{{ nxos_provider }}"
'''

RETURN = '''
proposed:
    description: k/v pairs of parameters passed into module.
    returned: always
    type: dict
    sample: {"action": "permit", "dest": "any", "name": "ANSIBLE",
            "proto": "tcp", "seq": "10", "src": "1.1.1.1/24"}
existing:
    description: k/v pairs of existing ACL entries.
    returned: always
    type: dict
    sample: {}
end_state:
    description: k/v pairs of ACL entries after module execution.
    returned: always
    type: dict
    sample: {"action": "permit", "dest": "any", "name": "ANSIBLE",
            "proto": "tcp", "seq": "10", "src": "1.1.1.1/24"}
updates:
    description: commands sent to the device
    returned: always
    type: list
    sample: ["ip access-list ANSIBLE", "10 permit tcp 1.1.1.1/24 any"]
changed:
    description: check to see if a change was made on the device
    returned: always
    type: boolean
    sample: true
'''

import collections
import json

# COMMON CODE FOR MIGRATION
import re

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

try:
    from ansible.module_utils.nxos import get_module
except ImportError:
    from ansible.module_utils.nxos import NetworkModule


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


def get_cli_body_ssh(command, response, module):
    """Get response for when transport=cli.  This is kind of a hack and mainly
    needed because these modules were originally written for NX-API.  And
    not every command supports "| json" when using cli/ssh.  As such, we assume
    if | json returns an XML string, it is a valid command, but that the
    resource doesn't exist yet. Instead, we assume if '^' is found in response,
    it is an invalid command.
    """
    if 'xml' in response[0]:
        body = []
    elif '^' in response[0]:
        body = response
    else:
        try:
            body = [json.loads(response[0])]
        except ValueError:
            module.fail_json(msg='Command does not support JSON output',
                             command=command)
    return body


def execute_show(cmds, module, command_type=None):
    command_type_map = {
        'cli_show': 'json',
        'cli_show_ascii': 'text'
    }

    try:
        if command_type:
            response = module.execute(cmds, command_type=command_type)
        else:
            response = module.execute(cmds)
    except ShellError:
        clie = get_exception()
        module.fail_json(msg='Error sending {0}'.format(cmds),
                         error=str(clie))
    except AttributeError:
        try:
            if command_type:
                command_type = command_type_map.get(command_type)
                module.cli.add_commands(cmds, output=command_type)
                response = module.cli.run_commands()
            else:
                module.cli.add_commands(cmds, output=command_type)
                response = module.cli.run_commands()
        except ShellError:
            clie = get_exception()
            module.fail_json(msg='Error sending {0}'.format(cmds),
                             error=str(clie))
    return response


def execute_show_command(command, module, command_type='cli_show'):
    if module.params['transport'] == 'cli':
        command += ' | json'
        cmds = [command]
        response = execute_show(cmds, module)
        body = get_cli_body_ssh(command, response, module)
    elif module.params['transport'] == 'nxapi':
        cmds = [command]
        body = execute_show(cmds, module, command_type=command_type)

    return body


def get_acl(module, acl_name, seq_number):
    command = 'show ip access-list'
    new_acl = []
    saveme = {}
    seqs = []
    acl_body = {}

    body = execute_show_command(command, module)[0]
    all_acl_body = body['TABLE_ip_ipv6_mac']['ROW_ip_ipv6_mac']

    for acl in all_acl_body:
        if acl.get('acl_name') == acl_name:
            acl_body = acl

    try:
        acl_entries = acl_body['TABLE_seqno']['ROW_seqno']
        acl_name = acl_body.get('acl_name')
    except KeyError:  # could be raised if no ACEs are configured for an ACL
        return saveme, [{'acl': 'no_entries'}], seqs

    if isinstance(acl_entries, dict):
        acl_entries = [acl_entries]

    for each in acl_entries:
        temp = collections.OrderedDict()
        keep = {}
        temp['name'] = acl_name
        temp['seq'] = str(each.get('seqno'))
        temp['options'] = {}
        remark = each.get('remark')
        if remark:
            temp['remark'] = remark
            temp['action'] = 'remark'
        else:
            temp['action'] = each.get('permitdeny')
            temp['proto'] = each.get('proto', each.get('proto_str', each.get('ip')))
            temp['src'] = each.get('src_any', each.get('src_ip_prefix'))
            temp['src_port_op'] = each.get('src_port_op')
            temp['src_port1'] = each.get('src_port1_num')
            temp['src_port2'] = each.get('src_port2_num')
            temp['dest'] = each.get('dest_any', each.get('dest_ip_prefix'))
            temp['dest_port_op'] = each.get('dest_port_op')
            temp['dest_port1'] = each.get('dest_port1_num')
            temp['dest_port2'] = each.get('dest_port2_num')

