# 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.

"""macOS platform implementation."""

import errno
import functools
import os
from collections import namedtuple

from . import _common
from . import _psposix
from . import _psutil_osx as cext
from . import _psutil_posix as cext_posix
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 isfile_strict
from ._common import memoize_when_activated
from ._common import parse_environ_block
from ._common import usage_percent
from ._compat import PermissionError
from ._compat import ProcessLookupError


__extra__all__ = []


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


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

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,
}

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,
}

kinfo_proc_map = dict(
    ppid=0,
    ruid=1,
    euid=2,
    suid=3,
    rgid=4,
    egid=5,
    sgid=6,
    ttynr=7,
    ctime=8,
    status=9,
    name=10,
)

pidtaskinfo_map = dict(
    cpuutime=0,
    cpustime=1,
    rss=2,
    vms=3,
    pfaults=4,
    pageins=5,
    numthreads=6,
    volctxsw=7,
)


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


# psutil.cpu_times()
scputimes = namedtuple('scputimes', ['user', 'nice', 'system', 'idle'])
# psutil.virtual_memory()
svmem = namedtuple(
    'svmem', ['total', 'available', 'percent', 'used', 'free',
              'active', 'inactive', 'wired'])
# psutil.Process.memory_info()
pmem = namedtuple('pmem', ['rss', 'vms', 'pfaults', 'pageins'])
# psutil.Process.memory_full_info()
pfullmem = namedtuple('pfullmem', pmem._fields + ('uss', ))


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


def virtual_memory():
    """System virtual memory as a namedtuple."""
    total, active, inactive, wired, free, speculative = cext.virtual_mem()
    # This is how Zabbix calculate avail and used mem:
    # https://github.com/zabbix/zabbix/blob/trunk/src/libs/zbxsysinfo/
    #     osx/memory.c
    # Also see: https://github.com/giampaolo/psutil/issues/1277
    avail = inactive + free
    used = active + wired
    # This is NOT how Zabbix calculates free mem but it matches "free"
    # cmdline utility.
    free -= speculative
    percent = usage_percent((total - avail), total, round_=1)
    return svmem(total, avail, percent, used, free,
                 active, inactive, wired)


def swap_memory():
    """Swap system memory as a (total, used, free, sin, sout) tuple."""
    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 CPU times as a namedtuple."""
    user, nice, system, idle = cext.cpu_times()
    return scputimes(user, nice, system, idle)


def per_cpu_times():
    """Return system CPU times as a named tuple"""
    ret = []
    for cpu_t in cext.per_cpu_times():
        user, nice, system, idle = cpu_t
        item = scputimes(user, nice, system, idle)
        ret.append(item)
    return ret


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


def cpu_count_cores():
    """Return the number of CPU cores in the system."""
    return cext.cpu_count_cores()


def cpu_stats():
    ctx_switches, interrupts, soft_interrupts, syscalls, traps = \
        cext.cpu_stats()
    return _common.scpustats(
        ctx_switches, interrupts, soft_interrupts, syscalls)


def cpu_freq():
    """Return CPU frequency.
    On macOS per-cpu frequency is not supported.
    Also, the returned frequency never changes, see:
    https://arstechnica.com/civis/viewtopic.php?f=19&t=465002
    """
    curr, min_, max_ = cext.cpu_freq()
    return [_common.scpufreq(curr, min_, max_)]


# =====================================================================
# --- disks
# =====================================================================


disk_usage = _psposix.disk_usage
disk_io_counters = cext.disk_io_counters


def disk_partitions(all=False):
    """Return mounted disk partitions as a list of namedtuples."""
    retlist = []
    partitions = cext.disk_partitions()
    for partition in partitions:
        device, mountpoint, fstype, opts = partition
        if device == 'none':
            device = ''
        if not all:
            if not os.path.isabs(device) or not os.path.exists(device):
                continue
        maxfile = maxpath = None  # set later
        ntuple = _common.sdiskpart(device, mountpoint, fstype, opts,
                                   maxfile, maxpath)
        retlist.append(ntuple)
    return retlist


# =====================================================================
# --- sensors
# =====================================================================


def sensors_battery():
    """Return battery information."""
    try:
        percent, minsleft, power_plugged = cext.sensors_battery()
    except NotImplementedError:
        # no power source - return None according to interface
        return None
    power_plugged = power_plugged == 1
    if power_plugged:
        secsleft = _common.POWER_TIME_UNLIMITED
    elif minsleft == -1:
        secsleft = _common.POWER_TIME_UNKNOWN
    else:
        secsleft = minsleft * 60
    return _common.sbattery(percent, secsleft, power_plugged)


# =====================================================================
# --- network
# =====================================================================


net_io_counters = cext.net_io_counters
net_if_addrs = cext_posix.net_if_addrs


def net_connections(kind='inet'):
    """System-wide network connections."""
    # Note: on macOS this will fail with AccessDenied unless
    # the process is owned by root.
    ret = []
    for pid in pids():
        try:
            cons = Process(pid).connections(kind)
        except NoSuchProcess:
            continue
        else:
            if cons:
                for c in cons:
                    c = list(c) + [pid]
                    ret.append(_common.sconn(*c))
    return ret


def net_if_stats():
    """Get NIC stats (isup, duplex, speed, mtu)."""
    names = net_io_counters().keys()
    ret = {}
    for name in names:
        try:
            mtu = cext_posix.net_if_mtu(name)
            flags = cext_posix.net_if_flags(name)
            duplex, speed = cext_posix.net_if_duplex_speed(name)
        except OSError as err:
            # https://github.com/giampaolo/psutil/issues/1279
            if err.errno != errno.ENODEV:
                raise
        else:
            if hasattr(_common, 'NicDuplex'):
                duplex = _common.NicDuplex(duplex)
            output_flags = ','.join(flags)
            isup = 'running' in flags
            ret[name] = _common.snicstats(isup, duplex, speed, mtu,
                                          output_flags)
    return ret


# =====================================================================
# --- other system functions
# =====================================================================


def boot_time():
    """The system boot time expressed in seconds since the epoch."""
    return cext.boot_time()


def users():
    """Return currently connected users as a list of namedtuples."""
    retlist = []
    rawlist = cext.users()
    for item in rawlist:
        user, tty, hostname, tstamp, pid = item
        if tty == '~':
            continue  # reboot or shutdown
        if not tstamp:
            continue
        nt = _common.suser(user, tty or None, hostname or None, tstamp, pid)
        retlist.append(nt)
    return retlist


# =====================================================================
# --- processes
# =====================================================================


def pids():
    ls = cext.pids()
    if 0 not in ls:
        # On certain macOS versions pids() C doesn't return PID 0 but
        # "ps" does and the process is querable via sysctl():
        # https://travis-ci.org/giampaolo/psutil/jobs/309619941
        try:
            Process(0).create_time()
            ls.insert(0, 0)
        except NoSuchProcess:
            pass
        except AccessDenied:
            ls.insert(0, 0)
    return ls


pid_exists = _psposix.pid_exists


def is_zombie(pid):
    try:
        st = cext.proc_kinfo_oneshot(pid)[kinfo_proc_map['status']]
        return st == cext.SZOMB
    except Exception:
        return False


def wrap_exceptions(fun):
    """Decorator which translates bare OSError exceptions into
    NoSuchProcess and AccessDenied.
    """
    @functools.wraps(fun)
    def wrapper(self, *args, **kwargs):
        try: