# -*- coding:utf-8 -*-
import math
import os
import re
import shutil
import threading
import time
from concurrent.futures import ProcessPoolExecutor, as_completed, ThreadPoolExecutor

import jieba
import redis
from bitarray import bitarray
from tqdm import tqdm

import utils
import logging

from constant import FILE_LONG_TAIL_MERGE

# 文件：长尾词_合并_分词.txt
FILE_LONG_TAIL_MERGE_SPLIT = "长尾词_合并_分词.txt"

# 文件：长尾词_合并_聚合.txt
FILE_LONG_TAIL_MERGE_AGG = "长尾词_合并_聚合.txt"

# 文件夹：历史聚合数据归档文件夹
DIR_AGG_FILE_ARCHIVE = "长尾词_聚合_归档_%s"

# 文件：长尾词_合并_分词倒排索引.txt
FILE_LONG_TAIL_MERGE_REVERSE_INDEX = "长尾词_合并_倒排索引.txt"

# 子文件：长尾词_合并_聚合_%s.txt
FILE_LONG_TAIL_MERGE_AGG_PID = "长尾词_合并_聚合_%s_%s.txt"

# 缓存前缀：分词词根
CACHE_WORD_STEM = "word:stem"

# 缓存前缀：倒排索引
CACHE_WORD_REVERSE_INDEX = "word:reverse_index"

# 缓存：长尾词缓存
CACHE_WORD = "word"

# 缓存：聚合位图
CACHE_UNUSED_BITMAP = "unused_bitmap"

# 字符集：UTF-8
CHARSET_UTF_8 = "UTF-8"

# redis缓存池
redis_pool: redis.ConnectionPool = None

# 线程池
thread_pool: ThreadPoolExecutor = None

# 线程本地变量
local_var = threading.local()


def agg_word(file_path: str):
    """
    长尾词聚合
    :param file_path:
    :return:
    """

    # 总长尾词数量
    # word_total_num = 0
    word_total_num = 1000000

    # 聚合阈值
    agg_threshold = 0.8

    # 每份任务计算量
    task_cal_num = 10000

    # 工作现成(减1是为了留一个处理器给redis)
    worker_num = os.cpu_count() - 1
    # worker_num = 1

    # 正则表达式：聚合文件分文件
    agg_file_pattern = re.compile(r"长尾词_合并_聚合_\d+_\d+.txt", re.I)

    # 最大线程数
    max_threads = 2

    # redis最大连接数（和工作线程数保持一致，免得浪费）
    redis_max_conns = max_threads

    # redis缓存
    m_redis_cache = redis.StrictRedis(host='127.0.0.1', port=6379)

    # 判断文件是否存在
    for file_name in [FILE_LONG_TAIL_MERGE, FILE_LONG_TAIL_MERGE_SPLIT,
                      FILE_LONG_TAIL_MERGE_REVERSE_INDEX]:
        input_file = os.path.join(file_path, file_name)
        if os.path.exists(input_file) and not os.path.isfile(input_file):
            raise Exception("文件不存在！文件路径：" + input_file)

    # 归档历史数据文件
    history_agg_file_list = [file for file in os.listdir(file_path) if agg_file_pattern.match(file)]
    if len(history_agg_file_list) > 0:
        archive_path = os.path.join(file_path, DIR_AGG_FILE_ARCHIVE % time.strftime('%Y%m%d%H%M%S'))
        os.makedirs(archive_path)
        for history_agg_file in history_agg_file_list:
            shutil.move(os.path.join(file_path, history_agg_file), archive_path)

