"""Cache, generate and load resources"""

import csv, json, os, sys
from nltk import word_tokenize
from itertools import permutations
from collections import OrderedDict
from lexmapr.definitions import ROOT
from lexmapr.pipeline_helpers import punctuation_treatment


def _create_lookup_table_skeleton():
    '''Generate an empty lookup table'''
    return({'abbreviations':{}, 'inflection_exceptions':{}, 'non_english_words':{},
            'spelling_mistakes':{}, 'stop_words':{}, 'suffixes':{}})


def _get_resource_dict(resource_file_name):
    '''Get dictionary of resources from CSV file'''
    ret_dic = {}
    with open(os.path.join(ROOT, 'predefined_resources', resource_file_name)) as RES_file:
        next(RES_file)
        for row in csv.reader(RES_file, delimiter=','):
            try:
                ret_dic[punctuation_treatment(row[0].strip())] = \
                    punctuation_treatment(row[1].strip())
            except IndexError:
                ret_dic[punctuation_treatment(row[0].strip())] = ''
    return(ret_dic)


def _add_predefined_resources_to_lookup_table(lookup_table):
    '''Adds elements from lexmapr/predefined_resources to lookup table'''
    lookup_table['abbreviations'] = _get_resource_dict('abbrv.csv')
    lookup_table['inflection_exceptions'] = _get_resource_dict('inflection_exceptions.csv')
    lookup_table['non_english_words'] = _get_resource_dict('nengwords.csv')
    lookup_table['spelling_mistakes'] = _get_resource_dict('ScorLex.csv') #only from v 0.7
    lookup_table['spelling_mistakes'].update(_get_resource_dict('misspellings.csv'))
    lookup_table['stop_words'] = _get_resource_dict('mining_stopwords.csv')
    lookup_table['suffixes'] = _get_resource_dict('suffixes.csv')
    return(lookup_table)


def get_predefined_resources():
    '''Creates lookup table'''
    lookup_table_path = os.path.join(ROOT, 'predefined_resources', 'lookup_table.json')
    if os.path.exists(lookup_table_path):
        with open(lookup_table_path) as LT_file:
            lookup_table = json.load(LT_file)
    else:
        lookup_table = _create_lookup_table_skeleton()
        lookup_table = _add_predefined_resources_to_lookup_table(lookup_table)
        with open(lookup_table_path, 'w') as LT_file:
            json.dump(lookup_table, LT_file)
    return(lookup_table)


def get_resource_label_permutations(resource_label):
    '''Get permutations of some term'''
    permutations_set = list(OrderedDict.fromkeys(permutations(resource_label.split())))
    ret_list = []
    for permutation_tuple in permutations_set:
        ret_list.append(' '.join(permutation_tuple))
    return(ret_list)