Update multipart_downloader.py

src/core/workers.py

@@ -410,6 +410,39 @@ class PostProcessorWorker:
         unique_id_for_part_file = uuid.uuid4().hex[:8]
         unique_part_file_stem_on_disk = f"{temp_file_base_for_unique_part}_{unique_id_for_part_file}"
         max_retries = 3
+        if not self.keep_in_post_duplicates:
+            final_save_path_check = os.path.join(target_folder_path, filename_to_save_in_main_path)
+            if os.path.exists(final_save_path_check):
+                try:
+                    # Use a HEAD request to get the expected size without downloading the body
+                    with requests.head(file_url, headers=headers, timeout=15, cookies=cookies_to_use_for_file, allow_redirects=True) as head_response:
+                        head_response.raise_for_status()
+                        expected_size = int(head_response.headers.get('Content-Length', -1))
+                    
+                    actual_size = os.path.getsize(final_save_path_check)
+
+                    if expected_size != -1 and actual_size == expected_size:
+                        self.logger(f"   -> Skip (File Exists & Complete): '{filename_to_save_in_main_path}' is already on disk with the correct size.")
+                        
+                        # We still need to add its hash to the session to prevent duplicates in other modes
+                        # This is a quick hash calculation for the already existing file
+                        try:
+                            md5_hasher = hashlib.md5()
+                            with open(final_save_path_check, 'rb') as f_verify:
+                                for chunk in iter(lambda: f_verify.read(8192), b""):
+                                    md5_hasher.update(chunk)
+                            
+                            with self.downloaded_hash_counts_lock:
+                                self.downloaded_hash_counts[md5_hasher.hexdigest()] += 1
+                        except Exception as hash_exc:
+                             self.logger(f"   ⚠️ Could not hash existing file '{filename_to_save_in_main_path}' for session: {hash_exc}")
+
+                        return 0, 1, filename_to_save_in_main_path, was_original_name_kept_flag, FILE_DOWNLOAD_STATUS_SKIPPED, None
+                    else:
+                        self.logger(f"   ⚠️ File '{filename_to_save_in_main_path}' exists but is incomplete (Expected: {expected_size}, Actual: {actual_size}). Re-downloading.")
+
+                except requests.RequestException as e:
+                    self.logger(f"   ⚠️ Could not verify size of existing file '{filename_to_save_in_main_path}': {e}. Proceeding with download.")
         retry_delay = 5
         downloaded_size_bytes = 0
         calculated_file_hash = None
@@ -741,8 +774,11 @@ class PostProcessorWorker:
             history_data_for_this_post = None
 
             parsed_api_url = urlparse(self.api_url_input)
-            referer_url = f"https://{parsed_api_url.netloc}/"
-            headers = {'User-Agent': 'Mozilla/5.0', 'Referer': referer_url, 'Accept': '*/*'}
+            post_data = self.post
+            post_id = post_data.get('id', 'unknown_id')
+
+            post_page_url = f"https://{parsed_api_url.netloc}/{self.service}/user/{self.user_id}/post/{post_id}"
+            headers = {'User-Agent': 'Mozilla/5.0', 'Referer': post_page_url, 'Accept': '*/*'}
             link_pattern = re.compile(r"""<a\s+.*?href=["'](https?://[^"']+)["'][^>]*>(.*?)</a>""", re.IGNORECASE | re.DOTALL)
             post_data = self.post
             post_title = post_data.get('title', '') or 'untitled_post'
@@ -752,6 +788,17 @@ class PostProcessorWorker:
 
             effective_unwanted_keywords_for_folder_naming = self.unwanted_keywords.copy()
             is_full_creator_download_no_char_filter = not self.target_post_id_from_initial_url and not current_character_filters
+           
+            if (self.show_external_links or self.extract_links_only):
+                embed_data = post_data.get('embed')
+                if isinstance(embed_data, dict) and embed_data.get('url'):
+                    embed_url = embed_data['url']
+                    embed_subject = embed_data.get('subject', embed_url) # Use subject as link text, fallback to URL
+                    platform = get_link_platform(embed_url)
+                    
+                    self.logger(f"   🔗 Found embed link: {embed_url}")
+                    self._emit_signal('external_link', post_title, embed_subject, embed_url, platform, "")
+           
             if is_full_creator_download_no_char_filter and self.creator_download_folder_ignore_words:
                 self.logger(f"   Applying creator download specific folder ignore words ({len(self.creator_download_folder_ignore_words)} words).")
                 effective_unwanted_keywords_for_folder_naming.update(self.creator_download_folder_ignore_words)
@@ -791,7 +838,7 @@ class PostProcessorWorker:
             all_files_from_post_api_for_char_check = []
             api_file_domain_for_char_check = urlparse(self.api_url_input).netloc
             if not api_file_domain_for_char_check or not any(d in api_file_domain_for_char_check.lower() for d in ['kemono.su', 'kemono.party', 'kemono.cr', 'coomer.su', 'coomer.party', 'coomer.st']):
-                api_file_domain_for_char_check = "kemono.su" if "kemono" in self.service.lower() else "coomer.st"
+                api_file_domain_for_char_check = "kemono.cr" if "kemono" in self.service.lower() else "coomer.st"
             if post_main_file_info and isinstance(post_main_file_info, dict) and post_main_file_info.get('path'):
                 original_api_name = post_main_file_info.get('name') or os.path.basename(post_main_file_info['path'].lstrip('/'))
                 if original_api_name:
@@ -834,9 +881,9 @@ class PostProcessorWorker:
                     try:
                         parsed_input_url_for_comments = urlparse(self.api_url_input)
                         api_domain_for_comments = parsed_input_url_for_comments.netloc
-                        if not any(d in api_domain_for_comments.lower() for d in ['kemono.su', 'kemono.party', 'coomer.su', 'coomer.party']):
+                        if not any(d in api_domain_for_comments.lower() for d in ['kemono.su', 'kemono.party', 'kemono.cr', 'coomer.su', 'coomer.party', 'coomer.st']):
                             self.logger(f"⚠️ Unrecognized domain '{api_domain_for_comments}' for comment API. Defaulting based on service.")
-                            api_domain_for_comments = "kemono.su" if "kemono" in self.service.lower() else "coomer.party"
+                            api_domain_for_comments = "kemono.cr" if "kemono" in self.service.lower() else "coomer.st"
                         comments_data = fetch_post_comments(
                             api_domain_for_comments, self.service, self.user_id, post_id,
                             headers, self.logger, self.cancellation_event, self.pause_event,
@@ -1321,7 +1368,7 @@ class PostProcessorWorker:
             all_files_from_post_api = []
             api_file_domain = urlparse(self.api_url_input).netloc
             if not api_file_domain or not any(d in api_file_domain.lower() for d in ['kemono.su', 'kemono.party', 'kemono.cr', 'coomer.su', 'coomer.party', 'coomer.st']):
-                api_file_domain = "kemono.su" if "kemono" in self.service.lower() else "coomer.st"
+                api_file_domain = "kemono.cr" if "kemono" in self.service.lower() else "coomer.st"
             if post_main_file_info and isinstance(post_main_file_info, dict) and post_main_file_info.get('path'):
                 file_path = post_main_file_info['path'].lstrip('/')
                 original_api_name = post_main_file_info.get('name') or os.path.basename(file_path)

src/services/drive_downloader.py

@@ -3,15 +3,19 @@ import os
 import re
 import traceback
 import json
+import base64
+import time
 from urllib.parse import urlparse, urlunparse, parse_qs, urlencode
 
 # --- Third-Party Library Imports ---
+# Make sure to install these: pip install requests pycryptodome gdown
 import requests
+
 try:
-    from mega import Mega
-    MEGA_AVAILABLE = True
+    from Crypto.Cipher import AES
+    PYCRYPTODOME_AVAILABLE = True
 except ImportError:
-    MEGA_AVAILABLE = False
+    PYCRYPTODOME_AVAILABLE = False
 
 try:
     import gdown
@@ -19,17 +23,15 @@ try:
 except ImportError:
     GDRIVE_AVAILABLE = False
 