    # 缓存关键词位置
    # word_file = os.path.join(file_path, FILE_LONG_TAIL_MERGE)
    # word_dict = {}
    # with open(word_file, "r", encoding="utf-8") as f:
    #     for position, word in enumerate(f, start=1):
    #         word = utils.remove_line_break(word)
    #         if not word:
    #             continue
    #         word_dict[position] = word
    # m_redis_cache.hset(CACHE_WORD, mapping=word_dict)
    # # 记录总关键词数
    # word_total_num = len(word_dict)
    # # 释放内存
    # del word_dict
    #
    # # 缓存分词
    # word_split_file = os.path.join(file_path, FILE_LONG_TAIL_MERGE_SPLIT)
    # word_split_dict = {}
    # with open(word_split_file, "r", encoding=CHARSET_UTF_8) as f:
    #     for position, word_split_line in enumerate(f, start=1):
    #         word_split_line = utils.remove_line_break(word_split_line)
    #         if not word_split_line:
    #             continue
    #         word_split_dict[position] = word_split_line
    # m_redis_cache.hset(CACHE_WORD_STEM, mapping=word_split_dict)
    # # 释放内存
    # del word_split_dict
    #
    # # 缓存倒排索引
    # word_reverse_index_file = os.path.join(file_path, FILE_LONG_TAIL_MERGE_REVERSE_INDEX)
    # word_reverse_index_dict = {}
    # # 分词
    # key_pattern = re.compile(r"([^,]+),\[", re.I)
    # # 索引
    # index_pattern = re.compile(r"\d+", re.I)
    # with open(word_reverse_index_file, "r", encoding="utf-8") as f:
    #     for word_split_line in f:
    #         key_m = key_pattern.match(word_split_line)
    #         key = key_m.group(1)
    #         val = index_pattern.findall(word_split_line[word_split_line.index(","):])
    #         word_reverse_index_dict[key] = ",".join(val)
    # m_redis_cache.hset(CACHE_WORD_REVERSE_INDEX, mapping=word_reverse_index_dict)
    # # 释放内存
    # del word_reverse_index_dict

    # 先清除，然后重新构建长尾词使用位图
    m_redis_cache.delete(CACHE_UNUSED_BITMAP)
    m_redis_cache.setbit(CACHE_UNUSED_BITMAP, word_total_num + 2, 1)

    # 提交任务 并输出结果
    word_agg_file = os.path.join(file_path, FILE_LONG_TAIL_MERGE_AGG)

    with ProcessPoolExecutor(max_workers=worker_num, initializer=init_process,
                             initargs=(redis_max_conns, max_threads, file_path)) as process_pool:
        # 计算任务边界
        task_list = utils.avg_split_task(word_total_num, task_cal_num, 1)

        # 提交任务
        process_futures = []
        for skip_line, pos in enumerate(task_list, start=1):
            skip_line = (skip_line % worker_num) + 1
            p_future = process_pool.submit(agg_word_process, agg_threshold, pos[0], pos[1], word_total_num,
                                           skip_line)
            process_futures.append(p_future)

        # 显示任务进度
        with tqdm(total=len(process_futures), desc='文本聚合进度', unit='份', unit_scale=True) as pbar:
            for p_future in as_completed(process_futures):
                p_result = p_future.result()
                # 更新发呆进度
                pbar.update(1)

        # 关闭线程
        process_pool.shutdown()

    # 获取子进程结果文件列表，并合并
    with open(word_agg_file, "w", encoding="UTF-8") as fo:
        for file in os.listdir(file_path):
            # 不是处理结果部分跳过
            if not agg_file_pattern.match(file):
                continue

            with open(os.path.join(file_path, file), "r", encoding="UTF-8") as fi:
                for word in fi:
                    fo.write(word)


def prepare_word_split_and_reverse_index(file_path: str):
    """
    预处理：长尾词分词、建立倒排索引
    :param file_path: 待处理文件夹路径
    :return:
    """

    # 判断文件是否存在
    word_input_file = os.path.join(file_path, FILE_LONG_TAIL_MERGE)
    if os.path.exists(word_input_file) and not os.path.isfile(word_input_file):
        print("文件不存在！ " + word_input_file)
        return

    # 总文本数量
    total_line_num = 0
    with open(word_input_file, "r", encoding="utf-8") as fi:
        total_line_num = sum(1 for line in fi)

    if total_line_num == 0:
        print("没有待处理的数据，文本量为0")
        return

    # 分割任务数量
    task_list = utils.avg_split_task(total_line_num, math.ceil(total_line_num / os.cpu_count()))

    # 任务进程处理结果
    p_result_list = []

    # 多进程处理
    with ProcessPoolExecutor(os.cpu_count()) as process_pool:
        # 提交任务
        process_futures = [process_pool.submit(word_split_reverse, word_input_file, task[0], task[1]) for task in
                           task_list]

        # 处理返回结果
        for p_future in as_completed(process_futures):
            p_result = p_future.result()
            if p_result:
                p_result_list.append(p_result)

