Update app.py

app.py

@@ -1,85 +1,145 @@
 import streamlit as st
 import libtorrent as lt
 import time
+import threading
 import os
-import tempfile
 
-def download_magnet_link(magnet_link):
-    """
-    使用libtorrent下载磁力链接，并显示下载进度。
-
-    参数:
-        magnet_link (str): 磁力链接
-
-    返回:
-        str: 下载文件的本地路径，如果下载失败则返回 None
-    """
+# Session状态初始化
+if 'download_progress' not in st.session_state:
+    st.session_state.download_progress = 0
+if 'downloading' not in st.session_state:
+    st.session_state.downloading = False
+if 'download_complete' not in st.session_state:
+    st.session_state.download_complete = False
+if 'download_filename' not in st.session_state:
+    st.session_state.download_filename = None
+if 'error_message' not in st.session_state:
+    st.session_state.error_message = None
+
+def download_torrent(magnet_link, save_path):
     try:
         ses = lt.session()
-        ses.listen_on(6881, 6891) # 监听端口范围，用于BT下载
-
-        params = lt.parse_magnet_uri(magnet_link)
-
-        add_params = lt.add_torrent_params()  # 创建 add_torrent_params 对象
-        # add_params.set_params(params)  #  移除此行：set_params 方法不存在
-        temp_dir = tempfile.TemporaryDirectory() # 创建临时目录用于存放下载文件
-        add_params.save_path = temp_dir.name  #  设置 save_path 为临时目录路径
-        add_params.params = params # 尝试直接赋值 params  (新的尝试)
-        handle = ses.add_torrent(add_params) # 使用 add_torrent_params 添加 torrent 任务
-
-
-        progress_bar = st.empty() # 创建一个空的占位符，用于显示进度条
-        progress_text = st.empty() # 创建一个空的占位符，用于显示进度文字
-
-        status = handle.status()
-        while not status.has_metadata(): # 等待获取 torrent 元数据
-            status = handle.status()
+        ses.listen_on(6881, 6891)
+        params = {
+            'save_path': save_path,
+            'storage_mode': lt.storage_mode_t(2)
+        }
+        
+        handle = lt.add_magnet_uri(ses, magnet_link, params)
+        ses.start_dht()
+        ses.start_lsd()
+        ses.start_upnp()
+        ses.start_natpmp()
+
+        # 等待元数据
+        st.session_state.error_message = "正在获取元数据..."
+        while not handle.has_metadata():
             time.sleep(1)
-
-        torrent_info = handle.get_torrent_info()
-        file_name = torrent_info.files()[0].path # 假设只下载第一个文件，您可以根据需求修改逻辑
-        download_path = os.path.join(temp_dir.name, file_name) # 拼接下载文件的完整路径
-
-
-        while status.state != lt.torrent_status.seeding: # 循环直到下载完成 (seeding 状态)
-            status = handle.status()
-
-            progress_percent = int(status.progress * 100) # 计算下载进度百分比
-            progress_bar.progress(progress_percent / 100) # 更新进度条
-            progress_text.text(f"下载进度: {progress_percent}% - 速度: {status.download_payload_rate / 1000:.2f} KB/s - 已下载: {status.total_done / (1024 * 1024):.2f} MB / 总大小: {status.total / (1024 * 1024):.2f} MB") # 更新进度文字
-
-            time.sleep(0.5) # 每0.5秒更新一次进度
-
-        ses.remove_torrent(handle) # 下载完成后移除 torrent 任务
-        ses.pause() # 暂停 libtorrent 会话
-
-        return download_path # 返回下载文件的完整路径
+            if not st.session_state.downloading:
+                return
+
+        # 获取文件信息
+        torinfo = handle.get_torrent_info()
+        files = torinfo.files()
+        if files.num_files() > 1:
+            st.session_state.error_message = "暂不支持多文件种子"
+            st.session_state.downloading = False
+            return
+
+        file_path = files.file_path(0)
+        st.session_state.download_filename = os.path.join(save_path, file_path)
+
+        st.session_state.error_message = None
+        st.session_state.downloading = True
+
+        # 更新下载进度
+        while handle.status().state != lt.torrent_status.seeding:
+            if not st.session_state.downloading:
+                handle.pause()
+                return
+            s = handle.status()
+            progress = s.progress * 100
+            st.session_state.download_progress = progress
+            time.sleep(0.5)
+
+        st.session_state.download_progress = 100
+        st.session_state.download_complete = True
+        st.session_state.downloading = False
 
