# Shortcuts to MIB instrumentation items used internally in SNMP applications
from pysnmp.smi.error import SmiError, NoSuchInstanceError
from pysnmp.entity import config

def getTargetAddr(snmpEngine, snmpTargetAddrName):
    mibBuilder = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder

    snmpTargetAddrEntry, = mibBuilder.importSymbols(
        'SNMP-TARGET-MIB', 'snmpTargetAddrEntry'
    )

    if 'getTargetAddr' not in snmpEngine.cache:
        snmpEngine.cache['getTargetAddr'] = { 'id': -1 }

    cache = snmpEngine.cache['getTargetAddr']

    if cache['id'] != snmpTargetAddrEntry.branchVersionId:
        cache['nameToTargetMap'] = {}

    nameToTargetMap = cache['nameToTargetMap']

    if snmpTargetAddrName not in nameToTargetMap:
        ( snmpTargetAddrTDomain,
          snmpTargetAddrTAddress,
          snmpTargetAddrTimeout,
          snmpTargetAddrRetryCount,
          snmpTargetAddrParams ) = mibBuilder.importSymbols(
                                      'SNMP-TARGET-MIB', 
                                      'snmpTargetAddrTDomain',
                                      'snmpTargetAddrTAddress',
                                      'snmpTargetAddrTimeout',
                                      'snmpTargetAddrRetryCount',
                                      'snmpTargetAddrParams'
                                   )
        ( snmpSourceAddrTAddress, ) = mibBuilder.importSymbols(
                                      'PYSNMP-SOURCE-MIB', 
                                      'snmpSourceAddrTAddress'
                                   )

        tblIdx = snmpTargetAddrEntry.getInstIdFromIndices(snmpTargetAddrName)

        try:
            snmpTargetAddrTDomain = snmpTargetAddrTDomain.getNode(
                snmpTargetAddrTDomain.name + tblIdx
            ).syntax
            snmpTargetAddrTAddress = snmpTargetAddrTAddress.getNode(
                snmpTargetAddrTAddress.name + tblIdx
            ).syntax
            snmpTargetAddrTimeout = snmpTargetAddrTimeout.getNode(
                 snmpTargetAddrTimeout.name + tblIdx
            ).syntax
            snmpTargetAddrRetryCount = snmpTargetAddrRetryCount.getNode(
                snmpTargetAddrRetryCount.name + tblIdx
            ).syntax
            snmpTargetAddrParams = snmpTargetAddrParams.getNode(
                snmpTargetAddrParams.name + tblIdx
            ).syntax
            snmpSourceAddrTAddress = snmpSourceAddrTAddress.getNode(
                snmpSourceAddrTAddress.name + tblIdx
            ).syntax
        except NoSuchInstanceError:
            raise SmiError('Target %s not configured to LCD' % snmpTargetAddrName)

        transport = snmpEngine.transportDispatcher.getTransport(snmpTargetAddrTDomain)

        if snmpTargetAddrTDomain[:len(config.snmpUDPDomain)] == config.snmpUDPDomain:
            SnmpUDPAddress, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('SNMPv2-TM', 'SnmpUDPAddress')
            snmpTargetAddrTAddress = transport.addressType(
                SnmpUDPAddress(snmpTargetAddrTAddress)
            ).setLocalAddress(SnmpUDPAddress(snmpSourceAddrTAddress))
        elif snmpTargetAddrTDomain[:len(config.snmpUDP6Domain)] == config.snmpUDP6Domain:
            TransportAddressIPv6, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('TRANSPORT-ADDRESS-MIB', 'TransportAddressIPv6')
            snmpTargetAddrTAddress = transport.addressType(
                TransportAddressIPv6(snmpTargetAddrTAddress)
            ).setLocalAddress(TransportAddressIPv6(snmpSourceAddrTAddress))
        elif snmpTargetAddrTDomain[:len(config.snmpLocalDomain)] == config.snmpLocalDomain:
            snmpTargetAddrTAddress = transport.addressType(
                snmpTargetAddrTAddress
            )

        nameToTargetMap[snmpTargetAddrName] = (
            snmpTargetAddrTDomain,
            snmpTargetAddrTAddress,
            snmpTargetAddrTimeout,
            snmpTargetAddrRetryCount,
            snmpTargetAddrParams
        )

        cache['id'] = snmpTargetAddrEntry.branchVersionId

    return nameToTargetMap[snmpTargetAddrName]


def getTargetParams(snmpEngine, paramsName):
    mibBuilder = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder

    snmpTargetParamsEntry, = mibBuilder.importSymbols(
        'SNMP-TARGET-MIB', 'snmpTargetParamsEntry'
    )

    if 'getTargetParams' not in snmpEngine.cache:
        snmpEngine.cache['getTargetParams'] = { 'id': -1 }

    cache = snmpEngine.cache['getTargetParams']

    if cache['id'] != snmpTargetParamsEntry.branchVersionId:
        cache['nameToParamsMap'] = {}

    nameToParamsMap = cache['nameToParamsMap']

    if paramsName not in nameToParamsMap:
        ( snmpTargetParamsMPModel,
          snmpTargetParamsSecurityModel,
          snmpTargetParamsSecurityName,
          snmpTargetParamsSecurityLevel ) = mibBuilder.importSymbols(
                                               'SNMP-TARGET-MIB', 
                                               'snmpTargetParamsMPModel',
                                               'snmpTargetParamsSecurityModel',
                                               'snmpTargetParamsSecurityName',
                                               'snmpTargetParamsSecurityLevel'
                                            )

        tblIdx = snmpTargetParamsEntry.getInstIdFromIndices(paramsName)

