#!/usr/bin/env python
#
# $Id$
#
# Copyright (c) 2009, Jay Loden, 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.

"""Windows platform implementation."""

import errno
import os
import sys
import platform

import _psutil_mswindows
from _psutil_mswindows import ERROR_ACCESS_DENIED
from psutil.error import AccessDenied, NoSuchProcess, TimeoutExpired
from psutil._common import *
from psutil._compat import PY3, xrange, long

# Windows specific extended namespace
__extra__all__ = ["ABOVE_NORMAL_PRIORITY_CLASS", "BELOW_NORMAL_PRIORITY_CLASS",
                  "HIGH_PRIORITY_CLASS", "IDLE_PRIORITY_CLASS",
                  "NORMAL_PRIORITY_CLASS", "REALTIME_PRIORITY_CLASS"]


# --- module level constants (gets pushed up to psutil module)

NUM_CPUS = _psutil_mswindows.get_num_cpus()
BOOT_TIME = _psutil_mswindows.get_system_uptime()
TOTAL_PHYMEM = _psutil_mswindows.get_virtual_mem()[0]
WAIT_TIMEOUT = 0x00000102 # 258 in decimal
ACCESS_DENIED_SET = frozenset([errno.EPERM, errno.EACCES, ERROR_ACCESS_DENIED])

# process priority constants:
# http://msdn.microsoft.com/en-us/library/ms686219(v=vs.85).aspx
from _psutil_mswindows import (ABOVE_NORMAL_PRIORITY_CLASS,
                               BELOW_NORMAL_PRIORITY_CLASS,
                               HIGH_PRIORITY_CLASS,
                               IDLE_PRIORITY_CLASS,
                               NORMAL_PRIORITY_CLASS,
                               REALTIME_PRIORITY_CLASS,
                               INFINITE)

@memoize
def _win32_QueryDosDevice(s):
    return _psutil_mswindows.win32_QueryDosDevice(s)

def _convert_raw_path(s):
    # convert paths using native DOS format like:
    # "\Device\HarddiskVolume1\Windows\systemew\file.txt"
    # into: "C:\Windows\systemew\file.txt"
    if PY3 and not isinstance(s, str):
        s = s.decode('utf8')
    rawdrive = '\\'.join(s.split('\\')[:3])
    driveletter = _win32_QueryDosDevice(rawdrive)
    return os.path.join(driveletter, s[len(rawdrive):])


# --- public functions

nt_virtmem_info = namedtuple('vmem', ' '.join([
    # all platforms
    'total', 'available', 'percent', 'used', 'free']))

def virtual_memory():
    """System virtual memory as a namedtuple."""
    mem = _psutil_mswindows.get_virtual_mem()
    totphys, availphys, totpagef, availpagef, totvirt, freevirt = mem
    #
    total = totphys
    avail = availphys
    free = availphys
    used = total - avail
    percent = usage_percent((total - avail), total, _round=1)
    return nt_virtmem_info(total, avail, percent, used, free)

def swap_memory():
    """Swap system memory as a (total, used, free, sin, sout) tuple."""
    mem = _psutil_mswindows.get_virtual_mem()
    total = mem[2]
    free = mem[3]
    used = total - free
    percent = usage_percent(used, total, _round=1)
    return nt_swapmeminfo(total, used, free, percent, 0, 0)

def get_disk_usage(path):
    """Return disk usage associated with path."""
    try:
        total, free = _psutil_mswindows.get_disk_usage(path)
    except WindowsError:
        err = sys.exc_info()[1]
        if not os.path.exists(path):
            raise OSError(errno.ENOENT, "No such file or directory: '%s'" % path)
        raise
    used = total - free
    percent = usage_percent(used, total, _round=1)
    return nt_diskinfo(total, used, free, percent)

def disk_partitions(all):
    """Return disk partitions."""
    rawlist = _psutil_mswindows.get_disk_partitions(all)
    return [nt_partition(*x) for x in rawlist]


_cputimes_ntuple = namedtuple('cputimes', 'user system idle')

def get_system_cpu_times():
    """Return system CPU times as a named tuple."""
    user, system, idle = 0, 0, 0
    # computes system global times summing each processor value
    for cpu_time in _psutil_mswindows.get_system_cpu_times():
        user += cpu_time[0]
        system += cpu_time[1]
        idle += cpu_time[2]
    return _cputimes_ntuple(user, system, idle)

def get_system_per_cpu_times():
    """Return system per-CPU times as a list of named tuples."""
    ret = []
    for cpu_t in _psutil_mswindows.get_system_cpu_times():
        user, system, idle = cpu_t
        item = _cputimes_ntuple(user, system, idle)
        ret.append(item)
    return ret

def get_system_users():
    """Return currently connected users as a list of namedtuples."""
    retlist = []
    rawlist = _psutil_mswindows.get_system_users()
    for item in rawlist:
        user, hostname, tstamp = item
        nt = nt_user(user, None, hostname, tstamp)
        retlist.append(nt)
    return retlist

get_pid_list = _psutil_mswindows.get_pid_list
pid_exists = _psutil_mswindows.pid_exists
network_io_counters = _psutil_mswindows.get_network_io_counters
disk_io_counters = _psutil_mswindows.get_disk_io_counters