     except Exception as e:
-        st.error(f"下载失败: {e}") # 显示错误信息
-        return None
-
-
-st.title("磁力链接下载器") # Streamlit 应用标题
-
-magnet_link_input = st.text_input("请输入磁力链接:") # 用户输入磁力链接的输入框
-
-if magnet_link_input: # 当用户输入磁力链接后
-    download_path = download_magnet_link(magnet_link_input) # 调用下载函数
-
-    if download_path: # 如果下载成功
-        st.success("下载完成！文件已保存在临时目录，您可以下载文件。") # 显示下载成功信息
-
-        try:
-            with open(download_path, "rb") as f: # 以二进制读取下载的文件
-                file_data = f.read() # 读取文件内容
-                file_name = os.path.basename(download_path) # 获取文件名
-
-                st.download_button( # 创建下载按钮
-                    label="下载文件", # 按钮标签
-                    data=file_data, # 下载的数据，即文件内容
-                    file_name=file_name, # 下载的文件名
-                    mime="application/octet-stream" # 设置MIME类型，通用二进制流
-                )
-        except Exception as e:
-            st.error(f"无法读取文件或创建下载链接: {e}") # 显示文件读取或下载链接创建失败的错误信息
+        st.session_state.error_message = f"下载出错：{str(e)}"
+        st.session_state.downloading = False
+        st.session_state.download_complete = False
+
+def start_download_thread(magnet_link):
+    save_path = './downloads'
+    if not os.path.exists(save_path):
+        os.makedirs(save_path)
+    
+    thread = threading.Thread(target=download_torrent, args=(magnet_link, save_path))
+    thread.start()
+
+# 界面布局
+st.title("磁力链接下载器 🧲")
+
+with st.form("magnet_form"):
+    magnet_link = st.text_input("输入磁力链接：", placeholder="magnet:?xt=urn:btih:...")
+    submitted = st.form_submit_button("开始下载")
+
+    if submitted and magnet_link:
+        if st.session_state.downloading:
+            st.warning("当前已有下载任务在进行中")
+        else:
+            # 重置状态
+            st.session_state.download_progress = 0
+            st.session_state.download_complete = False
+            st.session_state.download_filename = None
+            st.session_state.error_message = None
+            st.session_state.downloading = True
+            start_download_thread(magnet_link)
+
+if st.session_state.downloading:
+    st.info("下载状态")
+    progress_col, control_col = st.columns([4, 1])
+    
+    with progress_col:
+        progress_bar = st.progress(int(st.session_state.download_progress))
+        st.write(f"当前进度：{st.session_state.download_progress:.1f}%")
+    
+    with control_col:
+        if st.button("取消下载"):
+            st.session_state.downloading = False
+            st.session_state.download_complete = False
+            st.session_state.error_message = "下载已取消"
+            st.experimental_rerun()
+
+if st.session_state.error_message:
+    st.error(st.session_state.error_message)
+
+if st.session_state.download_complete:
+    st.success("下载完成！✅")
+    if st.session_state.download_filename and os.path.exists(st.session_state.download_filename):
+        file_size = os.path.getsize(st.session_state.download_filename)
+        st.write(f"文件大小：{file_size/1024/1024:.2f} MB")
+        
+        with open(st.session_state.download_filename, "rb") as f:
+            st.download_button(
+                label="下载文件",
+                data=f,
+                file_name=os.path.basename(st.session_state.download_filename),
+                mime="application/octet-stream"
+            )
+    else:
+        st.error("文件不存在，可能下载失败")
+
+# 注意事项提示
+st.markdown("---")
+st.info("""
+**使用说明：**
+1. 输入有效的磁力链接（必须以'magnet:?xt='开头）
+2. 点击开始下载按钮
+3. 下载完成后会出现文件下载按钮
+4. 大文件下载可能需要较长时间，请保持页面开启
+
+**注意：** 下载速度取决于种子可用性和网络环境
+""")