#
# (c) 2017 Red Hat Inc.
#
# This file is part of Ansible
#
# Ansible is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Ansible is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
#
from __future__ import absolute_import, division, print_function

__metaclass__ = type

DOCUMENTATION = """
author: Ansible Networking Team (@ansible-network)
name: junos
short_description: Use junos cliconf to run command on Juniper Junos OS platform
description:
- This junos plugin provides low level abstraction apis for sending and receiving
  CLI commands from Juniper Junos OS network devices.
version_added: 1.0.0
options:
  config_commands:
    description:
    - Specifies a list of commands that can make configuration changes
      to the target device.
    - When `ansible_network_single_user_mode` is enabled, if a command sent
      to the device is present in this list, the existing cache is invalidated.
    version_added: 2.0.0
    type: list
    elements: str
    default: []
    vars:
    - name: ansible_junos_config_commands
"""

import json
import re

from itertools import chain
from functools import wraps

from ansible.errors import AnsibleConnectionFailure
from ansible.module_utils._text import to_text
from ansible.module_utils.common._collections_compat import Mapping
from ansible_collections.ansible.netcommon.plugins.module_utils.network.common.utils import (
    to_list,
)
from ansible.plugins.cliconf import CliconfBase


def configure(func):
    @wraps(func)
    def wrapped(self, *args, **kwargs):
        prompt = self._connection.get_prompt()
        if (
            not to_text(prompt, errors="surrogate_or_strict")
            .strip()
            .endswith("#")
        ):
            self.send_command("configure")
        return func(self, *args, **kwargs)

    return wrapped


class Cliconf(CliconfBase):
    def __init__(self, *args, **kwargs):
        self._device_info = {}
        super(Cliconf, self).__init__(*args, **kwargs)

    def get_text(self, ele, tag):
        try:
            return to_text(
                ele.find(tag).text, errors="surrogate_then_replace"
            ).strip()
        except AttributeError:
            pass

    def get_device_info(self):
        if not self._device_info:
            device_info = {}
            device_info["network_os"] = "junos"

            reply = self.get(command="show version")
            data = to_text(reply, errors="surrogate_or_strict").strip()

            match = re.search(r"Junos: (\S+)", data)
            if match:
                device_info["network_os_version"] = match.group(1)

            match = re.search(r"Model: (\S+)", data, re.M)
            if match:
                device_info["network_os_model"] = match.group(1)

            match = re.search(r"Hostname: (\S+)", data, re.M)
            if match:
                device_info["network_os_hostname"] = match.group(1)

            self._device_info = device_info

        return self._device_info

    def get_config(self, source="running", format="text", flags=None):
        if source != "running":
            raise ValueError(
                "fetching configuration from %s is not supported" % source
            )

        options_values = self.get_option_values()
        if format not in options_values["format"]:
            raise ValueError(
                "'format' value %s is invalid. Valid values are %s"
                % (format, ",".join(options_values["format"]))
            )

        if format == "text":
            cmd = "show configuration"
        else:
            cmd = "show configuration | display %s" % format

        cmd += " ".join(to_list(flags))
        cmd = cmd.strip()
        return self.send_command(cmd)

    @configure
    def edit_config(
        self, candidate=None, commit=True, replace=None, comment=None
    ):

        operations = self.get_device_operations()
        self.check_edit_config_capability(
            operations, candidate, commit, replace, comment
        )

        resp = {}
        results = []
        requests = []

        if replace:
            candidate = "load override {0}".format(replace)

        for line in to_list(candidate):
            if not isinstance(line, Mapping):
                line = {"command": line}
            cmd = line["command"]
            try:
                results.append(self.send_command(**line))
            except AnsibleConnectionFailure as exc:
                if "error: commit failed" in exc.message:
                    self.discard_changes()
                raise
            requests.append(cmd)

        diff = self.compare_configuration()
        if diff:
            resp["diff"] = diff

            if commit:
                self.commit(comment=comment)
            else:
                self.discard_changes()

        else:
            self.send_command("top")
            self.discard_changes()

        resp["request"] = requests
        resp["response"] = results
        return resp

    def get(
        self,
        command,
        prompt=None,
        answer=None,
        sendonly=False,
        output=None,
        newline=True,
        check_all=False,
    ):
        if output:
            command = self._get_command_with_output(command, output)
        return self.send_command(
            command=command,
            prompt=prompt,
            answer=answer,
            sendonly=sendonly,
            newline=newline,
            check_all=check_all,
        )