        # 分词结果排序
        p_result_list = sorted(p_result_list, key=lambda v: v[0])
        # 输出分词结果
        split_output_file = os.path.join(file_path, FILE_LONG_TAIL_MERGE_SPLIT)
        with open(split_output_file, "w", encoding="UTF-8") as fo:
            for start_pos, word_arr_list, reverse_index in p_result_list:
                for word_arr in word_arr_list:
                    fo.write("%s\n" % ",".join([str(i) for i in word_arr]))

        # 关键词倒排索引
        word_reverse_index_dict = dict()
        # 合并倒排索引
        for start_pos, word_arr, reverse_index_dict in p_result_list:
            for key, value in reverse_index_dict.items():
                reverse_index_arr = word_reverse_index_dict.get(key)
                if reverse_index_arr:
                    reverse_index_arr.extend(value)
                else:
                    word_reverse_index_dict[key] = value
        # 输出倒排索引
        with open(os.path.join(file_path, FILE_LONG_TAIL_MERGE_REVERSE_INDEX), "w", encoding="UTF-8") as fo:
            for key, value in word_reverse_index_dict.items():
                fo.write("%s,%s\n" % (key, value))

        # 关闭进程池
        process_pool.shutdown()


def word_split_reverse(input_file: str, start_pos: int, end_pos: int):
    """
    分词和建立倒排索引
    :param input_file: 待处理的文件
    :param start_pos: 处理的开始位置
    :param end_pos: 处理的结束位置
    :return: (开始位置，分词结果，倒排索引)
    """

    # 加载停用词
    stop_word_dict = utils.load_stop_word()
    # 关键词存放容器
    word_arr_list = []
    # 倒排索引
    word_reverse_index = dict()

    with open(input_file, "r", encoding="utf-8") as fr:
        for i, tmp_word in enumerate(fr):

            # start_pos是行数，而i要从0开始
            if i + 1 < start_pos:
                continue

            # 当前位置
            cur_pos = i + 1

            # 到达任务边界，结束
            if cur_pos == end_pos:
                break

            # 分词
            word_list = jieba.cut_for_search(tmp_word.replace("\n", ""))

            # 分词过滤结果
            word_filter_arr = []

            # 过滤停用词
            for word in word_list:
                if word in stop_word_dict:
                    continue

                word_index_arr = word_reverse_index.get(word)
                if word_index_arr:
                    word_index_arr.append(cur_pos)
                else:
                    word_reverse_index[word] = [cur_pos]

                word_filter_arr.append(word)

            if len(word_filter_arr) == 0:
                word_arr_list.append([])
            else:
                word_arr_list.append(word_filter_arr)

    return start_pos, word_arr_list, word_reverse_index


def init_process(max_conns: int, max_threads: int, file_path: str):
    """
    初始化进程
    :param max_conns: redis最大连接数量
    :param max_threads: 线程最大数量
    :param file_path: 输出文件路径
    :return:
    """
    # redis缓存池 初始化
    global redis_pool
    redis_pool = redis.ConnectionPool(host='127.0.0.1', port=6379, max_connections=max_conns)

    global thread_pool
    thread_pool = ThreadPoolExecutor(max_threads, initializer=init_thread, initargs=(file_path,))


def agg_word_process(agg_threshold: float, start_pos: int, end_pos: int, final_pos: int,
                     skip_line: int):
    """
    长尾词聚合处理
    :param agg_threshold: 聚合阈值
    :param start_pos: 任务处理开始边界（包含）
    :param end_pos: 任务处理结束边界（不包含）
    :param final_pos: 总任务边界
    :param skip_line: 进度条显示位置
    :return:
    """

    # 进度长度
    process_len = 0
    if end_pos == -1:
        process_len = final_pos - start_pos
    else:
        process_len = end_pos - start_pos

    with tqdm(total=process_len, desc='子进程-%s：文本聚合进度' % os.getpid(), unit='份', unit_scale=True,
              position=skip_line) as pbar:

        thread_futures = [thread_pool.submit(agg_word_thread, main_word_position, agg_threshold) for main_word_position
                          in
                          range(start_pos, end_pos)]

        for t_future in as_completed(thread_futures):
            t_result = t_future.result()
            # 更新发呆进度
            pbar.update(1)

    return


def init_thread(file_path: str):
    """
    聚合线程初始化
    :param file_path: 输出文件路径
    :return:
    """
    # 初始化redis客户端
    local_var.redis_cache = redis.StrictRedis(connection_pool=redis_pool)
    # 初始化redis管道
    local_var.redis_pipeline = local_var.redis_cache.pipeline(transaction=False)

