"""This module provides command line parsers and corresponding commands."""

import argparse
import configparser
import ipaddress
import json
import os
import sys
import traceback

from . import brokertypes as bt
from .config import CONFIG
from .consts import CONFIG_FILE
from .controller import Controller
from .controller import Error as ControllerError
from .events import (
    DeployRequest,
    DeployResponse,
    GetConfigurationRequest,
    GetConfigurationResponse,
    GetIdValueRequest,
    GetIdValueResponse,
    GetInstancesRequest,
    GetInstancesResponse,
    GetNodesRequest,
    GetNodesResponse,
    RestartRequest,
    RestartResponse,
    StageConfigurationRequest,
    StageConfigurationResponse,
    TestTimeoutRequest,
    TestTimeoutResponse,
)
from .logs import LOG
from .types import (
    ClusterRole,
    Configuration,
    Enum,
    Instance,
    ManagementRole,
    NodeOutputs,
    NodeStatus,
    Result,
)

# For unit-testing, a central place to adjust where reads from stdin come from
# and writes to stdout go to. Fiddling with sys.stdin/sys.stdout directly in the
# tests can be tricky.
STDIN = sys.stdin
STDOUT = sys.stdout


# Broker's basic types aren't JSON-serializable, so patch that up
# in this json.dumps() wrapper for JSON serialization of any object.
# Could go into utils.py, but it easier here to keep free of cyclic
# dependencies.
def json_dumps(obj):
    def default(obj):
        # Check specific Python types:
        if isinstance(obj, ipaddress.IPv4Address):
            return str(obj)
        if isinstance(obj, ipaddress.IPv6Address):
            return str(obj)

        # Specific zeek-client types (types.py):
        if isinstance(obj, Enum):
            return obj.to_json_data()

        # Specific brokertypes:
        if isinstance(obj, bt.Port):
            return str(obj.number)
        if isinstance(obj, bt.Timespan):
            return f"{obj.value}{obj.unit.value}"
        # Fallback: assume the type's own Python representation is right.
        # json.dumps() will complain when that does not work.
        if isinstance(obj, bt.Type):
            return obj.to_py()

        raise TypeError(f"cannot serialize {type(obj)} ({str(obj)})")

    indent = 2 if CONFIG.getboolean("client", "pretty_json") else None
    return json.dumps(obj, default=default, sort_keys=True, indent=indent)


def create_controller():
    try:
        ctl = Controller()
    except ControllerError as err:
        LOG.error(str(err))
        return None

    if not ctl.connect():
        return None

    return ctl


def create_parser():
    parser = argparse.ArgumentParser(
        formatter_class=argparse.RawDescriptionHelpFormatter,
        description="A Zeek management client",
        epilog="environment variables:\n\n"
        "    ZEEK_CLIENT_CONFIG_FILE:      "
        "Same as `--configfile` argument, but lower precedence.\n"
        "    ZEEK_CLIENT_CONFIG_SETTINGS:  "
        "Same as a space-separated series of `--set` arguments, but lower precedence.\n",
    )

    controller = (
        f"{CONFIG.get('controller', 'host')}:{CONFIG.get('controller', 'port')}"
    )

    parser.add_argument(
        "-c",
        "--configfile",
        metavar="FILE",
        default=CONFIG_FILE,
        help=f"Path to zeek-client config file. (Default: {CONFIG_FILE})",
    )
    parser.add_argument(
        "--controller",
        metavar="HOST:PORT",
        help=(
            f"Address and port of the controller, either of which may "
            f"be omitted (default: {controller})"
        ),
    )
    arg = parser.add_argument(
        "--set",
        metavar="SECTION.KEY=VAL",
        action="append",
        default=[],
        help="Adjust a configuration setting. Can use repeatedly. "
        "See show-settings.",
    )

