import asyncio
import functools
import json
import logging
import os
from collections import defaultdict
from typing import Dict, List, Sequence, Set

import cerberus
import yaml
from defence360agent.api.integration_conf import (
    ClIntegrationConfig,
    IntegrationConfig,
)
from defence360agent.api.jwt_issuer import JWTIssuer
from defence360agent.application.determine_hosting_panel import (
    is_generic_panel_installed,
)
from defence360agent.rpc_tools.lookup import UserType
from defence360agent.utils import (
    CheckRunError,
    check_run,
    get_non_system_users,
)

from .. import base

logger = logging.getLogger(__name__)
_SCHEMA_PATH_TMPL = (
    os.path.dirname(__file__) + "/users_script_schemas/schema-{}.yaml"
)

ADMIN_LIST_FILE_PATH = "/etc/sysconfig/imunify360/auth.admin"
METADATA = "metadata"


@functools.lru_cache(maxsize=2)
def _get_validator(script: str) -> cerberus.Validator:
    """Returns a validator for given script."""
    with open(_SCHEMA_PATH_TMPL.format(script)) as schema_file:
        schema = yaml.safe_load(schema_file)
        if script is not METADATA:
            schema[METADATA] = {"required": True}
        return cerberus.Validator(schema)


def get_users_default_impl():
    return [dict(name=pw.pw_name) for pw in get_non_system_users()]


def _get_conf_path(cl, script):
    d = cl.to_dict()
    if "integration_scripts" in d and script in d["integration_scripts"]:
        return d["integration_scripts"][script]
    return None


async def get_integration_data(script: str):
    path = _get_conf_path(IntegrationConfig(), script)
    if not path:
        path = _get_conf_path(ClIntegrationConfig(), script)
    if not path:
        raise IntegrationScriptError(
            "%s not found neither in "
            "/etc/sysconfig/imunify360/integration.conf "
            "nor in /opt/cpvendor/etc/integration.ini." % script
        )

    return await _get_integration_data(script, path)


async def _get_integration_data(script: str, path: str):
    try:
        stdout = await check_run(path, shell=True)
    except CheckRunError as e:
        raise IntegrationScriptError(
            "Integrations script {script} "
            "failed with exit code {e.returncode} \n"
            "{e.stderr}".format(script=script, e=e)
        )

    try:
        data = json.loads(stdout.decode())
    except (UnicodeDecodeError, json.JSONDecodeError) as e:
        raise IntegrationScriptError(
            "Cannot decode output of %s as JSON" % path
        ) from e
    if not isinstance(data, dict):
        raise IntegrationScriptError("%s should return dict" % path)

    metadata_validator = _get_validator(METADATA)
    if not metadata_validator.validate(data):
        raise IntegrationScriptError(
            "Validation error in metadata of %s script: %s"
            % (script, metadata_validator.errors)
        )

    if data[METADATA]["result"] != "ok":
        metadata_error = data[METADATA]["result"]
        if "message" in data[METADATA]:
            metadata_error += ": %s" % data[METADATA]["message"]
        raise IntegrationScriptError(metadata_error)

    validator = _get_validator(script)
    if not validator.validate(data):
        raise IntegrationScriptError(
            "Validation error in %s script: %s" % (script, validator.errors)
        )

    return data["data"]


async def _get_client_data():
    try:
        users = await get_users_integration_data()
        domains = await get_integration_data("domains")
        for k, v in domains.items():
            if v["owner"]:
                user_domains = users.setdefault(v["owner"], [])
                user_domains.append(k)
        return [{"name": k, "domains": v} for k, v in users.items()]

    except IntegrationScriptError:
        logger.warning(
            "Applying default implementation of users and domains lists"
        )
        return get_users_default_impl()


async def get_users_integration_data():
    users = await get_integration_data("users")
    users_dict = {}

    for user in users:
        if not user["username"]:
            logger.warning(f"Found user with an empty username: {user}")
        else:
            users_dict[user["username"]] = []

    return users_dict


async def get_domain_data():
    try:
        return await get_integration_data("domains")
    except IntegrationScriptError:
        logger.warning("Could not parse domains lists")
        return {}


async def get_admin_list() -> List[str]:
    script_name = "admins"
    admins_set = {"root"}
    admins_from_integration_scripts = await asyncio.gather(
        _get_integration_data(
            script_name,
            _get_conf_path(
                IntegrationConfig(),
                script_name,
            ),
        ),
        _get_integration_data(
            script_name,
            _get_conf_path(
                ClIntegrationConfig(),
                script_name,
            ),
        ),
        return_exceptions=True,
    )
    custom_admins = {
        admin["name"]
        for admins in admins_from_integration_scripts
        if isinstance(admins, list)  # skip exceptions
        for admin in admins
    }

    if not custom_admins:
        logger.warning(
            "Error occurred during extracting admins "
            "from integration configs: %s",
            admins_from_integration_scripts,
        )

    admins_set |= custom_admins
    try:
        with open(ADMIN_LIST_FILE_PATH) as admin_list_file:
            admins_set.update(admin_list_file.read().splitlines())
    except OSError:
        logger.warning(
            "Failed to retrieve admins list from %s", ADMIN_LIST_FILE_PATH
        )
    return list(admins_set)


class IntegrationScriptError(base.PanelException):
    def __init__(self, *args, **kwargs):
        super().__init__(*args)
        logger.warning(self)


class GenericPanel(base.AbstractPanel):
    """
    Panel, UI to which is provided by
    imunify{-antivirus,360-firewall}-generic.{rpm,deb}
    """

    NAME = "generic panel"
    exception = IntegrationScriptError

    @classmethod
    def is_installed(cls):
        return is_generic_panel_installed()  # pragma: no cover

    async def enable_imunify360_plugin(self, name=None):
        pass

    async def disable_imunify360_plugin(self, plugin_name=None):
        pass

    @classmethod
    async def version(cls):
        try:
            info = await get_integration_data("panel_info")
            return "{name} {version}".format(**info)
        except IntegrationScriptError:
            return "0"

    async def get_user_domains(self):
        users = await _get_client_data()
        result = []
        for user in users:
            result.extend(user.get("domains", tuple()))
        return result

    async def get_users(self) -> List[str]:
        users = await _get_client_data()
        return [user["name"] for user in users]

    async def get_domain_to_owner(self) -> Dict[str, List[str]]:
        users = await _get_client_data()
        result = defaultdict(list)
        for user in users:
            for domain in user.get("domains", []):
                result[domain].append(user["name"])
        return result

    async def get_domains_per_user(self) -> Dict[str, List[str]]:
        users = await _get_client_data()

        return {user["name"]: user.get("domains", []) for user in users}

    def authenticate(self, protocol, data: dict):
        if protocol._uid != 0 and data["command"] != ["login", "pam"]:
            token = data["params"].pop("jwt", None)
            parsed_token = JWTIssuer.parse_token(token)
            return parsed_token["user_type"], (
                parsed_token["user_name"]
                if parsed_token["user_type"] == UserType.NON_ROOT
                else None
            )
        else:
            return protocol.user, None

    def basedirs(self) -> Set[str]:
        conf = IntegrationConfig().to_dict()
        if "malware" in conf and "basedir" in conf["malware"]:
            return set(conf["malware"]["basedir"].split())
        return set()

    async def list_docroots(self) -> Dict[str, str]:
        domains = await get_domain_data()
        return {v["document_root"]: domain for domain, v in domains.items()}