#
# 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 = """
module: eos_eapi
author: Peter Sprygada (@privateip)
short_description: Manage and configure Arista EOS eAPI.
requirements:
- EOS v4.12 or greater
description:
- Use to enable or disable eAPI access, and set the port and state of http, https,
  local_http and unix-socket servers.
- When enabling eAPI access the default is to enable HTTP on port 80, enable HTTPS
  on port 443, disable local HTTP, and disable Unix socket server. Use the options
  listed below to override the default configuration.
- Requires EOS v4.12 or greater.
version_added: 1.0.0
options:
  http:
    description:
    - The C(http) argument controls the operating state of the HTTP transport protocol
      when eAPI is present in the running-config. When the value is set to True, the
      HTTP protocol is enabled and when the value is set to False, the HTTP protocol
      is disabled. By default, when eAPI is first configured, the HTTP protocol is
      disabled.
    type: bool
    aliases:
    - enable_http
  http_port:
    description:
    - Configures the HTTP port that will listen for connections when the HTTP transport
      protocol is enabled.  This argument accepts integer values in the valid range
      of 1 to 65535.
    type: int
  https:
    description:
    - The C(https) argument controls the operating state of the HTTPS transport protocol
      when eAPI is present in the running-config. When the value is set to True, the
      HTTPS protocol is enabled and when the value is set to False, the HTTPS protocol
      is disabled. By default, when eAPI is first configured, the HTTPS protocol is
      enabled.
    type: bool
    aliases:
    - enable_https
  https_port:
    description:
    - Configures the HTTP port that will listen for connections when the HTTP transport
      protocol is enabled.  This argument accepts integer values in the valid range
      of 1 to 65535.
    type: int
  local_http:
    description:
    - The C(local_http) argument controls the operating state of the local HTTP transport
      protocol when eAPI is present in the running-config.  When the value is set
      to True, the HTTP protocol is enabled and restricted to connections from localhost
      only.  When the value is set to False, the HTTP local protocol is disabled.
    - Note is value is independent of the C(http) argument
    type: bool
    aliases:
    - enable_local_http
  local_http_port:
    description:
    - Configures the HTTP port that will listen for connections when the HTTP transport
      protocol is enabled.  This argument accepts integer values in the valid range
      of 1 to 65535.
    type: int
  socket:
    description:
    - The C(socket) argument controls the operating state of the UNIX Domain Socket
      used to receive eAPI requests.  When the value of this argument is set to True,
      the UDS will listen for eAPI requests.  When the value is set to False, the
      UDS will not be available to handle requests.  By default when eAPI is first
      configured, the UDS is disabled.
    type: bool
    aliases:
    - enable_socket
  timeout:
    description:
    - The time (in seconds) to wait for the eAPI configuration to be reflected in
      the running-config.
    type: int
    default: 30
  vrf:
    description:
    - The C(vrf) argument will configure eAPI to listen for connections in the specified
      VRF.  By default, eAPI transports will listen for connections in the global
      table.  This value requires the VRF to already be created otherwise the task
      will fail.
    default: default
    type: str
  config:
    description:
    - The module, by default, will connect to the remote device and retrieve the current
      running-config to use as a base for comparing against the contents of source.  There
      are times when it is not desirable to have the task get the current running-config
      for every task in a playbook.  The I(config) argument allows the implementer
      to pass in the configuration to use as the base config for comparison.
    type: str
  state:
    description:
    - The C(state) argument controls the operational state of eAPI on the remote device.  When
      this argument is set to C(started), eAPI is enabled to receive requests and
      when this argument is C(stopped), eAPI is disabled and will not receive requests.
    type: str
    default: started
    choices:
    - started
    - stopped
"""

EXAMPLES = """
- name: Enable eAPI access with default configuration
  arista.eos.eos_eapi:
    state: started

- name: Enable eAPI with no HTTP, HTTPS at port 9443, local HTTP at port 80, and socket
    enabled
  arista.eos.eos_eapi:
    state: started
    http: false
    https_port: 9443
    local_http: yes
    local_http_port: 80
    socket: yes

- name: Shutdown eAPI access
  arista.eos.eos_eapi:
    state: stopped
"""

RETURN = """
commands:
  description: The list of configuration mode commands to send to the device
  returned: always
  type: list
  sample:
    - management api http-commands
    - protocol http port 81
    - no protocol https
urls:
  description: Hash of URL endpoints eAPI is listening on per interface
  returned: when eAPI is started
  type: dict
  sample: {'Management1': ['http://172.26.10.1:80']}
session_name:
  description: The EOS config session name used to load the configuration
  returned: when changed is True
  type: str
  sample: ansible_1479315771
"""
import re
import time

from ansible.module_utils.basic import AnsibleModule
from ansible.module_utils.six import iteritems

from ansible_collections.arista.eos.plugins.module_utils.network.eos.eos import (
    load_config,
    run_commands,
)


def validate_http_port(value, module):
    if not 1 <= value <= 65535:
        module.fail_json(msg="http_port must be between 1 and 65535")


def validate_https_port(value, module):
    if not 1 <= value <= 65535:
        module.fail_json(msg="http_port must be between 1 and 65535")


def validate_local_http_port(value, module):
    if not 1 <= value <= 65535:
        module.fail_json(msg="http_port must be between 1 and 65535")


def validate_vrf(value, module):
    out = run_commands(module, ["show vrf"])
    configured_vrfs = []
    lines = out[0].strip().splitlines()[3:]
    for line in lines:
        if not line:
            continue
        splitted_line = re.split(r"\s{2,}", line.strip())
        if len(splitted_line) > 2:
            configured_vrfs.append(splitted_line[0])

    configured_vrfs.append("default")
    if value not in configured_vrfs:
        module.fail_json(
            msg="vrf `%s` is not configured on the system" % value,
        )


