import json
import copy
import splunk.rest
import splunk.field_extractor.mgr as mgr
from splunk.field_extractor.RegexBuilder import  FXData, TableUINewRule, TableUIExistingRule, TableUIEvents
from copy import deepcopy

def check(args, kwargs, required=True):
    for rarg, (rtype, rvals) in args.items():
        if rarg not in kwargs:
            if required:
                raise Exception("Missing required argument: %s" % rarg)
            else: continue
        val = kwargs[rarg]
        if rtype == 'choice' and val not in rvals:
            raise Exception("Value for %s must be one of the following: %s" % (rarg, rvals))
        elif rtype == 'int':
            try:
                rmin, rmax = rvals
                val = int(val)
                if val < rmin or val > rmax: raise Exception
                kwargs[rarg] = val
            except:
                raise Exception("Value for %s must be an integer between %d and %d" %(rarg,rmin,rmax))
        elif rtype == "json":
            try:
                kwargs[rarg] = json.loads(kwargs[rarg])
            except Exception as e:
                raise e
        else: pass
    return kwargs


def checkArgs(required_args, optional_args, kwargs):
    check(required_args, kwargs)
    check(optional_args, kwargs, False)
    for k in kwargs:
        if k not in required_args and k not in optional_args:
            raise Exception("Unknown argument %s" % k)
    return kwargs

def mungeExamples(examples, fieldName):
    munged = copy.deepcopy(examples)
    for example in munged:
        if '_rawtext' in example:
            fulltext = example['_rawtext']
            del example['_rawtext']
            eventDict = dict()
            eventDict[fieldName] = fulltext
            example['_event'] = eventDict
       
    return munged


TableUIHandlers = {
            'rules_new': TableUINewRule(),
            'rules_existing': TableUIExistingRule(),
            'events': TableUIEvents(),
        }

class RegexGenHandler(splunk.rest.BaseRestHandler):
    def handle_GET(self):
        required_args = {
            "field": ('string', None),
            "examples": ('json', None),
            "sid": ('string', None)
        }
        optional_args = {
            "filter": ('string', None),
            "counter_examples": ('json', None),
            "count": ('int', (1,500)),
            "offset": ('int', (0,1000))
        }
        kwargs = checkArgs(required_args, optional_args, self.args)

        ex = mungeExamples(kwargs['examples'], kwargs['field'])
        rules = mgr.gtfo(
            self.sessionKey, 
            kwargs['field'], 
            mungeExamples(kwargs['examples'], kwargs['field']), 
            mungeExamples(kwargs.get('counter_examples', []), kwargs['field']), 
            kwargs.get('filter', ''), 
            kwargs['sid'], 
            kwargs.get('offset', 0), 
            kwargs.get('count', 100)
        )

        self.response.setHeader('content-type', 'application/json')
        response = { 'rules': rules }
        response.update(kwargs)
        self.response.write(json.dumps(response))

    def handle_POST(self):
        fxd = FXData(require={'sid': ('string', None), 
                                'type': ('choice', ('rules_new', 'rules_existing', 'events'))})
        fxd.check(self.args, ignoreOthers=True)
        results = TableUIHandlers[self.args['type']].setSessionKey(self.sessionKey).results(self.args)
        self.response.setHeader('content-type', 'application/json')
        self.response.write(json.dumps(results, indent=2, ensure_ascii=False))