# --- decorator

def wrap_exceptions(callable):
    """Call callable into a try/except clause so that if a
    WindowsError 5 AccessDenied exception is raised we translate it
    into psutil.AccessDenied
    """
    def wrapper(self, *args, **kwargs):
        try:
            return callable(self, *args, **kwargs)
        except OSError:
            err = sys.exc_info()[1]
            if err.errno in ACCESS_DENIED_SET:
                raise AccessDenied(self.pid, self._process_name)
            if err.errno == errno.ESRCH:
                raise NoSuchProcess(self.pid, self._process_name)
            raise
    return wrapper


class Process(object):
    """Wrapper class around underlying C implementation."""

    __slots__ = ["pid", "_process_name"]

    def __init__(self, pid):
        self.pid = pid
        self._process_name = None

    @wrap_exceptions
    def get_process_name(self):
        """Return process name as a string of limited len (15)."""
        return _psutil_mswindows.get_process_name(self.pid)

    @wrap_exceptions
    def get_process_exe(self):
        # Note: os.path.exists(path) may return False even if the file
        # is there, see:
        # http://stackoverflow.com/questions/3112546/os-path-exists-lies
        return _convert_raw_path(_psutil_mswindows.get_process_exe(self.pid))

    @wrap_exceptions
    def get_process_cmdline(self):
        """Return process cmdline as a list of arguments."""
        return _psutil_mswindows.get_process_cmdline(self.pid)

    @wrap_exceptions
    def get_process_ppid(self):
        """Return process parent pid."""
        return _psutil_mswindows.get_process_ppid(self.pid)

    def _get_raw_meminfo(self):
        try:
            return _psutil_mswindows.get_process_memory_info(self.pid)
        except OSError:
            err = sys.exc_info()[1]
            if err.errno in ACCESS_DENIED_SET:
                return _psutil_mswindows.get_process_memory_info_2(self.pid)
            raise

    @wrap_exceptions
    def get_memory_info(self):
        """Returns a tuple or RSS/VMS memory usage in bytes."""
        # on Windows RSS == WorkingSetSize and VSM == PagefileUsage
        # fields of PROCESS_MEMORY_COUNTERS struct:
        # http://msdn.microsoft.com/en-us/library/windows/desktop/ms684877(v=vs.85).aspx
        t = self._get_raw_meminfo()
        return nt_meminfo(t[2], t[7])

    _nt_ext_mem = namedtuple('meminfo',
        ' '.join(['num_page_faults',
                  'peak_wset',
                  'wset',
                  'peak_paged_pool',
                  'paged_pool',
                  'peak_nonpaged_pool',
                  'nonpaged_pool',
                  'pagefile',
                  'peak_pagefile',
                  'private',]))

    @wrap_exceptions
    def get_ext_memory_info(self):
        return self._nt_ext_mem(*self._get_raw_meminfo())

    nt_mmap_grouped = namedtuple('mmap', 'path rss')
    nt_mmap_ext = namedtuple('mmap', 'addr perms path rss')

    def get_memory_maps(self):
        try:
            raw = _psutil_mswindows.get_process_memory_maps(self.pid)
        except OSError:
            # XXX - can't use wrap_exceptions decorator as we're
            # returning a generator; probably needs refactoring.
            err = sys.exc_info()[1]
            if err.errno in (errno.EPERM, errno.EACCES, ERROR_ACCESS_DENIED):
                raise AccessDenied(self.pid, self._process_name)
            if err.errno == errno.ESRCH:
                raise NoSuchProcess(self.pid, self._process_name)
            raise
        else:
            for addr, perm, path, rss in raw:
                path = _convert_raw_path(path)
                addr = hex(addr)
                yield (addr, perm, path, rss)

    @wrap_exceptions
    def kill_process(self):
        """Terminates the process with the given PID."""
        return _psutil_mswindows.kill_process(self.pid)

    @wrap_exceptions
    def process_wait(self, timeout=None):
        if timeout is None:
            timeout = INFINITE
        else:
            # WaitForSingleObject() expects time in milliseconds
            timeout = int(timeout * 1000)
        ret = _psutil_mswindows.process_wait(self.pid, timeout)
        if ret == WAIT_TIMEOUT:
            raise TimeoutExpired(self.pid, self._process_name)
        return ret

    @wrap_exceptions
    def get_process_username(self):
        """Return the name of the user that owns the process"""
        if self.pid in (0, 4):
            return 'NT AUTHORITY\\SYSTEM'
        return _psutil_mswindows.get_process_username(self.pid)

    @wrap_exceptions
    def get_process_create_time(self):
        # special case for kernel process PIDs; return system boot time
        if self.pid in (0, 4):
            return BOOT_TIME
        try:
            return _psutil_mswindows.get_process_create_time(self.pid)
        except OSError:
            err = sys.exc_info()[1]
            if err.errno in ACCESS_DENIED_SET:
                return _psutil_mswindows.get_process_create_time_2(self.pid)
            raise