    # This is for argcomplete users and has no effect otherwise.
    arg.completer = CONFIG.completer

    verbosity_group = parser.add_mutually_exclusive_group()
    verbosity_group.add_argument(
        "--quiet",
        "-q",
        action="store_true",
        help="Suppress informational output to stderr.",
    )
    verbosity_group.add_argument(
        "--verbose",
        "-v",
        action="count",
        help="Increase informational output to stderr. "
        "Repeat for more output (e.g. -vvv).",
    )

    parser.add_argument(
        "--version",
        action="store_true",
        help="Show version number and exit.",
    )

    command_parser = parser.add_subparsers(
        title="commands",
        dest="command",
        help="See `%(prog)s <command> -h` for per-command usage info.",
    )

    sub_parser = command_parser.add_parser(
        "deploy",
        help="Deploy a staged cluster configuration.",
    )
    sub_parser.set_defaults(run_cmd=cmd_deploy)

    sub_parser = command_parser.add_parser(
        "deploy-config",
        help="Upload a cluster configuration and deploy it.",
    )
    sub_parser.set_defaults(run_cmd=cmd_deploy_config)
    sub_parser.add_argument(
        "config",
        metavar="FILE",
        help='Cluster configuration file, "-" for stdin',
    )

    sub_parser = command_parser.add_parser(
        "get-config",
        help="Retrieve staged or deployed cluster configuration.",
    )
    sub_parser.set_defaults(run_cmd=cmd_get_config)
    sub_parser.add_argument(
        "--filename",
        "-f",
        metavar="FILE",
        default="-",
        help="Output file for the configuration, default stdout",
    )
    sub_parser.add_argument(
        "--as-json",
        action="store_true",
        help="Report in JSON instead of INI-style config file",
    )
    get_config_group = sub_parser.add_mutually_exclusive_group()
    get_config_group.add_argument(
        "--deployed",
        action="store_true",
        dest="deployed",
        default=False,
        help="Return deployed configuration",
    )
    get_config_group.add_argument(
        "--staged",
        action="store_false",
        dest="deployed",
        help="Return staged configuration (default)",
    )

    sub_parser = command_parser.add_parser(
        "get-id-value",
        help="Show the value of a given identifier in Zeek cluster nodes.",
    )
    sub_parser.set_defaults(run_cmd=cmd_get_id_value)
    sub_parser.add_argument(
        "id",
        metavar="IDENTIFIER",
        help="Name of the Zeek script identifier to retrieve.",
    )
    sub_parser.add_argument(
        "nodes",
        metavar="NODES",
        nargs="*",
        default=[],
        help="Name(s) of Zeek cluster nodes to query. "
        "When omitted, queries all nodes.",
    )

    sub_parser = command_parser.add_parser(
        "get-instances",
        help="Show instances connected to the controller.",
    )
    sub_parser.set_defaults(run_cmd=cmd_get_instances)

    sub_parser = command_parser.add_parser(
        "get-nodes",
        help="Show active Zeek nodes at each instance.",
    )
    sub_parser.set_defaults(run_cmd=cmd_get_nodes)

    sub_parser = command_parser.add_parser(
        "monitor",
        help="For troubleshooting: do nothing, just report events.",
    )
    sub_parser.set_defaults(run_cmd=cmd_monitor)

    sub_parser = command_parser.add_parser("restart", help="Restart cluster nodes.")
    sub_parser.set_defaults(run_cmd=cmd_restart)
    sub_parser.add_argument(
        "nodes",
        metavar="NODES",
        nargs="*",
        default=[],
        help="Name(s) of Zeek cluster nodes to restart. "
        "When omitted, restarts all nodes.",
    )

    sub_parser = command_parser.add_parser(
        "stage-config",
        help="Upload a cluster configuration for later deployment.",
    )
    sub_parser.set_defaults(run_cmd=cmd_stage_config)
    sub_parser.add_argument(
        "config",
        metavar="FILE",
        help='Cluster configuration file, "-" for stdin',
    )

    sub_parser = command_parser.add_parser(
        "show-settings",
        help="Show zeek-client's own configuration.",
    )
    sub_parser.set_defaults(run_cmd=cmd_show_settings)

