#!/usr/bin/python
# -*- coding: utf-8 -*-
from __future__ import absolute_import, division, print_function

__metaclass__ = type

# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)


DOCUMENTATION = """
module: nxos_snapshot
extends_documentation_fragment:
- cisco.nxos.nxos
short_description: Manage snapshots of the running states of selected features.
description:
- Create snapshots of the running states of selected features, add new show commands
  for snapshot creation, delete and compare existing snapshots.
version_added: 1.0.0
author:
- Gabriele Gerbino (@GGabriele)
notes:
- Tested against NXOSv 7.3.(0)D1(1) on VIRL
- C(transport=cli) may cause timeout errors.
- The C(element_key1) and C(element_key2) parameter specify the tags used to distinguish
  among row entries. In most cases, only the element_key1 parameter needs to specified
  to be able to distinguish among row entries.
- C(action=compare) will always store a comparison report on a local file.
options:
  action:
    description:
    - Define what snapshot action the module would perform.
    required: true
    choices:
    - add
    - compare
    - create
    - delete
    - delete_all
  snapshot_name:
    description:
    - Snapshot name, to be used when C(action=create) or C(action=delete).
  description:
    description:
    - Snapshot description to be used when C(action=create).
  snapshot1:
    description:
    - First snapshot to be used when C(action=compare).
  snapshot2:
    description:
    - Second snapshot to be used when C(action=compare).
  comparison_results_file:
    description:
    - Name of the file where snapshots comparison will be stored when C(action=compare).
  compare_option:
    description:
    - Snapshot options to be used when C(action=compare).
    choices:
    - summary
    - ipv4routes
    - ipv6routes
  section:
    description:
    - Used to name the show command output, to be used when C(action=add).
  show_command:
    description:
    - Specify a new show command, to be used when C(action=add).
  row_id:
    description:
    - Specifies the tag of each row entry of the show command's XML output, to be
      used when C(action=add).
  element_key1:
    description:
    - Specify the tags used to distinguish among row entries, to be used when C(action=add).
  element_key2:
    description:
    - Specify the tags used to distinguish among row entries, to be used when C(action=add).
  save_snapshot_locally:
    description:
    - Specify to locally store a new created snapshot, to be used when C(action=create).
    type: bool
    default: no
  path:
    description:
    - Specify the path of the file where new created snapshot or snapshots comparison
      will be stored, to be used when C(action=create) and C(save_snapshot_locally=true)
      or C(action=compare).
    default: ./
"""

EXAMPLES = """
# Create a snapshot and store it locally
- cisco.nxos.nxos_snapshot:
    action: create
    snapshot_name: test_snapshot
    description: Done with Ansible
    save_snapshot_locally: true
    path: /home/user/snapshots/

# Delete a snapshot
- cisco.nxos.nxos_snapshot:
    action: delete
    snapshot_name: test_snapshot

# Delete all existing snapshots
- cisco.nxos.nxos_snapshot:
    action: delete_all

# Add a show command for snapshots creation
- cisco.nxos.nxos_snapshot:
    section: myshow
    show_command: show ip interface brief
    row_id: ROW_intf
    element_key1: intf-name

# Compare two snapshots
- cisco.nxos.nxos_snapshot:
    action: compare
    snapshot1: pre_snapshot
    snapshot2: post_snapshot
    comparison_results_file: compare_snapshots.txt
    compare_option: summary
    path: ../snapshot_reports/
"""

RETURN = """
commands:
    description: commands sent to the device
    returned: verbose mode
    type: list
    sample: ["snapshot create post_snapshot Post-snapshot"]
"""

import os
import re

from ansible.module_utils.basic import AnsibleModule
from ansible_collections.cisco.nxos.plugins.module_utils.network.nxos.nxos import (
    load_config,
    run_commands,
)
from ansible_collections.cisco.nxos.plugins.module_utils.network.nxos.nxos import (
    nxos_argument_spec,
)


def execute_show_command(command, module):
    command = [{"command": command, "output": "text"}]

    return run_commands(module, command)


def get_existing(module):
    existing = []
    command = "show snapshots"

    body = execute_show_command(command, module)[0]
    if body:
        split_body = body.splitlines()
        snapshot_regex = (
            r"(?P<name>\S+)\s+(?P<date>\w+\s+\w+\s+\d+\s+\d+"
            r":\d+:\d+\s+\d+)\s+(?P<description>.*)"
        )
        for snapshot in split_body:
            temp = {}
            try:
                match_snapshot = re.match(snapshot_regex, snapshot, re.DOTALL)
                snapshot_group = match_snapshot.groupdict()
                temp["name"] = snapshot_group["name"]
                temp["date"] = snapshot_group["date"]
                temp["description"] = snapshot_group["description"]
                existing.append(temp)
            except AttributeError:
                pass

    return existing


def action_create(module, existing_snapshots):
    commands = list()
    exist = False
    for snapshot in existing_snapshots:
        if module.params["snapshot_name"] == snapshot["name"]:
            exist = True

    if exist is False:
        commands.append(
            "snapshot create {0} {1}".format(
                module.params["snapshot_name"], module.params["description"]
            )
        )

    return commands


def action_add(module, existing_snapshots):
    commands = list()
    command = "show snapshot sections"
    sections = []
    body = execute_show_command(command, module)[0]

