'''
Apache Solr Salt Module
=======================

Author: Jed Glazner
Version: 0.2.1
Modified: 12/09/2011

This module uses HTTP requests to talk to the apache solr request handlers
to gather information and report errors. Because of this the minion doesn't
necessarily need to reside on the actual slave.  However if you want to
use the signal function the minion must reside on the physical solr host.

This module supports multi-core and standard setups.  Certain methods are
master/slave specific.  Make sure you set the solr.type. If you have
questions or want a feature request please ask.

Coming Features in 0.3
----------------------

1. Add command for checking for replication failures on slaves
2. Improve match_index_versions since it's pointless on busy solr masters
3. Add additional local fs checks for backups to make sure they succeeded

Override these in the minion config
-----------------------------------

solr.cores
    A list of core names eg ['core1','core2'].
    An empty list indicates non-multicore setup.
solr.baseurl
    The root level URL to access solr via HTTP
solr.request_timeout
    The number of seconds before timing out an HTTP/HTTPS/FTP request. If
    nothing is specified then the python global timeout setting is used.
solr.type
    Possible values are 'master' or 'slave'
solr.backup_path
    The path to store your backups. If you are using cores and you can specify
    to append the core name to the path in the backup method.
solr.num_backups
    For versions of solr >= 3.5. Indicates the number of backups to keep. This
    option is ignored if your version is less.
solr.init_script
    The full path to your init script with start/stop options
solr.dih.options
    A list of options to pass to the DIH.

Required Options for DIH
------------------------

clean : False
    Clear the index before importing
commit : True
    Commit the documents to the index upon completion
optimize : True
    Optimize the index after commit is complete
verbose : True
    Get verbose output
'''

# Import python Libs
import json
import os

# Import salt libs
import salt.utils
from salt._compat import string_types, url_open


########################## PRIVATE METHODS ##############################

def __virtual__():
    '''
    PRIVATE METHOD
    Solr needs to be installed to use this.

    Return: str/bool
    '''
    if salt.utils.which('solr'):
        return 'solr'
    if salt.utils.which('apache-solr'):
        return 'solr'
    return False


def _get_none_or_value(value):
    '''
    PRIVATE METHOD
    Checks to see if the value of a primitive or built-in container such as
    a list, dict, set, tuple etc is empty or none. None type is returned if the
    value is empty/None/False. Number data types that are 0 will return None.

    value : obj
        The primitive or built-in container to evaluate.

    Return: None or value
    '''
    if value is None:
        return None
    elif not value:
        return value
    # if it's a string, and it's not empty check for none
    elif isinstance(value, string_types):
        if value.lower() == 'none':
            return None
        return value
    # return None
    else:
        return None


def _check_for_cores():
    '''
    PRIVATE METHOD
    Checks to see if using_cores has been set or not. if it's been set
    return it, otherwise figure it out and set it. Then return it

    Return: boolean

        True if one or more cores defined in __opts__['solr.cores']
    '''
    return len(__salt__['config.option']('solr.cores')) > 0


def _get_return_dict(success=True, data=None, errors=None, warnings=None):
    '''
    PRIVATE METHOD
    Creates a new return dict with default values. Defaults may be overwritten.

    success : boolean (True)
        True indicates a successful result.
    data : dict<str,obj> ({})
        Data to be returned to the caller.
    errors : list<str> ([()])
        A list of error messages to be returned to the caller
    warnings : list<str> ([])
        A list of warnings to be returned to the caller.

    Return: dict<str,obj>::

        {'success':boolean, 'data':dict, 'errors':list, 'warnings':list}
    '''
    data = {} if data is None else data
    errors = [] if errors is None else errors
    warnings = [] if warnings is None else warnings
    ret = {'success': success,
           'data': data,
           'errors': errors,
           'warnings': warnings}

    return ret


def _update_return_dict(ret, success, data, errors=None, warnings=None):
    '''
    PRIVATE METHOD
    Updates the return dictionary and returns it.

    ret : dict<str,obj>
        The original return dict to update. The ret param should have
        been created from _get_return_dict()
    success : boolean (True)
        True indicates a successful result.
    data : dict<str,obj> ({})
        Data to be returned to the caller.
    errors : list<str> ([()])
        A list of error messages to be returned to the caller
    warnings : list<str> ([])
        A list of warnings to be returned to the caller.