        try:
            snmpTargetParamsMPModel = snmpTargetParamsMPModel.getNode(
                snmpTargetParamsMPModel.name + tblIdx
            ).syntax
            snmpTargetParamsSecurityModel = snmpTargetParamsSecurityModel.getNode(
                snmpTargetParamsSecurityModel.name + tblIdx
            ).syntax
            snmpTargetParamsSecurityName = snmpTargetParamsSecurityName.getNode(
                snmpTargetParamsSecurityName.name + tblIdx
            ).syntax
            snmpTargetParamsSecurityLevel = snmpTargetParamsSecurityLevel.getNode(
                snmpTargetParamsSecurityLevel.name + tblIdx
            ).syntax
        except NoSuchInstanceError:
            raise SmiError('Parameters %s not configured at LCD' % paramsName)

        nameToParamsMap[paramsName] = (
            snmpTargetParamsMPModel,
            snmpTargetParamsSecurityModel,
            snmpTargetParamsSecurityName,
            snmpTargetParamsSecurityLevel
        )

        cache['id'] = snmpTargetParamsEntry.branchVersionId

    return nameToParamsMap[paramsName]

def getTargetInfo(snmpEngine, snmpTargetAddrName):
    # Transport endpoint
    ( snmpTargetAddrTDomain,
      snmpTargetAddrTAddress,
      snmpTargetAddrTimeout,
      snmpTargetAddrRetryCount,
      snmpTargetAddrParams ) = getTargetAddr(snmpEngine, snmpTargetAddrName)

    ( snmpTargetParamsMPModel,
      snmpTargetParamsSecurityModel,
      snmpTargetParamsSecurityName,
      snmpTargetParamsSecurityLevel ) = getTargetParams(snmpEngine, snmpTargetAddrParams)

    return ( snmpTargetAddrTDomain,
             snmpTargetAddrTAddress,
             snmpTargetAddrTimeout,
             snmpTargetAddrRetryCount,
             snmpTargetParamsMPModel,
             snmpTargetParamsSecurityModel,
             snmpTargetParamsSecurityName,
             snmpTargetParamsSecurityLevel )

def getNotificationInfo(snmpEngine, notificationTarget):
    mibBuilder = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder

    snmpNotifyEntry, = mibBuilder.importSymbols(
        'SNMP-NOTIFICATION-MIB', 'snmpNotifyEntry'
    )

    if 'getNotificationInfo' not in snmpEngine.cache:
        snmpEngine.cache['getNotificationInfo'] = { 'id': -1 }

    cache = snmpEngine.cache['getNotificationInfo']

    if cache['id'] != snmpNotifyEntry.branchVersionId:
        cache['targetToNotifyMap'] = {}

    targetToNotifyMap = cache['targetToNotifyMap']

    if notificationTarget not in targetToNotifyMap:
        ( snmpNotifyTag,
          snmpNotifyType ) = mibBuilder.importSymbols(
                                 'SNMP-NOTIFICATION-MIB', 
                                 'snmpNotifyTag',
                                 'snmpNotifyType'
                             )

        tblIdx = snmpNotifyEntry.getInstIdFromIndices(notificationTarget)

        try:
            snmpNotifyTag = snmpNotifyTag.getNode(
                snmpNotifyTag.name + tblIdx
            ).syntax
            snmpNotifyType = snmpNotifyType.getNode(
                snmpNotifyType.name + tblIdx
            ).syntax

        except NoSuchInstanceError:
            raise SmiError('Target %s not configured at LCD' % notificationTarget)

        targetToNotifyMap[notificationTarget] = (
            snmpNotifyTag,
            snmpNotifyType
        )

        cache['id'] = snmpNotifyEntry.branchVersionId

    return targetToNotifyMap[notificationTarget]

def getTargetNames(snmpEngine, tag):
    mibBuilder = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder

    snmpTargetAddrEntry, = mibBuilder.importSymbols(
        'SNMP-TARGET-MIB', 'snmpTargetAddrEntry'
    )

    if 'getTargetNames' not in snmpEngine.cache:
        snmpEngine.cache['getTargetNames'] = { 'id': -1 }

    cache = snmpEngine.cache['getTargetNames']

    if cache['id'] == snmpTargetAddrEntry.branchVersionId:
        tagToTargetsMap = cache['tagToTargetsMap']
    else:
        cache['tagToTargetsMap'] = {}

        tagToTargetsMap = cache['tagToTargetsMap']

        ( SnmpTagValue,
          snmpTargetAddrName,
          snmpTargetAddrTagList ) = mibBuilder.importSymbols(
                                        'SNMP-TARGET-MIB',
                                        'SnmpTagValue',
                                        'snmpTargetAddrName',
                                        'snmpTargetAddrTagList'
                                    )
        targetNames = []
        mibNode =  snmpTargetAddrTagList
        while 1:
            try:
                mibNode = snmpTargetAddrTagList.getNextNode(mibNode.name)
            except NoSuchInstanceError:
                break

            idx = mibNode.name[len(snmpTargetAddrTagList.name):]

            _snmpTargetAddrName = snmpTargetAddrName.getNode(snmpTargetAddrName.name + idx).syntax

            for _tag in mibNode.syntax.asOctets().split():
                _tag = SnmpTagValue(_tag)
                if _tag not in tagToTargetsMap:
                    tagToTargetsMap[_tag] = []
                tagToTargetsMap[_tag].append(_snmpTargetAddrName)

        cache['id'] = snmpTargetAddrEntry.branchVersionId

    if tag not in tagToTargetsMap:
        raise SmiError('Transport tag %s not configured at LCD' % tag)

    return tagToTargetsMap[tag]

# convert cmdrsp/cmdgen into this api