#
# -*- coding: utf-8 -*-
# Copyright 2019 Red Hat
# GNU General Public License v3.0+
# (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
"""
The iosxr_lldp_interfaces class
It is in this file where the current configuration (as dict)
is compared to the provided configuration (as dict) and the command set
necessary to bring the current configuration to it's desired end-state is
created
"""

from __future__ import absolute_import, division, print_function


__metaclass__ = type


from ansible.module_utils.six import iteritems
from ansible_collections.ansible.netcommon.plugins.module_utils.network.common.cfg.base import (
    ConfigBase,
)
from ansible_collections.ansible.netcommon.plugins.module_utils.network.common.utils import (
    dict_diff,
    remove_empties,
    search_obj_in_list,
    to_list,
)

from ansible_collections.cisco.iosxr.plugins.module_utils.network.iosxr.facts.facts import Facts
from ansible_collections.cisco.iosxr.plugins.module_utils.network.iosxr.utils.utils import (
    dict_delete,
    flatten_dict,
    pad_commands,
)


class Lldp_interfaces(ConfigBase):
    """
    The iosxr_lldp_interfaces class
    """

    gather_subset = ["!all", "!min"]

    gather_network_resources = ["lldp_interfaces"]

    def __init__(self, module):
        super(Lldp_interfaces, self).__init__(module)

    def get_lldp_interfaces_facts(self, data=None):
        """Get the 'facts' (the current configuration)

        :rtype: A dictionary
        :returns: The current configuration as a dictionary
        """
        facts, _warnings = Facts(self._module).get_facts(
            self.gather_subset,
            self.gather_network_resources,
            data=data,
        )
        lldp_interfaces_facts = facts["ansible_network_resources"].get(
            "lldp_interfaces",
        )
        if not lldp_interfaces_facts:
            return []
        return lldp_interfaces_facts

    def execute_module(self):
        """Execute the module

        :rtype: A dictionary
        :returns: The result from module execution
        """
        result = {"changed": False}
        warnings = list()
        commands = list()

        if self.state in self.ACTION_STATES:
            existing_lldp_interfaces_facts = self.get_lldp_interfaces_facts()
        else:
            existing_lldp_interfaces_facts = []

        if self.state in self.ACTION_STATES or self.state == "rendered":
            commands.extend(self.set_config(existing_lldp_interfaces_facts))

        if commands and self.state in self.ACTION_STATES:
            if not self._module.check_mode:
                self._connection.edit_config(commands)
            result["changed"] = True

        if self.state in self.ACTION_STATES:
            result["commands"] = commands

        if self.state in self.ACTION_STATES or self.state == "gathered":
            changed_lldp_interfaces_facts = self.get_lldp_interfaces_facts()
        elif self.state == "rendered":
            result["rendered"] = commands

        elif self.state == "parsed":
            running_config = self._module.params["running_config"]
            if not running_config:
                self._module.fail_json(
                    msg="value of running_config parameter must not be empty for state parsed",
                )
            result["parsed"] = self.get_lldp_interfaces_facts(
                data=running_config,
            )

        if self.state in self.ACTION_STATES:
            result["before"] = existing_lldp_interfaces_facts
            if result["changed"]:
                result["after"] = changed_lldp_interfaces_facts
        elif self.state == "gathered":
            result["gathered"] = changed_lldp_interfaces_facts

        result["warnings"] = warnings
        return result

    def set_config(self, existing_lldp_interfaces_facts):
        """Collect the configuration from the args passed to the module,
            collect the current configuration (as a dict from facts)

        :rtype: A list
        :returns: the commands necessary to migrate the current configuration
                  to the desired configuration
        """
        want = self._module.params["config"]
        have = existing_lldp_interfaces_facts
        resp = self.set_state(want, have)
        return to_list(resp)

    def set_state(self, want, have):
        """Select the appropriate function based on the state provided

        :param want: the desired configuration as a dictionary
        :param have: the current configuration as a dictionary
        :rtype: A list
        :returns: the commands necessary to migrate the current configuration
                  to the desired configuration
        """
        state = self._module.params["state"]
        commands = []
        if state in ("overridden", "merged", "replaced", "rendered") and not want:
            self._module.fail_json(
                msg="value of config parameter must not be empty for state {0}".format(
                    state,
                ),
            )

        if state == "overridden":
            commands.extend(self._state_overridden(want, have))

        elif state == "deleted":
            if not want:
                for intf in have:
                    commands.extend(
                        self._state_deleted({"name": intf["name"]}, intf),
                    )
            else:
                for item in want:
                    obj_in_have = search_obj_in_list(item["name"], have)
                    commands.extend(self._state_deleted(item, obj_in_have))

        else:
            for item in want:
                name = item["name"]
                obj_in_have = search_obj_in_list(name, have)

                if state in ("merged", "rendered"):
                    commands.extend(self._state_merged(item, obj_in_have))

                elif state == "replaced":
                    commands.extend(self._state_replaced(item, obj_in_have))

        return commands

    def _state_replaced(self, want, have):
        """The command generator when state is replaced

        :rtype: A list
        :returns: the commands necessary to migrate the current configuration
                  to the desired configuration
        """
        commands = []
        replaced_commands = []
        merged_commands = []

        if have:
            replaced_commands = self._state_deleted(want, have)

        merged_commands = self._state_merged(want, have)

        if merged_commands and replaced_commands:
            del merged_commands[0]

        commands.extend(replaced_commands)
        commands.extend(merged_commands)

        return commands

    def _state_overridden(self, want, have):
        """The command generator when state is overridden

        :rtype: A list
        :returns: the commands necessary to migrate the current configuration
                  to the desired configuration
        """
        commands = []

        for intf in have:
            intf_in_want = search_obj_in_list(intf["name"], want)
            if not intf_in_want:
                commands.extend(
                    self._state_deleted({"name": intf["name"]}, intf),
                )

        for intf in want:
            intf_in_have = search_obj_in_list(intf["name"], have)
            commands.extend(self._state_replaced(intf, intf_in_have))

        return commands

    def _state_merged(self, want, have):
        """The command generator when state is merged

        :rtype: A list
        :returns: the commands necessary to merge the provided into
                  the current configuration
        """
        commands = []
        if not have:
            have = {"name": want["name"]}

        for key, value in iteritems(
            flatten_dict(remove_empties(dict_diff(have, want))),
        ):
            commands.append(self._compute_commands(key, value))

        if commands:
            pad_commands(commands, want["name"])

        return commands

    def _state_deleted(self, want, have):
        """The command generator when state is deleted

        :rtype: A list
        :returns: the commands necessary to remove the current configuration
                  of the provided objects
        """
        commands = []

        for key, value in iteritems(
            flatten_dict(dict_delete(have, remove_empties(want))),
        ):
            commands.append(self._compute_commands(key, value, remove=True))

        if commands:
            pad_commands(commands, have["name"])

        return commands

    def _compute_commands(self, key, value=None, remove=False):
        if key == "mac_address":
            cmd = "lldp destination mac-address {0}".format(value)
            if remove:
                return "no {0}".format(cmd)
            else:
                return cmd

        else:
            cmd = "lldp {0} disable".format(key)
            if not value and not remove:
                return cmd
            elif (value and not remove) or (not value and remove):
                return "no {0}".format(cmd)