    @configure
    def commit(
        self, comment=None, confirmed=False, at_time=None, synchronize=False
    ):
        """
        Execute commit command on remote device.
        :param comment: Comment to be associated with commit
        :param confirmed: Boolean flag to indicate if the previous commit should confirmed
        :param at_time: Time at which to activate configuration changes
        :param synchronize: Boolean flag to indicate if commit should synchronize on remote peers
        :return: Command response received from device
        """
        command = "commit"
        if comment:
            command += " comment {0}".format(comment)
        if confirmed:
            command += " confirmed"
        if at_time:
            command += " {0}".format(at_time)
        if synchronize:
            command += " peers-synchronize"

        command += " and-quit"

        try:
            response = self.send_command(command)
        except AnsibleConnectionFailure:
            self.discard_changes()
            raise

        return response

    @configure
    def discard_changes(self):
        command = "rollback 0"
        for cmd in chain(to_list(command), ["exit"]):
            self.send_command(cmd)

    @configure
    def validate(self):
        return self.send_command("commit check")

    @configure
    def compare_configuration(self, rollback_id=None):
        command = "show | compare"
        if rollback_id is not None:
            command += " rollback %s" % int(rollback_id)
        resp = self.send_command(command)

        r = resp.splitlines()
        if (
            len(r) == 1
            and "[edit]" in r[0]
            or len(r) == 4
            and r[1].startswith("- version")
        ):
            resp = ""

        return resp

    @configure
    def rollback(self, rollback_id, commit=True):
        resp = {}
        self.send_command("rollback %s" % int(rollback_id))
        resp["diff"] = self.compare_configuration()
        if commit:
            self.commit()
        else:
            self.discard_changes()
        return resp

    def get_diff(self, rollback_id=None):
        diff = {"config_diff": None}
        response = self.compare_configuration(rollback_id=rollback_id)
        if response:
            diff["config_diff"] = response
        return diff

    def get_device_operations(self):
        return {
            "supports_diff_replace": False,
            "supports_commit": True,
            "supports_rollback": True,
            "supports_defaults": False,
            "supports_onbox_diff": True,
            "supports_commit_comment": True,
            "supports_multiline_delimiter": False,
            "supports_diff_match": False,
            "supports_diff_ignore_lines": False,
            "supports_generate_diff": False,
            "supports_replace": True,
        }

    def get_option_values(self):
        return {
            "format": ["text", "set", "xml", "json"],
            "diff_match": [],
            "diff_replace": [],
            "output": ["text", "set", "xml", "json"],
        }

    def get_capabilities(self):
        result = super(Cliconf, self).get_capabilities()
        result["rpc"] += [
            "commit",
            "discard_changes",
            "run_commands",
            "compare_configuration",
            "validate",
            "get_diff",
        ]
        result["device_operations"] = self.get_device_operations()
        result.update(self.get_option_values())
        return json.dumps(result)

    def set_cli_prompt_context(self):
        """
        Make sure we are in the operational cli mode
        :return: None
        """
        if self._connection.connected:
            self._update_cli_prompt_context(config_context="#")

    def _get_command_with_output(self, command, output):
        options_values = self.get_option_values()
        if output not in options_values["output"]:
            raise ValueError(
                "'output' value %s is invalid. Valid values are %s"
                % (output, ",".join(options_values["output"]))
            )

        if output == "json" and not command.endswith("| display json"):
            cmd = "%s | display json" % command
        elif output == "xml" and not command.endswith("| display xml"):
            cmd = "%s | display xml" % command
        elif output == "text" and (
            command.endswith("| display json")
            or command.endswith("| display xml")
        ):
            cmd = command.rsplit("|", 1)[0]
        else:
            cmd = command
        return cmd