# Copyright (c) 2009, Giampaolo Rodola'. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""FreeBSD, OpenBSD and NetBSD platforms implementation."""

import contextlib
import errno
import functools
import os
import xml.etree.ElementTree as ET
from collections import defaultdict
from collections import namedtuple

from . import _common
from . import _psposix
from . import _psutil_bsd as cext
from . import _psutil_posix as cext_posix
from ._common import FREEBSD
from ._common import NETBSD
from ._common import OPENBSD
from ._common import AccessDenied
from ._common import NoSuchProcess
from ._common import ZombieProcess
from ._common import conn_tmap
from ._common import conn_to_ntuple
from ._common import memoize
from ._common import memoize_when_activated
from ._common import usage_percent
from ._compat import FileNotFoundError
from ._compat import PermissionError
from ._compat import ProcessLookupError
from ._compat import which


__extra__all__ = []


# =====================================================================
# --- globals
# =====================================================================


if FREEBSD:
    PROC_STATUSES = {
        cext.SIDL: _common.STATUS_IDLE,
        cext.SRUN: _common.STATUS_RUNNING,
        cext.SSLEEP: _common.STATUS_SLEEPING,
        cext.SSTOP: _common.STATUS_STOPPED,
        cext.SZOMB: _common.STATUS_ZOMBIE,
        cext.SWAIT: _common.STATUS_WAITING,
        cext.SLOCK: _common.STATUS_LOCKED,
    }
elif OPENBSD:
    PROC_STATUSES = {
        cext.SIDL: _common.STATUS_IDLE,
        cext.SSLEEP: _common.STATUS_SLEEPING,
        cext.SSTOP: _common.STATUS_STOPPED,
        # According to /usr/include/sys/proc.h SZOMB is unused.
        # test_zombie_process() shows that SDEAD is the right
        # equivalent. Also it appears there's no equivalent of
        # psutil.STATUS_DEAD. SDEAD really means STATUS_ZOMBIE.
        # cext.SZOMB: _common.STATUS_ZOMBIE,
        cext.SDEAD: _common.STATUS_ZOMBIE,
        cext.SZOMB: _common.STATUS_ZOMBIE,
        # From http://www.eecs.harvard.edu/~margo/cs161/videos/proc.h.txt
        # OpenBSD has SRUN and SONPROC: SRUN indicates that a process
        # is runnable but *not* yet running, i.e. is on a run queue.
        # SONPROC indicates that the process is actually executing on
        # a CPU, i.e. it is no longer on a run queue.
        # As such we'll map SRUN to STATUS_WAKING and SONPROC to
        # STATUS_RUNNING
        cext.SRUN: _common.STATUS_WAKING,
        cext.SONPROC: _common.STATUS_RUNNING,
    }
elif NETBSD:
    PROC_STATUSES = {
        cext.SIDL: _common.STATUS_IDLE,
        cext.SSLEEP: _common.STATUS_SLEEPING,
        cext.SSTOP: _common.STATUS_STOPPED,
        cext.SZOMB: _common.STATUS_ZOMBIE,
        cext.SRUN: _common.STATUS_WAKING,
        cext.SONPROC: _common.STATUS_RUNNING,
    }

TCP_STATUSES = {
    cext.TCPS_ESTABLISHED: _common.CONN_ESTABLISHED,
    cext.TCPS_SYN_SENT: _common.CONN_SYN_SENT,
    cext.TCPS_SYN_RECEIVED: _common.CONN_SYN_RECV,
    cext.TCPS_FIN_WAIT_1: _common.CONN_FIN_WAIT1,
    cext.TCPS_FIN_WAIT_2: _common.CONN_FIN_WAIT2,
    cext.TCPS_TIME_WAIT: _common.CONN_TIME_WAIT,
    cext.TCPS_CLOSED: _common.CONN_CLOSE,
    cext.TCPS_CLOSE_WAIT: _common.CONN_CLOSE_WAIT,
    cext.TCPS_LAST_ACK: _common.CONN_LAST_ACK,
    cext.TCPS_LISTEN: _common.CONN_LISTEN,
    cext.TCPS_CLOSING: _common.CONN_CLOSING,
    cext.PSUTIL_CONN_NONE: _common.CONN_NONE,
}