-# --- Helper Functions ---
+# --- Constants ---
+MEGA_API_URL = "https://g.api.mega.co.nz"
+
+# --- Helper Functions (Original and New) ---
 
 def _get_filename_from_headers(headers):
     """
     Extracts a filename from the Content-Disposition header.
-
-    Args:
-        headers (dict): A dictionary of HTTP response headers.
-
-    Returns:
-        str or None: The extracted filename, or None if not found.
+    (This is from your original file and is kept for Dropbox downloads)
     """
     cd = headers.get('content-disposition')
     if not cd:
@@ -37,64 +39,180 @@ def _get_filename_from_headers(headers):
     
     fname_match = re.findall('filename="?([^"]+)"?', cd)
     if fname_match:
-        # Sanitize the filename to prevent directory traversal issues
-        # and remove invalid characters for most filesystems.
         sanitized_name = re.sub(r'[<>:"/\\|?*]', '_', fname_match[0].strip())
         return sanitized_name
         
     return None
 
-# --- Main Service Downloader Functions ---
+# --- NEW: Helper functions for Mega decryption ---
+
+def urlb64_to_b64(s):
+    """Converts a URL-safe base64 string to a standard base64 string."""
+    s = s.replace('-', '+').replace('_', '/')
+    s += '=' * (-len(s) % 4)
+    return s
+
+def b64_to_bytes(s):
+    """Decodes a URL-safe base64 string to bytes."""
+    return base64.b64decode(urlb64_to_b64(s))
+
+def bytes_to_hex(b):
+    """Converts bytes to a hex string."""
+    return b.hex()
+
+def hex_to_bytes(h):
+    """Converts a hex string to bytes."""
+    return bytes.fromhex(h)
+
+def hrk2hk(hex_raw_key):
+    """Derives the final AES key from the raw key components for Mega."""
+    key_part1 = int(hex_raw_key[0:16], 16)
+    key_part2 = int(hex_raw_key[16:32], 16)
+    key_part3 = int(hex_raw_key[32:48], 16)
+    key_part4 = int(hex_raw_key[48:64], 16)
+    
+    final_key_part1 = key_part1 ^ key_part3
+    final_key_part2 = key_part2 ^ key_part4
+    
+    return f'{final_key_part1:016x}{final_key_part2:016x}'
+
+def decrypt_at(at_b64, key_bytes):
+    """Decrypts the 'at' attribute to get file metadata."""
+    at_bytes = b64_to_bytes(at_b64)
+    iv = b'\0' * 16
+    cipher = AES.new(key_bytes, AES.MODE_CBC, iv)
+    decrypted_at = cipher.decrypt(at_bytes)
+    return decrypted_at.decode('utf-8').strip('\0').replace('MEGA', '')
+
+# --- NEW: Core Logic for Mega Downloads ---
+
+def get_mega_file_info(file_id, file_key, session, logger_func):
+    """Fetches file metadata and the temporary download URL from the Mega API."""
+    try:
+        hex_raw_key = bytes_to_hex(b64_to_bytes(file_key))
+        hex_key = hrk2hk(hex_raw_key)
+        key_bytes = hex_to_bytes(hex_key)
+
+        # Request file attributes
+        payload = [{"a": "g", "p": file_id}]
+        response = session.post(f"{MEGA_API_URL}/cs", json=payload, timeout=20)
+        response.raise_for_status()
+        res_json = response.json()
+
+        if isinstance(res_json, list) and isinstance(res_json[0], int) and res_json[0] < 0:
+            logger_func(f"   [Mega] ❌ API Error: {res_json[0]}. The link may be invalid or removed.")
+            return None
+
+        file_size = res_json[0]['s']
+        at_b64 = res_json[0]['at']
+
+        # Decrypt attributes to get the file name
+        at_dec_json_str = decrypt_at(at_b64, key_bytes)
+        at_dec_json = json.loads(at_dec_json_str)
+        file_name = at_dec_json['n']
+
+        # Request the temporary download URL
+        payload = [{"a": "g", "g": 1, "p": file_id}]
+        response = session.post(f"{MEGA_API_URL}/cs", json=payload, timeout=20)
+        response.raise_for_status()
+        res_json = response.json()
+        dl_temp_url = res_json[0]['g']
+
+        return {
+            'file_name': file_name,
+            'file_size': file_size,
+            'dl_url': dl_temp_url,
+            'hex_raw_key': hex_raw_key
+        }
+    except (requests.RequestException, json.JSONDecodeError, KeyError, ValueError) as e:
+        logger_func(f"   [Mega] ❌ Failed to get file info: {e}")
+        return None
+
+def download_and_decrypt_mega_file(info, download_path, logger_func):
+    """Downloads the file and decrypts it chunk by chunk, reporting progress."""
+    file_name = info['file_name']
+    file_size = info['file_size']
+    dl_url = info['dl_url']
+    hex_raw_key = info['hex_raw_key']
+
+    final_path = os.path.join(download_path, file_name)
+
+    if os.path.exists(final_path) and os.path.getsize(final_path) == file_size:
+        logger_func(f"   [Mega] ℹ️ File '{file_name}' already exists with the correct size. Skipping.")
+        return
+
+    # Prepare for decryption
+    key = hex_to_bytes(hrk2hk(hex_raw_key))
+    iv_hex = hex_raw_key[32:48] + '0000000000000000'
+    iv_bytes = hex_to_bytes(iv_hex)
+    cipher = AES.new(key, AES.MODE_CTR, initial_value=iv_bytes, nonce=b'')
+
+    try:
+        with requests.get(dl_url, stream=True, timeout=(15, 300)) as r:
+            r.raise_for_status()
+            downloaded_bytes = 0
+            last_log_time = time.time()
+            
+            with open(final_path, 'wb') as f:
+                for chunk in r.iter_content(chunk_size=8192):
+                    if not chunk:
+                        continue
+                    decrypted_chunk = cipher.decrypt(chunk)
+                    f.write(decrypted_chunk)
+                    downloaded_bytes += len(chunk)
+                    
+                    # Log progress every second
+                    current_time = time.time()
+                    if current_time - last_log_time > 1:
+                        progress_percent = (downloaded_bytes / file_size) * 100 if file_size > 0 else 0
+                        logger_func(f"   [Mega] Downloading '{file_name}': {downloaded_bytes/1024/1024:.2f}MB / {file_size/1024/1024:.2f}MB ({progress_percent:.1f}%)")
+                        last_log_time = current_time
+        
+        logger_func(f"   [Mega] ✅ Successfully downloaded '{file_name}' to '{download_path}'")
+    except requests.RequestException as e:
+        logger_func(f"   [Mega] ❌ Download failed for '{file_name}': {e}")
+    except IOError as e:
+        logger_func(f"   [Mega] ❌ Could not write to file '{final_path}': {e}")
+    except Exception as e:
+        logger_func(f"   [Mega] ❌ An unexpected error occurred during download/decryption: {e}")
+
+
+# --- REPLACEMENT Main Service Downloader Function for Mega ---
 
 def download_mega_file(mega_url, download_path, logger_func=print):
     """
-    Downloads a file from a Mega.nz URL.
-    Handles both public links and links that include a decryption key.
+    Downloads a file from a Mega.nz URL using direct requests and decryption.
+    This replaces the old mega.py implementation.
     """
-    if not MEGA_AVAILABLE:
-        logger_func("❌ Mega download failed: 'mega.py' library is not installed.")
+    if not PYCRYPTODOME_AVAILABLE:
+        logger_func("❌ Mega download failed: 'pycryptodome' library is not installed. Please run: pip install pycryptodome")
         return
 