    Return: dict<str,obj>::

        {'success':boolean, 'data':dict, 'errors':list, 'warnings':list}
    '''
    errors = [] if errors is None else errors
    warnings = [] if warnings is None else warnings
    ret['success'] = success
    ret['data'].update(data)
    ret['errors'] = ret['errors'] + errors
    ret['warnings'] = ret['warnings'] + warnings
    return ret


def _format_url(handler, host=None, core_name=None, extra=None):
    '''
    PRIVATE METHOD
    Formats the URL based on parameters, and if cores are used or not

    handler : str
        The request handler to hit.
    host : str (None)
        The solr host to query. __opts__['host'] is default
    core_name : str (None)
        The name of the solr core if using cores. Leave this blank if you
        are not using cores or if you want to check all cores.
    extra : list<str> ([])
        A list of name value pairs in string format. eg ['name=value']

    Return: str
        Fully formatted URL (http://<host>:<port>/solr/<handler>?wt=json&<extra>)
    '''
    extra = [] if extra is None else extra
    if _get_none_or_value(host) is None or host == 'None':
        host = __salt__['config.option']('solr.host')
    port = __salt__['config.option']('solr.port')
    baseurl = __salt__['config.option']('solr.baseurl')
    if _get_none_or_value(core_name) is None:
        if extra is None or len(extra) == 0:
            return "http://{0}:{1}{2}/{3}?wt=json".format(
                    host, port, baseurl, handler)
        else:
            return "http://{0}:{1}{2}/{3}?wt=json&{4}".format(
                    host, port, baseurl, handler, "&".join(extra))
    else:
        if extra is None or len(extra) == 0:
            return "http://{0}:{1}{2}/{3}/{4}?wt=json".format(
                    host, port, baseurl, core_name, handler)
        else:
            return "http://{0}:{1}{2}/{3}/{4}?wt=json&{5}".format(
                    host, port, baseurl, core_name, handler, "&".join(extra))


def _http_request(url, request_timeout=None):
    '''
    PRIVATE METHOD
    Uses json.load to fetch the JSON results from the solr API.

    url : str
        a complete URL that can be passed to urllib.open
    request_timeout : int (None)
        The number of seconds before the timeout should fail. Leave blank/None
        to use the default. __opts__['solr.request_timeout']

    Return: dict<str,obj>::

         {'success':boolean, 'data':dict, 'errors':list, 'warnings':list}
    '''
    try:

        request_timeout = __salt__['config.option']('solr.request_timeout')
        if request_timeout is None:
            data = json.load(url_open(url))
        else:
            data = json.load(url_open(url, timeout=request_timeout))
        return _get_return_dict(True, data, [])
    except Exception as err:
        return _get_return_dict(False, {}, ["{0} : {1}".format(url, err)])


def _replication_request(command, host=None, core_name=None, params=None):
    '''
    PRIVATE METHOD
    Performs the requested replication command and returns a dictionary with
    success, errors and data as keys. The data object will contain the JSON
    response.

    command : str
        The replication command to execute.
    host : str (None)
        The solr host to query. __opts__['host'] is default
    core_name: str (None)
        The name of the solr core if using cores. Leave this blank if you are
        not using cores or if you want to check all cores.
    params : list<str> ([])
        Any additional parameters you want to send. Should be a lsit of
        strings in name=value format. eg ['name=value']

    Return: dict<str, obj>::

        {'success':boolean, 'data':dict, 'errors':list, 'warnings':list}
    '''
    params = [] if params is None else params
    extra = ["command={0}".format(command)] + params
    url = _format_url('replication', host=host, core_name=core_name,
                      extra=extra)
    return _http_request(url)


def _get_admin_info(command, host=None, core_name=None):
    '''
    PRIVATE METHOD
    Calls the _http_request method and passes the admin command to execute
    and stores the data. This data is fairly static but should be refreshed
    periodically to make sure everything this OK. The data object will contain
    the JSON response.

    command : str
        The admin command to execute.
    host : str (None)
        The solr host to query. __opts__['host'] is default
    core_name: str (None)
        The name of the solr core if using cores. Leave this blank if you are
        not using cores or if you want to check all cores.

    Return: dict<str,obj>::

        {'success':boolean, 'data':dict, 'errors':list, 'warnings':list}
    '''
    url = _format_url("admin/{0}".format(command), host, core_name=core_name)
    resp = _http_request(url)
    return resp


def _is_master():
    '''
    PRIVATE METHOD
    Simple method to determine if the minion is configured as master or slave

    Return: boolean::

        True if __opts__['solr.type'] = master
    '''
    return __salt__['config.option']('solr.type') == 'master'


def _merge_options(options):
    '''
    PRIVATE METHOD
    updates the default import options from __opts__['solr.dih.import_options']
    with the dictionary passed in.  Also converts booleans to strings
    to pass to solr.

    options : dict<str,boolean>
        Dictionary the over rides the default options defined in
        __opts__['solr.dih.import_options']

    Return: dict<str,boolean>::

        {option:boolean}
    '''
    defaults = __salt__['config.option']('solr.dih.import_options')
    if isinstance(options, dict):
        defaults.update(options)
    for key, val in defaults.items():
        if isinstance(val, bool):
            defaults[key] = str(val).lower()
    return defaults


def _pre_index_check(handler, host=None, core_name=None):
    '''
    PRIVATE METHOD - MASTER CALL
    Does a pre-check to make sure that all the options are set and that
    we can talk to solr before trying to send a command to solr. This
    Command should only be issued to masters.

    handler : str
        The import handler to check the state of
    host : str (None):
        The solr host to query. __opts__['host'] is default
    core_name (None):
        The name of the solr core if using cores. Leave this blank if you are
        not using cores or if you want to check all cores.
        REQUIRED if you are using cores.