    # 生成临时结果文件
    word_agg_file = os.path.join(file_path,
                                 FILE_LONG_TAIL_MERGE_AGG_PID % (os.getpid(), threading.current_thread().ident))
    local_var.file_writer = open(word_agg_file, "w", encoding=CHARSET_UTF_8)

    # 已使用位图副本
    local_var.unused_bitmap = bitarray()

    # 从倒排索引中获取候选词的位置索引
    local_var.candidate_position_set = set()

    # 结果列表
    local_var.result_list = []


def agg_word_thread(main_word_position: int, agg_threshold: float):
    try:
        # 获取已使用位图副本
        local_var.unused_bitmap.frombytes(local_var.redis_cache.get(CACHE_UNUSED_BITMAP))

        # 判断主词是否为已使用，是则跳过，否则设置为已使用
        if local_var.unused_bitmap[main_word_position]:
            return
        else:
            local_var.redis_cache.setbit(CACHE_UNUSED_BITMAP, main_word_position, 1)
            local_var.unused_bitmap[main_word_position] = 1

        # 获取主词和对应的词根
        local_var.redis_pipeline.hget(CACHE_WORD, main_word_position)
        local_var.redis_pipeline.hget(CACHE_WORD_STEM, main_word_position)
        main_result = local_var.redis_pipeline.execute()
        main_word = main_result[0]
        main_word_stem = main_result[1]

        # 如果存在为空则返回
        if not main_word or not main_word_stem:
            return

        main_word_stem_list = main_word_stem.decode(CHARSET_UTF_8).split(",")

        # 从倒排索引获取长尾词位置
        temp_candidate_position_list = local_var.redis_cache.hmget(CACHE_WORD_REVERSE_INDEX, main_word_stem_list)
        for temp_candidate_position in temp_candidate_position_list:
            if not temp_candidate_position:
                continue
            # 排除已聚合
            for candidate_position in temp_candidate_position.decode(CHARSET_UTF_8).split(","):
                if local_var.unused_bitmap[int(candidate_position)]:
                    continue
                local_var.candidate_position_set.add(candidate_position)

        # 没有找到需要计算的候选词则跳过
        if not local_var.candidate_position_set:
            return

        # 从缓存获取关键词列表、分词列表，如果为空则跳过
        local_var.redis_pipeline.hmget(CACHE_WORD, local_var.candidate_position_set)
        local_var.redis_pipeline.hmget(CACHE_WORD_STEM, local_var.candidate_position_set)
        candidate_result = local_var.redis_pipeline.execute()
        candidate_word_cache_list = candidate_result[0]
        candidate_word_stem_cache_list = candidate_result[1]
        if not candidate_word_cache_list or not candidate_word_stem_cache_list:
            return

        # 延后编码成字符，以防前面直接返回
        main_word = main_word.decode(CHARSET_UTF_8)

        # 计算相似度
        for candidate_position in range(len(local_var.candidate_position_set)):

            # 获取关键词、分词，如果存在为空则跳过
            candidate_word = candidate_word_cache_list[int(candidate_position)]
            if not candidate_word:
                continue
            candidate_word_stem = candidate_word_stem_cache_list[int(candidate_position)]
            if not candidate_word_stem:
                continue
            candidate_word = candidate_word.decode(CHARSET_UTF_8)
            candidate_word_stem_list = candidate_word_stem.decode(CHARSET_UTF_8).split(",")

            # 计算相关性
            try:
                val = utils.cal_cos_sim(main_word, main_word_stem_list, candidate_word,
                                        candidate_word_stem_list)
                if val >= agg_threshold:
                    local_var.redis_cache.setbit(CACHE_UNUSED_BITMAP, candidate_position, 1)
                    local_var.result_list.append(candidate_word)
            except Exception as e:
                logging.error("主关键词：%s 发生异常，涉及的副关键词信息-关键词：%s，分词：%s" % (
                    main_word, candidate_word, candidate_word_stem_list), e)

        # 保存结果
        if not local_var.result_list:
            return
        local_var.file_writer.write("%s\n" % main_word)
        for candidate_word in local_var.result_list:
            local_var.file_writer.write("%s\n" % candidate_word)
        local_var.file_writer.write("\n")

    except Exception as e:
        logging.error("子进程发生异常", e)
    finally:
        # 清除容器数据
        local_var.candidate_position_set.clear()
        local_var.result_list.clear()
        local_var.unused_bitmap.clear()

    return