import agent_util
import logging


logger = logging.getLogger(__name__)


def execute_query(query):
    ret, output = agent_util.execute_command(query)
    return str(output);


class VarnishPlugin(agent_util.Plugin):
    textkey = "varnish"
    label = "Varnish"

    @classmethod
    def get_metadata(self, config):
        status = agent_util.SUPPORTED
        msg = None

        # check if varnish is even installed or running
        installed = agent_util.which("varnishd")
        if not installed:
            self.log.info("The varnishd binary was not found")
            status = agent_util.UNSUPPORTED
            msg = "varnish binary not found"
            return {}

        stat_binary_path = agent_util.which("varnishstat")
        if not stat_binary_path:
            msg = "The varnishstat binary was not found."
            status = agent_util.MISCONFIGURED
            self.log.info(msg)

        data = {
            "client_conn": {
                "label": "Client connections accepted",
                "options": None,
                "status": status,
                "error_message": msg
            },
            "client_req": {
                "label": "Client requests received",
                "options": None,
                "status": status,
                "error_message": msg
            },
            "cache_hit": {
                "label": "Cache hits",
                "options": None,
                "status": status,
                "error_message": msg
            },
            "cache_hitpass": {
                "label": "Cache hits for pass",
                "options": None,
                "status": status,
                "error_message": msg
            },

            "backend_fail": {
                "label": "Backend conn. failures",
                "options": None,
                "status": status,
                "error_message": msg
            },
            "cache_miss": {
                "label": "Cache misses",
                "options": None,
                "status": status,
                "error_message": msg
            },
            "n_object": {
                "label": "Nstruct object",
                "options": None,
                "status": status,
                "error_message": msg
            },
            "n_wrk": {
                "label": "Nworker threads",
                "options": None,
                "status": status,
                "error_message": msg
            },
            "n_wrk_create": {
                "label": "Nworker threads created",
                "options": None,
                "status": status,
                "error_message": msg
            },
            "n_wrk_failed": {
                "label": "Nworker threads not created",
                "options": None,
                "status": status,
                "error_message": msg
            },
            "n_wrk_max": {
                "label": "Nworker threads limited",
                "options": None,
                "status": status,
                "error_message": msg
            },
            "n_wrk_drop": {
                "label": "Ndropped work requests",
                "options": None,
                "status": status,
                "error_message": msg
            },
            "n_lru_nuked": {
                "label": "NLRU nuked objects",
                "options": None,
                "status": status,
                "error_message": msg
            },
            "esi_errors": {
                "label": "ESI parse errors (unlock)",
                "options": None,
                "status": status,
                "error_message": msg
            },
            "n_expired": {
                "label": "Nexpired objects",
                "options": None,
                "status": status,
                "error_message": msg
            },
        }
        if "extended_metrics" in config:
            extended_metrics = [m.strip().lower() for m in config["extended_metrics"].split(',')]
            for m in extended_metrics:
                data["extended_metric.%s" % m] = {
                    "label": "Varnish %s" % m.replace('_', " "),
                    "options": None,
                    "status": status,
                    "error_message": msg
                }
        return data

    def check(self, textkey, data, config):
        stat_binary_path = agent_util.which("varnishstat")
        query = '%s -1 -f %s'
        if "extended_metric" in textkey:
            result = execute_query(query % (stat_binary_path, textkey.replace("extended_metric.", "")))
        else:
            result = execute_query(query % (stat_binary_path, textkey))
        fields = result.split()
        try:
            return int(fields[1])
        except:
            return 0
            self.log.debug("%s: %s" % (textkey.replace("extended_metric.", "").title(), str(result)))