    Return:  dict<str,obj>::

        {'success':boolean, 'data':dict, 'errors':list, 'warnings':list}
    '''
    #make sure that it's a master minion
    if _get_none_or_value(host) is None and not _is_master():
        err = [
            'solr.pre_indexing_check can only be called by "master" minions']
        return _get_return_dict(False, err)
    #solr can run out of memory quickly if the dih is processing multiple
    #handlers at the same time, so if it's a multicore setup require a
    #core_name param.
    if _get_none_or_value(core_name) is None and _check_for_cores():
        errors = ['solr.full_import is not safe to multiple handlers at once']
        return _get_return_dict(False, errors=errors)
    #check to make sure that we're not already indexing
    resp = import_status(handler, host, core_name)
    if resp['success']:
        status = resp['data']['status']
        if status == 'busy':
            warn = ['An indexing process is already running.']
            return _get_return_dict(True, warnings=warn)
        if status != 'idle':
            errors = ['Unknown status: "{0}"'.format(status)]
            return _get_return_dict(False, data=resp['data'], errors=errors)
    else:
        errors = ['Status check failed. Response details: {0}'.format(resp)]
        return _get_return_dict(False, data=resp['data'], errors=errors)

    return resp


def _find_value(ret_dict, key, path=None):
    '''
    PRIVATE METHOD
    Traverses a dictionary of dictionaries/lists to find key
    and return the value stored.
    TODO:// this method doesn't really work very well, and it's not really
            very useful in its current state. The purpose for this method is
            to simplify parsing the JSON output so you can just pass the key
            you want to find and have it return the value.
    ret : dict<str,obj>
        The dictionary to search through. Typically this will be a dict
        returned from solr.
    key : str
        The key (str) to find in the dictionary

    Return: list<dict<str,obj>>::

        [{path:path, value:value}]
    '''
    if path is None:
        path = key
    else:
        path = "{0}:{1}".format(path, key)

    ret = []
    for ikey, val in ret_dict.items():
        if ikey == key:
            ret.append({path: val})
        if isinstance(val, list):
            for item in val:
                if isinstance(item, dict):
                    ret = ret + _find_value(item, key, path)
        if isinstance(val, dict):
            ret = ret + _find_value(val, key, path)
    return ret


########################## PUBLIC METHODS ##############################

def lucene_version(core_name=None):
    '''
    Gets the lucene version that solr is using. If you are running a multi-core
    setup you should specify a core name since all the cores run under the same
    servlet container, they will all have the same version.

    core_name : str (None)
        The name of the solr core if using cores. Leave this blank if you are
        not using cores or if you want to check all cores.

    Return: dict<str,obj>::

        {'success':boolean, 'data':dict, 'errors':list, 'warnings':list}

    CLI Example::

        salt '*' solr.lucene_version
    '''
    ret = _get_return_dict()
    #do we want to check for all the cores?
    if _get_none_or_value(core_name) is None and _check_for_cores():
        success = True
        for name in __salt__['config.option']('solr.cores'):
            resp = _get_admin_info('system', core_name=name)
            if resp['success']:
                version = resp['data']['lucene']['lucene-spec-version']
                data = {name: {'lucene_version': version}}
            else:  # generally this means that an exception happened.
                data = {name: {'lucene_version': None}}
                success = False
            ret = _update_return_dict(ret, success, data, resp['errors'])
        return ret
    else:
        resp = _get_admin_info('system', core_name=core_name)
        if resp['success']:
            version = resp['data']['lucene']['lucene-spec-version']
            return _get_return_dict(True, {'version': version}, resp['errors'])
        else:
            return resp


def version(core_name=None):
    '''
    Gets the solr version for the core specified.  You should specify a core
    here as all the cores will run under the same servlet container and so will
    all have the same version.

    core_name : str (None)
        The name of the solr core if using cores. Leave this blank if you are
        not using cores or if you want to check all cores.