-    logger_func(f"   [Mega] Initializing Mega client...")
-    try:
-        mega = Mega()
-        # Anonymous login is sufficient for public links
-        m = mega.login()
+    logger_func(f"   [Mega] Initializing download for: {mega_url}")
+    
+    # Regex to capture file ID and key from both old and new URL formats
+    match = re.search(r'mega(?:\.co)?\.nz/(?:file/|#!)?([a-zA-Z0-9]+)(?:#|!)([a-zA-Z0-9_.-]+)', mega_url)
+    if not match:
+        logger_func(f"   [Mega] ❌ Error: Invalid Mega URL format.")
+        return
+        
+    file_id = match.group(1)
+    file_key = match.group(2)
 
-        # --- MODIFIED PART: Added error handling for invalid links ---
-        try:
-            file_details = m.find(mega_url)
-            if file_details is None:
-                logger_func(f"   [Mega] ❌ Download failed. The link appears to be invalid or has been taken down: {mega_url}")
-                return
-        except (ValueError, json.JSONDecodeError) as e:
-            # This block catches the "Expecting value" error
-            logger_func(f"   [Mega] ❌ Download failed. The link is likely invalid or expired. Error: {e}")
-            return
-        except Exception as e:
-            # Catch other potential errors from the mega.py library
-            logger_func(f"   [Mega] ❌ An unexpected error occurred trying to access the link: {e}")
-            return
-        # --- END OF MODIFIED PART ---
+    session = requests.Session()
+    session.headers.update({'User-Agent': 'Kemono-Downloader-PyQt/1.0'})
+    
+    file_info = get_mega_file_info(file_id, file_key, session, logger_func)
+    if not file_info:
+        logger_func(f"   [Mega] ❌ Failed to get file info. The link may be invalid or expired. Aborting.")
+        return
 
-        filename = file_details[1]['a']['n']
-        logger_func(f"   [Mega] File found: '{filename}'. Starting download...")
+    logger_func(f"   [Mega] File found: '{file_info['file_name']}' (Size: {file_info['file_size'] / 1024 / 1024:.2f} MB)")
+    
+    download_and_decrypt_mega_file(file_info, download_path, logger_func)
 
-        # Sanitize filename before saving
-        safe_filename = "".join([c for c in filename if c.isalpha() or c.isdigit() or c in (' ', '.', '_', '-')]).rstrip()
-        final_path = os.path.join(download_path, safe_filename)
 
-        # Check if file already exists
-        if os.path.exists(final_path):
-            logger_func(f"   [Mega] ℹ️ File '{safe_filename}' already exists. Skipping download.")
-            return
-
-        # Start the download
-        m.download_url(mega_url, dest_path=download_path, dest_filename=safe_filename)
-        logger_func(f"   [Mega] ✅ Successfully downloaded '{safe_filename}' to '{download_path}'")
-
-    except Exception as e:
-        logger_func(f"   [Mega] ❌ An unexpected error occurred during the Mega download process: {e}")
+# --- ORIGINAL Functions for Google Drive and Dropbox (Unchanged) ---
 
 def download_gdrive_file(url, download_path, logger_func=print):
     """Downloads a file from a Google Drive link."""
@@ -103,12 +221,9 @@ def download_gdrive_file(url, download_path, logger_func=print):
         return
     try:
         logger_func(f"   [G-Drive] Starting download for: {url}")
-        # --- MODIFIED PART: Added a message and set quiet=True ---
         logger_func("   [G-Drive] Download in progress... This may take some time. Please wait.")
         
-        # By setting quiet=True, the progress bar will no longer be printed to the terminal.
         output_path = gdown.download(url, output=download_path, quiet=True, fuzzy=True)
-        # --- END OF MODIFIED PART ---
         
         if output_path and os.path.exists(output_path):
             logger_func(f"   [G-Drive] ✅ Successfully downloaded to '{output_path}'")
@@ -120,15 +235,9 @@ def download_gdrive_file(url, download_path, logger_func=print):
 def download_dropbox_file(dropbox_link, download_path=".", logger_func=print):
     """
     Downloads a file from a public Dropbox link by modifying the URL for direct download.
-
-    Args:
-        dropbox_link (str): The public Dropbox link to the file.
-        download_path (str): The directory to save the downloaded file.
-        logger_func (callable): Function to use for logging.
     """
     logger_func(f"   [Dropbox] Attempting to download: {dropbox_link}")
     
-    # Modify the Dropbox URL to force a direct download instead of showing the preview page.
     parsed_url = urlparse(dropbox_link)
     query_params = parse_qs(parsed_url.query)
     query_params['dl'] = ['1']
@@ -145,13 +254,11 @@ def download_dropbox_file(dropbox_link, download_path=".", logger_func=print):
         with requests.get(direct_download_url, stream=True, allow_redirects=True, timeout=(10, 300)) as r:
             r.raise_for_status()
             
-            # Determine filename from headers or URL
             filename = _get_filename_from_headers(r.headers) or os.path.basename(parsed_url.path) or "dropbox_file"
             full_save_path = os.path.join(download_path, filename)
             
             logger_func(f"   [Dropbox] Starting download of '{filename}'...")
             
-            # Write file to disk in chunks
             with open(full_save_path, 'wb') as f:
                 for chunk in r.iter_content(chunk_size=8192):
                     f.write(chunk)

src/services/multipart_downloader.py

@@ -1,4 +1,5 @@
 # --- Standard Library Imports ---
+# --- Standard Library Imports ---
 import os
 import time
 import hashlib
@@ -10,27 +11,49 @@ from concurrent.futures import ThreadPoolExecutor, as_completed
 
 # --- Third-Party Library Imports ---
 import requests
+MULTIPART_DOWNLOADER_AVAILABLE = True
 
 # --- Module Constants ---
 CHUNK_DOWNLOAD_RETRY_DELAY = 2
 MAX_CHUNK_DOWNLOAD_RETRIES = 1
 DOWNLOAD_CHUNK_SIZE_ITER = 1024 * 256  # 256 KB per iteration chunk
 
-# Flag to indicate if this module and its dependencies are available.
-MULTIPART_DOWNLOADER_AVAILABLE = True
-
 
 def _download_individual_chunk(
-    chunk_url, temp_file_path, start_byte, end_byte, headers,
+    chunk_url, chunk_temp_file_path, start_byte, end_byte, headers,
     part_num, total_parts, progress_data, cancellation_event,
     skip_event, pause_event, global_emit_time_ref, cookies_for_chunk,
     logger_func, emitter=None, api_original_filename=None
 ):
     """
-    Downloads a single segment (chunk) of a larger file. This function is
-    intended to be run in a separate thread by a ThreadPoolExecutor.
+    Downloads a single segment (chunk) of a larger file to its own unique part file.
+    This function is intended to be run in a separate thread by a ThreadPoolExecutor.
 
-    It handles retries, pauses, and cancellations for its specific chunk.
+    It handles retries, pauses, and cancellations for its specific chunk. If a
+    download fails, the partial chunk file is removed, allowing a clean retry later.
+
+    Args:
+        chunk_url (str): The URL to download the file from.
+        chunk_temp_file_path (str): The unique path to save this specific chunk
+                                    (e.g., 'my_video.mp4.part0').
+        start_byte (int): The starting byte for the Range header.
+        end_byte (int): The ending byte for the Range header.
+        headers (dict): The HTTP headers to use for the request.
+        part_num (int): The index of this chunk (e.g., 0 for the first part).
+        total_parts (int): The total number of chunks for the entire file.
+        progress_data (dict): A thread-safe dictionary for sharing progress.
+        cancellation_event (threading.Event): Event to signal cancellation.
+        skip_event (threading.Event): Event to signal skipping the file.
+        pause_event (threading.Event): Event to signal pausing the download.
+        global_emit_time_ref (list): A mutable list with one element (a timestamp)
+                                     to rate-limit UI updates.
+        cookies_for_chunk (dict): Cookies to use for the request.
+        logger_func (function): A function to log messages.
+        emitter (queue.Queue or QObject): Emitter for sending progress to the UI.
+        api_original_filename (str): The original filename for UI display.
+
+    Returns:
+        tuple: A tuple containing (bytes_downloaded, success_flag).
     """
     # --- Pre-download checks for control events ---
     if cancellation_event and cancellation_event.is_set():
@@ -48,18 +71,16 @@ def _download_individual_chunk(
             time.sleep(0.2)
         logger_func(f"   [Chunk {part_num + 1}/{total_parts}] Download resumed.")
 
