Playlist deletion is now possible. Titles that are in multiple playlists get saved from doom. New utils out of necessity.

app.py

@@ -2,7 +2,7 @@ from flask import Flask, current_app, g
 from flask_wtf.csrf import CSRFProtect
 
 from frontend import frontend
-from backend import get_db
+from db_tools import get_db
 from os import urandom
 
 

backend.py

@@ -8,9 +8,20 @@ from urllib.request import urlopen
 from urllib.error import URLError
 from base64 import b64encode
 from threading import Thread
+from shutil import rmtree
 
-from db_tools import *
+from db_tools import (
+    add_new_video_to_collection,
+    query_db,
+    query_db_threaded,
+    db_add_via_update,
+    db_add_via_download,
+    update_playlist_folder_by_rowid,
+    remove_video,
+    remove_playlist
+)
 from file_cache import *
+from utils import downloads_path, dissect_file_name
 
 
 # adds thread to queue and starts it
@@ -79,6 +90,10 @@ def process_download(url, ext, parent, query, current_thread):
             # this throws DownloadError when not downloading playlist
             ydl.YoutubeDL({'quiet': True}).extract_info('https://www.youtube.com/watch?v=' + video['id'],
                                                         download=False)
+
+            # replace url with name of playlist
+            queued_downloads[0][0] = parent
+
             # add new entry to file_cache
             ids.append(video['id'])
             titles.append(video['title'])
@@ -103,6 +118,9 @@ def process_download(url, ext, parent, query, current_thread):
                     add_new_video_to_collection(parent, video['id'])
                     continue
 
+                # replace url with name of channel
+                queued_downloads[0][0] = parent
+
                 # there have been cases of duplicate urls or some with '/watch?v=@channel_name'
                 # but no consistency has been observed
                 # still works though so will not be checked for now
@@ -127,6 +145,9 @@ def process_download(url, ext, parent, query, current_thread):
             titles.append(query['title'])
             urls.append('https://www.youtube.com/watch?v=' + query['id'])
 
+        # replace url with name of video
+        queued_downloads[0][0] = query['title']
+
         # start download
         download_all(url, ext=ext)
 
@@ -134,15 +155,15 @@ def process_download(url, ext, parent, query, current_thread):
     except Exception as e:
         print('*** ' + str(e) + ' ***')
 
-    # todo: a site with (not) finished downloads (url/datetime) would be nice so you know when it's done
-    #  downloading large playlists does take quite a while after all
-
     thread_queue.remove(current_thread)
     return
 
 
 # this is the 'controller' for the update process
 def process_update(parent, query, current_thread):
+    # replace url with name of playlist
+    queued_downloads[0][0] = parent
+
     # if updating playlist
     try:
         # this throws KeyError when downloading single file
@@ -154,6 +175,7 @@ def process_update(parent, query, current_thread):
             # this throws DownloadError when not downloading playlist
             ydl.YoutubeDL({'quiet': True}).extract_info('https://www.youtube.com/watch?v=' + video['id'],
                                                         download=False)
+
             # add new entry to file_cache
             ids.append(video['id'])
             titles.append(video['title'])
@@ -216,7 +238,8 @@ def download_all(url, ext, parent=None):
     if parent is not None:
         # insert new playlist into db and get the rowid of the new entry
         rowid_new = query_db_threaded('INSERT INTO playlist(name, url) VALUES (:name, :url) RETURNING ROWID',
-                                      {'name': parent, 'url': url})[0][0]
+                                      {'name': parent, 'url': url},
+                                      True)[0]
 
         # set the base relative path for playlists
         relativePath = parent + '\\'
@@ -232,7 +255,8 @@ def download_all(url, ext, parent=None):
             if not len(subdirs) > 0:
                 # get rowid of current playlist in 'downloads/parent/' directory
                 parent_rowid = query_db_threaded('SELECT ROWID FROM playlist WHERE name = :playlist',
-                                                 {'playlist': parent})[0][0]
+                                                 {'playlist': parent},
+                                                 True)[0]
 
                 # update previous parents directory
                 query_db_threaded('UPDATE playlist SET folder = :folder WHERE ROWID = :rowid',
@@ -327,12 +351,6 @@ def yt_download(location, ext='mp3'):
     return
 
 
-# a way to get the 'parent_root/downloads' directory; alternative for nonexistent global immutable
-# since app context does not exist where this is called, using app.config will not work
-def downloads_path() -> str:
-    return os.path.dirname(os.path.abspath(__file__)) + '\\downloads\\'
-
-
 # updates zip in or creates new zip of given directory
 def zip_folder(full_rel_path) -> tuple[str, str]:
     # get playlist name
@@ -373,6 +391,7 @@ def zip_folder(full_rel_path) -> tuple[str, str]:
     return full_rel_path, filename
 
