#!/usr/bin/python
# -*- coding: utf-8 -*-

# (c) 2017, Ansible by Red Hat, inc
# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)

from __future__ import absolute_import, division, print_function


__metaclass__ = type


DOCUMENTATION = """
module: junos_config
author: Peter Sprygada (@privateip)
short_description: Manage configuration on devices running Juniper JUNOS
description:
- This module provides an implementation for working with the active configuration
  running on Juniper JUNOS devices.  It provides a set of arguments for loading configuration,
  performing rollback operations and zeroing the active configuration on the device.
version_added: 1.0.0
extends_documentation_fragment:
- junipernetworks.junos.junos
options:
  lines:
    description:
    - This argument takes a list of C(set) or C(delete) configuration lines to push
      into the remote device.  Each line must start with either C(set) or C(delete).  This
      argument is mutually exclusive with the I(src) argument.
    type: list
    aliases:
    - commands
    elements: str
  src:
    description:
    - The I(src) argument provides a path to the configuration file to load into the
      remote system. The path can either be a full system path to the configuration
      file if the value starts with / or relative to the root of the implemented role
      or playbook. This argument is mutually exclusive with the I(lines) argument.
    type: path
  src_format:
    description:
    - The I(src_format) argument specifies the format of the configuration found int
      I(src).  If the I(src_format) argument is not provided, the module will attempt
      to determine the format of the configuration file specified in I(src).
    type: str
    choices:
    - xml
    - set
    - text
    - json
  rollback:
    description:
    - The C(rollback) argument instructs the module to rollback the current configuration
      to the identifier specified in the argument.  If the specified rollback identifier
      does not exist on the remote device, the module will fail.  To rollback to the
      most recent commit, set the C(rollback) argument to 0.
    type: int
  zeroize:
    description:
    - The C(zeroize) argument is used to completely sanitize the remote device configuration
      back to initial defaults.  This argument will effectively remove all current
      configuration statements on the remote device.
    type: bool
    default: false
  confirm:
    description:
    - The C(confirm) argument will configure a time out value in minutes for the commit
      to be confirmed before it is automatically rolled back. If the value for this argument
      is set to 0, the commit is confirmed immediately which is also the default behaviour.
    type: int
    default: 0
  comment:
    description:
    - The C(comment) argument specifies a text string to be used when committing the
      configuration.  If the C(confirm) argument is set to False, this argument is
      silently ignored.
    default: configured by junos_config
    type: str
  replace:
    description:
    - The C(replace) argument will instruct the remote device to replace the current
      configuration hierarchy with the one specified in the corresponding hierarchy
      of the source configuration loaded from this module.
    - Note this argument should be considered deprecated.  To achieve the equivalent,
      set the I(update) argument to C(replace). This argument will be removed in a
      future release. The C(replace) and C(update) argument is mutually exclusive.
    type: bool
  backup:
    description:
    - This argument will cause the module to create a full backup of the current C(running-config)
      from the remote device before any changes are made. If the C(backup_options)
      value is not given, the backup file is written to the C(backup) folder in the
      playbook root directory or role root directory, if playbook is part of an ansible
      role. If the directory does not exist, it is created.
    type: bool
    default: false
  update:
    description:
    - This argument will decide how to load the configuration data particularly when
      the candidate configuration and loaded configuration contain conflicting statements.
      Following are accepted values. C(merge) combines the data in the loaded configuration
      with the candidate configuration. If statements in the loaded configuration
      conflict with statements in the candidate configuration, the loaded statements
      replace the candidate ones. C(override) discards the entire candidate configuration
      and replaces it with the loaded configuration. C(replace) substitutes each hierarchy
      level in the loaded configuration for the corresponding level. C(update) is
      similar to the override option. The new configuration completely replaces the
      existing configuration. The difference comes when the configuration is later
      committed. This option performs a 'diff' between the new candidate configuration
      and the existing committed configuration. It then only notifies system processes
      responsible for the changed portions of the configuration, and only marks the
      actual configuration changes as 'changed'.
    type: str
    default: merge
    choices:
    - merge
    - override
    - replace
    - update
  confirm_commit:
    description:
    - This argument will execute commit operation on remote device. It can be used
      to confirm a previous commit.
    type: bool
    default: false
  check_commit:
    description:
    - This argument will check correctness of syntax; do not apply changes.
    - Note that this argument can be used to confirm verified configuration done via
      commit confirmed operation
    type: bool
    default: false
  backup_options:
    description:
    - This is a dict object containing configurable options related to backup file
      path. The value of this option is read only when C(backup) is set to I(true),
      if C(backup) is set to I(false) this option will be silently ignored.
    suboptions:
      filename:
        description:
        - The filename to be used to store the backup configuration. If the filename
          is not given it will be generated based on the hostname, current time and
          date in format defined by <hostname>_config.<current-date>@<current-time>
        type: str
      dir_path:
        description:
        - This option provides the path ending with directory name in which the backup
          configuration file will be stored. If the directory does not exist it will
          be first created and the filename is either the value of C(filename) or
          default filename as described in C(filename) options description. If the
          path value is not given in that case a I(backup) directory will be created
          in the current working directory and backup configuration will be copied
          in C(filename) within I(backup) directory.
        type: path
      backup_format:
        description:
        - This argument specifies the format of the configuration the backup file will
          be stored as.  If the argument is not specified, the module will use the 'set'
          format.
        type: str
        default: set
        choices:
        - xml
        - set
        - text
        - json
    type: dict
requirements:
- ncclient (>=v0.5.2)
notes:
- This module requires the netconf system service be enabled on the remote device
  being managed.
- Abbreviated commands are NOT idempotent, see L(Network FAQ,../network/user_guide/faq.html)
- Loading JSON-formatted configuration I(json) is supported starting in Junos OS Release
  16.1 onwards.
- Update C(override) not currently compatible with C(set) notation.
- Tested against vSRX JUNOS version 15.1X49-D15.4, vqfx-10000 JUNOS Version 15.1X53-D60.4.
- Recommended connection is C(netconf). See L(the Junos OS Platform Options,../network/user_guide/platform_junos.html).
- This module also works with C(local) connections for legacy playbooks.
"""

