新增下载接口

main.py

@@ -1,4 +1,4 @@
-from flask import Flask, jsonify, request, redirect
+from flask import Flask, jsonify, request, redirect, send_file
 from datetime import datetime, date
 import ipaddress
 from zoneinfo import ZoneInfo, available_timezones
@@ -113,6 +113,7 @@ a:hover{text-decoration:underline;}</style>
 <tr><td>时间接口</td><td><a href="/time/api">/time/api</a></td><td><a href="/time/help">/time/help</a></td></tr>
 <tr><td>谜语接口</td><td><a href="/riddle/api">/riddle/api</a></td><td><a href="/riddle/help">/riddle/help</a></td></tr>
 <tr><td>期刊接口</td><td><a href="/sci/api">/sci/api</a></td><td><a href="/sci/help">/sci/help</a></td></tr>
+<tr><td>下载接口</td><td><a href="/pan/api">/pan/api</a></td><td><a href="/pan/help">/pan/help</a></td></tr>
 </tbody></table></body></html>
 """
 
@@ -583,6 +584,70 @@ def sci():
     return jsonify(resp)
 
 
+@app.route("/pan/help")
+def pan_help():
+    return jsonify({
+        "路径": "/pan/api",
+        "功能": "下载文件", 
+        "参数": {
+            "name=xxx": "必填，文件名",
+            "download=true/false": "下载/预览",
+            },
+        "列表": ["anian-music.js"]
+    })
+
+@app.route("/pan/api")
+def pan_file_download():
+    args_lower = {k.lower(): v for k, v in request.args.items()}
+    allowed_keys = {"name", "download"}
+    extra_params = set(args_lower.keys()) - allowed_keys
+    if extra_params:
+        return jsonify({
+            "error": f"{extra_params}参数非法",
+            "allowed_params": ["name=xxx", "download=true/false"],
+        })
+    file_name = args_lower.get("name", "").strip()
+    download_param = args_lower.get("download", "").strip()
+    if download_param and download_param.lower() not in {"true", "false"}:
+        resp = {
+            "error": f"download参数[{download_param}]不为true/false",
+            "params": {"name": file_name, "download": download_param}
+        }
+        return jsonify(resp)
+    force_download = download_param.lower() == "true"
+    params = {"name": file_name, "download": download_param if download_param else "false(默认)"}
+    if not file_name:
+        resp = {
+            "error": "name参数不能为空",
+            "params": params
+        }
+        return jsonify(resp)
+    pan_dir = Path(__file__).parent / "data" / "pan"
+    target_file = pan_dir / file_name
+    real_pan = pan_dir.resolve()
+    real_target = target_file.resolve()
+    if not str(real_target).startswith(str(real_pan)):
+        resp = {
+            "error": "文件名非法",
+            "params": params
+        }
+        return jsonify(resp)
+    if not target_file.is_file():
+        resp = {
+            "error": f"文件 {file_name} 不存在",
+            "help": "请前往/pan/help查看文件列表",
+            "params": params
+        }
+        return jsonify(resp)
+
+    # 在线预览/播放核心：as_attachment=False
+    return send_file(
+        target_file,
+        as_attachment=force_download,
+        download_name=file_name
+    )
+
+
 @app.errorhandler(404)
 def not_found(_error):
     return redirect("/"), 302