 
+# adds all files that are in the playlist but not in its folder to the zip
 def zip_folder_not_in_directory(zip_full_rel_path):
     video_not_in_directory = query_db_threaded('SELECT path, name, ext FROM video '
                                                'INNER JOIN collection ON video.id = collection.video '
@@ -395,6 +414,7 @@ def zip_folder_not_in_directory(zip_full_rel_path):
     return
 
 
+# returns name of first zip found or empty string
 def directory_contains_zip(full_rel_path):
     for file in os.scandir(downloads_path() + full_rel_path):
         if file.name.endswith('.zip'):
@@ -402,9 +422,39 @@ def directory_contains_zip(full_rel_path):
     return ''
 
 
+# checks if yt or any given target can be reached
 def internet_available(target='http://www.youtube.com'):
     try:
         urlopen(target)
         return True
     except URLError:
         return False
+
+
+# does what it says; does not need thread of its own since it's reasonably fast
+def delete_file_or_playlist(file_name):
+    # deleting single download is simple enough
+    if '.' in file_name:
+        remove_video(file_name)
+        os.remove(downloads_path() + file_name)
+        return
+
+    # get folder from file_name
+    folder, _, _ = dissect_file_name(file_name)
+
+    # remove playlist from db and get videos that are also in other playlists
+    # todo: this needs to be tested at some point
+    videos_to_move = remove_playlist(folder)
+
+    # move all videos rescued from being deleted
+    if videos_to_move:
+        for video in videos_to_move:
+            os.rename(
+                downloads_path() + video[0] + video[1] + video[2],
+                downloads_path() + video[1] + video[2]
+            )
+
+    # delete the folder in which the playlist was stored
+    rmtree(downloads_path() + folder)
+    return
+

db_tools.py

@@ -1,6 +1,7 @@
 from flask import g
 import sqlite3
 from file_cache import ids, titles
+from utils import dissect_file_name
 
 
 # fetches db from app context
@@ -92,3 +93,55 @@ def update_playlist_folder_by_rowid(folder, rowid):
     query_db_threaded('UPDATE playlist SET folder = :folder WHERE ROWID = :rowid',
                       {'folder': folder, 'rowid': rowid})
     return
+
+
+# removes a single video
+def remove_video(file_name: str) -> bool:
+    folder, name, ext = dissect_file_name(file_name)
+
+    rowid = query_db('DELETE FROM video '
+                     'WHERE name = :name AND path = :path AND ext = :ext '
+                     'RETURNING ROWID',
+                     {'name': name, 'path': folder, 'ext': ext},
+                     True)
+
+    return True if rowid else False
+
+
+# removes playlist and all contained videos from db
+def remove_playlist(folder):
+    rescued = rescue_videos(folder)
+
+    query_db_threaded('DELETE FROM playlist '
+                      'WHERE folder = :folder',
+                      {'folder': folder})
+
+    query_db_threaded('DELETE FROM collection '
+                      'WHERE playlist = :folder ',
+                      {'folder': folder})
+
+    query_db('DELETE FROM video '
+             'WHERE path = :path ',
+             {'path': folder})
+
+    return rescued
+
+
+# removes videos from the playlist to delete if they are also in other playlists
+# and sets path to download root
+def rescue_videos(folder):
+    videos = query_db('SELECT id, path, name, ext FROM collection '
+                      'LEFT JOIN video ON video = id '
+                      'WHERE NOT path = playlist AND path = :path',
+                      {'path': folder})
+
+    if videos:
+        for video in videos:
+            query_db('UPDATE video SET path = \'\' '
+                     'WHERE id = :id',
+                     {'id': video[0]})
+            query_db('DELETE FROM collection '
+                     'WHERE video = :id AND playlist = :playlist',
+                     {'id': video[0], 'playlist': folder})
+
+    return [(x['path'], x['name'], x['ext']) for x in videos] if videos else None

frontend.py

@@ -4,9 +4,16 @@ from __future__ import unicode_literals
 from flask import Blueprint, request, render_template, flash, send_from_directory, send_file
 
 from forms.download import DownloadForm
-from backend import zip_folder, zip_folder_not_in_directory, downloads_path, enqueue_download, internet_available
+from backend import (
+    zip_folder,
+    zip_folder_not_in_directory,
+    enqueue_download,
+    internet_available,
+    delete_file_or_playlist
+)
 from db_tools import query_db
 from file_cache import *
+from utils import downloads_path, dissect_file_name
 
 frontend = Blueprint('frontend', __name__)
 
@@ -51,52 +58,6 @@ def downloader():
     return render_template('flash-message.html')
 