    Return : dict<str,obj>::

        {'success':boolean, 'data':dict, 'errors':list, 'warnings':list}

    CLI Example::

        salt '*' solr.version
    '''
    ret = _get_return_dict()
    #do we want to check for all the cores?
    if _get_none_or_value(core_name) is None and _check_for_cores():
        success = True
        for name in __opts__['solr.cores']:
            resp = _get_admin_info('system', core_name=name)
            if resp['success']:
                lucene = resp['data']['lucene']
                data = {name: {'version': lucene['solr-spec-version']}}
            else:
                success = False
                data = {name: {'version': None}}
            ret = _update_return_dict(ret, success, data,
                                      resp['errors'], resp['warnings'])
        return ret
    else:
        resp = _get_admin_info('system', core_name=core_name)
        if resp['success']:
            version = resp['data']['lucene']['solr-spec-version']
            return _get_return_dict(True, {'version': version},
                                    resp['errors'], resp['warnings'])
        else:
            return resp


def optimize(host=None, core_name=None):
    '''
    Search queries fast, but it is a very expensive operation. The ideal
    process is to run this with a master/slave configuration.  Then you
    can optimize the master, and push the optimized index to the slaves.
    If you are running a single solr instance, or if you are going to run
    this on a slave be aware than search performance will be horrible
    while this command is being run. Additionally it can take a LONG time
    to run and your HTTP request may timeout. If that happens adjust your
    timeout settings.

    host : str (None)
        The solr host to query. __opts__['host'] is default.
    core_name : str (None)
        The name of the solr core if using cores. Leave this blank if you are
        not using cores or if you want to check all cores.

    Return : dict<str,obj>::

        {'success':boolean, 'data':dict, 'errors':list, 'warnings':list}

    CLI Example::

        salt '*' solr.optimize music
    '''
    ret = _get_return_dict()

    if _get_none_or_value(core_name) is None and _check_for_cores():
        success = True
        for name in __salt__['config.option']('solr.cores'):
            url = _format_url('update', host=host, core_name=name,
                              extra=["optimize=true"])
            resp = _http_request(url)
            if resp['success']:
                data = {name: {'data': resp['data']}}
                ret = _update_return_dict(ret, success, data,
                                           resp['errors'], resp['warnings'])
            else:
                success = False
                data = {name: {'data': resp['data']}}
                ret = _update_return_dict(ret, success, data,
                                           resp['errors'], resp['warnings'])
        return ret
    else:
        url = _format_url('update', host=host, core_name=core_name,
                          extra=["optimize=true"])
        return _http_request(url)


def ping(host=None, core_name=None):
    '''
    Does a health check on solr, makes sure solr can talk to the indexes.

    host : str (None)
        The solr host to query. __opts__['host'] is default.
    core_name : str (None)
        The name of the solr core if using cores. Leave this blank if you are
        not using cores or if you want to check all cores.

    Return : dict<str,obj>::

        {'success':boolean, 'data':dict, 'errors':list, 'warnings':list}

    CLI Example::

        salt '*' solr.ping music
    '''
    ret = _get_return_dict()
    if _get_none_or_value(core_name) is None and _check_for_cores():
        success = True
        for name in __opts__['solr.cores']:
            resp = _get_admin_info('ping', host=host, core_name=name)
            if resp['success']:
                data = {name: {'status': resp['data']['status']}}
            else:
                success = False
                data = {name: {'status': None}}
            ret = _update_return_dict(ret, success, data, resp['errors'])
        return ret
    else:
        resp = _get_admin_info('ping', host=host, core_name=core_name)
        return resp


def is_replication_enabled(host=None, core_name=None):
    '''
    SLAVE CALL
    Check for errors, and determine if a slave is replicating or not.

    host : str (None)
        The solr host to query. __opts__['host'] is default.
    core_name : str (None)
        The name of the solr core if using cores. Leave this blank if you are
        not using cores or if you want to check all cores.

    Return : dict<str,obj>::

        {'success':boolean, 'data':dict, 'errors':list, 'warnings':list}

    CLI Example::

        salt '*' solr.is_replication_enabled music
    '''
    ret = _get_return_dict()
    success = True
    # since only slaves can call this let's check the config:
    if _is_master() and host is None:
        errors = ['Only "slave" minions can run "is_replication_enabled"']
        return ret.update({'success': False, 'errors': errors})

    #define a convenience method so we don't duplicate code
    def _checks(ret, success, resp, core):
        if response['success']:
            slave = resp['data']['details']['slave']
            # we need to initialize this to false in case there is an error
            # on the master and we can't get this info.
            enabled = 'false'
            master_url = slave['masterUrl']
            #check for errors on the slave
            if 'ERROR' in slave:
                success = False
                err = "{0}: {1} - {2}".format(name, slave['ERROR'], master_url)
                resp['errors'].append(err)
                #if there is an error return everything
                data = slave if core is None else {core: {'data': slave}}
            else:
                enabled = slave['masterDetails']['master'][
                    'replicationEnabled']
                #if replication is turned off on the master, or polling is
                #disabled we need to return false. These may not be errors,
                #but the purpose of this call is to check to see if the slaves
                #can replicate.
            if enabled == 'false':
                resp['warnings'].append("Replication is disabled on master.")
                success = False
            if slave['isPollingDisabled'] == 'true':
                success = False
                resp['warning'].append("Polling is disabled")
            #update the return
            ret = _update_return_dict(ret, success, data,
                                        resp['errors'], resp['warnings'])
        return (ret, success)