EXAMPLES = """
- name: load configure file into device
  junipernetworks.junos.junos_config:
    src: srx.cfg
    comment: update config

- name: load configure lines into device
  junipernetworks.junos.junos_config:
    lines:
      - set interfaces ge-0/0/1 unit 0 description "Test interface"
      - set vlans vlan01 description "Test vlan"
    comment: update config

- name: Set routed VLAN interface (RVI) IPv4 address
  junipernetworks.junos.junos_config:
    lines:
      - set vlans vlan01 vlan-id 1
      - set interfaces irb unit 10 family inet address 10.0.0.1/24
      - set vlans vlan01 l3-interface irb.10

- name: Check correctness of commit configuration
  junipernetworks.junos.junos_config:
    check_commit: true

- name: rollback the configuration to id 10
  junipernetworks.junos.junos_config:
    rollback: 10

- name: zero out the current configuration
  junipernetworks.junos.junos_config:
    zeroize: true

- name: Set VLAN access and trunking
  junipernetworks.junos.junos_config:
    lines:
      - set vlans vlan02 vlan-id 6
      - set interfaces ge-0/0/6.0 family ethernet-switching interface-mode access vlan
        members vlan02
      - set interfaces ge-0/0/6.0 family ethernet-switching interface-mode trunk vlan
        members vlan02

- name: confirm a previous commit
  junipernetworks.junos.junos_config:
    confirm_commit: true

- name: for idempotency, use full-form commands
  junipernetworks.junos.junos_config:
    lines:
      - set interfaces ge-0/0/1 unit 0 description "Test interface"

- name: configurable backup path
  junipernetworks.junos.junos_config:
    src: srx.cfg
    backup: true
    backup_options:
      filename: backup.cfg
      dir_path: /home/user