-    # --- START: FIX ---
     # Set this chunk's status to 'active' before starting the download.
     with progress_data['lock']:
         progress_data['chunks_status'][part_num]['active'] = True
-    # --- END: FIX ---
 
     try:
         # Prepare headers for the specific byte range of this chunk
         chunk_headers = headers.copy()
         if end_byte != -1:
             chunk_headers['Range'] = f"bytes={start_byte}-{end_byte}"
-        
+
         bytes_this_chunk = 0
         last_speed_calc_time = time.time()
         bytes_at_last_speed_calc = 0
@@ -77,13 +98,14 @@ def _download_individual_chunk(
                     bytes_at_last_speed_calc = bytes_this_chunk
 
                 logger_func(f"   🚀 [Chunk {part_num + 1}/{total_parts}] Starting download: bytes {start_byte}-{end_byte if end_byte != -1 else 'EOF'}")
-                
+
                 response = requests.get(chunk_url, headers=chunk_headers, timeout=(10, 120), stream=True, cookies=cookies_for_chunk)
                 response.raise_for_status()
 
                 # --- Data Writing Loop ---
-                with open(temp_file_path, 'r+b') as f:
-                    f.seek(start_byte)
+                # We open the unique chunk file in write-binary ('wb') mode.
+                # No more seeking is required.
+                with open(chunk_temp_file_path, 'wb') as f:
                     for data_segment in response.iter_content(chunk_size=DOWNLOAD_CHUNK_SIZE_ITER):
                         if cancellation_event and cancellation_event.is_set():
                             return bytes_this_chunk, False
@@ -98,12 +120,12 @@ def _download_individual_chunk(
                         if data_segment:
                             f.write(data_segment)
                             bytes_this_chunk += len(data_segment)
-                            
+
                             # Update shared progress data structure
                             with progress_data['lock']:
                                 progress_data['total_downloaded_so_far'] += len(data_segment)
                                 progress_data['chunks_status'][part_num]['downloaded'] = bytes_this_chunk
-                                
+
                                 # Calculate and update speed for this chunk
                                 current_time = time.time()
                                 time_delta = current_time - last_speed_calc_time
@@ -113,7 +135,7 @@ def _download_individual_chunk(
                                     progress_data['chunks_status'][part_num]['speed_bps'] = current_speed_bps
                                     last_speed_calc_time = current_time
                                     bytes_at_last_speed_calc = bytes_this_chunk
-                                
+
                                 # Emit progress signal to the UI via the queue
                                 if emitter and (current_time - global_emit_time_ref[0] > 0.25):
                                     global_emit_time_ref[0] = current_time
@@ -122,7 +144,8 @@ def _download_individual_chunk(
                                         emitter.put({'type': 'file_progress', 'payload': (api_original_filename, status_list_copy)})
                                     elif hasattr(emitter, 'file_progress_signal'):
                                         emitter.file_progress_signal.emit(api_original_filename, status_list_copy)
-                
+
+                # If we get here, the download for this chunk is successful
                 return bytes_this_chunk, True
 
             except (requests.exceptions.ConnectionError, requests.exceptions.Timeout, http.client.IncompleteRead) as e:
@@ -134,8 +157,10 @@ def _download_individual_chunk(
                 logger_func(f"   ❌ [Chunk {part_num + 1}/{total_parts}] Unexpected error: {e}\n{traceback.format_exc(limit=1)}")
                 return bytes_this_chunk, False
 
+        # If the retry loop finishes without a successful download
         return bytes_this_chunk, False
     finally:
+        # This block runs whether the download succeeded or failed
         with progress_data['lock']:
             progress_data['chunks_status'][part_num]['active'] = False
             progress_data['chunks_status'][part_num]['speed_bps'] = 0.0
@@ -144,17 +169,37 @@ def _download_individual_chunk(
 def download_file_in_parts(file_url, save_path, total_size, num_parts, headers, api_original_filename,
                            emitter_for_multipart, cookies_for_chunk_session,
                            cancellation_event, skip_event, logger_func, pause_event):
-    logger_func(f"⬇️ Initializing Multi-part Download ({num_parts} parts) for: '{api_original_filename}' (Size: {total_size / (1024*1024):.2f} MB)")
-    temp_file_path = save_path + ".part"
+    """
+    Manages a resilient, multipart file download by saving each chunk to a separate file.
 
-    try:
-        with open(temp_file_path, 'wb') as f_temp:
-            if total_size > 0:
-                f_temp.truncate(total_size)
-    except IOError as e:
-        logger_func(f"   ❌ Error creating/truncating temp file '{temp_file_path}': {e}")
-        return False, 0, None, None
+    This function orchestrates the download process by:
+    1. Checking for already completed chunk files to resume a previous download.
+    2. Submitting only the missing chunks to a thread pool for parallel download.
+    3. Assembling the final file from the individual chunks upon successful completion.
+    4. Cleaning up temporary chunk files after assembly.
+    5. Leaving completed chunks on disk if the download fails, allowing for a future resume.
 
+    Args:
+        file_url (str): The URL of the file to download.
+        save_path (str): The final desired path for the downloaded file (e.g., 'my_video.mp4').
+        total_size (int): The total size of the file in bytes.
+        num_parts (int): The number of parts to split the download into.
+        headers (dict): HTTP headers for the download requests.
+        api_original_filename (str): The original filename for UI progress display.
+        emitter_for_multipart (queue.Queue or QObject): Emitter for UI signals.
+        cookies_for_chunk_session (dict): Cookies for the download requests.
+        cancellation_event (threading.Event): Event to signal cancellation.
+        skip_event (threading.Event): Event to signal skipping the file.
+        logger_func (function): A function for logging messages.
+        pause_event (threading.Event): Event to signal pausing the download.
+
+    Returns:
+        tuple: A tuple containing (success_flag, total_bytes_downloaded, md5_hash, file_handle).
+               The file_handle will be for the final assembled file if successful, otherwise None.
+    """
+    logger_func(f"⬇️ Initializing Resumable Multi-part Download ({num_parts} parts) for: '{api_original_filename}' (Size: {total_size / (1024*1024):.2f} MB)")
+
+    # Calculate the byte range for each chunk
     chunk_size_calc = total_size // num_parts
     chunks_ranges = []
     for i in range(num_parts):
@@ -162,76 +207,119 @@ def download_file_in_parts(file_url, save_path, total_size, num_parts, headers,
         end = start + chunk_size_calc - 1 if i < num_parts - 1 else total_size - 1
         if start <= end:
             chunks_ranges.append((start, end))
-        elif total_size == 0 and i == 0:
+        elif total_size == 0 and i == 0: # Handle zero-byte files
             chunks_ranges.append((0, -1))
 
+    # Calculate the expected size of each chunk
     chunk_actual_sizes = []
     for start, end in chunks_ranges:
-        if end == -1 and start == 0:
-            chunk_actual_sizes.append(0)
-        else:
-            chunk_actual_sizes.append(end - start + 1)
+        chunk_actual_sizes.append(end - start + 1 if end != -1 else 0)
 
     if not chunks_ranges and total_size > 0:
-        logger_func(f"   ⚠️ No valid chunk ranges for multipart download of '{api_original_filename}'. Aborting multipart.")
-        if os.path.exists(temp_file_path): os.remove(temp_file_path)
+        logger_func(f"   ⚠️ No valid chunk ranges for multipart download of '{api_original_filename}'. Aborting.")
         return False, 0, None, None
 
