# -*- coding:utf-8 -*-

import config
import re
import numpy as np

def merge_stem(a_stem:list, b_stem:list):
    """
    合并词根
    """
    return list(set(a_stem).union(set(b_stem)))

def gen_word_vec(a_word:str, b_word:str, stem:list):
    """
    生成词向量
    """
    a_vec, b_vec = [], []
    for word in stem:
        # if re.findall(word, config.RE_SPECIAL_SIMBOL):
        if word in config.RE_SPECIAL_SIMBOL:
            word = "\\" + word
        if word == "c++":
            word = "c\\+\\+"
        a_vec.append(len(re.findall(word, a_word)))
        b_vec.append(len(re.findall(word, b_word)))
    return a_vec, b_vec

def col_sim(vec1, vec2):
    """
    计算余弦相似性
    """
    return vec1.dot(vec2) / (np.linalg.norm(vec1) * np.linalg.norm(vec2))


def cal_cos_sim(a_word:str, a_stem:list, b_word:str, b_stem:list):
    """
    计算余弦相似性
    """
    union_stem = merge_stem(a_stem, b_stem)
    a_vec, b_vec = gen_word_vec(a_word, b_word, union_stem)
    val = col_sim(np.array(a_vec), np.array(b_vec))
    return val