# 关于利用doi，批量下载文献的方法

import requests
from bs4 import BeautifulSoup
import os
import threading
import time
from queue import Queue
from requests.adapters import HTTPAdapter
from urllib3.util.retry import Retry

# 设置下载文献存储的文件夹路径
path = r"E:\Quantum computing folder"#这里要换
if not os.path.exists(path):
    os.makedirs(path)

# 日志文件路径
error_log_path = os.path.join(path, "error.log")

# 请求头
headers = {
    "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) "
                  "AppleWebKit/537.36 (KHTML, like Gecko) "
                  "Chrome/129.0.0.0 Safari/537.36"
}

# Sci-Hub 域名
scihub_domain = "https://sci-hub.usualwant.com"#这个域名经常变化，网页查完更换

# 重试策略
retry_strategy = Retry(
    total=5,
    backoff_factor=1,
    status_forcelist=[429, 500, 502, 503, 504],
    allowed_methods=["HEAD", "GET", "OPTIONS"]  # 更新为 allowed_methods
)
adapter = HTTPAdapter(max_retries=retry_strategy)
http = requests.Session()
http.headers.update(headers)
http.mount("https://", adapter)
http.mount("http://", adapter)

# 下载文献的函数
def download_paper(doi):
    url = f"{scihub_domain}/{doi}"
    pdf_url = ""  # 初始化 pdf_url 避免 UnboundLocalError
    try:
        # 发送HTTP请求并解析HTML页面
        response = http.get(url, timeout=10)
        response.raise_for_status()
        soup = BeautifulSoup(response.text, "html.parser")

        # 解析得到文献下载链接
        iframe = soup.find("iframe")
        if iframe:
            pdf_url = iframe.get("src")
        else:
            embed = soup.find("embed")
            if embed:
                pdf_url = embed.get("src")

        if not pdf_url:
            raise ValueError("文献下载链接获取失败.")

        # 处理链接前缀
        if pdf_url.startswith('//'):
            pdf_url = 'https:' + pdf_url
        elif not pdf_url.startswith('http'):
            pdf_url = f"{scihub_domain}/{pdf_url}"

        # 下载文献并保存到文件
        pdf_response = http.get(pdf_url, timeout=20)
        pdf_response.raise_for_status()

        pdf_filename = os.path.join(path, doi.replace("/", "_") + ".pdf")
        with open(pdf_filename, "wb") as pdf_file:
            pdf_file.write(pdf_response.content)

        print(f"{doi} 文献下载成功.")
        time.sleep(0.1)  # 防止频繁请求Sci-Hub，设置适当的延迟

    except Exception as e:
        with open(error_log_path, "a", encoding="utf-8") as error_log:
            error_log.write(f"{doi} 下载失败!\n")
            if pdf_url:
                error_log.write(f"下载url链接为: {pdf_url}\n")
            error_log.write(f"错误信息: {e}\n\n")
        print(f"{doi} 下载失败: {e}")

# 读取包含DOI号的txt文件并下载文献
def main():
    doi_file_path = r"C:\Users\James\Desktop\doi.txt"  # 已经是绝对路径
    with open(doi_file_path, "r", encoding="utf-8") as file:
        dois = [doi.strip() for doi in file.readlines()]

    # 创建下载队列
    queue = Queue()

    # 将DOI号加入队列
    for doi in dois:
        if doi:
            queue.put(doi)

    # 下载任务函数
    def worker():
        while not queue.empty():
            doi = queue.get()
            download_paper(doi)
            queue.task_done()

    # 设置线程数
    thread_count = 4
    threads = []

    # 创建并启动线程
    for _ in range(thread_count):
        thread = threading.Thread(target=worker)
        thread.daemon = True  # 设置为守护线程，程序退出时自动结束
        threads.append(thread)
        thread.start()

    # 等待所有线程完成
    queue.join()

    # 可选：等待所有线程结束
    for thread in threads:
        thread.join()

if __name__ == "__main__":
    main()