+    # --- Resumption Logic: Check for existing complete chunks ---
+    chunks_to_download = []
+    total_bytes_resumed = 0
+    for i, (start, end) in enumerate(chunks_ranges):
+        chunk_part_path = f"{save_path}.part{i}"
+        expected_chunk_size = chunk_actual_sizes[i]
+
+        if os.path.exists(chunk_part_path) and os.path.getsize(chunk_part_path) == expected_chunk_size:
+            logger_func(f"   [Chunk {i + 1}/{num_parts}] Resuming with existing complete chunk file.")
+            total_bytes_resumed += expected_chunk_size
+        else:
+            chunks_to_download.append({'index': i, 'start': start, 'end': end})
+
+    # Setup the shared progress data structure
     progress_data = {
         'total_file_size': total_size,
-        'total_downloaded_so_far': 0,
-        'chunks_status': [
-            {'id': i, 'downloaded': 0, 'total': chunk_actual_sizes[i] if i < len(chunk_actual_sizes) else 0, 'active': False, 'speed_bps': 0.0}
-            for i in range(num_parts)
-        ],
+        'total_downloaded_so_far': total_bytes_resumed,
+        'chunks_status': [],
         'lock': threading.Lock(),
         'last_global_emit_time': [time.time()]
     }
+    for i in range(num_parts):
+        is_resumed = not any(c['index'] == i for c in chunks_to_download)
+        progress_data['chunks_status'].append({
+            'id': i,
+            'downloaded': chunk_actual_sizes[i] if is_resumed else 0,
+            'total': chunk_actual_sizes[i],
+            'active': False,
+            'speed_bps': 0.0
+        })
 
+    # --- Download Phase ---
     chunk_futures = []
     all_chunks_successful = True
-    total_bytes_from_chunks = 0
+    total_bytes_from_threads = 0
 
     with ThreadPoolExecutor(max_workers=num_parts, thread_name_prefix=f"MPChunk_{api_original_filename[:10]}_") as chunk_pool:
-        for i, (start, end) in enumerate(chunks_ranges):
-            if cancellation_event and cancellation_event.is_set(): all_chunks_successful = False; break
-            chunk_futures.append(chunk_pool.submit(
-                _download_individual_chunk, chunk_url=file_url, temp_file_path=temp_file_path,
+        for chunk_info in chunks_to_download:
+            if cancellation_event and cancellation_event.is_set():
+                all_chunks_successful = False
+                break
+            
+            i, start, end = chunk_info['index'], chunk_info['start'], chunk_info['end']
+            chunk_part_path = f"{save_path}.part{i}"
+            
+            future = chunk_pool.submit(
+                _download_individual_chunk,
+                chunk_url=file_url,
+                chunk_temp_file_path=chunk_part_path,
                 start_byte=start, end_byte=end, headers=headers, part_num=i, total_parts=num_parts,
-                progress_data=progress_data, cancellation_event=cancellation_event, skip_event=skip_event, global_emit_time_ref=progress_data['last_global_emit_time'],
-                pause_event=pause_event, cookies_for_chunk=cookies_for_chunk_session, logger_func=logger_func, emitter=emitter_for_multipart,
+                progress_data=progress_data, cancellation_event=cancellation_event,
+                skip_event=skip_event, global_emit_time_ref=progress_data['last_global_emit_time'],
+                pause_event=pause_event, cookies_for_chunk=cookies_for_chunk_session,
+                logger_func=logger_func, emitter=emitter_for_multipart,
                 api_original_filename=api_original_filename
-            ))
+            )
+            chunk_futures.append(future)
 
         for future in as_completed(chunk_futures):
-            if cancellation_event and cancellation_event.is_set(): all_chunks_successful = False; break
-            bytes_downloaded_this_chunk, success_this_chunk = future.result()
-            total_bytes_from_chunks += bytes_downloaded_this_chunk
-            if not success_this_chunk:
+            if cancellation_event and cancellation_event.is_set():
                 all_chunks_successful = False
+            bytes_downloaded, success = future.result()
+            total_bytes_from_threads += bytes_downloaded
+            if not success:
+                all_chunks_successful = False
+
+    total_bytes_final = total_bytes_resumed + total_bytes_from_threads
 
     if cancellation_event and cancellation_event.is_set():
         logger_func(f"   Multi-part download for '{api_original_filename}' cancelled by main event.")
         all_chunks_successful = False
-    if emitter_for_multipart:
-        with progress_data['lock']:
-            status_list_copy = [dict(s) for s in progress_data['chunks_status']]
-            if isinstance(emitter_for_multipart, queue.Queue):
-                emitter_for_multipart.put({'type': 'file_progress', 'payload': (api_original_filename, status_list_copy)})
-            elif hasattr(emitter_for_multipart, 'file_progress_signal'):
-                emitter_for_multipart.file_progress_signal.emit(api_original_filename, status_list_copy)
 
-    if all_chunks_successful and (total_bytes_from_chunks == total_size or total_size == 0):
-        logger_func(f"   ✅ Multi-part download successful for '{api_original_filename}'. Total bytes: {total_bytes_from_chunks}")
+    # --- Assembly and Cleanup Phase ---
+    if all_chunks_successful and (total_bytes_final == total_size or total_size == 0):
+        logger_func(f"   ✅ All {num_parts} chunks complete. Assembling final file...")
         md5_hasher = hashlib.md5()
-        with open(temp_file_path, 'rb') as f_hash:
-            for buf in iter(lambda: f_hash.read(4096*10), b''):
-                md5_hasher.update(buf)
-        calculated_hash = md5_hasher.hexdigest()
-        return True, total_bytes_from_chunks, calculated_hash, open(temp_file_path, 'rb')
+        try:
+            with open(save_path, 'wb') as final_file:
+                for i in range(num_parts):
+                    chunk_part_path = f"{save_path}.part{i}"
+                    with open(chunk_part_path, 'rb') as chunk_file:
+                        content = chunk_file.read()
+                        final_file.write(content)
+                        md5_hasher.update(content)
+            
+            calculated_hash = md5_hasher.hexdigest()
+            logger_func(f"   ✅ Assembly successful for '{api_original_filename}'. Total bytes: {total_bytes_final}")
+            return True, total_bytes_final, calculated_hash, open(save_path, 'rb')
+        except Exception as e:
+            logger_func(f"   ❌ Critical error during file assembly: {e}. Cleaning up.")
+            return False, total_bytes_final, None, None
+        finally:
+            # Cleanup all individual chunk files after successful assembly
+            for i in range(num_parts):
+                chunk_part_path = f"{save_path}.part{i}"
+                if os.path.exists(chunk_part_path):
+                    try:
+                        os.remove(chunk_part_path)
+                    except OSError as e:
+                        logger_func(f"    ⚠️ Failed to remove temp part file '{chunk_part_path}': {e}")
     else:
-        logger_func(f"   ❌ Multi-part download failed for '{api_original_filename}'. Success: {all_chunks_successful}, Bytes: {total_bytes_from_chunks}/{total_size}. Cleaning up.")
-        if os.path.exists(temp_file_path):
-            try: os.remove(temp_file_path)
-            except OSError as e: logger_func(f"    Failed to remove temp part file '{temp_file_path}': {e}")
-        return False, total_bytes_from_chunks, None, None
+        # If download failed, we do NOT clean up, allowing for resumption later
+        logger_func(f"   ❌ Multi-part download failed for '{api_original_filename}'. Success: {all_chunks_successful}, Bytes: {total_bytes_final}/{total_size}. Partial chunks saved for future resumption.")
+        return False, total_bytes_final, None, None

src/ui/dialogs/FavoriteArtistsDialog.py

@@ -37,13 +37,13 @@ class FavoriteArtistsDialog (QDialog ):
         self ._init_ui ()
         self ._fetch_favorite_artists ()
 
