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

__metaclass__ = type

# Copyright: (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)


DOCUMENTATION = """
module: eos_logging
author: Trishna Guha (@trishnaguha)
short_description: Manage logging on network devices
description:
- This module provides declarative management of logging on Arista Eos devices.
version_added: 1.0.0
notes:
- Tested against EOS 4.15
options:
  dest:
    description:
    - Destination of the logs.
    choices:
    - on
    - host
    - console
    - monitor
    - buffered
  name:
    description:
    - The hostname or IP address of the destination.
    - Required when I(dest=host).
  size:
    description:
    - Size of buffer. The acceptable value is in range from 10 to 2147483647 bytes.
  facility:
    description:
    - Set logging facility.
  level:
    description:
    - Set logging severity levels.
    choices:
    - emergencies
    - alerts
    - critical
    - errors
    - warnings
    - notifications
    - informational
    - debugging
  aggregate:
    description: List of logging definitions.
  state:
    description:
    - State of the logging configuration.
    default: present
    choices:
    - present
    - absent
extends_documentation_fragment:
- arista.eos.eos
"""

EXAMPLES = """
- name: configure host logging
  arista.eos.eos_logging:
    dest: host
    name: 172.16.0.1
    state: present

- name: remove host logging configuration
  arista.eos.eos_logging:
    dest: host
    name: 172.16.0.1
    state: absent

- name: configure console logging level and facility
  arista.eos.eos_logging:
    dest: console
    facility: local7
    level: debugging
    state: present

- name: enable logging to all
  arista.eos.eos_logging:
    dest: on

- name: configure buffer size
  arista.eos.eos_logging:
    dest: buffered
    size: 5000

- name: Configure logging using aggregate
  arista.eos.eos_logging:
    aggregate:
    - {dest: console, level: warnings}
    - {dest: buffered, size: 480000}
    state: present
"""

RETURN = """
commands:
  description: The list of configuration mode commands to send to the device
  returned: always
  type: list
  sample:
    - logging facility local7
    - logging host 172.16.0.1
"""

import re


from copy import deepcopy
from ansible.module_utils.basic import AnsibleModule
from ansible_collections.ansible.netcommon.plugins.module_utils.network.common.utils import (
    remove_default_spec,
)
from ansible_collections.arista.eos.plugins.module_utils.network.eos.eos import (
    get_config,
    load_config,
)
from ansible_collections.arista.eos.plugins.module_utils.network.eos.eos import (
    eos_argument_spec,
)


DEST_GROUP = ["on", "host", "console", "monitor", "buffered"]
LEVEL_GROUP = [
    "emergencies",
    "alerts",
    "critical",
    "errors",
    "warnings",
    "notifications",
    "informational",
    "debugging",
]


def validate_size(value, module):
    if value:
        if not int(10) <= value <= int(2147483647):
            module.fail_json(msg="size must be between 10 and 2147483647")
        else:
            return value


def map_obj_to_commands(updates, module):
    commands = list()
    want, have = updates

    for w in want:
        dest = w["dest"]
        name = w["name"]
        size = w["size"]
        facility = w["facility"]
        level = w["level"]
        state = w["state"]
        del w["state"]

        if state == "absent" and w in have:
            if dest:
                if dest == "host":
                    commands.append("no logging host {0}".format(name))

                elif dest in DEST_GROUP:
                    commands.append("no logging {0}".format(dest))

                else:
                    module.fail_json(
                        msg="dest must be among console, monitor, buffered, host, on"
                    )

            if facility:
                commands.append("no logging facility {0}".format(facility))

        if state == "present" and w not in have:
            if facility:
                present = False

                # Iterate over every dictionary in the 'have' list to check if
                # similar configuration for facility exists or not

                for entry in have:
                    if not entry["dest"] and entry["facility"] == facility:
                        present = True

                if not present:
                    commands.append("logging facility {0}".format(facility))

            if dest == "host":
                commands.append("logging host {0}".format(name))

            elif dest == "on":
                commands.append("logging on")

            elif dest == "buffered" and size:

                present = False

                # Deals with the following two cases:
                # Case 1:       logging buffered <size> <level>
                #               logging buffered <same-size>
                #
                # Case 2:       Same buffered logging configuration
                #               already exists (i.e., both size &
                #               level are same)

                for entry in have:
                    if entry["dest"] == "buffered" and entry["size"] == size:

                        if not level or entry["level"] == level:
                            present = True

                if not present:
                    if size and level:
                        commands.append(
                            "logging buffered {0} {1}".format(size, level)
                        )
                    else:
                        commands.append("logging buffered {0}".format(size))

            else:
                if dest:
                    dest_cmd = "logging {0}".format(dest)
                    if level:
                        dest_cmd += " {0}".format(level)

                    commands.append(dest_cmd)
    return commands


def parse_facility(line):
    facility = None
    match = re.search(r"logging facility (\S+)", line, re.M)
    if match:
        facility = match.group(1)

    return facility


def parse_size(line, dest):
    size = None

    if dest == "buffered":
        match = re.search(r"logging buffered (\S+)", line, re.M)
        if match:
            try:
                int_size = int(match.group(1))
            except ValueError:
                int_size = None

            if int_size:
                if isinstance(int_size, int):
                    size = str(match.group(1))
                else:
                    size = str(10)

    return size


def parse_name(line, dest):
    name = None
    if dest == "host":
        match = re.search(r"logging host (\S+)", line, re.M)
        if match:
            name = match.group(1)

    return name


def parse_level(line, dest):
    level = None

    if dest != "host":

        # Line for buffer logging entry in running-config is of the form:
        # logging buffered <size> <level>

        if dest == "buffered":
            match = re.search(r"logging buffered (?:\d+) (\S+)", line, re.M)

        else:
            match = re.search(r"logging {0} (\S+)".format(dest), line, re.M)

        if match:
            if match.group(1) in LEVEL_GROUP:
                level = match.group(1)

    return level


def map_config_to_obj(module):
    obj = []

    data = get_config(module, flags=["section logging"])

    for line in data.split("\n"):

        match = re.search(r"logging (\S+)", line, re.M)

        if match:
            if match.group(1) in DEST_GROUP:
                dest = match.group(1)

            else:
                dest = None

            obj.append(
                {
                    "dest": dest,
                    "name": parse_name(line, dest),
                    "size": parse_size(line, dest),
                    "facility": parse_facility(line),
                    "level": parse_level(line, dest),
                }
            )

    return obj


def parse_obj(obj, module):
    if module.params["size"] is None:
        obj.append(
            {
                "dest": module.params["dest"],
                "name": module.params["name"],
                "size": module.params["size"],
                "facility": module.params["facility"],
                "level": module.params["level"],
                "state": module.params["state"],
            }
        )

    else:
        obj.append(
            {
                "dest": module.params["dest"],
                "name": module.params["name"],
                "size": str(validate_size(module.params["size"], module)),
                "facility": module.params["facility"],
                "level": module.params["level"],
                "state": module.params["state"],
            }
        )

    return obj


def map_params_to_obj(module, required_if=None):
    obj = []
    aggregate = module.params.get("aggregate")
    if aggregate:
        for item in aggregate:
            for key in item:
                if item.get(key) is None:
                    item[key] = module.params[key]

            module._check_required_if(required_if, item)
            d = item.copy()

            if d["dest"] != "host":
                d["name"] = None

            if d["dest"] == "buffered":
                if "size" in d:
                    d["size"] = str(validate_size(d["size"], module))
                elif "size" not in d:
                    d["size"] = str(10)
                else:
                    pass

            if d["dest"] != "buffered":
                d["size"] = None

            obj.append(d)

    else:
        if module.params["dest"] != "host":
            module.params["name"] = None

        if module.params["dest"] == "buffered":
            if not module.params["size"]:
                module.params["size"] = str(10)
        else:
            module.params["size"] = None

        parse_obj(obj, module)

    return obj


def main():
    """ main entry point for module execution
    """
    element_spec = dict(
        dest=dict(choices=DEST_GROUP),
        name=dict(),
        size=dict(type="int"),
        facility=dict(),
        level=dict(choices=LEVEL_GROUP),
        state=dict(default="present", choices=["present", "absent"]),
    )

    aggregate_spec = deepcopy(element_spec)

    # remove default in aggregate spec, to handle common arguments
    remove_default_spec(aggregate_spec)

    argument_spec = dict(
        aggregate=dict(type="list", elements="dict", options=aggregate_spec)
    )

    argument_spec.update(element_spec)
    argument_spec.update(eos_argument_spec)

    required_if = [("dest", "host", ["name"])]

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

    warnings = list()

    result = {"changed": False}
    if warnings:
        result["warnings"] = warnings

    have = map_config_to_obj(module)
    want = map_params_to_obj(module, required_if=required_if)

    commands = map_obj_to_commands((want, have), module)
    result["commands"] = commands

    if commands:
        commit = not module.check_mode
        response = load_config(module, commands, commit=commit)
        if response.get("diff") and module._diff:
            result["diff"] = {"prepared": response.get("diff")}
        result["session_name"] = response.get("session")
        result["changed"] = True

    module.exit_json(**result)


if __name__ == "__main__":
    main()