    if _get_none_or_value(core_name) is None and _check_for_cores():
        for name in __opts__['solr.cores']:
            response = _replication_request('details', host=host,
                                            core_name=name)
            ret, success = _checks(ret, success, response, name)
    else:
        response = _replication_request('details', host=host,
                                        core_name=core_name)
        ret, success = _checks(ret, success, response, core_name)

    return ret


def match_index_versions(host=None, core_name=None):
    '''
    SLAVE CALL
    Verifies that the master and the slave versions are in sync by
    comparing the index version. If you are constantly pushing updates
    the index the master and slave versions will seldom match. A solution
    to this is pause indexing every so often to allow the slave to replicate
    and then call this method before allowing indexing to resume.

    host : str (None)
        The solr host to query. __opts__['host'] is default.
    core_name : str (None)
        The name of the solr core if using cores. Leave this blank if you are
        not using cores or if you want to check all cores.

    Return : dict<str,obj>::

        {'success':boolean, 'data':dict, 'errors':list, 'warnings':list}

    CLI Example::

        salt '*' solr.match_index_versions music
    '''
    # since only slaves can call this let's check the config:
    ret = _get_return_dict()
    success = True
    if _is_master() and _get_none_or_value(host) is None:
        return ret.update({
            'success': False,
            'errors': [
                'solr.match_index_versions can only be called by '
                '"slave" minions'
            ]
        })
    # get the default return dict

    def _match(ret, success, resp, core):
        if response['success']:
            slave = resp['data']['details']['slave']
            master_url = resp['data']['details']['slave']['masterUrl']
            if 'ERROR' in slave:
                error = slave['ERROR']
                success = False
                err = "{0}: {1} - {2}".format(name, error, master_url)
                resp['errors'].append(err)
                #if there was an error return the entire response so the
                #alterer can get what it wants
                data = slave if core is None else {core: {'data': slave}}
            else:
                versions = {
                    'master': slave['masterDetails']['master'][
                        'replicatableIndexVersion'],
                    'slave': resp['data']['details']['indexVersion'],
                    'next_replication': slave['nextExecutionAt'],
                    'failed_list': []
               }
                if 'replicationFailedAtList' in slave:
                    versions.update({'failed_list': slave[
                        'replicationFailedAtList']})
                #check the index versions
                if versions['master'] != versions['slave']:
                    success = False
                    resp['errors'].append(
                        'Master and Slave index versions do not match.'
                    )
                data = versions if core is None else {core: {'data': versions}}
            ret = _update_return_dict(ret, success, data,
                                        resp['errors'], resp['warnings'])
        else:
            success = False
            err = resp['errors']
            data = resp['data']
            ret = _update_return_dict(ret, success, data, errors=err)
        return (ret, success)

    #check all cores?
    if _get_none_or_value(core_name) is None and _check_for_cores():
        success = True
        for name in __opts__['solr.cores']:
            response = _replication_request('details', host=host,
                                            core_name=name)
            ret, success = _match(ret, success, response, name)
    else:
        response = _replication_request('details', host=host,
                                        core_name=core_name)
        ret, success = _match(ret, success, response, core_name)

    return ret


def replication_details(host=None, core_name=None):
    '''
    Get the full replication details.

    host : str (None)
        The solr host to query. __opts__['host'] is default.
    core_name : str (None)
        The name of the solr core if using cores. Leave this blank if you are
        not using cores or if you want to check all cores.

    Return : dict<str,obj>::

        {'success':boolean, 'data':dict, 'errors':list, 'warnings':list}

    CLI Example::

        salt '*' solr.replication_details music
    '''
    ret = _get_return_dict()
    if _get_none_or_value(core_name) is None:
        success = True
        for name in __opts__['solr.cores']:
            resp = _replication_request('details', host=host, core_name=name)
            data = {name: {'data': resp['data']}}
            ret = _update_return_dict(ret, success, data,
                                        resp['errors'], resp['warnings'])
    else:
        resp = _replication_request('details', host=host, core_name=core_name)
        if resp['success']:
            ret = _update_return_dict(ret, resp['success'], resp['data'],
                                        resp['errors'], resp['warnings'])
        else:
            return resp
    return ret


def backup(host=None, core_name=None, append_core_to_path=False):
    '''
    Tell solr make a backup.  This method can be mis-leading since it uses the
    backup API.  If an error happens during the backup you are not notified.
    The status: 'OK' in the response simply means that solr received the
    request successfully.

    host : str (None)
        The solr host to query. __opts__['host'] is default.
    core_name : str (None)
        The name of the solr core if using cores. Leave this blank if you are
        not using cores or if you want to check all cores.
    append_core_to_path : boolean (False)
        If True add the name of the core to the backup path. Assumes that
        minion backup path is not None.