    sub_parser = command_parser.add_parser(
        "test-timeout",
        help="Send timeout test event.",
    )
    sub_parser.set_defaults(run_cmd=cmd_test_timeout)
    sub_parser.add_argument(
        "--with-state",
        action="store_true",
        help="Make request stateful in the controller.",
    )

    return parser


def cmd_deploy(_args, controller=None):
    # The deploy-config command first stages a configuration and then calls this
    # function to deploy. We re-use its controller, passed to us.
    if controller is None:
        controller = create_controller()
    if controller is None:
        return 1

    resp, msg = controller.transact(DeployRequest, DeployResponse)

    if resp is None:
        LOG.error("no response received: %s", msg)
        return 1

    retval = 0
    json_data = {
        "results": {},
        "errors": [],
    }

    for broker_data in resp.results:
        res = Result.from_brokertype(broker_data)

        if not res.success:
            retval = 1

        if not res.success and res.node is None and res.error:
            # If a failure doesn't mention a node, it's either an agent
            # reporting an internal error, or the controller reporting a
            # config validation error.
            json_data["errors"].append(res.error)
            continue

        if res.success and res.node is None and res.instance is None and res.data:
            # It's success from the controller (since the instance field is
            # empty): the data field contains the ID of the deployed config.
            json_data["results"]["id"] = res.data
            continue

        # At this point we only expect responses from the agents:
        if res.instance is None:
            LOG.warning("skipping unexpected response %s", res)
            continue

        if res.node is None:
            # This happens when an agent handles deployment successfully, and
            # had no nodes to deploy. We skip this silently.
            continue

        # Everything else is node-specific results from agents.

        if "nodes" not in json_data["results"]:
            json_data["results"]["nodes"] = {}

        json_data["results"]["nodes"][res.node] = {
            "success": res.success,
            "instance": res.instance,
        }

        # If launching this node failed, we should have a NodeOutputs record as
        # data member in the result record. ("should", because on occasion
        # buffering in the node -> stem -> supervisor pipeline delays the
        # output.)
        if res.data:
            node_outputs = NodeOutputs.from_brokertype(res.data)
            json_data["results"]["nodes"][res.node]["stdout"] = node_outputs.stdout
            json_data["results"]["nodes"][res.node]["stderr"] = node_outputs.stderr

    print(json_dumps(json_data), file=STDOUT)
    return retval


def cmd_get_config(args):
    controller = create_controller()
    if controller is None:
        return 1

    resp, msg = controller.transact(
        GetConfigurationRequest,
        GetConfigurationResponse,
        args.deployed,
    )

    if resp is None:
        LOG.error("no response received: %s", msg)
        return 1

    res = Result.from_brokertype(resp.result)

    if not res.success:
        msg = res.error if res.error else "no reason given"
        LOG.error(msg)
        return 1

    if not res.data:
        LOG.error("received result did not contain configuration data: %s", resp)
        return 1

    config = Configuration.from_brokertype(res.data)

    with (
        open(
            args.filename,
            "w",
            encoding="utf-8",
        )
        if args.filename and args.filename != "-"
        else STDOUT as hdl
    ):
        if args.as_json:
            hdl.write(json_dumps(config.to_json_data()) + "\n")
        else:
            cfp = config.to_config_parser()
            cfp.write(hdl)

    return 0


def cmd_get_id_value(args):
    controller = create_controller()
    if controller is None:
        return 1

    resp, msg = controller.transact(
        GetIdValueRequest,
        GetIdValueResponse,
        args.id,
        set(args.nodes),
    )

    if resp is None:
        LOG.error("no response received: %s", msg)
        return 1

    json_data = {
        "results": {},
        "errors": [],
    }

    # The Result records have both instance and node filled in, so use both for
    # ordering. While for the JSON serialization we can outsource the ordering
    # task to Python, for our error reporting it's up to us, and we want be
    # reproducible.

    results = [Result.from_brokertype(broker_data) for broker_data in resp.results]

    for res in sorted(results):
        if not res.success:
            json_data["errors"].append(
                {
                    "source": res.node,
                    "error": res.error,
                },
            )
            continue