- name: Set description with timer to confirm commit
  junipernetworks.junos.junos_config:
    lines:
      - set interfaces fxp0 description "wait for a commit confirmation for 3 minutes; otherwise, it will be rolled back."
    confirm: 3

- name: Perform confirm commit
  junipernetworks.junos.junos_config:
    confirm_commit: true
"""

RETURN = """
backup_path:
  description: The full path to the backup file
  returned: when backup is true
  type: str
  sample: /playbooks/ansible/backup/config.2016-07-16@22:28:34
filename:
  description: The name of the backup file
  returned: when backup is true and filename is not specified in backup options
  type: str
  sample: junos01_config.2016-07-16@22:28:34
shortname:
  description: The full path to the backup file excluding the timestamp
  returned: when backup is true and filename is not specified in backup options
  type: str
  sample: /playbooks/ansible/backup/junos01_config
date:
  description: The date extracted from the backup file name
  returned: when backup is true
  type: str
  sample: "2016-07-16"
time:
  description: The time extracted from the backup file name
  returned: when backup is true
  type: str
  sample: "22:28:34"
"""
import json
import re

from ansible.module_utils._text import to_native, to_text
from ansible.module_utils.basic import AnsibleModule
from ansible.module_utils.six import string_types
from ansible_collections.ansible.netcommon.plugins.module_utils.network.common.netconf import (
    exec_rpc,
)

from ansible_collections.junipernetworks.junos.plugins.module_utils.network.junos.junos import (
    commit_configuration,
    discard_changes,
    get_configuration,
    get_diff,
    load_config,
    load_configuration,
    locked_config,
    tostring,
)


try:
    from lxml.etree import Element, fromstring
except ImportError:
    from xml.etree.ElementTree import Element, fromstring

try:
    from lxml.etree import ParseError
except ImportError:
    try:
        from xml.etree.ElementTree import ParseError
    except ImportError:
        # for Python < 2.7
        from xml.parsers.expat import ExpatError

        ParseError = ExpatError

USE_PERSISTENT_CONNECTION = True
DEFAULT_COMMENT = "configured by junos_config"


def check_args(module, warnings):
    if module.params["replace"] is not None:
        module.fail_json(msg="argument replace is deprecated, use update")


def zeroize(module):
    return exec_rpc(
        module,
        tostring(Element("request-system-zeroize")),
        ignore_warning=False,
    )


def rollback(ele, id="0"):
    return get_diff(ele, id)


def guess_format(config):
    try:
        json.loads(config)
        return "json"
    except ValueError:
        pass

    try:
        fromstring(config)
        return "xml"
    except ParseError:
        pass

    if config.startswith("set") or config.startswith("delete"):
        return "set"

    return "text"


def filter_delete_statements(module, candidate):
    reply = get_configuration(module, format="set")
    match = reply.find(".//configuration-set")
    if match is None:
        # Could not find configuration-set in reply, perhaps device does not support it?
        return candidate
    config = to_native(match.text, encoding="latin-1")

    modified_candidate = candidate[:]
    for index, line in reversed(list(enumerate(candidate))):
        if line.startswith("delete"):
            newline = re.sub("^delete", "set", line)
            if newline not in config:
                del modified_candidate[index]

    return modified_candidate


def configure_device(module, warnings, candidate):
    kwargs = {}
    config_format = None

    if module.params["src"]:
        config_format = module.params["src_format"] or guess_format(
            str(candidate),
        )
        if config_format == "set":
            kwargs.update({"format": "text", "action": "set"})
        else:
            kwargs.update(
                {"format": config_format, "action": module.params["update"]},
            )

    if isinstance(candidate, string_types):
        candidate = candidate.split("\n")