    @wrap_exceptions
    def get_process_num_threads(self):
        return _psutil_mswindows.get_process_num_threads(self.pid)

    @wrap_exceptions
    def get_process_threads(self):
        rawlist = _psutil_mswindows.get_process_threads(self.pid)
        retlist = []
        for thread_id, utime, stime in rawlist:
            ntuple = nt_thread(thread_id, utime, stime)
            retlist.append(ntuple)
        return retlist

    @wrap_exceptions
    def get_cpu_times(self):
        try:
            ret = _psutil_mswindows.get_process_cpu_times(self.pid)
        except OSError:
            err = sys.exc_info()[1]
            if err.errno in ACCESS_DENIED_SET:
                ret = _psutil_mswindows.get_process_cpu_times_2(self.pid)
            else:
                raise
        return nt_cputimes(*ret)

    @wrap_exceptions
    def suspend_process(self):
        return _psutil_mswindows.suspend_process(self.pid)

    @wrap_exceptions
    def resume_process(self):
        return _psutil_mswindows.resume_process(self.pid)

    @wrap_exceptions
    def get_process_cwd(self):
        if self.pid in (0, 4):
            raise AccessDenied(self.pid, self._process_name)
        # return a normalized pathname since the native C function appends
        # "\\" at the and of the path
        path = _psutil_mswindows.get_process_cwd(self.pid)
        return os.path.normpath(path)

    @wrap_exceptions
    def get_open_files(self):
        if self.pid in (0, 4):
            return []
        retlist = []
        # Filenames come in in native format like:
        # "\Device\HarddiskVolume1\Windows\systemew\file.txt"
        # Convert the first part in the corresponding drive letter
        # (e.g. "C:\") by using Windows's QueryDosDevice()
        raw_file_names = _psutil_mswindows.get_process_open_files(self.pid)
        for file in raw_file_names:
            file = _convert_raw_path(file)
            if isfile_strict(file) and file not in retlist:
                ntuple = nt_openfile(file, -1)
                retlist.append(ntuple)
        return retlist

    @wrap_exceptions
    def get_connections(self, kind='inet'):
        if kind not in conn_tmap:
            raise ValueError("invalid %r kind argument; choose between %s"
                             % (kind, ', '.join([repr(x) for x in conn_tmap])))
        families, types = conn_tmap[kind]
        ret = _psutil_mswindows.get_process_connections(self.pid, families, types)
        return [nt_connection(*conn) for conn in ret]

    @wrap_exceptions
    def get_process_nice(self):
        return _psutil_mswindows.get_process_priority(self.pid)

    @wrap_exceptions
    def set_process_nice(self, value):
        return _psutil_mswindows.set_process_priority(self.pid, value)

    @wrap_exceptions
    def get_process_io_counters(self):
        try:
            ret = _psutil_mswindows.get_process_io_counters(self.pid)
        except OSError:
            err = sys.exc_info()[1]
            if err.errno in ACCESS_DENIED_SET:
                ret = _psutil_mswindows.get_process_io_counters_2(self.pid)
            else:
                raise
        return nt_io(*ret)

    @wrap_exceptions
    def get_process_status(self):
        suspended = _psutil_mswindows.is_process_suspended(self.pid)
        if suspended:
            return STATUS_STOPPED
        else:
            return STATUS_RUNNING

    @wrap_exceptions
    def get_process_cpu_affinity(self):
        from_bitmask = lambda x: [i for i in xrange(64) if (1 << i) & x]
        bitmask = _psutil_mswindows.get_process_cpu_affinity(self.pid)
        return from_bitmask(bitmask)

    @wrap_exceptions
    def set_process_cpu_affinity(self, value):
        def to_bitmask(l):
            if not l:
                raise ValueError("invalid argument %r" % l)
            out = 0
            for b in l:
                if not isinstance(b, (int, long)) or b < 0:
                    raise ValueError("invalid argument %r" % b)
                out |= 2**b
            return out

        # SetProcessAffinityMask() states that ERROR_INVALID_PARAMETER
        # is returned for an invalid CPU but this seems not to be true,
        # therefore we check CPUs validy beforehand.
        allcpus = list(range(len(get_system_per_cpu_times())))
        for cpu in value:
            if cpu not in allcpus:
                raise ValueError("invalid CPU %i" % cpu)

        bitmask = to_bitmask(value)
        _psutil_mswindows.set_process_cpu_affinity(self.pid, bitmask)

    @wrap_exceptions
    def get_num_handles(self):
        try:
            return _psutil_mswindows.get_process_num_handles(self.pid)
        except OSError:
            err = sys.exc_info()[1]
            if err.errno in ACCESS_DENIED_SET:
                return _psutil_mswindows.get_process_num_handles_2(self.pid)
            raise

    @wrap_exceptions
    def get_num_ctx_switches(self):
        return nt_ctxsw(*_psutil_mswindows.get_process_num_ctx_switches(self.pid))