PAGESIZE = cext_posix.getpagesize()
AF_LINK = cext_posix.AF_LINK

HAS_PER_CPU_TIMES = hasattr(cext, "per_cpu_times")
HAS_PROC_NUM_THREADS = hasattr(cext, "proc_num_threads")
HAS_PROC_OPEN_FILES = hasattr(cext, 'proc_open_files')
HAS_PROC_NUM_FDS = hasattr(cext, 'proc_num_fds')

kinfo_proc_map = dict(
    ppid=0,
    status=1,
    real_uid=2,
    effective_uid=3,
    saved_uid=4,
    real_gid=5,
    effective_gid=6,
    saved_gid=7,
    ttynr=8,
    create_time=9,
    ctx_switches_vol=10,
    ctx_switches_unvol=11,
    read_io_count=12,
    write_io_count=13,
    user_time=14,
    sys_time=15,
    ch_user_time=16,
    ch_sys_time=17,
    rss=18,
    vms=19,
    memtext=20,
    memdata=21,
    memstack=22,
    cpunum=23,
    name=24,
)


# =====================================================================
# --- named tuples
# =====================================================================


# psutil.virtual_memory()
svmem = namedtuple(
    'svmem', ['total', 'available', 'percent', 'used', 'free',
              'active', 'inactive', 'buffers', 'cached', 'shared', 'wired'])
# psutil.cpu_times()
scputimes = namedtuple(
    'scputimes', ['user', 'nice', 'system', 'idle', 'irq'])
# psutil.Process.memory_info()
pmem = namedtuple('pmem', ['rss', 'vms', 'text', 'data', 'stack'])
# psutil.Process.memory_full_info()
pfullmem = pmem
# psutil.Process.cpu_times()
pcputimes = namedtuple('pcputimes',
                       ['user', 'system', 'children_user', 'children_system'])
# psutil.Process.memory_maps(grouped=True)
pmmap_grouped = namedtuple(
    'pmmap_grouped', 'path rss, private, ref_count, shadow_count')
# psutil.Process.memory_maps(grouped=False)
pmmap_ext = namedtuple(
    'pmmap_ext', 'addr, perms path rss, private, ref_count, shadow_count')
# psutil.disk_io_counters()
if FREEBSD:
    sdiskio = namedtuple('sdiskio', ['read_count', 'write_count',
                                     'read_bytes', 'write_bytes',
                                     'read_time', 'write_time',
                                     'busy_time'])
else:
    sdiskio = namedtuple('sdiskio', ['read_count', 'write_count',
                                     'read_bytes', 'write_bytes'])


# =====================================================================
# --- memory
# =====================================================================


def virtual_memory():
    """System virtual memory as a namedtuple."""
    mem = cext.virtual_mem()
    total, free, active, inactive, wired, cached, buffers, shared = mem
    if NETBSD:
        # On NetBSD buffers and shared mem is determined via /proc.
        # The C ext set them to 0.
        with open('/proc/meminfo', 'rb') as f:
            for line in f:
                if line.startswith(b'Buffers:'):
                    buffers = int(line.split()[1]) * 1024
                elif line.startswith(b'MemShared:'):
                    shared = int(line.split()[1]) * 1024
                elif line.startswith(b'Cached:'):
                    cached = int(line.split()[1]) * 1024
    avail = inactive + cached + free
    used = active + wired + cached
    percent = usage_percent((total - avail), total, round_=1)
    return svmem(total, avail, percent, used, free,
                 active, inactive, buffers, cached, shared, wired)


def swap_memory():
    """System swap memory as (total, used, free, sin, sout) namedtuple."""
    total, used, free, sin, sout = cext.swap_mem()
    percent = usage_percent(used, total, round_=1)
    return _common.sswap(total, used, free, percent, sin, sout)


# =====================================================================
# --- CPU
# =====================================================================


def cpu_times():
    """Return system per-CPU times as a namedtuple"""
    user, nice, system, idle, irq = cext.cpu_times()
    return scputimes(user, nice, system, idle, irq)


if HAS_PER_CPU_TIMES:
    def per_cpu_times():
        """Return system CPU times as a namedtuple"""
        ret = []
        for cpu_t in cext.per_cpu_times():
            user, nice, system, idle, irq = cpu_t
            item = scputimes(user, nice, system, idle, irq)
            ret.append(item)
        return ret
else:
    # XXX
    # Ok, this is very dirty.
    # On FreeBSD < 8 we cannot gather per-cpu information, see:
    # https://github.com/giampaolo/psutil/issues/226
    # If num cpus > 1, on first call we return single cpu times to avoid a
    # crash at psutil import time.
    # Next calls will fail with NotImplementedError
    def per_cpu_times():
        """Return system CPU times as a namedtuple"""
        if cpu_count_logical() == 1:
            return [cpu_times()]
        if per_cpu_times.__called__:
            raise NotImplementedError("supported only starting from FreeBSD 8")
        per_cpu_times.__called__ = True
        return [cpu_times()]

    per_cpu_times.__called__ = False


def cpu_count_logical():
    """Return the number of logical CPUs in the system."""
    return cext.cpu_count_logical()


if OPENBSD or NETBSD:
    def cpu_count_cores():
        # OpenBSD and NetBSD do not implement this.
        return 1 if cpu_count_logical() == 1 else None
else:
    def cpu_count_cores():
        """Return the number of CPU cores in the system."""
        # From the C module we'll get an XML string similar to this:
        # http://manpages.ubuntu.com/manpages/precise/man4/smp.4freebsd.html
        # We may get None in case "sysctl kern.sched.topology_spec"
        # is not supported on this BSD version, in which case we'll mimic
        # os.cpu_count() and return None.
        ret = None
        s = cext.cpu_topology()
        if s is not None:
            # get rid of padding chars appended at the end of the string
            index = s.rfind("</groups>")
            if index != -1:
                s = s[:index + 9]
                root = ET.fromstring(s)
                try:
                    ret = len(root.findall('group/children/group/cpu')) or None
                finally:
                    # needed otherwise it will memleak
                    root.clear()
        if not ret:
            # If logical CPUs == 1 it's obvious we' have only 1 core.
            if cpu_count_logical() == 1:
                return 1
        return ret


def cpu_stats():
    """Return various CPU stats as a named tuple."""
    if FREEBSD:
        # Note: the C ext is returning some metrics we are not exposing:
        # traps.
        ctxsw, intrs, soft_intrs, syscalls, traps = cext.cpu_stats()
    elif NETBSD:
        # XXX
        # Note about intrs: the C extension returns 0. intrs
        # can be determined via /proc/stat; it has the same value as
        # soft_intrs thought so the kernel is faking it (?).
        #
        # Note about syscalls: the C extension always sets it to 0 (?).
        #
        # Note: the C ext is returning some metrics we are not exposing:
        # traps, faults and forks.
        ctxsw, intrs, soft_intrs, syscalls, traps, faults, forks = \
            cext.cpu_stats()
        with open('/proc/stat', 'rb') as f:
            for line in f:
                if line.startswith(b'intr'):
                    intrs = int(line.split()[1])
    elif OPENBSD:
        # Note: the C ext is returning some metrics we are not exposing:
        # traps, faults and forks.
        ctxsw, intrs, soft_intrs, syscalls, traps, faults, forks = \
            cext.cpu_stats()
    return _common.scpustats(ctxsw, intrs, soft_intrs, syscalls)


if FREEBSD:
    def cpu_freq():
        """Return frequency metrics for CPUs. As of Dec 2018 only
        CPU 0 appears to be supported by FreeBSD and all other cores
        match the frequency of CPU 0.
        """
        ret = []
        num_cpus = cpu_count_logical()
        for cpu in range(num_cpus):
            try:
                current, available_freq = cext.cpu_freq(cpu)
            except NotImplementedError:
                continue
            if available_freq:
                try:
                    min_freq = int(available_freq.split(" ")[-1].split("/")[0])
                except (IndexError, ValueError):
                    min_freq = None
                try:
                    max_freq = int(available_freq.split(" ")[0].split("/")[0])
                except (IndexError, ValueError):
                    max_freq = None
            ret.append(_common.scpufreq(current, min_freq, max_freq))
        return ret
elif OPENBSD:
    def cpu_freq():
        curr = float(cext.cpu_freq())
        return [_common.scpufreq(curr, 0.0, 0.0)]


# =====================================================================