-    def _get_domain_for_service (self ,service_name ):
-        service_lower =service_name .lower ()
-        coomer_primary_services ={'onlyfans','fansly','manyvids','candfans'}
-        if service_lower in coomer_primary_services :
-            return "coomer.su"
-        else :
-            return "kemono.su"
+    def _get_domain_for_service(self, service_name):
+        service_lower = service_name.lower()
+        coomer_primary_services = {'onlyfans', 'fansly', 'manyvids', 'candfans'}
+        if service_lower in coomer_primary_services:
+            return "coomer.st"  # Use the new domain
+        else:
+            return "kemono.cr"   # Use the new domain
 
     def _tr (self ,key ,default_text =""):
         """Helper to get translation based on current app language."""
@@ -128,9 +128,29 @@ class FavoriteArtistsDialog (QDialog ):
     def _fetch_favorite_artists (self ):
 
         if self.cookies_config['use_cookie']:
-            # Check if we can load cookies for at least one of the services.
-            kemono_cookies = prepare_cookies_for_request(True, self.cookies_config['cookie_text'], self.cookies_config['selected_cookie_file'], self.cookies_config['app_base_dir'], self._logger, target_domain="kemono.su")
-            coomer_cookies = prepare_cookies_for_request(True, self.cookies_config['cookie_text'], self.cookies_config['selected_cookie_file'], self.cookies_config['app_base_dir'], self._logger, target_domain="coomer.su")
+            # --- Kemono Check with Fallback ---
+            kemono_cookies = prepare_cookies_for_request(
+                True, self.cookies_config['cookie_text'], self.cookies_config['selected_cookie_file'],
+                self.cookies_config['app_base_dir'], self._logger, target_domain="kemono.cr"
+            )
+            if not kemono_cookies:
+                self._logger("No cookies for kemono.cr, trying fallback kemono.su...")
+                kemono_cookies = prepare_cookies_for_request(
+                    True, self.cookies_config['cookie_text'], self.cookies_config['selected_cookie_file'],
+                    self.cookies_config['app_base_dir'], self._logger, target_domain="kemono.su"
+                )
+
+            # --- Coomer Check with Fallback ---
+            coomer_cookies = prepare_cookies_for_request(
+                True, self.cookies_config['cookie_text'], self.cookies_config['selected_cookie_file'],
+                self.cookies_config['app_base_dir'], self._logger, target_domain="coomer.st"
+            )
+            if not coomer_cookies:
+                self._logger("No cookies for coomer.st, trying fallback coomer.su...")
+                coomer_cookies = prepare_cookies_for_request(
+                    True, self.cookies_config['cookie_text'], self.cookies_config['selected_cookie_file'],
+                    self.cookies_config['app_base_dir'], self._logger, target_domain="coomer.su"
+                )
 
             if not kemono_cookies and not coomer_cookies:
                 # If cookies are enabled but none could be loaded, show help and stop.
@@ -139,7 +159,7 @@ class FavoriteArtistsDialog (QDialog ):
                 cookie_help_dialog = CookieHelpDialog(self.parent_app, self)
                 cookie_help_dialog.exec_()
                 self.download_button.setEnabled(False)
-                return # Stop further execution
+                return  # Stop further execution
 
         kemono_fav_url ="https://kemono.su/api/v1/account/favorites?type=artist"
         coomer_fav_url ="https://coomer.su/api/v1/account/favorites?type=artist"
@@ -149,9 +169,12 @@ class FavoriteArtistsDialog (QDialog ):
         errors_occurred =[]
         any_cookies_loaded_successfully_for_any_source =False 
 
-        api_sources =[
-        {"name":"Kemono.su","url":kemono_fav_url ,"domain":"kemono.su"},
-        {"name":"Coomer.su","url":coomer_fav_url ,"domain":"coomer.su"}
+        kemono_cr_fav_url = "https://kemono.cr/api/v1/account/favorites?type=artist"
+        coomer_st_fav_url = "https://coomer.st/api/v1/account/favorites?type=artist"
+
+        api_sources = [
+            {"name": "Kemono.cr", "url": kemono_cr_fav_url, "domain": "kemono.cr"},
+            {"name": "Coomer.st", "url": coomer_st_fav_url, "domain": "coomer.st"}
         ]
 
         for source in api_sources :
@@ -159,20 +182,41 @@ class FavoriteArtistsDialog (QDialog ):
             self .status_label .setText (self ._tr ("fav_artists_loading_from_source_status","⏳ Loading favorites from {source_name}...").format (source_name =source ['name']))
             QCoreApplication .processEvents ()
 
-            cookies_dict_for_source =None 
-            if self .cookies_config ['use_cookie']:
-                cookies_dict_for_source =prepare_cookies_for_request (
-                True ,
-                self .cookies_config ['cookie_text'],
-                self .cookies_config ['selected_cookie_file'],
-                self .cookies_config ['app_base_dir'],
-                self ._logger ,
-                target_domain =source ['domain']
+            cookies_dict_for_source = None
+            if self.cookies_config['use_cookie']:
+                primary_domain = source['domain']
+                fallback_domain = None
+                if primary_domain == "kemono.cr":
+                    fallback_domain = "kemono.su"
+                elif primary_domain == "coomer.st":
+                    fallback_domain = "coomer.su"
+
+                # First, try the primary domain
+                cookies_dict_for_source = prepare_cookies_for_request(
+                    True,
+                    self.cookies_config['cookie_text'],
+                    self.cookies_config['selected_cookie_file'],
+                    self.cookies_config['app_base_dir'],
+                    self._logger,
+                    target_domain=primary_domain
                 )
-                if cookies_dict_for_source :
-                    any_cookies_loaded_successfully_for_any_source =True 
-                else :
-                    self ._logger (f"Warning ({source ['name']}): Cookies enabled but could not be loaded for this domain. Fetch might fail if cookies are required.")
+
+                # If no cookies found, try the fallback domain
+                if not cookies_dict_for_source and fallback_domain:
+                    self._logger(f"Warning ({source['name']}): No cookies found for '{primary_domain}'. Trying fallback '{fallback_domain}'...")
+                    cookies_dict_for_source = prepare_cookies_for_request(
+                        True,
+                        self.cookies_config['cookie_text'],
+                        self.cookies_config['selected_cookie_file'],
+                        self.cookies_config['app_base_dir'],
+                        self._logger,
+                        target_domain=fallback_domain
+                    )
+                
+                if cookies_dict_for_source:
+                    any_cookies_loaded_successfully_for_any_source = True
+                else:
+                    self._logger(f"Warning ({source['name']}): Cookies enabled but could not be loaded for this source (including fallbacks). Fetch might fail.")
             try :
                 headers ={'User-Agent':'Mozilla/5.0'}
                 response =requests .get (source ['url'],headers =headers ,cookies =cookies_dict_for_source ,timeout =20 )
@@ -223,7 +267,7 @@ class FavoriteArtistsDialog (QDialog ):
         if self .cookies_config ['use_cookie']and not any_cookies_loaded_successfully_for_any_source :
             self .status_label .setText (self ._tr ("fav_artists_cookies_required_status","Error: Cookies enabled but could not be loaded for any source."))
             self ._logger ("Error: Cookies enabled but no cookies loaded for any source. Showing help dialog.")
-            cookie_help_dialog =CookieHelpDialog (self )
+            cookie_help_dialog = CookieHelpDialog(self.parent_app, self)
             cookie_help_dialog .exec_ ()
             self .download_button .setEnabled (False )
             if not fetched_any_successfully :

src/ui/dialogs/FavoritePostsDialog.py

@@ -34,28 +34,30 @@ class FavoritePostsFetcherThread (QThread ):
         self .target_domain_preference =target_domain_preference 
         self .cancellation_event =threading .Event ()
         self .error_key_map ={
-        "Kemono.su":"kemono_su",
-        "Coomer.su":"coomer_su"
+        "kemono.cr":"kemono_su",
+        "coomer.st":"coomer_su"
         }
 
     def _logger (self ,message ):
         self .parent_logger_func (f"[FavPostsFetcherThread] {message }")
 