    Return : dict<str,obj>::

        {'success':boolean, 'data':dict, 'errors':list, 'warnings':list}

    CLI Example::

        salt '*' solr.backup music
    '''
    path = __opts__['solr.backup_path']
    num_backups = __opts__['solr.num_backups']
    if path is not None:
        if not path.endswith(os.path.sep):
            path += os.path.sep

    ret = _get_return_dict()
    if _get_none_or_value(core_name) is None and _check_for_cores():
        success = True
        for name in __opts__['solr.cores']:
            params = []
            if path is not None:
                path = path + name if append_core_to_path else path
                params.append("&location={0}".format(path + name))
            params.append("&numberToKeep={0}".format(num_backups))
            resp = _replication_request('backup', host=host, core_name=name,
                                        params=params)
            if not resp['success']:
                success = False
            data = {name: {'data': resp['data']}}
            ret = _update_return_dict(ret, success, data,
                                        resp['errors'], resp['warnings'])
        return ret
    else:
        if core_name is not None and path is not None:
            if append_core_to_path:
                path += core_name
        if path is not None:
            params = ["location={0}".format(path)]
        params.append("&numberToKeep={0}".format(num_backups))
        resp = _replication_request('backup', host=host, core_name=core_name,
                                    params=params)
        return resp


def set_is_polling(polling, host=None, core_name=None):
    '''
    SLAVE CALL
    Prevent the slaves from polling the master for updates.

    polling : boolean
        True will enable polling. False will disable it.
    host : str (None)
        The solr host to query. __opts__['host'] is default.
    core_name : str (None)
        The name of the solr core if using cores. Leave this blank if you are
        not using cores or if you want to check all cores.

    Return : dict<str,obj>::

        {'success':boolean, 'data':dict, 'errors':list, 'warnings':list}

    CLI Example::

        salt '*' solr.set_is_polling False
    '''

    ret = _get_return_dict()
    # since only slaves can call this let's check the config:
    if _is_master() and _get_none_or_value(host) is None:
        err = ['solr.set_is_polling can only be called by "slave" minions']
        return ret.update({'success': False, 'errors': err})

    cmd = "enablepoll" if polling else "disapblepoll"
    if _get_none_or_value(core_name) is None and _check_for_cores():
        success = True
        for name in __opts__['solr.cores']:
            resp = set_is_polling(cmd, host=host, core_name=name)
            if not resp['success']:
                success = False
            data = {name: {'data': resp['data']}}
            ret = _update_return_dict(ret, success, data,
                                        resp['errors'], resp['warnings'])
        return ret
    else:
        resp = _replication_request(cmd, host=host, core_name=core_name)
        return resp


def set_replication_enabled(status, host=None, core_name=None):
    '''
    MASTER ONLY
    Sets the master to ignore poll requests from the slaves. Useful when you
    don't want the slaves replicating during indexing or when clearing the
    index.

    status : boolean
        Sets the replication status to the specified state.
    host : str (None)
        The solr host to query. __opts__['host'] is default.

    core_name : str (None)
        The name of the solr core if using cores. Leave this blank if you are
        not using cores or if you want to set the status on all cores.

    Return : dict<str,obj>::

        {'success':boolean, 'data':dict, 'errors':list, 'warnings':list}

    CLI Example::

        salt '*' solr.set_replication_enabled false, None, music
    '''
    if not _is_master() and _get_none_or_value(host) is None:
        return _get_return_dict(False,
                errors=['Only minions configured as master can run this'])
    cmd = 'enablereplication' if status else 'disablereplication'
    if _get_none_or_value(core_name) is None and _check_for_cores():
        ret = _get_return_dict()
        success = True
        for name in __opts__['solr.cores']:
            resp = set_replication_enabled(status, host, name)
            if not resp['success']:
                success = False
            data = {name: {'data': resp['data']}}
            ret = _update_return_dict(ret, success, data,
                    resp['errors'], resp['warnings'])
        return ret
    else:
        if status:
            return  _replication_request(cmd, host=host, core_name=core_name)
        else:
            return  _replication_request(cmd, host=host, core_name=core_name)


def signal(signal=None):
    '''
    Signals Apache Solr to start, stop, or restart. Obviously this is only
    going to work if the minion resides on the solr host. Additionally Solr
    doesn't ship with an init script so one must be created.

    signal : str (None)
        The command to pass to the apache solr init valid values are 'start',
        'stop', and 'restart'

    CLI Example::

        salt '*' solr.signal restart
    '''
    valid_signals = ('start', 'stop', 'restart')

