import json
import logging
import time
from textwrap import dedent
from teuthology.orchestra.run import CommandFailedError
from teuthology import misc

from teuthology.orchestra import remote as orchestra_remote
from teuthology.orchestra import run
from teuthology.contextutil import MaxWhileTries
from tasks.cephfs.mount import CephFSMount

log = logging.getLogger(__name__)


UMOUNT_TIMEOUT = 300


class KernelMount(CephFSMount):
    def __init__(self, ctx, test_dir, client_id, client_remote,
                 ipmi_user, ipmi_password, ipmi_domain):
        super(KernelMount, self).__init__(ctx, test_dir, client_id, client_remote)

        self.mounted = False
        self.ipmi_user = ipmi_user
        self.ipmi_password = ipmi_password
        self.ipmi_domain = ipmi_domain

    def mount(self, mount_path=None, mount_fs_name=None, mountpoint=None):
        if mountpoint is not None:
            self.mountpoint = mountpoint
        self.setupfs(name=mount_fs_name)

        log.info('Mounting kclient client.{id} at {remote} {mnt}...'.format(
            id=self.client_id, remote=self.client_remote, mnt=self.mountpoint))

        self.client_remote.run(args=['mkdir', '-p', self.mountpoint],
                               timeout=(5*60))

        if mount_path is None:
            mount_path = "/"

        opts = 'name={id},norequire_active_mds,conf={conf}'.format(id=self.client_id,
                                                        conf=self.config_path)

        if mount_fs_name is not None:
            opts += ",mds_namespace={0}".format(mount_fs_name)

        self.client_remote.run(
            args=[
                'sudo',
                'adjust-ulimits',
                'ceph-coverage',
                '{tdir}/archive/coverage'.format(tdir=self.test_dir),
                '/bin/mount',
                '-t',
                'ceph',
                ':{mount_path}'.format(mount_path=mount_path),
                self.mountpoint,
                '-v',
                '-o',
                opts
            ],
            timeout=(30*60),
        )

        self.client_remote.run(
            args=['sudo', 'chmod', '1777', self.mountpoint], timeout=(5*60))

        self.mounted = True

    def umount(self, force=False):
        if not self.is_mounted():
            return

        log.debug('Unmounting client client.{id}...'.format(id=self.client_id))

        cmd=['sudo', 'umount', self.mountpoint]
        if force:
            cmd.append('-f')

        try:
            self.client_remote.run(args=cmd, timeout=(15*60))
        except Exception as e:
            self.client_remote.run(args=[
                'sudo',
                run.Raw('PATH=/usr/sbin:$PATH'),
                'lsof',
                run.Raw(';'),
                'ps', 'auxf',
            ], timeout=(15*60))
            raise e

        rproc = self.client_remote.run(
            args=[
                'rmdir',
                '--',
                self.mountpoint,
            ],
            wait=False
        )
        run.wait([rproc], UMOUNT_TIMEOUT)
        self.mounted = False

    def cleanup(self):
        pass

    def umount_wait(self, force=False, require_clean=False, timeout=900):
        """
        Unlike the fuse client, the kernel client's umount is immediate
        """
        if not self.is_mounted():
            return

        try:
            self.umount(force)
        except (CommandFailedError, MaxWhileTries):
            if not force:
                raise

            self.kill()
            self.kill_cleanup()

        self.mounted = False

    def is_mounted(self):
        return self.mounted

    def wait_until_mounted(self):
        """
        Unlike the fuse client, the kernel client is up and running as soon
        as the initial mount() function returns.
        """
        assert self.mounted

    def teardown(self):
        super(KernelMount, self).teardown()
        if self.mounted:
            self.umount()

    def kill(self):
        """
        The Ceph kernel client doesn't have a mechanism to kill itself (doing
        that in side the kernel would be weird anyway), so we reboot the whole node
        to get the same effect.

        We use IPMI to reboot, because we don't want the client to send any
        releases of capabilities.
        """

        con = orchestra_remote.getRemoteConsole(self.client_remote.hostname,
                                                self.ipmi_user,
                                                self.ipmi_password,
                                                self.ipmi_domain)
        con.hard_reset(wait_for_login=False)

        self.mounted = False

    def kill_cleanup(self):
        assert not self.mounted

        # We need to do a sleep here because we don't know how long it will
        # take for a hard_reset to be effected.
        time.sleep(30)

        try:
            # Wait for node to come back up after reboot
            misc.reconnect(None, 300, [self.client_remote])
        except:
            # attempt to get some useful debug output:
            con = orchestra_remote.getRemoteConsole(self.client_remote.hostname,
                                                    self.ipmi_user,
                                                    self.ipmi_password,
                                                    self.ipmi_domain)
            con.check_status(timeout=60)
            raise

        # Remove mount directory
        self.client_remote.run(args=['uptime'], timeout=10)

        # Remove mount directory
        self.client_remote.run(
            args=[
                'rmdir',
                '--',
                self.mountpoint,
            ],
            timeout=(5*60),
            check_status=False,
        )

    def _find_debug_dir(self):
        """
        Find the debugfs folder for this mount
        """
        pyscript = dedent("""
            import glob
            import os
            import json

            def get_id_to_dir():
                result = {}
                for dir in glob.glob("/sys/kernel/debug/ceph/*"):
                    mds_sessions_lines = open(os.path.join(dir, "mds_sessions")).readlines()
                    client_id = mds_sessions_lines[1].split()[1].strip('"')

                    result[client_id] = dir
                return result

            print(json.dumps(get_id_to_dir()))
            """)

        output = self.client_remote.sh([
            'sudo', 'python3', '-c', pyscript
        ], timeout=(5*60))
        client_id_to_dir = json.loads(output)

        try:
            return client_id_to_dir[self.client_id]
        except KeyError:
            log.error("Client id '{0}' debug dir not found (clients seen were: {1})".format(
                self.client_id, ",".join(client_id_to_dir.keys())
            ))
            raise

    def _read_debug_file(self, filename):
        debug_dir = self._find_debug_dir()

        pyscript = dedent("""
            import os

            print(open(os.path.join("{debug_dir}", "{filename}")).read())
            """).format(debug_dir=debug_dir, filename=filename)

        output = self.client_remote.sh([
            'sudo', 'python3', '-c', pyscript
        ], timeout=(5*60))
        return output

    def get_global_id(self):
        """
        Look up the CephFS client ID for this mount, using debugfs.
        """

        assert self.mounted

        mds_sessions = self._read_debug_file("mds_sessions")
        lines = mds_sessions.split("\n")
        return int(lines[0].split()[1])

    def get_osd_epoch(self):
        """
        Return 2-tuple of osd_epoch, osd_epoch_barrier
        """
        osd_map = self._read_debug_file("osdmap")
        lines = osd_map.split("\n")
        first_line_tokens = lines[0].split()
        epoch, barrier = int(first_line_tokens[1]), int(first_line_tokens[3])

        return epoch, barrier