    if body:
        section_regex = r".*\[(?P<section>\S+)\].*"
        split_body = body.split("\n\n")
        for section in split_body:
            temp = {}
            for line in section.splitlines():
                try:
                    match_section = re.match(section_regex, section, re.DOTALL)
                    temp["section"] = match_section.groupdict()["section"]
                except (AttributeError, KeyError):
                    pass

                if "show command" in line:
                    temp["show_command"] = line.split("show command: ")[1]
                elif "row id" in line:
                    temp["row_id"] = line.split("row id: ")[1]
                elif "key1" in line:
                    temp["element_key1"] = line.split("key1: ")[1]
                elif "key2" in line:
                    temp["element_key2"] = line.split("key2: ")[1]

            if temp:
                sections.append(temp)

    proposed = {
        "section": module.params["section"],
        "show_command": module.params["show_command"],
        "row_id": module.params["row_id"],
        "element_key1": module.params["element_key1"],
        "element_key2": module.params["element_key2"] or "-",
    }

    if proposed not in sections:
        if module.params["element_key2"]:
            commands.append(
                'snapshot section add {0} "{1}" {2} {3} {4}'.format(
                    module.params["section"],
                    module.params["show_command"],
                    module.params["row_id"],
                    module.params["element_key1"],
                    module.params["element_key2"],
                )
            )
        else:
            commands.append(
                'snapshot section add {0} "{1}" {2} {3}'.format(
                    module.params["section"],
                    module.params["show_command"],
                    module.params["row_id"],
                    module.params["element_key1"],
                )
            )

    return commands


def action_compare(module, existing_snapshots):
    command = "show snapshot compare {0} {1}".format(
        module.params["snapshot1"], module.params["snapshot2"]
    )

    if module.params["compare_option"]:
        command += " {0}".format(module.params["compare_option"])

    body = execute_show_command(command, module)[0]
    return body


def action_delete(module, existing_snapshots):
    commands = list()

    exist = False
    for snapshot in existing_snapshots:
        if module.params["snapshot_name"] == snapshot["name"]:
            exist = True

    if exist:
        commands.append(
            "snapshot delete {0}".format(module.params["snapshot_name"])
        )

    return commands


def action_delete_all(module, existing_snapshots):
    commands = list()
    if existing_snapshots:
        commands.append("snapshot delete all")
    return commands


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


def write_on_file(content, filename, module):
    path = module.params["path"]
    if path[-1] != "/":
        path += "/"
    filepath = "{0}{1}".format(path, filename)
    try:
        report = open(filepath, "w")
        report.write(content)
        report.close()
    except Exception:
        module.fail_json(msg="Error while writing on file.")

    return filepath


def main():
    argument_spec = dict(
        action=dict(
            required=True,
            choices=["create", "add", "compare", "delete", "delete_all"],
        ),
        snapshot_name=dict(type="str"),
        description=dict(type="str"),
        snapshot1=dict(type="str"),
        snapshot2=dict(type="str"),
        compare_option=dict(choices=["summary", "ipv4routes", "ipv6routes"]),
        comparison_results_file=dict(type="str"),
        section=dict(type="str"),
        show_command=dict(type="str"),
        row_id=dict(type="str"),
        element_key1=dict(type="str"),
        element_key2=dict(type="str"),
        save_snapshot_locally=dict(type="bool", default=False),
        path=dict(type="str", default="./"),
    )

    argument_spec.update(nxos_argument_spec)

    required_if = [
        (
            "action",
            "compare",
            ["snapshot1", "snapshot2", "comparison_results_file"],
        ),
        ("action", "create", ["snapshot_name", "description"]),
        (
            "action",
            "add",
            ["section", "show_command", "row_id", "element_key1"],
        ),
        ("action", "delete", ["snapshot_name"]),
    ]

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

    action = module.params["action"]
    comparison_results_file = module.params["comparison_results_file"]

    if not os.path.isdir(module.params["path"]):
        module.fail_json(
            msg="{0} is not a valid directory name.".format(
                module.params["path"]
            )
        )

    existing_snapshots = invoke("get_existing", module)
    action_results = invoke("action_%s" % action, module, existing_snapshots)

    result = {"changed": False, "commands": []}

    if not module.check_mode:
        if action == "compare":
            result["commands"] = []

            if module.params["path"] and comparison_results_file:
                snapshot1 = module.params["snapshot1"]
                snapshot2 = module.params["snapshot2"]
                compare_option = module.params["compare_option"]
                command = "show snapshot compare {0} {1}".format(
                    snapshot1, snapshot2
                )
                if compare_option:
                    command += " {0}".format(compare_option)
                content = execute_show_command(command, module)[0]
                if content:
                    write_on_file(content, comparison_results_file, module)
        else:
            if action_results:
                load_config(module, action_results)
                result["commands"] = action_results
                result["changed"] = True

            if (
                action == "create"
                and module.params["path"]
                and module.params["save_snapshot_locally"]
            ):
                command = "show snapshot dump {0} | json".format(
                    module.params["snapshot_name"]
                )
                content = execute_show_command(command, module)[0]
                if content:
                    write_on_file(
                        str(content), module.params["snapshot_name"], module
                    )

    module.exit_json(**result)


if __name__ == "__main__":
    main()