        # Upon success, we should always have res.node filled in. But guard anyway.
        if res.node:
            # res.data should be a string containing JSON rendered by Zeek's
            # to_json() BiF. Parse it into a data structure to render
            # seamlessly.
            if not isinstance(res.data, bt.String):
                json_data["errors"].append(
                    {
                        "source": res.node,
                        "error": f"invalid result data type {repr(res.data)}",
                    },
                )
                continue

            try:
                json_data["results"][res.node] = json.loads(res.data.to_py())
            except json.JSONDecodeError as err:
                json_data["errors"].append(
                    {
                        "source": res.node,
                        "error": f"JSON decode error: {err}",
                    },
                )
            continue

        json_data["errors"].append(
            {
                "error": f"result lacking node: {res.data}",
            },
        )

    print(json_dumps(json_data), file=STDOUT)
    return 0 if len(json_data["errors"]) == 0 else 1


def cmd_get_instances(_args):
    controller = create_controller()
    if controller is None:
        return 1

    resp, msg = controller.transact(GetInstancesRequest, GetInstancesResponse)

    if resp is None:
        LOG.error("no response received: %s", msg)
        return 1

    res = Result.from_brokertype(resp.result)

    if not res.success:
        msg = res.error if res.error else "no reason given"
        LOG.error(msg)
        return 1

    if res.data is None:
        LOG.error("received result did not contain instance data: %s", resp)
        return 1

    json_data = {}

    # res.data is a (possibly empty) vector of Instances. Make the list of
    # instances easier to comprehend than raw Broker data: turn it into Instance
    # objects, then render these JSON-friendly.
    try:
        for inst in sorted([Instance.from_brokertype(inst) for inst in res.data]):
            json_data[inst.name] = inst.to_json_data()
            json_data[inst.name].pop("name")
    except TypeError as err:
        LOG.error("instance data invalid: %s", err)

    print(json_dumps(json_data), file=STDOUT)
    return 0


def cmd_get_nodes(_args):
    controller = create_controller()
    if controller is None:
        return 1

    resp, msg = controller.transact(GetNodesRequest, GetNodesResponse)

    if resp is None:
        LOG.error("no response received: %s", msg)
        return 1

    json_data = {
        "results": {},
        "errors": [],
    }

    results = [Result.from_brokertype(broker_data) for broker_data in resp.results]

    for res in sorted(results):
        if not res.success:
            json_data["errors"].append(
                {
                    "source": res.instance,
                    "error": res.error,
                },
            )
            continue

        if res.data is None:
            json_data["errors"].append(
                {
                    "source": res.instance,
                    "error": "result does not contain node status data",
                },
            )
            continue

        json_data["results"][res.instance] = {}

        # res.data is a NodeStatusVec
        try:
            nstats = [NodeStatus.from_brokertype(nstat_data) for nstat_data in res.data]
            for nstat in sorted(nstats):
                # If either of the two role enums are "NONE", we make them
                # None. That way they stay in the reporting, but are more easily
                # distinguished from "actual" values.
                mgmt_role = (
                    nstat.mgmt_role if nstat.mgmt_role != ManagementRole.NONE else None
                )
                cluster_role = (
                    nstat.cluster_role
                    if nstat.cluster_role != ClusterRole.NONE
                    else None
                )

                json_data["results"][res.instance][nstat.node] = {
                    "state": nstat.state,
                    "mgmt_role": mgmt_role,
                    "cluster_role": cluster_role,
                }

                if nstat.pid is not None:
                    json_data["results"][res.instance][nstat.node]["pid"] = nstat.pid
                if nstat.port is not None:
                    json_data["results"][res.instance][nstat.node]["port"] = nstat.port
                if nstat.metrics_port is not None:
                    json_data["results"][res.instance][nstat.node]["metrics_port"] = (
                        nstat.metrics_port
                    )
        except TypeError as err:
            LOG.error("NodeStatus data invalid: %s", err)
            LOG.debug(traceback.format_exc())

    print(json_dumps(json_data), file=STDOUT)
    return 0 if len(json_data["errors"]) == 0 else 1


def cmd_monitor(_args):
    controller = create_controller()
    if controller is None:
        return 1