            options = collections.OrderedDict()
            options['log'] = each.get('log')
            options['urg'] = each.get('urg')
            options['ack'] = each.get('ack')
            options['psh'] = each.get('psh')
            options['rst'] = each.get('rst')
            options['syn'] = each.get('syn')
            options['fin'] = each.get('fin')
            options['established'] = each.get('established')
            options['dscp'] = each.get('dscp_str')
            options['precedence'] = each.get('precedence_str')
            options['fragments'] = each.get('fragments')
            options['time_range'] = each.get('timerange')

            options_no_null = {}
            for key, value in options.iteritems():
                if value is not None:
                    options_no_null[key] = value

            keep['options'] = options_no_null

        for key, value in temp.iteritems():
            if value:
                keep[key] = value
        # ensure options is always in the dict
        if keep.get('options', 'DNE') == 'DNE':
            keep['options'] = {}

        if keep.get('seq') == seq_number:
            saveme = dict(keep)

        seqs.append(str(keep.get('seq')))
        new_acl.append(keep)

    return saveme, new_acl, seqs


def _acl_operand(operand, srcp1, sprcp2):
    sub_entry = ' ' + operand

    if operand == 'range':
        sub_entry += ' ' + srcp1 + ' ' + sprcp2
    else:
        sub_entry += ' ' + srcp1

    return sub_entry


def config_core_acl(proposed):
    seq = proposed.get('seq')
    action = proposed.get('action')
    remark = proposed.get('remark')
    proto = proposed.get('proto')
    src = proposed.get('src')
    src_port_op = proposed.get('src_port_op')
    src_port1 = proposed.get('src_port1')
    src_port2 = proposed.get('src_port2')

    dest = proposed.get('dest')
    dest_port_op = proposed.get('dest_port_op')
    dest_port1 = proposed.get('dest_port1')
    dest_port2 = proposed.get('dest_port2')

    ace_start_entries = [action, proto, src]
    if not remark:
        ace = seq + ' ' + ' '.join(ace_start_entries)
        if src_port_op:
            ace += _acl_operand(src_port_op, src_port1, src_port2)
        ace += ' ' + dest
        if dest_port_op:
            ace += _acl_operand(dest_port_op, dest_port1, dest_port2)
    else:
        ace = seq + ' remark ' + remark

    return ace


def config_acl_options(options):
    ENABLE_ONLY = ['psh', 'urg', 'log', 'ack', 'syn',
                   'established', 'rst', 'fin', 'fragments',
                   'log']

    OTHER = ['dscp', 'precedence', 'time-range']
    # packet-length is the only option not currently supported

    if options.get('time_range'):
        options['time-range'] = options.get('time_range')
        options.pop('time_range')

    command = ''
    for option, value in options.iteritems():
        if option in ENABLE_ONLY:
            if value == 'enable':
                command += ' ' + option
        elif option in OTHER:
            command += ' ' + option + ' ' + value
    if command:
        command = command.strip()
        return command


def flatten_list(command_lists):
    flat_command_list = []
    for command in command_lists:
        if isinstance(command, list):
            flat_command_list.extend(command)
        else:
            flat_command_list.append(command)
    return flat_command_list


def execute_config_command(commands, module):
    try:
        module.configure(commands)
    except ShellError:
        clie = get_exception()
        module.fail_json(msg='Error sending CLI commands',
                         error=str(clie), commands=commands)


def main():
    argument_spec = dict(
            seq=dict(required=False, type='str'),
            name=dict(required=True, type='str'),
            action=dict(required=False, choices=['remark', 'permit', 'deny']),
            remark=dict(requried=False, type='str'),
            proto=dict(required=False, type='str'),
            src=dict(required=False, type='str'),
            src_port_op=dict(required=False),
            src_port1=dict(required=False, type='str'),
            src_port2=dict(required=False, type='str'),
            dest=dict(required=False, type='str'),
            dest_port_op=dict(required=False),
            dest_port1=dict(required=False, type='str'),
            dest_port2=dict(required=False, type='str'),
            log=dict(required=False, choices=['enable']),
            urg=dict(required=False, choices=['enable']),
            ack=dict(required=False, choices=['enable']),
            psh=dict(required=False, choices=['enable']),
            rst=dict(required=False, choices=['enable']),
            syn=dict(required=False, choices=['enable']),
            fragments=dict(required=False, choices=['enable']),
            fin=dict(required=False, choices=['enable']),
            established=dict(required=False, choices=['enable']),
            time_range=dict(required=False),
            precedence=dict(required=False, choices=['critical', 'flash',
                                                     'flash-override',
                                                     'immediate', 'internet',
                                                     'network', 'priority',
                                                     'routine']),
            dscp=dict(required=False, choices=['af11', 'af12', 'af13', 'af21',
                                               'af22', 'af23', 'af31', 'af32',
                                               'af33', 'af41', 'af42', 'af43',
                                               'cs1', 'cs2', 'cs3', 'cs4',
                                               'cs5', 'cs6', 'cs7', 'default',
                                               'ef']),
            state=dict(choices=['absent', 'present', 'delete_acl'],
                       default='present'),
            protocol=dict(choices=['http', 'https'], default='http'),
            host=dict(required=True),
            username=dict(type='str'),
            password=dict(no_log=True, type='str'),
            include_defaults=dict(default=False),
            config=dict(),
            save=dict(type='bool', default=False)
    )
    module = get_network_module(argument_spec=argument_spec,
                                supports_check_mode=True)

