# coding=utf-8
import json
import time
import random
import traceback
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
from selenium.common.exceptions import (
    TimeoutException, NoSuchElementException,
)
from selenium.webdriver.common.action_chains import ActionChains
from config import create_browser,_scroll_into_view
def find_valid_detail_tab(driver, origin_handle, timeout=10):
    """从现有句柄中挑出一个不是原始窗口的有效新标签页。"""
    end_time = time.time() + timeout
    while time.time() < end_time:
        for handle in driver.window_handles:
            if handle != origin_handle:
                try:
                    driver.switch_to.window(handle)
                    current_url = driver.current_url
                    if not current_url.startswith("chrome://") and current_url != "about:blank":
                        print(f"[切换窗口] 成功 → {driver.title}")
                        return handle
                except Exception:
                    pass
        time.sleep(0.5)
    raise Exception("未能在规定时间内找到有效详情页窗口")
# ---------主函数 ---------
def extract_row_info(row, driver):
    """抓取单条记录信息并返回字典"""

    try:
        type_text = row.find_element(By.XPATH, 'div / div / div[1] / span').text.strip()
    except Exception:
        type_text = ""
    # 如果不是期刊论文，直接跳过
    if type_text != "Research article":
        return None
    title_element = row.find_element(By.XPATH, './/h2/a/span/span/span')
    title = title_element.text.strip()
    print("论文名称",title)

    try:
        # 提取期刊名
        journal_element = row.find_element(By.XPATH, './/div[@class="SubType hor text-xs u-clr-grey6"]//a')
        source = journal_element.text.strip()
        # 提取时间（在 srctitle-date-fields 里，期刊名后面的 span）
        time_element = row.find_element(By.XPATH,'.//div[@class="SubType hor text-xs u-clr-grey6"]//span[@class="srctitle-date-fields"]/span[last()]')
        date = time_element.text.strip()

    except:
        source=""
        date=""
        print(f"未找到期刊或时间")

    print(f"期刊: {source} | 时间: {date}")
    print("类型:", type_text)

    time.sleep(1)
    origin = driver.current_window_handle
    existing_handles = driver.window_handles
    try:
        _scroll_into_view(driver, title_element)
        title_element.click()
    except Exception:
        try:
            ActionChains(driver).move_to_element(title_element).pause(1).click(title_element).perform()
        except Exception:
            driver.execute_script("arguments[0].click();", title_element)

    try:
        WebDriverWait(driver, 10).until(EC.new_window_is_opened(existing_handles))
    except TimeoutException:
        print("[警告] 未检测到新窗口，跳过")
        return None

    try:
        detail_tab = find_valid_detail_tab(driver, origin)
        if detail_tab not in driver.window_handles:
            return None
        driver.switch_to.window(detail_tab)
        time.sleep(3)
        #获取摘要信息
        abstract_elem = driver.find_elements(By.CSS_SELECTOR, "#sp0010")
        summary_text = abstract_elem.text.strip()
        print("摘要：", summary_text)
        authors = driver.find_elements(By.CSS_SELECTOR, "#author-group .react-xocs-alternative-link")

        author_names = [a.text.strip() for a in authors if a.text.strip()]
        print(author_names)

        time.sleep(1)
    finally:
        # 仅关闭非原窗口
        if driver.current_window_handle != origin:
            driver.close()
        driver.switch_to.window(origin)
        time.sleep(random.uniform(0.5, 1.5))

    return {
        "title": title,  # 确保函数里有定义
        "author": author_names,
        "source": source,
        "summary": summary_text
    }
def crawl_current_sort(driver, limit):
    """抓取当前排序下的 limit 条记录"""
    fetched_count = 0
    results = []

    while fetched_count < limit:
        try:
            WebDriverWait(driver, 10).until(
                EC.presence_of_element_located((By.XPATH, '//*[@id="main_content"]/div[3]/div[1]/div[2]/div[2]'))
            )
        except TimeoutException:
            print("[警告] 本页结果表格未出现，尝试继续")
        time.sleep(2)

        rows = driver.find_elements(By.XPATH, '// *[ @ id = "srp-results-list"] / ol / li')

        for row in rows:
            if fetched_count >= limit:
                break
            try:
                info = extract_row_info(row, driver)
                if info:
                    results.append(info)
                    time.sleep(2)
                    fetched_count += 1

            except Exception as e:
                print(f"[错误] {e}")
                traceback.print_exc()
                try:
                    if driver.window_handles:
                        driver.switch_to.window(driver.window_handles[0])
                except Exception:
                    pass

        # 翻页
        try:
            next_btn = driver.find_element(By.XPATH, "//*[@id='srp-pagination']/li[2]/a/span")

            if not next_btn.is_enabled() or fetched_count >= limit:
                break
            _scroll_into_view(driver, next_btn)
            try:
                next_btn.click()
            except Exception:
                try:
                    ActionChains(driver).move_to_element(next_btn).pause(1).click(next_btn).perform()
                except Exception:
                    driver.execute_script("arguments[0].click();", next_btn)
            time.sleep(5)
        except Exception:
            print("[INFO] 已到最后一页或翻页失败")
            break

    return results
def scienceDirect(keyword, limit):
    """主函数：三种排序抓取"""
    driver = create_browser()
    wait = WebDriverWait(driver, 15)
    all_results = {}

    sortings = {
        "relevance": None,
        "publication_time": "#srp-sorting-options > div > a > span",
   }

    try:
        driver.get("https://www.sciencedirect.com/")

        search_input = WebDriverWait(driver, 10).until(
            EC.presence_of_element_located((By.ID, "qs"))
        )
        search_input.send_keys(keyword)
        time.sleep(2)
        search_button = driver.find_element(By.XPATH, '//*[@id="searchbar"]/div/div/form/div[2]/button')
        search_button.click()
        time.sleep(3)

        for sort_name, css_selector in sortings.items():
            if css_selector:
                try:
                    driver.find_element(By.CSS_SELECTOR, css_selector).click()
                    time.sleep(5)
                except Exception:
                    print(f"[WARN] 点击排序 {sort_name} 失败")

            results = crawl_current_sort(driver, limit)
            all_results[sort_name] = results
    finally:
        try:
            driver.quit()
        except Exception:
            pass
        print("[DONE] PDF处理完成")
    print(json.dumps(all_results, ensure_ascii=False, indent=2))

    return json.dumps(all_results, ensure_ascii=False, indent=2)

if __name__ == '__main__':
    keyword = "graphrag"
    limit=10
    scienceDirect(keyword,limit)