    # Give a friendly error message for invalid signals
    # TODO: Fix this logic to be reusable and used by apache.signal
    if signal not in valid_signals:
        msg = valid_signals[:-1] + ('or {0}'.format(valid_signals[-1]),)
        return '{0} is an invalid signal. Try: one of: {1}'.format(
            signal, ', '.join(msg))

    cmd = "{0} {1}".format(__opts__['solr.init_script'], signal)
    __salt__['cmd.run'](cmd)


def reload_core(host=None, core_name=None):
    '''
    MULTI-CORE HOSTS ONLY
    Load a new core from the same configuration as an existing registered core.
    While the "new" core is initializing, the "old" one will continue to accept
    requests. Once it has finished, all new request will go to the "new" core,
    and the "old" core will be unloaded.

    host : str (None)
        The solr host to query. __opts__['host'] is default.
    core_name : str
        The name of the core to reload

    Return : dict<str,obj>::

        {'success':boolean, 'data':dict, 'errors':list, 'warnings':list}

    CLI Example::

        salt '*' solr.reload_core None music

        {'success':bool, 'data':dict, 'errors':list, 'warnings':list}
    '''
    ret = _get_return_dict()
    if not _check_for_cores():
        err = ['solr.reload_core can only be called by "multi-core" minions']
        return ret.update({'success': False, 'errors': err})

    if _get_none_or_value(core_name) is None and _check_for_cores():
        success = True
        for name in __opts__['solr.cores']:
            resp = reload_core(host, name)
            if not resp['success']:
                success = False
            data = {name: {'data': resp['data']}}
            ret = _update_return_dict(ret, success, data,
                    resp['errors'], resp['warnings'])
        return ret
    extra = ['action=RELOAD', 'core={0}'.format(core_name)]
    url = _format_url('admin/cores', host=host, core_name=None, extra=extra)
    return _http_request(url)


def core_status(host=None, core_name=None):
    '''
    MULTI-CORE HOSTS ONLY
    Get the status for a given core or all cores if no core is specified

    host : str (None)
        The solr host to query. __opts__['host'] is default.
    core_name : str
        The name of the core to reload

    Return : dict<str,obj>::

        {'success':boolean, 'data':dict, 'errors':list, 'warnings':list}

    CLI Example::

        salt '*' solr.core_status None music
    '''
    ret = _get_return_dict()
    if not _check_for_cores():
        err = ['solr.reload_core can only be called by "multi-core" minions']
        return ret.update({'success': False, 'errors': err})

    if _get_none_or_value(core_name) is None and _check_for_cores():
        success = True
        for name in __opts__['solr.cores']:
            resp = reload_core(host, name)
            if not resp['success']:
                success = False
            data = {name: {'data': resp['data']}}
            ret = _update_return_dict(ret, success, data,
                    resp['errors'], resp['warnings'])
        return ret
    extra = ['action=STATUS', 'core={0}'.format(core_name)]
    url = _format_url('admin/cores', host=host, core_name=None, extra=extra)
    return _http_request(url)


################### DIH (Direct Import Handler) COMMANDS #####################

def reload_import_config(handler, host=None, core_name=None, verbose=False):
    '''
    MASTER ONLY
    re-loads the handler config XML file.
    This command can only be run if the minion is a 'master' type

    handler : str
        The name of the data import handler.
    host : str (None)
        The solr host to query. __opts__['host'] is default.
    core : str (None)
        The core the handler belongs to.
    verbose : boolean (False)
        Run the command with verbose output.

    Return : dict<str,obj>::

        {'success':boolean, 'data':dict, 'errors':list, 'warnings':list}

    CLI Example::

        salt '*' solr.reload_import_config dataimport None music {'clean':True}
    '''

    #make sure that it's a master minion
    if not _is_master() and _get_none_or_value(host) is None:
        err = [
            'solr.pre_indexing_check can only be called by "master" minions']
        return _get_return_dict(False, err)

    if _get_none_or_value(core_name) is None and _check_for_cores():
        err = ['No core specified when minion is configured as "multi-core".']
        return _get_return_dict(False, err)

    params = ['command=reload-config']
    if verbose:
        params.append("verbose=true")
    url = _format_url(handler, host=host, core_name=core_name, extra=params)
    return _http_request(url)


def abort_import(handler, host=None, core_name=None, verbose=False):
    '''
    MASTER ONLY
    Aborts an existing import command to the specified handler.
    This command can only be run if the minion is configured with
    solr.type=master

    handler : str
        The name of the data import handler.
    host : str (None)
        The solr host to query. __opts__['host'] is default.
    core : str (None)
        The core the handler belongs to.
    verbose : boolean (False)
        Run the command with verbose output.