 
-# downloads a single file
-@frontend.route('/download/<path:file_path>', methods=['GET'])
-def download(file_path):
-    # if the path does not end with a slash, a single file is requested
-    if '.' in file_path:
-        split_path = file_path.split('/')
-        file_folder = ''.join([x if x not in split_path[-1] else '' for x in split_path])
-
-        video = query_db('SELECT path, name, ext FROM video WHERE name = :name AND path = :path',
-                         {
-                             'name': split_path[-1].split('.')[0],
-                             'path': file_folder + '\\' if file_folder else ''
-                         },
-                         True)
-
-        return send_from_directory(
-            downloads_path() + video['path'],
-            video['name'] + video['ext']
-        )
-
-    # else a directory is requested
-    else:
-        zip_path, zip_name = zip_folder(file_path)
-        print(zip_path, zip_name)
-        zip_folder_not_in_directory(zip_path + zip_name)
-
-        # zip and send
-        return send_from_directory(
-            downloads_path() + zip_path,
-            zip_name
-        )
-
-
-@frontend.route('/update/<int:url_rowid>', methods=['GET'])
-def update(url_rowid):
-    url = query_db('SELECT url FROM playlist WHERE ROWID = :url_rowid',
-                   {'url_rowid': url_rowid})[0][0]
-
-    # kick off download process
-    enqueue_download(url, update=True)
-
-    # show download start confirmation
-    flash('Update enqueued and will finish in background.', 'primary')
-    return render_template('flash-message.html', titles=titles, urls=urls, amount=len(urls))
-
-
 @frontend.route('/library', methods=['GET'])
 def library():
     videos = query_db("SELECT name, ext, path FROM video "
@@ -105,6 +66,8 @@ def library():
     if not playlists and not videos:
         flash('Library ist currently empty. Try downloading something!', 'primary')
 
+    # todo: searching your library for a song would be nice
+
     return render_template('library.html', videos=videos, playlists=playlists, amount=len(playlists))
 
 
@@ -127,6 +90,62 @@ def library_playlist():
     return render_template('collection.html', videos=videos, folder=folder)
 
 
+# sends file or playlist to client
+@frontend.route('/download/<path:file_path>', methods=['GET'])
+def download(file_path):
+    # if the path does not end with a slash, a single file is requested
+    if '.' in file_path:
+        path, name, _ = dissect_file_name(file_path)
+
+        video = query_db('SELECT path, name, ext FROM video WHERE name = :name AND path = :path',
+                         {'name': name, 'path': path},
+                         True)
+
+        return send_from_directory(
+            downloads_path() + video['path'],
+            video['name'] + video['ext']
+        )
+
+    # else a directory is requested
+    else:
+        zip_path, zip_name = zip_folder(file_path)
+        print(zip_path, zip_name)
+        zip_folder_not_in_directory(zip_path + zip_name)
+
+        # zip and send
+        return send_from_directory(
+            downloads_path() + zip_path,
+            zip_name
+        )
+
+
+@frontend.route('/delete/<path:file_name>', methods=['GET'])
+def delete(file_name):
+    delete_file_or_playlist(file_name)
+
+    if '.' in file_name:
+        flash('File has been deleted.', 'primary')
+    else:
+        flash('Playlist has been deleted.', 'primary')
+
+    return render_template('flash-message.html')
+
+
+@frontend.route('/update/<int:url_rowid>', methods=['GET'])
+def update(url_rowid):
+    url = query_db('SELECT url FROM playlist WHERE ROWID = :url_rowid',
+                   {'url_rowid': url_rowid})[0][0]
+
+    # kick off download process
+    enqueue_download(url, update=True)
+
+    # show download start confirmation
+    flash('Update enqueued and will finish in background.', 'primary')
+    return render_template('flash-message.html', titles=titles, urls=urls, amount=len(urls))
+
+
+# player as well as serve are placeholders for now
+# todo: add functionality to library
 @frontend.route('/player', methods=['GET'])
 def player():
     return render_template('video-player.html')

templates/collection.html

@@ -25,6 +25,9 @@
             </div>
         </div>
         <div class="container" style="padding: 1.5%">
+            <form action="/delete/{{ folder }}">
+                <input type="submit" class="btn btn-danger float-start" value="Delete playlist">
+            </form>
             <form action="/download/{{ folder }}">
                 <input type="submit" class="btn btn-primary float-end" value="Download all"/>
             </form>

utils.py

@@ -0,0 +1,19 @@
+import os.path as path
+
+
+# a way to get the 'parent_root/downloads' directory; alternative for nonexistent global immutable
+# since app context does not exist where this is called, using app.config will not work
+def downloads_path() -> str:
+    return path.dirname(path.abspath(__file__)) + '\\downloads\\'
+
+
+# dissects a given full path to a file into its components
+def dissect_file_name(file_name: str) -> tuple[str, str, str]:
+    split_path = file_name.replace('/', '\\').split('\\')
+    full_name = split_path[-1].split('.')
+
+    folder = ''.join([x + '\\' if x and '.' not in x else '' for x in split_path])
+    name = full_name[0] if full_name[0] else ''
+    ext = '.' + full_name[1] if full_name[0] else ''
+
+    return folder, name, ext