#
# -*- 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 ios_vlans 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_collections.ansible.netcommon.plugins.module_utils.network.common.cfg.base import (
    ConfigBase,
)
from ansible_collections.ansible.netcommon.plugins.module_utils.network.common.utils import (
    to_list,
)
from ansible_collections.cisco.ios.plugins.module_utils.network.ios.facts.facts import (
    Facts,
)
from ansible_collections.cisco.ios.plugins.module_utils.network.ios.utils.utils import (
    dict_to_set,
)


class Vlans(ConfigBase):
    """
    The ios_vlans class
    """

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

    gather_network_resources = ["vlans"]

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

    def get_vlans_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
        )
        interfaces_facts = facts["ansible_network_resources"].get("vlans")
        if not interfaces_facts:
            return []
        return interfaces_facts

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

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

        if self.state in self.ACTION_STATES:
            existing_vlans_facts = self.get_vlans_facts()
        else:
            existing_vlans_facts = []

        if self.state in self.ACTION_STATES or self.state == "rendered":
            commands.extend(self.set_config(existing_vlans_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_vlans_facts = self.get_vlans_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_vlans_facts(data=running_config)
        else:
            changed_vlans_facts = []

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

        result["warnings"] = warnings
        return result

    def set_config(self, existing_vlans_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_vlans_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
        """

        if (
            self.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(
                    self.state
                )
            )

        if self.state == "overridden":
            commands = self._state_overridden(want, have)
        elif self.state == "deleted":
            commands = self._state_deleted(want, have)
        elif self.state in ("merged", "rendered"):
            commands = self._state_merged(want, have)
        elif self.state == "replaced":
            commands = self._state_replaced(want, 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 = []

        check = False
        for each in want:
            for every in have:
                if every["vlan_id"] == each["vlan_id"]:
                    check = True
                    break
                continue
            if check:
                commands.extend(self._set_config(each, every))
            else:
                commands.extend(self._set_config(each, dict()))

        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 = []

        want_local = want
        for each in have:
            count = 0
            for every in want_local:
                if each["vlan_id"] == every["vlan_id"]:
                    break
                count += 1
            else:
                # We didn't find a matching desired state, which means we can
                # pretend we received an empty desired state.
                commands.extend(self._clear_config(every, each))
                continue
            commands.extend(self._set_config(every, each))
            # as the pre-existing VLAN are now configured by
            # above set_config call, deleting the respective
            # VLAN entry from the want_local list
            del want_local[count]

        # Iterating through want_local list which now only have new VLANs to be
        # configured
        for each in want_local:
            commands.extend(self._set_config(each, dict()))

        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 = []

        check = False
        for each in want:
            for every in have:
                if each.get("vlan_id") == every.get("vlan_id"):
                    check = True
                    break
                continue
            if check:
                commands.extend(self._set_config(each, every))
            else:
                commands.extend(self._set_config(each, dict()))

        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 = []

        if want:
            check = False
            for each in want:
                for every in have:
                    if each.get("vlan_id") == every.get("vlan_id"):
                        check = True
                        break
                    check = False
                    continue
                if check:
                    commands.extend(self._clear_config(each, every))
        else:
            for each in have:
                commands.extend(self._clear_config(dict(), each))

        return commands

    def remove_command_from_config_list(self, vlan, cmd, commands):
        if vlan not in commands and cmd != "vlan":
            commands.insert(0, vlan)
        elif cmd == "vlan":
            commands.append("no %s" % vlan)
            return commands
        commands.append("no %s" % cmd)
        return commands

    def add_command_to_config_list(self, vlan_id, cmd, commands):
        if vlan_id not in commands:
            commands.insert(0, vlan_id)
        if cmd not in commands:
            commands.append(cmd)

    def _set_config(self, want, have):
        # Set the interface config based on the want and have config
        commands = []
        vlan = "vlan {0}".format(want.get("vlan_id"))

        def negate_have_config(want_diff, have_diff, vlan, commands):
            name = dict(have_diff).get("name")
            if name and not dict(want_diff).get("name"):
                self.remove_command_from_config_list(
                    vlan, "name {0}".format(name), commands
                )
            state = dict(have_diff).get("state")
            if state and not dict(want_diff).get("state"):
                self.remove_command_from_config_list(
                    vlan, "state {0}".format(state), commands
                )
            shutdown = dict(have_diff).get("shutdown")
            if shutdown and not dict(want_diff).get("shutdown"):
                self.remove_command_from_config_list(
                    vlan, "shutdown", commands
                )
            mtu = dict(have_diff).get("mtu")
            if mtu and not dict(want_diff).get("mtu"):
                self.remove_command_from_config_list(
                    vlan, "mtu {0}".format(mtu), commands
                )
            remote_span = dict(have_diff).get("remote_span")
            if remote_span and not dict(want_diff).get("remote_span"):
                self.remove_command_from_config_list(
                    vlan, "remote-span", commands
                )

        # Get the diff b/w want n have
        want_dict = dict_to_set(want)
        have_dict = dict_to_set(have)
        diff = want_dict - have_dict
        have_diff = have_dict - want_dict

        if diff:
            if have_diff and (
                self.state == "replaced" or self.state == "overridden"
            ):
                negate_have_config(diff, have_diff, vlan, commands)

            name = dict(diff).get("name")
            state = dict(diff).get("state")
            shutdown = dict(diff).get("shutdown")
            mtu = dict(diff).get("mtu")
            remote_span = dict(diff).get("remote_span")
            if name:
                self.add_command_to_config_list(
                    vlan, "name {0}".format(name), commands
                )
            if state:
                self.add_command_to_config_list(
                    vlan, "state {0}".format(state), commands
                )
            if mtu:
                self.add_command_to_config_list(
                    vlan, "mtu {0}".format(mtu), commands
                )
            if remote_span:
                self.add_command_to_config_list(vlan, "remote-span", commands)
            if shutdown == "enabled":
                self.add_command_to_config_list(vlan, "shutdown", commands)
            elif shutdown == "disabled":
                self.add_command_to_config_list(vlan, "no shutdown", commands)
        elif have_diff and (
            self.state == "replaced" or self.state == "overridden"
        ):
            negate_have_config(diff, have_diff, vlan, commands)

        return commands

    def _clear_config(self, want, have):
        # Delete the interface config based on the want and have config
        commands = []
        vlan = "vlan {0}".format(have.get("vlan_id"))

        if (
            have.get("vlan_id")
            and "default" not in have.get("name")
            and (
                have.get("vlan_id") != want.get("vlan_id")
                or self.state == "deleted"
            )
        ):
            self.remove_command_from_config_list(vlan, "vlan", commands)
        elif "default" not in have.get("name"):
            if have.get("mtu") != want.get("mtu"):
                self.remove_command_from_config_list(vlan, "mtu", commands)
            if have.get("remote_span") != want.get("remote_span") and want.get(
                "remote_span"
            ):
                self.remove_command_from_config_list(
                    vlan, "remote-span", commands
                )
            if have.get("shutdown") != want.get("shutdown") and want.get(
                "shutdown"
            ):
                self.remove_command_from_config_list(
                    vlan, "shutdown", commands
                )
            if have.get("state") != want.get("state") and want.get("state"):
                self.remove_command_from_config_list(vlan, "state", commands)

        return commands