    Return : dict<str,obj>::

        {'success':boolean, 'data':dict, 'errors':list, 'warnings':list}

    CLI Example::

        salt '*' solr.abort_import dataimport None music {'clean':True}
    '''
    if not _is_master() and _get_none_or_value(host) is None:
        err = ['solr.abort_import can only be called on "master" minions']
        return _get_return_dict(False, errors=err)

    if _get_none_or_value(core_name) is None and _check_for_cores():
        err = ['No core specified when minion is configured as "multi-core".']
        return _get_return_dict(False, err)

    params = ['command=abort']
    if verbose:
        params.append("verbose=true")
    url = _format_url(handler, host=host, core_name=core_name, extra=params)
    return _http_request(url)


def full_import(handler, host=None, core_name=None, options=None, extra=None):
    '''
    MASTER ONLY
    Submits an import command to the specified handler using specified options.
    This command can only be run if the minion is configured with
    solr.type=master

    handler : str
        The name of the data import handler.
    host : str (None)
        The solr host to query. __opts__['host'] is default.
    core : str (None)
        The core the handler belongs to.
    options : dict (__opts__)
        A list of options such as clean, optimize commit, verbose, and
        pause_replication. leave blank to use __opts__ defaults. options will
        be merged with __opts__
    extra : dict ([])
        Extra name value pairs to pass to the handler. e.g. ["name=value"]

    Return : dict<str,obj>::

        {'success':boolean, 'data':dict, 'errors':list, 'warnings':list}

    CLI Example::

        salt '*' solr.full_import dataimport None music {'clean':True}
    '''
    options = {} if options is None else options
    extra = [] if extra is None else extra
    if not _is_master():
        err = ['solr.full_import can only be called on "master" minions']
        return _get_return_dict(False, errors=err)

    if _get_none_or_value(core_name) is None and _check_for_cores():
        err = ['No core specified when minion is configured as "multi-core".']
        return _get_return_dict(False, err)

    resp = _pre_index_check(handler, host, core_name)
    if not resp['success']:
        return resp
    options = _merge_options(options)
    if options['clean']:
        resp = set_replication_enabled(False, host=host, core_name=core_name)
        if not resp['success']:
            errors = ['Failed to set the replication status on the master.']
            return _get_return_dict(False, errors=errors)
    params = ['command=full-import']
    for key, val in options.items():
        params.append('&{0}={1}'.format(key, val))
    url = _format_url(handler, host=host, core_name=core_name,
                      extra=params + extra)
    return _http_request(url)


def delta_import(handler, host=None, core_name=None, options=None, extra=None):
    '''
    Submits an import command to the specified handler using specified options.
    This command can only be run if the minion is configured with
    solr.type=master

    handler : str
        The name of the data import handler.
    host : str (None)
        The solr host to query. __opts__['host'] is default.
    core : str (None)
        The core the handler belongs to.
    options : dict (__opts__)
        A list of options such as clean, optimize commit, verbose, and
        pause_replication. leave blank to use __opts__ defaults. options will
        be merged with __opts__

    extra : dict ([])
        Extra name value pairs to pass to the handler. eg ["name=value"]

    Return : dict<str,obj>::

        {'success':boolean, 'data':dict, 'errors':list, 'warnings':list}

    CLI Example::

        salt '*' solr.delta_import dataimport None music {'clean':True}
    '''
    options = {} if options is None else options
    extra = [] if extra is None else extra
    if not _is_master() and _get_none_or_value(host) is None:
        err = ['solr.delta_import can only be called on "master" minions']
        return _get_return_dict(False, errors=err)

    resp = _pre_index_check(handler, host=host, core_name=core_name)
    if not resp['success']:
        return resp
    options = _merge_options(options)
    #if we're nuking data, and we're multi-core disable replication for safty
    if options['clean'] and _check_for_cores():
        resp = set_replication_enabled(False, host=host, core_name=core_name)
        if not resp['success']:
            errors = ['Failed to set the replication status on the master.']
            return _get_return_dict(False, errors=errors)
    params = ['command=delta-import']
    for key, val in options.items():
        params.append("{0}={1}".format(key, val))
    url = _format_url(handler, host=host, core_name=core_name,
                      extra=params + extra)
    return _http_request(url)


def import_status(handler, host=None, core_name=None, verbose=False):
    '''
    Submits an import command to the specified handler using specified options.
    This command can only be run if the minion is configured with
    solr.type: 'master'

    handler : str
        The name of the data import handler.
    host : str (None)
        The solr host to query. __opts__['host'] is default.
    core : str (None)
        The core the handler belongs to.
    verbose : boolean (False)
        Specifies verbose output

    Return : dict<str,obj>::

        {'success':boolean, 'data':dict, 'errors':list, 'warnings':list}

    CLI Example::

        salt '*' solr.import_status dataimport None music False
    '''
    if not _is_master() and _get_none_or_value(host) is None:
        errors = ['solr.import_status can only be called by "master" minions']
        return _get_return_dict(False, errors=errors)

    extra = ["command=status"]
    if verbose:
        extra.append("verbose=true")
    url = _format_url(handler, host=host, core_name=core_name, extra=extra)
    return _http_request(url)