    while True:
        resp, msg = controller.receive(timeout_secs=None)

        if resp is None:
            print(f"no response received: {msg}")
        else:
            print(f'received "{resp}"')

    return 0


def cmd_restart(args):
    controller = create_controller()
    if controller is None:
        return 1

    resp, msg = controller.transact(RestartRequest, RestartResponse, set(args.nodes))

    if resp is None:
        LOG.error("no response received: %s", msg)
        return 1

    json_data = {
        "results": {},
        "errors": [],
    }

    # The Result records have both instance and node filled in, so use both for
    # ordering. While for the JSON serialization we can outsource the ordering
    # task to Python, for our error reporting it's up to us, and we want be
    # reproducible.

    results = [Result.from_brokertype(broker_data) for broker_data in resp.results]

    for res in sorted(results):
        if not res.success and res.instance is None:
            # The controller generated this one, so add to errors section.
            json_data["errors"].append(
                {
                    "source": res.node,
                    "error": res.error,
                },
            )
            continue

        # Upon success, we should always have a node filled in. But guard anyway.
        if res.node:
            json_data["results"][res.node] = res.success
            continue

        json_data["errors"].append(
            {
                "error": f"result lacking node: {res}",
            },
        )

    print(json_dumps(json_data), file=STDOUT)
    return 0 if len(json_data["errors"]) == 0 else 1


def cmd_stage_config_impl(args):
    """Internals of cmd_stage_config() to enable chaining with other commands.

    Returns a tuple of exit code, any JSON data to show to the user/caller, and
    the created controller object, if any.
    """
    if not args.config or (args.config != "-" and not os.path.isfile(args.config)):
        LOG.error("please provide a cluster configuration file.")
        return 1, None, None

    # We use a config parser to parse the cluster configuration. For instances,
    # we allow names without value to designate agents that connect to the
    # controller, like this:
    #
    # [instances]
    # foobar
    #
    # All other keys must have a value.
    config = Configuration()
    cfp = configparser.ConfigParser(allow_no_value=True)

    if args.config == "-":
        cfp.read_file(STDIN)
    else:
        cfp.read(args.config)

    config = Configuration.from_config_parser(cfp)

    if config is None:
        LOG.error("configuration has errors, not sending")
        return 1, None, None

    controller = create_controller()
    if controller is None:
        return 1, None, None

    resp, msg = controller.transact(
        StageConfigurationRequest,
        StageConfigurationResponse,
        config.to_brokertype(),
    )

    if resp is None:
        LOG.error("no response received: %s", msg)
        return 1, None, controller

    retval = 0
    json_data = {
        "results": {},
        "errors": [],
    }

    for broker_data in resp.results:
        res = Result.from_brokertype(broker_data)

        if not res.success:
            retval = 1

            # Failures are config validation problems, trouble while
            # auto-assigning ports, or internal controller errors.
            # They should all come with error messages.
            json_data["errors"].append(res.error if res.error else "no reason given")
            continue

        if res.data:
            json_data["results"]["id"] = res.data

    return retval, json_data, controller


def cmd_stage_config(args):
    ret, json_data, _ = cmd_stage_config_impl(args)

    if json_data:
        print(json_dumps(json_data), file=STDOUT)

    return ret


def cmd_deploy_config(args):
    ret, json_data, controller = cmd_stage_config_impl(args)

    if ret != 0:
        if json_data:
            print(json_dumps(json_data), file=STDOUT)
        return ret

    return cmd_deploy(args, controller=controller)


def cmd_show_settings(_args):
    CONFIG.write(STDOUT)
    return 0


def cmd_test_timeout(args):
    controller = create_controller()
    if controller is None:
        return 1

    resp, msg = controller.transact(
        TestTimeoutRequest,
        TestTimeoutResponse,
        args.with_state,
    )

    if resp is None:
        LOG.error("no response received: %s", msg)
        return 1

    res = Result.from_brokertype(resp.result)
    print(json_dumps({"success": res.success, "error": res.error}), file=STDOUT)
    return 0
