# -*- coding: utf-8 -*-
'''
The networking module for Non-RH/Deb Linux distros
'''
from __future__ import absolute_import
import salt.utils
from salt.ext.six.moves import zip

__virtualname__ = 'ip'


def __virtual__():
    '''
    Confine this module to Non-RH/Deb Linux distros
    '''
    if salt.utils.is_windows():
        return (False, 'Module linux_ip: Windows systems are not supported.')
    if __grains__['os_family'] == 'RedHat':
        return (False, 'Module linux_ip: RedHat systems are not supported.')
    if __grains__['os_family'] == 'Debian':
        return (False, 'Module linux_ip: Debian systems are not supported.')
    if not salt.utils.which('ip'):
        return (False, 'The linux_ip execution module cannot be loaded: '
                'the ip binary is not in the path.')
    return __virtualname__


def down(iface, iface_type=None):
    '''
    Shutdown a network interface

    CLI Example:

    .. code-block:: bash

        salt '*' ip.down eth0
    '''
    # Slave devices are controlled by the master.
    if iface_type not in ['slave']:
        return __salt__['cmd.run']('ip link set {0} down'.format(iface))
    return None


def get_interface(iface):
    '''
    Return the contents of an interface script

    CLI Example:

    .. code-block:: bash

        salt '*' ip.get_interface eth0
    '''
    ifaces = _ip_ifaces()
    return ifaces.get(iface)


def _ip_ifaces():
    '''
    Parse output from 'ip a'
    '''
    tmp = {}
    ret = {}
    if_ = None
    at_ = None
    out = __salt__['cmd.run']('ip a')
    for line in out.splitlines():
        if not line.startswith(' '):
            comps = line.split(':')
            if_ = comps[1].strip()
            opts_comps = comps[2].strip().split()
            flags = opts_comps.pop(0).lstrip('<').rstrip('>').split(',')
            opts_iter = iter(opts_comps)
            ret[if_] = {
                'flags': flags,
                'options': dict(list(zip(opts_iter, opts_iter)))
            }
        else:
            if line.strip().startswith('link'):
                comps = iter(line.strip().split())
                ret[if_]['link_layer'] = dict(list(zip(comps, comps)))
            elif line.strip().startswith('inet'):
                comps = line.strip().split()
                at_ = comps[0]
                if len(comps) % 2 != 0:
                    last = comps.pop()
                    comps[-1] += ' {0}'.format(last)
                ifi = iter(comps)
                ret[if_][at_] = dict(list(zip(ifi, ifi)))
            else:
                comps = line.strip().split()
                ifi = iter(comps)
                ret[if_][at_].update(dict(list(zip(ifi, ifi))))
    return ret


def up(iface, iface_type=None):
    '''
    Start up a network interface

    CLI Example:

    .. code-block:: bash

        salt '*' ip.up eth0
    '''
    # Slave devices are controlled by the master.
    if iface_type not in ['slave']:
        return __salt__['cmd.run']('ip link set {0} up'.format(iface))
    return None


def get_routes(iface=None):
    '''
    Return the current routing table

    CLI Examples:

    .. code-block:: bash

        salt '*' ip.get_routes
        salt '*' ip.get_routes eth0
    '''
    routes = _parse_routes()
    if iface is not None:
        return routes.get(iface)
    return routes


def _parse_routes():
    '''
    Parse the contents of ``/proc/net/route``
    '''
    with salt.utils.fopen('/proc/net/route', 'r') as fp_:
        out = fp_.read()

    ret = {}
    for line in out.splitlines():
        tmp = {}
        if not line.strip():
            continue
        if line.startswith('Iface'):
            continue
        comps = line.split()
        tmp['iface'] = comps[0]
        tmp['destination'] = _hex_to_octets(comps[1])
        tmp['gateway'] = _hex_to_octets(comps[2])
        tmp['flags'] = _route_flags(int(comps[3]))
        tmp['refcnt'] = comps[4]
        tmp['use'] = comps[5]
        tmp['metric'] = comps[6]
        tmp['mask'] = _hex_to_octets(comps[7])
        tmp['mtu'] = comps[8]
        tmp['window'] = comps[9]
        tmp['irtt'] = comps[10]
        if comps[0] not in ret:
            ret[comps[0]] = []
        ret[comps[0]].append(tmp)
    return ret


def _hex_to_octets(addr):
    '''
    Convert hex fields from /proc/net/route to octects
    '''
    return '{0}:{1}:{2}:{3}'.format(
        int(addr[6:8], 16),
        int(addr[4:6], 16),
        int(addr[2:4], 16),
        int(addr[0:2], 16),
    )


def _route_flags(rflags):
    '''
    https://github.com/torvalds/linux/blob/master/include/uapi/linux/route.h
    https://github.com/torvalds/linux/blob/master/include/uapi/linux/ipv6_route.h
    '''
    flags = ''
    fmap = {
        0x0001: 'U',  # RTF_UP, route is up
        0x0002: 'G',  # RTF_GATEWAY, use gateway
        0x0004: 'H',  # RTF_HOST, target is a host
        0x0008: 'R',  # RET_REINSTATE, reinstate route for dynamic routing
        0x0010: 'D',  # RTF_DYNAMIC, dynamically installed by daemon or redirect
        0x0020: 'M',  # RTF_MODIFIED, modified from routing daemon or redirect
        0x00040000: 'A',  # RTF_ADDRCONF, installed by addrconf
        0x01000000: 'C',  # RTF_CACHE, cache entry
        0x0200: '!',  # RTF_REJECT, reject route
    }
    for item in fmap.keys():
        if rflags & item:
            flags += fmap[item]
    return flags
