#
# -*- 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 nxos_l2_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

import re

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,
)

from ansible_collections.cisco.nxos.plugins.module_utils.network.nxos.facts.facts import Facts
from ansible_collections.cisco.nxos.plugins.module_utils.network.nxos.utils.utils import (
    flatten_dict,
    normalize_interface,
    search_obj_in_list,
    vlan_list_to_range,
    vlan_range_to_list,
)


class L2_interfaces(ConfigBase):
    """
    The nxos_l2_interfaces class
    """

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

    gather_network_resources = ["l2_interfaces"]

    exclude_params = ["vlan", "allowed_vlans", "native_vlans"]

    def __init__(self, module):
        super(L2_interfaces, self).__init__(module)

    def get_l2_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,
        )
        l2_interfaces_facts = facts["ansible_network_resources"].get("l2_interfaces")
        if not l2_interfaces_facts:
            return []
        return l2_interfaces_facts

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

        :rtype: A dictionary
        :returns: The result from module execution
        """
        result = {"changed": False}
        commands = []
        warnings = []

        if self.state in self.ACTION_STATES:
            existing_l2_interfaces_facts = self.get_l2_interfaces_facts()
        else:
            existing_l2_interfaces_facts = []

        if self.state in self.ACTION_STATES or self.state == "rendered":
            commands.extend(self.set_config(existing_l2_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_l2_interfaces_facts = self.get_l2_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_l2_interfaces_facts(data=running_config)

        if self.state in self.ACTION_STATES:
            result["before"] = existing_l2_interfaces_facts
            if result["changed"]:
                result["after"] = changed_l2_interfaces_facts

        elif self.state == "gathered":
            result["gathered"] = changed_l2_interfaces_facts

        result["warnings"] = warnings
        return result

    def set_config(self, existing_l2_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
        """
        config = self._module.params.get("config")
        want = []
        if config:
            for w in config:
                w.update({"name": normalize_interface(w["name"])})
                self.expand_trunk_allowed_vlans(w)
                want.append(remove_empties(w))
        have = existing_l2_interfaces_facts
        for h in have:
            self.expand_trunk_allowed_vlans(h)
        resp = self.set_state(want, have) or []
        self._reconstruct_commands(resp)

        return resp

    def expand_trunk_allowed_vlans(self, d):
        if not d:
            return None
        if "trunk" in d and d["trunk"]:
            if "allowed_vlans" in d["trunk"]:
                allowed_vlans = vlan_range_to_list(d["trunk"]["allowed_vlans"])
                vlans_list = [str(line) for line in sorted(allowed_vlans)]
                d["trunk"]["allowed_vlans"] = ",".join(vlans_list)

    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"]
        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),
            )

        commands = list()
        if state == "overridden":
            commands.extend(self._state_overridden(want, have))
        elif state == "deleted":
            commands.extend(self._state_deleted(want, have))
        else:
            for w in want:
                if state in ["merged", "rendered"]:
                    commands.extend(self._state_merged(flatten_dict(w), have))
                elif state == "replaced":
                    commands.extend(self._state_replaced(flatten_dict(w), have))
        return commands

    def _state_replaced(self, w, 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 = []
        obj_in_have = flatten_dict(search_obj_in_list(w["name"], have, "name"))
        if obj_in_have:
            diff = dict_diff(w, obj_in_have)
        else:
            diff = w
        merged_commands = self.set_commands(w, have, True)
        if "name" not in diff:
            diff["name"] = w["name"]

        dkeys = diff.keys()
        for k in w.copy():
            if k in self.exclude_params and k in dkeys:
                del diff[k]
        replaced_commands = self.del_attribs(diff)

        if merged_commands or replaced_commands:
            cmds = set(replaced_commands).intersection(set(merged_commands))
            for cmd in cmds:
                merged_commands.remove(cmd)
            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 h in have:
            h = flatten_dict(h)
            obj_in_want = flatten_dict(search_obj_in_list(h["name"], want, "name"))
            if h == obj_in_want:
                continue
            for w in want:
                w = flatten_dict(w)
                if h["name"] == w["name"]:
                    wkeys = w.keys()
                    hkeys = h.keys()
                    for k in wkeys:
                        if k in self.exclude_params and k in hkeys:
                            del h[k]
            commands.extend(self.del_attribs(h))
        for w in want:
            commands.extend(self.set_commands(flatten_dict(w), have, True))
        return commands