-    def run (self ):
-        kemono_fav_posts_url ="https://kemono.su/api/v1/account/favorites?type=post"
-        coomer_fav_posts_url ="https://coomer.su/api/v1/account/favorites?type=post"
+    def run(self):
+        kemono_su_fav_posts_url = "https://kemono.su/api/v1/account/favorites?type=post"
+        coomer_su_fav_posts_url = "https://coomer.su/api/v1/account/favorites?type=post"
+        kemono_cr_fav_posts_url = "https://kemono.cr/api/v1/account/favorites?type=post"
+        coomer_st_fav_posts_url = "https://coomer.st/api/v1/account/favorites?type=post"
 
-        all_fetched_posts_temp =[]
-        error_messages_for_summary =[]
-        fetched_any_successfully =False 
-        any_cookies_loaded_successfully_for_any_source =False 
+        all_fetched_posts_temp = []
+        error_messages_for_summary = []
+        fetched_any_successfully = False
+        any_cookies_loaded_successfully_for_any_source = False
 
-        self .status_update .emit ("key_fetching_fav_post_list_init")
-        self .progress_bar_update .emit (0 ,0 )
+        self.status_update.emit("key_fetching_fav_post_list_init")
+        self.progress_bar_update.emit(0, 0)
 
-        api_sources =[
-        {"name":"Kemono.su","url":kemono_fav_posts_url ,"domain":"kemono.su"},
-        {"name":"Coomer.su","url":coomer_fav_posts_url ,"domain":"coomer.su"}
+        api_sources = [
+            {"name": "Kemono.cr", "url": kemono_cr_fav_posts_url, "domain": "kemono.cr"},
+            {"name": "Coomer.st", "url": coomer_st_fav_posts_url, "domain": "coomer.st"}
         ]
 
         api_sources_to_try =[]
@@ -76,20 +78,41 @@ class FavoritePostsFetcherThread (QThread ):
             if self .cancellation_event .is_set ():
                 self .finished .emit ([],"KEY_FETCH_CANCELLED_DURING")
                 return 
-            cookies_dict_for_source =None 
-            if self .cookies_config ['use_cookie']:
-                cookies_dict_for_source =prepare_cookies_for_request (
-                True ,
-                self .cookies_config ['cookie_text'],
-                self .cookies_config ['selected_cookie_file'],
-                self .cookies_config ['app_base_dir'],
-                self ._logger ,
-                target_domain =source ['domain']
+            cookies_dict_for_source = None
+            if self.cookies_config['use_cookie']:
+                primary_domain = source['domain']
+                fallback_domain = None
+                if primary_domain == "kemono.cr":
+                    fallback_domain = "kemono.su"
+                elif primary_domain == "coomer.st":
+                    fallback_domain = "coomer.su"
+
+                # First, try the primary domain
+                cookies_dict_for_source = prepare_cookies_for_request(
+                    True,
+                    self.cookies_config['cookie_text'],
+                    self.cookies_config['selected_cookie_file'],
+                    self.cookies_config['app_base_dir'],
+                    self._logger,
+                    target_domain=primary_domain
                 )
-                if cookies_dict_for_source :
-                    any_cookies_loaded_successfully_for_any_source =True 
-                else :
-                    self ._logger (f"Warning ({source ['name']}): Cookies enabled but could not be loaded for this domain. Fetch might fail if cookies are required.")
+
+                # If no cookies found, try the fallback domain
+                if not cookies_dict_for_source and fallback_domain:
+                    self._logger(f"Warning ({source['name']}): No cookies found for '{primary_domain}'. Trying fallback '{fallback_domain}'...")
+                    cookies_dict_for_source = prepare_cookies_for_request(
+                        True,
+                        self.cookies_config['cookie_text'],
+                        self.cookies_config['selected_cookie_file'],
+                        self.cookies_config['app_base_dir'],
+                        self._logger,
+                        target_domain=fallback_domain
+                    )
+
+                if cookies_dict_for_source:
+                    any_cookies_loaded_successfully_for_any_source = True
+                else:
+                    self._logger(f"Warning ({source['name']}): Cookies enabled but could not be loaded for this domain. Fetch might fail if cookies are required.")
 
             self ._logger (f"Attempting to fetch favorite posts from: {source ['name']} ({source ['url']})")
             source_key_part =self .error_key_map .get (source ['name'],source ['name'].lower ().replace ('.','_'))
@@ -409,14 +432,14 @@ class FavoritePostsDialog (QDialog ):
             if status_key .startswith ("KEY_COOKIES_REQUIRED_BUT_NOT_FOUND_FOR_DOMAIN_")or status_key =="KEY_COOKIES_REQUIRED_BUT_NOT_FOUND_GENERIC":
                 status_label_text_key ="fav_posts_cookies_required_error"
                 self ._logger (f"Cookie error: {status_key }. Showing help dialog.")
-                cookie_help_dialog =CookieHelpDialog (self )
+                cookie_help_dialog = CookieHelpDialog(self.parent_app, self)
                 cookie_help_dialog .exec_ ()
             elif status_key =="KEY_AUTH_FAILED":
                 status_label_text_key ="fav_posts_auth_failed_title"
                 self ._logger (f"Auth error: {status_key }. Showing help dialog.")
                 QMessageBox .warning (self ,self ._tr ("fav_posts_auth_failed_title","Authorization Failed (Posts)"),
                 self ._tr ("fav_posts_auth_failed_message_generic","...").format (domain_specific_part =specific_domain_msg_part ))
-                cookie_help_dialog =CookieHelpDialog (self )
+                cookie_help_dialog = CookieHelpDialog(self.parent_app, self)
                 cookie_help_dialog .exec_ ()
             elif status_key =="KEY_NO_FAVORITES_FOUND_ALL_PLATFORMS":
                 status_label_text_key ="fav_posts_no_posts_found_status"

src/ui/dialogs/HelpGuideDialog.py

@@ -4,7 +4,7 @@ from PyQt5.QtCore import QUrl, QSize, Qt
 from PyQt5.QtGui import QIcon, QDesktopServices
 from PyQt5.QtWidgets import (
     QApplication, QDialog, QHBoxLayout, QLabel, QPushButton, QVBoxLayout,
-    QStackedWidget, QScrollArea, QFrame, QWidget
+    QStackedWidget, QListWidget, QFrame, QWidget, QScrollArea
 )
 from ...i18n.translator import get_translation
 from ..main_window import get_app_icon_object
@@ -46,13 +46,12 @@ class TourStepWidget(QWidget):
         layout.addWidget(scroll_area, 1)
 
 
-class HelpGuideDialog (QDialog ):
-    """A multi-page dialog for displaying the feature guide."""
-    def __init__ (self ,steps_data ,parent_app ,parent =None ):
-        super ().__init__ (parent )
-        self .current_step =0 
-        self .steps_data =steps_data 
-        self .parent_app =parent_app 
+class HelpGuideDialog(QDialog):
+    """A multi-page dialog for displaying the feature guide with a navigation list."""
+    def __init__(self, steps_data, parent_app, parent=None):
+        super().__init__(parent)
+        self.steps_data = steps_data
+        self.parent_app = parent_app
 
         scale = self.parent_app.scale_factor if hasattr(self.parent_app, 'scale_factor') else 1.0
 
@@ -61,7 +60,7 @@ class HelpGuideDialog (QDialog ):
             self.setWindowIcon(app_icon)
 
         self.setModal(True)
-        self.resize(int(650 * scale), int(600 * scale))
+        self.resize(int(800 * scale), int(650 * scale))
 
         dialog_font_size = int(11 * scale)
         