    state = module.params['state']
    action = module.params['action']
    remark = module.params['remark']
    dscp = module.params['dscp']
    precedence = module.params['precedence']
    seq = module.params['seq']
    name = module.params['name']
    seq = module.params['seq']

    if action == 'remark' and not remark:
        module.fail_json(msg='when state is action, remark param is also '
                             'required')

    REQUIRED = ['seq', 'name', 'action', 'proto', 'src', 'dest']
    ABSENT = ['name', 'seq']
    if state == 'present':
        if action and remark and seq:
            pass
        else:
            for each in REQUIRED:
                if module.params[each] is None:
                    module.fail_json(msg="req'd params when state is present:",
                                     params=REQUIRED)
    elif state == 'absent':
        for each in ABSENT:
            if module.params[each] is None:
                module.fail_json(msg='require params when state is absent',
                                 params=ABSENT)
    elif state == 'delete_acl':
        if module.params['name'] is None:
            module.fail_json(msg="param name req'd when state is delete_acl")

    if dscp and precedence:
        module.fail_json(msg='only one of the params dscp/precedence '
                             'are allowed')

    OPTIONS_NAMES = ['log', 'urg', 'ack', 'psh', 'rst', 'syn', 'fin',
                     'established', 'dscp', 'precedence', 'fragments',
                     'time_range']

    CORE = ['seq', 'name', 'action', 'proto', 'src', 'src_port_op',
            'src_port1', 'src_port2', 'dest', 'dest_port_op',
            'dest_port1', 'dest_port2', 'remark']

    proposed_core = dict((param, value) for (param, value) in
                         module.params.iteritems()
                         if param in CORE and value is not None)

    proposed_options = dict((param, value) for (param, value) in
                            module.params.iteritems()
                            if param in OPTIONS_NAMES and value is not None)
    proposed = {}
    proposed.update(proposed_core)
    proposed.update(proposed_options)

    existing_options = {}

    # getting existing existing_core=dict, acl=list, seq=list
    existing_core, acl, seqs = get_acl(module, name, seq)
    if existing_core:
        existing_options = existing_core.get('options')
        existing_core.pop('options')

    end_state = acl
    commands = []
    changed = False
    delta_core = {}
    delta_options = {}

    if not existing_core.get('remark'):
        delta_core = dict(
            set(proposed_core.iteritems()).difference(
                existing_core.iteritems())
            )
        delta_options = dict(
            set(proposed_options.iteritems()).difference(
                existing_options.iteritems())
        )

    if state == 'present':
        if delta_core or delta_options:
            if existing_core:  # if the ace exists already
                commands.append(['no {0}'.format(seq)])
            if delta_options:
                myacl_str = config_core_acl(proposed_core)
                myacl_str += ' ' + config_acl_options(proposed_options)
            else:
                myacl_str = config_core_acl(proposed_core)
            command = [myacl_str]
            commands.append(command)
    elif state == 'absent':
        if existing_core:
            commands.append(['no {0}'.format(seq)])
    elif state == 'delete_acl':
        if acl[0].get('acl') != 'no_entries':
            commands.append(['no ip access-list {0}'.format(name)])

    results = {}
    cmds = []
    if commands:
        preface = []
        if state in ['present', 'absent']:
            preface = ['ip access-list {0}'.format(name)]
            commands.insert(0, preface)

        cmds = flatten_list(commands)
        if module.check_mode:
            module.exit_json(changed=True, commands=cmds)
        else:
            execute_config_command(cmds, module)
            changed = True
            new_existing_core, end_state, seqs = get_acl(module, name, seq)

    results['proposed'] = proposed
    results['existing'] = existing_core
    results['changed'] = changed
    results['updates'] = cmds
    results['end_state'] = end_state

    module.exit_json(**results)


if __name__ == '__main__':
    main()