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

        :rtype: A list
        :returns: the commands necessary to merge the provided into
                  the current configuration
        """
        return self.set_commands(w, have)

    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:
            for w in want:
                obj_in_have = flatten_dict(search_obj_in_list(w["name"], have, "name"))
                commands.extend(self.del_attribs(obj_in_have))
        else:
            if not have:
                return commands
            for h in have:
                commands.extend(self.del_attribs(flatten_dict(h)))
        return commands

    def del_attribs(self, obj):
        commands = []
        if not obj or len(obj.keys()) == 1:
            return commands

        cmd = "no switchport "
        if "vlan" in obj:
            commands.append(cmd + "access vlan")
        if "mode" in obj:
            commands.append(cmd + "mode")
        if "allowed_vlans" in obj:
            commands.append(cmd + "trunk allowed vlan")
        if "native_vlan" in obj:
            commands.append(cmd + "trunk native vlan")
        if commands:
            commands.insert(0, "interface " + obj["name"])
        return commands

    def diff_of_dicts(self, w, obj):
        diff = set(w.items()) - set(obj.items())
        diff = dict(diff)
        if diff and w["name"] == obj["name"]:
            diff.update({"name": w["name"]})
        return diff

    def add_commands(self, d, vlan_exists=False):
        commands = []
        if not d:
            return commands

        cmd = "switchport "
        if "mode" in d:
            commands.append(cmd + "mode {0}".format(d["mode"]))
        if "vlan" in d:
            commands.append(cmd + "access vlan " + str(d["vlan"]))
        if "allowed_vlans" in d:
            if vlan_exists:
                commands.append(cmd + "trunk allowed vlan add " + str(d["allowed_vlans"]))
            else:
                commands.append(cmd + "trunk allowed vlan " + str(d["allowed_vlans"]))
        if "native_vlan" in d:
            commands.append(cmd + "trunk native vlan " + str(d["native_vlan"]))
        if commands:
            commands.insert(0, "interface " + d["name"])
        return commands

    def set_commands(self, w, have, replace=False):
        commands = []

        obj_in_have = flatten_dict(search_obj_in_list(w["name"], have, "name"))
        if not obj_in_have:
            commands = self.add_commands(w)
        else:
            diff = self.diff_of_dicts(w, obj_in_have)
            if diff and not replace:
                if "mode" in diff.keys() and diff["mode"]:
                    commands = self.add_commands(diff)
                if "allowed_vlans" in diff.keys() and diff["allowed_vlans"]:
                    vlan_tobe_added = diff["allowed_vlans"].split(",")
                    vlan_list = vlan_tobe_added[:]
                    if obj_in_have.get("allowed_vlans"):
                        have_vlans = obj_in_have["allowed_vlans"].split(",")
                    else:
                        have_vlans = []
                    for w_vlans in vlan_list:
                        if w_vlans in have_vlans:
                            vlan_tobe_added.pop(vlan_tobe_added.index(w_vlans))
                    if vlan_tobe_added:
                        diff.update({"allowed_vlans": ",".join(vlan_tobe_added)})
                        if have_vlans:
                            commands = self.add_commands(diff, True)
                        else:
                            commands = self.add_commands(diff)
                    return commands
            commands = self.add_commands(diff)
        return commands

    def _reconstruct_commands(self, cmds):
        for idx, cmd in enumerate(cmds):
            match = re.search(
                r"^(?P<cmd>(no\s)?switchport trunk allowed vlan(\sadd)?)\s(?P<vlans>.+)",
                cmd,
            )
            if match:
                data = match.groupdict()
                unparsed = vlan_list_to_range(data["vlans"].split(","))
                cmds[idx] = data["cmd"] + " " + unparsed