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

    def needs_update(x):
        return want.get(x) is not None and (want.get(x) != have.get(x))

    def add(cmd):
        if "management api http-commands" not in commands:
            commands.insert(0, "management api http-commands")
        commands.append(cmd)

    if any((needs_update("http"), needs_update("http_port"))):
        if want["http"] is False:
            add("no protocol http")
        else:
            if have["http"] is False and want["http"] in (False, None):
                warnings.append(
                    "protocol http is not enabled, not configuring http port value",
                )
            else:
                port = want["http_port"] or 80
                add("protocol http port %s" % port)

    if any((needs_update("https"), needs_update("https_port"))):
        if want["https"] is False:
            add("no protocol https")
        else:
            if have["https"] is False and want["https"] in (False, None):
                warnings.append(
                    "protocol https is not enabled, not configuring https port value",
                )
            else:
                port = want["https_port"] or 443
                add("protocol https port %s" % port)

    if any((needs_update("local_http"), needs_update("local_http_port"))):
        if want["local_http"] is False:
            add("no protocol http localhost")
        else:
            if have["local_http"] is False and want["local_http"] in (
                False,
                None,
            ):
                warnings.append(
                    "protocol local_http is not enabled, not configuring local_http port value",
                )
            else:
                port = want["local_http_port"] or 8080
                add("protocol http localhost port %s" % port)

    if any((needs_update("socket"), needs_update("socket"))):
        if want["socket"] is False:
            add("no protocol unix-socket")
        else:
            add("protocol unix-socket")
    if needs_update("state"):
        if want["state"] == "stopped":
            add("shutdown")
        elif want["state"] == "started":
            add("no shutdown")

    if needs_update("vrf"):
        add("vrf %s" % want["vrf"])
        # switching operational vrfs here
        # need to add the desired state as well
        if want["state"] == "stopped":
            add("shutdown")
        elif want["state"] == "started":
            add("no shutdown")

    return commands


def parse_state(data):
    if data[0]["enabled"]:
        return "started"
    else:
        return "stopped"


def map_config_to_obj(module):
    out = run_commands(module, ["show management api http-commands | json"])
    return {
        "http": out[0]["httpServer"]["configured"],
        "http_port": out[0]["httpServer"]["port"],
        "https": out[0]["httpsServer"]["configured"],
        "https_port": out[0]["httpsServer"]["port"],
        "local_http": out[0]["localHttpServer"]["configured"],
        "local_http_port": out[0]["localHttpServer"]["port"],
        "socket": out[0]["unixSocketServer"]["configured"],
        "vrf": out[0]["vrf"] or "default",
        "state": parse_state(out),
    }


def map_params_to_obj(module):
    obj = {
        "http": module.params["http"],
        "http_port": module.params["http_port"],
        "https": module.params["https"],
        "https_port": module.params["https_port"],
        "local_http": module.params["local_http"],
        "local_http_port": module.params["local_http_port"],
        "socket": module.params["socket"],
        "vrf": module.params["vrf"],
        "state": module.params["state"],
    }

    for key, value in iteritems(obj):
        if value:
            validator = globals().get("validate_%s" % key)
            if validator:
                validator(value, module)

    return obj


def verify_state(updates, module):
    want, have = updates

    invalid_state = [
        ("http", "httpServer"),
        ("https", "httpsServer"),
        ("local_http", "localHttpServer"),
        ("socket", "unixSocketServer"),
    ]

    timeout = module.params["timeout"]
    state = module.params["state"]

    while invalid_state:
        out = run_commands(
            module,
            ["show management api http-commands | json"],
        )
        for index, item in enumerate(invalid_state):
            want_key, eapi_key = item
            if want[want_key] is not None:
                if want[want_key] == out[0][eapi_key]["running"]:
                    del invalid_state[index]
            elif state == "stopped":
                if not out[0][eapi_key]["running"]:
                    del invalid_state[index]
            else:
                del invalid_state[index]
        time.sleep(1)
        timeout -= 1
        if timeout == 0:
            module.fail_json(
                msg="timeout expired before eapi running state changed",
            )


def collect_facts(module, result):
    out = run_commands(module, ["show management api http-commands | json"])
    facts = dict(eos_eapi_urls=dict())
    for each in out[0]["urls"]:
        intf, url = each.split(":", 1)
        key = str(intf).strip()
        if key not in facts["eos_eapi_urls"]:
            facts["eos_eapi_urls"][key] = list()
        facts["eos_eapi_urls"][key].append(str(url).strip())
    result["ansible_facts"] = facts


def main():
    """main entry point for module execution"""
    argument_spec = dict(
        http=dict(aliases=["enable_http"], type="bool"),
        http_port=dict(type="int"),
        https=dict(aliases=["enable_https"], type="bool"),
        https_port=dict(type="int"),
        local_http=dict(aliases=["enable_local_http"], type="bool"),
        local_http_port=dict(type="int"),
        socket=dict(aliases=["enable_socket"], type="bool"),
        timeout=dict(type="int", default=30),
        vrf=dict(default="default"),
        config=dict(),
        state=dict(default="started", choices=["stopped", "started"]),
    )

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

    result = {"changed": False}

    warnings = list()
    if module.params["config"]:
        warnings.append(
            "config parameter is no longer necessary and will be ignored",
        )

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

    commands = map_obj_to_commands((want, have), module, warnings)
    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

    if result["changed"]:
        verify_state((want, have), module)

    collect_facts(module, result)

    if warnings:
        result["warnings"] = warnings

    module.exit_json(**result)


if __name__ == "__main__":
    main()