import datetime
import re
import time
from concurrent.futures import ThreadPoolExecutor, wait

from pymongo.errors import DocumentTooLarge

from common.databases import mongo_table, redis_client
from common.log import logger
from common.tools import sha1
from crawler.analysis import parser_items
from crawler.download import Downloader
from crawler.utils import (
    extract_page_title,
    extract_host,
    err_details,
    extract_text
)

hospital = mongo_table('tmp_crawl', 'hospital_info')
r = redis_client()
r_key = 'hospital_2022'

down_loader = Downloader()
seed_tasks = [
    ('http://www.hnsrmyy.net', '河南省人民医院'),
    ('https://www.zzsetyy.cn/index.html', '河南省儿童医院'),
    ('https://www.pumch.cn/index.html', '北京协和医院'),
]


def create_task(host: str, title: str, href: str, depth: int, **kwargs):
    sid = sha1(href)
    if not r.hexists(r_key, sid):
        hospital.insert_one({
            'host': host,
            'href': href,
            'title': title,
            'depth': depth,
            'is_crawl': False,
            'create_at': datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S'),
            **kwargs
        })
        r.hset(r_key, sid, '')
        return True
    return False


def push_tasks():
    for url, title in seed_tasks:
        item = {
            'host': extract_host(url),
            'href': url,
            'title': title,
            'site': title,
            'depth': 1,
        }
        create_task(**item)


def get_tasks(**kwargs):
    _results = []
    _projection = kwargs.pop('projection', {})
    projection = {
        'host': 1,
        'site': 1,
        'href': 1,
        'depth': 1,
        'is_crawl': 1,
        **_projection
    }
    cursor = hospital.find({'is_crawl': False}, projection=projection)
    for item in cursor.sort([('depth', 1)]).limit(100):
        _results.append(item)
    return _results


def update_data(mongo_id, source, source_text):
    item = {
        'source': source,
        'source_text': source_text,
        'is_crawl': True,
        'update_at': datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S')
    }
    try:
        hospital.update_one({'_id': mongo_id}, {'$set': item})
    except DocumentTooLarge:
        item['source'] = ''
        hospital.update_one({'_id': mongo_id}, {'$set': item})


def crawl_request(url, host):
    suffix = re.search('([.][a-zA-Z]{3,5})$', url)
    if suffix is not None and suffix.group().find('.htm') == -1:
        raise ValueError(f'无法挖掘的url:{url}')

    response = down_loader.get(url, timeout=10, max_retries=1, disable_debug_log=False)
    if response.status_code == 200 and response.text not in [None, '']:
        items = parser_items(response.text, url=host, mode=1)
        title = extract_page_title(response.text)
        source_text = "&_&".join(extract_text(response.text).split())
    else:
        title = f'请求异常-{response.status_code}-{response.reason}'
        source_text = ''
        items = []
    results = {
        'host': host,
        'href': url,
        'source': response.text,
        'title': title,
        'source_text': source_text,
        'items': items,
    }
    return results


def crawl_spider(task):
    _id = task['_id']
    _total, _success, _err = 0, 0, 0
    try:
        dic_data = crawl_request(task['href'], task['host'])
        # 创建挖掘任务
        for item in dic_data['items']:
            href = item['href']
            title = item['title']
            sub_item = {
                'host': task['host'],
                'title': title,
                'href': href,
                'depth': task['depth'] + 1,
            }
            success = create_task(**sub_item, site=task['site'])
            if success:
                _success += 1
            else:
                _err += 1
            _total += 1
    except ValueError:
        dic_data = {}

    # 更新挖掘结果
    update_data(**dict(
        mongo_id=_id,
        source=dic_data.get('source', None),
        source_text=dic_data.get('source_text', None)))
    logger.info(f"[{str(_id)}]采集成功{_total}条,上传成功{_success}条,删除重复{_err}条")


def start():
    push_tasks()
    while True:
        tasks = get_tasks()
        logger.info(f"加载采集任务{len(tasks)}条")
        with ThreadPoolExecutor(max_workers=4, thread_name_prefix='hospital') as Executor:
            futures = []
            for task in tasks:
                future = Executor.submit(crawl_spider, task)
                future.add_done_callback(err_details)
                futures.append(future)
            wait(futures)
        logger.info(f"完成采集任务{len(tasks)}条,等待加载")
        time.sleep(10)


if __name__ == '__main__':
    start()