    # this is done to filter out `delete ...` statements which map to
    # nothing in the config as that will cause an exception to be raised
    if any((module.params["lines"], config_format == "set")):
        candidate = filter_delete_statements(module, candidate)
        kwargs["format"] = "text"
        kwargs["action"] = "set"

    return load_config(module, candidate, warnings, **kwargs)


def main():
    """main entry point for module execution"""
    backup_spec = dict(
        filename=dict(),
        dir_path=dict(type="path"),
        backup_format=dict(
            default="set",
            choices=["xml", "text", "set", "json"],
        ),
    )
    argument_spec = dict(
        lines=dict(aliases=["commands"], type="list", elements="str"),
        src=dict(type="path"),
        src_format=dict(choices=["xml", "text", "set", "json"]),
        # update operations
        update=dict(
            default="merge",
            choices=["merge", "override", "replace", "update"],
        ),
        # deprecated replace in Ansible 2.3
        replace=dict(type="bool"),
        confirm=dict(default=0, type="int"),
        comment=dict(default=DEFAULT_COMMENT),
        confirm_commit=dict(type="bool", default=False),
        check_commit=dict(type="bool", default=False),
        # config operations
        backup=dict(type="bool", default=False),
        backup_options=dict(type="dict", options=backup_spec),
        rollback=dict(type="int"),
        zeroize=dict(default=False, type="bool"),
    )

    mutually_exclusive = [("lines", "src", "rollback", "zeroize")]

    module = AnsibleModule(
        argument_spec=argument_spec,
        mutually_exclusive=mutually_exclusive,
        supports_check_mode=True,
    )

    warnings = list()
    check_args(module, warnings)

    candidate = module.params["lines"] or module.params["src"]
    commit = not module.check_mode

    result = {"changed": False, "warnings": warnings}

    if module.params["backup"]:
        if module.params["backup_options"] is not None:
            conf_format = module.params["backup_options"]["backup_format"]
        else:
            conf_format = "set"
        reply = get_configuration(module, format=conf_format)
        if reply is None:
            module.fail_json(msg="unable to retrieve device configuration")
        else:
            if conf_format in ["set", "text"]:
                reply = reply.find(
                    ".//configuration-%s" % conf_format,
                ).text.strip()
            elif conf_format in "xml":
                reply = str(
                    tostring(reply.find(".//configuration"), pretty_print=True),
                ).strip()
            elif conf_format in "json":
                reply = str(reply.xpath("//rpc-reply/text()")[0]).strip()
            if not isinstance(reply, str):
                module.fail_json(
                    msg="unable to format retrieved device configuration",
                )
            result["__backup__"] = reply

    rollback_id = module.params["rollback"]
    if isinstance(rollback_id, int) and rollback_id >= 0:
        diff = rollback(module, rollback_id)
        if commit:
            kwargs = {"comment": module.params["comment"]}
            with locked_config(module):
                load_configuration(module, rollback=rollback_id)
                commit_configuration(module, **kwargs)
            if module._diff:
                result["diff"] = {"prepared": diff}
        result["changed"] = True

    elif module.params["zeroize"]:
        if commit:
            zeroize(module)
        result["changed"] = True

    else:
        if candidate:
            with locked_config(module):
                diff = configure_device(module, warnings, candidate)
                if diff:
                    if commit:
                        kwargs = {
                            "comment": module.params["comment"],
                            "check": module.params["check_commit"],
                        }

                        confirm = module.params["confirm"]
                        if confirm > 0:
                            kwargs.update(
                                {
                                    "confirm": True,
                                    "confirm_timeout": to_text(
                                        confirm,
                                        errors="surrogate_then_replace",
                                    ),
                                },
                            )
                        commit_configuration(module, **kwargs)
                    else:
                        discard_changes(module)
                    result["changed"] = True

                    if module._diff:
                        result["diff"] = {"prepared": diff}

        elif module.params["check_commit"]:
            commit_configuration(module, check=True)

        elif module.params["confirm_commit"]:
            with locked_config(module):
                # confirm a previous commit
                commit_configuration(module)

            result["changed"] = True

    module.exit_json(**result)


if __name__ == "__main__":
    main()