import json
import logging
import subprocess
import signal
from urllib.parse import quote

from defence360agent.utils import check_run, CheckRunError
from defence360agent.subsys.panels.base import PanelException

logger = logging.getLogger(__name__)

# use complete path as recommended by cPanel docs
# https://documentation.cpanel.net/display/DD/WHM+API+1+Functions+-+modsec_is_installed
WHMAPI1_CMD = "/usr/sbin/whmapi1"
WHMAPI_CERT_ERROR_LIST = [
    "no certificate",
    "no key with the id",
    "cannot read license file",
    "invalid license file",
    "license file expired",
]


class WHMAPIException(PanelException):
    """Got broken output or other problem during WHMAPI call"""

    pass


class WHMAPILicenseError(WHMAPIException):
    """Raises when cannot Read License File"""

    pass


async def whmapi1(function, sudo=False, **kwargs):
    cmd = ["sudo"] if sudo else []
    cmd.extend([WHMAPI1_CMD, "--output=json", function])
    params = ["{}={}".format(k, quote(v)) for k, v in kwargs.items()]
    try:
        raw_output = (await check_run(cmd + params)).decode()
    except CheckRunError as e:
        if e.returncode == -signal.SIGTERM:
            logger.warning(e)
            raise WHMAPIException(e)
        else:
            raise e
    try:
        output = json.loads(raw_output)
    except json.JSONDecodeError as e:
        raise WHMAPIException(
            f"Broken output from whmapi1: {raw_output!r}, reason: {e}"
        ) from e

    try:
        if output["metadata"]["result"]:
            return output["data"]
        else:
            raise WHMAPIException(
                "whmapi {} command failed: {}".format(
                    output["metadata"]["command"], output["metadata"]["reason"]
                )
            )
    except KeyError as e:
        if ("statusmsg", "Cannot Read License File") in output.items():
            logger.warning("Cannot Read CPanel License File")
            raise WHMAPILicenseError
        else:
            raise WHMAPIException(
                "Broken output from whmapi1 (KeyError: {}): {!r}".format(
                    e, output
                )
            )


def run_whmapi(args, *path_list):
    # FIXME: this script partly copypaste 'whmapi1' function
    cmd = [WHMAPI1_CMD, *args, "--output=json"]

    try:
        logger.debug("subprocess.run(%r)", cmd)
        res = subprocess.run(cmd, check=True, stdout=subprocess.PIPE)

    except subprocess.CalledProcessError as e:
        raise WHMAPIException("Failed to run whmapi1: %s" % e) from e

    if path_list:
        decoded_output = json.loads(res.stdout.decode())
        result = []
        for i, element_path in enumerate(path_list):
            try:
                item = decoded_output
                for key in element_path:
                    item = item[key]
                result.append(item)
            except KeyError as e:
                if i == 0:
                    # we guarantee to *always* return first element from
                    # path_list
                    raise WHMAPIException(
                        "Could not parse whmapi1 output"
                    ) from e
                else:
                    # and have no guarantee for the rest of path_list
                    result.append(None)
    else:
        return

    if len(result) == 1:
        return result[0]
    else:
        return result


def run_whmapi_result(args):
    return run_whmapi(args, ["metadata", "result"])


def run_whmapi_result_and_reason(args):
    result, reason = run_whmapi(
        args, ["metadata", "result"], ["metadata", "reason"]
    )
    # explicit is better than implicit!
    return result, reason