#!/usr/bin/env python3
import argparse
from pprint import pprint
from subprocess import check_output

import nagiosplugin


def lvs_output():
    return [
        line.strip().split(":", 5)
        for line in check_output(
            [
                "sudo",
                "lvs",
                "--noheadings",
                "--separator",
                ":",
                "--select",
                "lv_attr =~ ^t",
                "-o",
                "lvattr,lv_name,vg_name,data_percent,metadata_percent",
            ],
            env={"LC_ALL": "C"},
            encoding="UTF-8",
        ).splitlines()
    ]


class LVMThinPools(nagiosplugin.Resource):
    def __init__(self):
        self.pool_data = lvs_output()

    def get_lv_names(self):
        return [f"{vg_name}/{lv_name}" for _, lv_name, vg_name, _, _ in self.pool_data]

    def probe(self):
        data_max = 0.0
        metadata_max = 0.0

        metrics = []

        for lv_attr, lv_name, vg_name, data_percent, metadata_percent in self.pool_data:
            metrics += [
                nagiosplugin.Metric(
                    f"data_{vg_name}/{lv_name}",
                    float(data_percent),
                    "%",
                    0,
                    100,
                ),
                nagiosplugin.Metric(
                    f"meta_{vg_name}/{lv_name}",
                    float(metadata_percent),
                    "%",
                    0,
                    100,
                ),
            ]

            data_max = max(data_max, float(data_percent))
            metadata_max = max(metadata_max, float(metadata_percent))

        metrics += [
            nagiosplugin.Metric("data_percent", data_max, "%", 0, 100),
            nagiosplugin.Metric("metadata_percent", metadata_max, "%", 0, 100),
        ]

        return metrics


def parse_args():
    argp = argparse.ArgumentParser()
    argp.add_argument("--dpw", "--data-warning-percent", metavar="RANGE", default="70")
    argp.add_argument("--dpc", "--data-critical-percent", metavar="RANGE", default="90")
    argp.add_argument(
        "--mpw", "--metadata-warning-percent", metavar="RANGE", default="70"
    )
    argp.add_argument(
        "--mpc", "--metadata-critical-percent", metavar="RANGE", default="90"
    )
    argp.add_argument(
        "-v",
        "--verbose",
        action="count",
        default=0,
        help="increase output verbosity (use up to 3 times)",
    )
    return argp.parse_args()


@nagiosplugin.guarded
def main():
    args = parse_args()

    pools = LVMThinPools()

    check = nagiosplugin.Check(
        pools,
        nagiosplugin.ScalarContext("data_percent", args.dpw, args.dpc),
        nagiosplugin.ScalarContext("metadata_percent", args.mpw, args.mpc),
    )

    for lv_full_name in pools.get_lv_names():
        check.add(nagiosplugin.ScalarContext(f"data_{lv_full_name}", args.dpw, args.dpc,
                                             "data percent (%s) is {valueunit}" % lv_full_name))
        check.add(nagiosplugin.ScalarContext(f"meta_{lv_full_name}", args.dpw, args.dpc,
                                             "meta data percent (%s) is {valueunit}" % lv_full_name))
    check.main(args.verbose)


if __name__ == "__main__":
    main()