Implement download functionality

- directories are served as a zip-file

interface.py

@@ -1,6 +1,6 @@
 #!/usr/bin/python3
 
-from flask import Flask, render_template, request, redirect
+from flask import Flask, render_template, request, redirect, send_file
 import variables as var
 import util
 import os.path
@@ -149,6 +149,36 @@ def upload():
     else:
         return redirect("./", code=409)
 
+@web.route('/download', methods=["GET"])
+def download():
+    if 'file' in request.args:
+        requested_file = request.args['file']
+        if '../' not in requested_file:
+            folder_path = var.music_folder
+            files = util.get_recursive_filelist_sorted(var.music_folder)
+
+            if requested_file in files:
+                filepath = os.path.join(folder_path, requested_file)
+                try:
+                    return send_file(filepath, as_attachment=True)
+                except Exception as e:
+                    self.log.exception(e)
+                    self.Error(400)
+    elif 'directory' in request.args:
+        requested_dir = request.args['directory']
+        folder_path = var.music_folder
+        requested_dir_fullpath = os.path.abspath(os.path.join(folder_path, requested_dir)) + '/'
+        if requested_dir_fullpath.startswith(folder_path):
+            prefix = secure_filename(os.path.relpath(requested_dir_fullpath, folder_path))
+            zipfile = util.zipdir(requested_dir_fullpath, requested_dir)
+            try:
+                return send_file(zipfile, as_attachment=True)
+            except Exception as e:
+                self.log.exception(e)
+                self.Error(400)
+
+    return redirect("./", code=400)
+
 
 if __name__ == '__main__':
     web.run(port=8181, host="127.0.0.1")

templates/index.html

@@ -29,11 +29,11 @@
                 {% for file in files %}
                 <li class="file">
                     <form method="post" class="file file_add">
-                        <input type="text" value="{{ subdirpath }}/{{ file }}" name="add_file" hidden>
+                        <input type="text" value="{{ subdirpath }}{{ file }}" name="add_file" hidden>
                         <input type="submit" value="Add">
                     </form>
                     <form action="./download" method="get"  class="file file_download">
-                        <input type="text" value="{{ subdirpath }}/{{ file }}" name="file" hidden>
+                        <input type="text" value="{{ subdirpath }}{{ file }}" name="file" hidden>
                         <input type="submit" value="Download">
                         &nbsp;{{ file }}
                     </form>

util.py

@@ -1,8 +1,10 @@
 #!/usr/bin/python3
 
 import configparser
+import hashlib
 import os
 import variables as var
+import zipfile
 
 __CONFIG = configparser.ConfigParser(interpolation=None)
 __CONFIG.read("configuration.ini", encoding='latin-1')
@@ -23,6 +25,36 @@ def get_recursive_filelist_sorted(path):
     filelist.sort()
     return filelist
 
+# - zips all files of the given zippath (must be a directory)
+# - returns the absolute path of the created zip file
+# - zip file will be in the applications tmp folder (according to configuration)
+# - format of the filename itself = prefix_hash.zip
+#       - prefix can be controlled by the caller
+#       - hash is a sha1 of the string representation of the directories' contents (which are
+#           zipped)
+def zipdir(zippath, zipname_prefix=None):
+    zipname = __CONFIG.get('bot', 'tmp_folder')
+    if zipname_prefix and '../' not in zipname_prefix:
+        zipname += zipname_prefix.strip().replace('/', '_') + '_'
+
+    files = get_recursive_filelist_sorted(zippath)
+    hash = hashlib.sha1((str(files).encode())).hexdigest()
+    zipname += hash + '.zip'
+
+    if os.path.exists(zipname):
+        return zipname
+
+    zipf = zipfile.ZipFile(zipname, 'w', zipfile.ZIP_DEFLATED)
+
+    for file in files:
+        filepath = os.path.dirname(file)
+        file_to_add = os.path.join(zippath, file)
+        add_file_as = os.path.relpath(os.path.join(zippath, file), os.path.join(zippath, '..'))
+        zipf.write(file_to_add, add_file_as)
+
+    zipf.close()
+    return zipname
+
 class Dir(object):
     def __init__(self, name):
         self.name = name