@@ -69,6 +68,7 @@ class HelpGuideDialog (QDialog ):
         if hasattr(self.parent_app, 'current_theme') and self.parent_app.current_theme == "dark":
             current_theme_style = get_dark_theme(scale)
         else:
+            # Basic light theme fallback
             current_theme_style = f"""
                 QDialog {{ background-color: #F0F0F0; border: 1px solid #B0B0B0; }}
                 QLabel {{ color: #1E1E1E; }}
@@ -86,118 +86,107 @@ class HelpGuideDialog (QDialog ):
             """
 
         self.setStyleSheet(current_theme_style)
-        self ._init_ui ()
-        if self .parent_app :
-            self .move (self .parent_app .geometry ().center ()-self .rect ().center ())
+        self._init_ui()
+        if self.parent_app:
+            self.move(self.parent_app.geometry().center() - self.rect().center())
 
-    def _tr (self ,key ,default_text =""):
+    def _tr(self, key, default_text=""):
         """Helper to get translation based on current app language."""
-        if callable (get_translation )and self .parent_app :
-            return get_translation (self .parent_app .current_selected_language ,key ,default_text )
-        return default_text 
+        if callable(get_translation) and self.parent_app:
+            return get_translation(self.parent_app.current_selected_language, key, default_text)
+        return default_text
 
+    def _init_ui(self):
+        main_layout = QVBoxLayout(self)
+        main_layout.setContentsMargins(15, 15, 15, 15)
+        main_layout.setSpacing(10)
 
-    def _init_ui (self ):
-        main_layout =QVBoxLayout (self )
-        main_layout .setContentsMargins (0 ,0 ,0 ,0 )
-        main_layout .setSpacing (0 )
+        # Title
+        title_label = QLabel(self._tr("help_guide_dialog_title", "Kemono Downloader - Feature Guide"))
+        scale = getattr(self.parent_app, 'scale_factor', 1.0)
+        title_font_size = int(16 * scale)
+        title_label.setStyleSheet(f"font-size: {title_font_size}pt; font-weight: bold; color: #E0E0E0;")
+        title_label.setAlignment(Qt.AlignCenter)
+        main_layout.addWidget(title_label)
 
-        self .stacked_widget =QStackedWidget ()
-        main_layout .addWidget (self .stacked_widget ,1 )
+        # Content Layout (Navigation + Stacked Pages)
+        content_layout = QHBoxLayout()
+        main_layout.addLayout(content_layout, 1)
 
-        self .tour_steps_widgets =[]
-        scale = self.parent_app.scale_factor if hasattr(self.parent_app, 'scale_factor') else 1.0
-        for title, content in self.steps_data:
-            step_widget = TourStepWidget(title, content, scale=scale) 
-            self.tour_steps_widgets.append(step_widget)
+        self.nav_list = QListWidget()
+        self.nav_list.setFixedWidth(int(220 * scale))
+        self.nav_list.setStyleSheet(f"""
+            QListWidget {{
+                background-color: #2E2E2E;
+                border: 1px solid #4A4A4A;
+                border-radius: 4px;
+                font-size: {int(11 * scale)}pt;
+            }}
+            QListWidget::item {{
+                padding: 10px;
+                border-bottom: 1px solid #4A4A4A;
+            }}
+            QListWidget::item:selected {{
+                background-color: #87CEEB;
+                color: #2E2E2E;
+                font-weight: bold;
+            }}
+        """)
+        content_layout.addWidget(self.nav_list)
+
+        self.stacked_widget = QStackedWidget()
+        content_layout.addWidget(self.stacked_widget)
+
+        for title_key, content_key in self.steps_data:
+            title = self._tr(title_key, title_key)
+            content = self._tr(content_key, f"Content for {content_key} not found.")
+            
+            self.nav_list.addItem(title)
+            
+            step_widget = TourStepWidget(title, content, scale=scale)
             self.stacked_widget.addWidget(step_widget)
 
-        self .setWindowTitle (self ._tr ("help_guide_dialog_title","Kemono Downloader - Feature Guide"))
+        self.nav_list.currentRowChanged.connect(self.stacked_widget.setCurrentIndex)
+        if self.nav_list.count() > 0:
+            self.nav_list.setCurrentRow(0)
 
-        buttons_layout =QHBoxLayout ()
-        buttons_layout .setContentsMargins (15 ,10 ,15 ,15 )
-        buttons_layout .setSpacing (10 )
+        # Footer Layout (Social links and Close button)
+        footer_layout = QHBoxLayout()
+        footer_layout.setContentsMargins(0, 10, 0, 0)
+        
+        # Social Media Icons
+        if getattr(sys, 'frozen', False) and hasattr(sys, '_MEIPASS'):
+            assets_base_dir = sys._MEIPASS
+        else:
+            assets_base_dir = os.path.abspath(os.path.join(os.path.dirname(__file__), '..', '..', '..'))
 
-        self .back_button =QPushButton (self ._tr ("tour_dialog_back_button","Back"))
-        self .back_button .clicked .connect (self ._previous_step )
-        self .back_button .setEnabled (False )
+        github_icon_path = os.path.join(assets_base_dir, "assets", "github.png")
+        instagram_icon_path = os.path.join(assets_base_dir, "assets", "instagram.png")
+        discord_icon_path = os.path.join(assets_base_dir, "assets", "discord.png")
 
-        if getattr (sys ,'frozen',False )and hasattr (sys ,'_MEIPASS'):
-            assets_base_dir =sys ._MEIPASS 
-        else :
-            assets_base_dir =os.path.abspath(os.path.join(os.path.dirname(__file__), '..', '..', '..'))
+        self.github_button = QPushButton(QIcon(github_icon_path), "")
+        self.instagram_button = QPushButton(QIcon(instagram_icon_path), "")
+        self.discord_button = QPushButton(QIcon(discord_icon_path), "")
 
-        github_icon_path =os .path .join (assets_base_dir ,"assets","github.png")
-        instagram_icon_path =os .path .join (assets_base_dir ,"assets","instagram.png")
-        discord_icon_path =os .path .join (assets_base_dir ,"assets","discord.png")
-
-        self .github_button =QPushButton (QIcon (github_icon_path ),"")
-        self .instagram_button =QPushButton (QIcon (instagram_icon_path ),"")
-        self .Discord_button =QPushButton (QIcon (discord_icon_path ),"")
-
-        scale = self.parent_app.scale_factor if hasattr(self.parent_app, 'scale_factor') else 1.0
         icon_dim = int(24 * scale)
         icon_size = QSize(icon_dim, icon_dim)
-        self .github_button .setIconSize (icon_size )
-        self .instagram_button .setIconSize (icon_size )
-        self .Discord_button .setIconSize (icon_size )
+        
+        for button, tooltip_key, url in [
+            (self.github_button, "help_guide_github_tooltip", "https://github.com/Yuvi9587"),
+            (self.instagram_button, "help_guide_instagram_tooltip", "https://www.instagram.com/uvi.arts/"),
+            (self.discord_button, "help_guide_discord_tooltip", "https://discord.gg/BqP64XTdJN")
+        ]:
+            button.setIconSize(icon_size)
+            button.setToolTip(self._tr(tooltip_key))
+            button.setFixedSize(icon_size.width() + 8, icon_size.height() + 8)
+            button.setStyleSheet("background-color: transparent; border: none;")
+            button.clicked.connect(lambda _, u=url: QDesktopServices.openUrl(QUrl(u)))
+            footer_layout.addWidget(button)
 
-        self .next_button =QPushButton (self ._tr ("tour_dialog_next_button","Next"))
-        self .next_button .clicked .connect (self ._next_step_action )
-        self .next_button .setDefault (True )
-        self .github_button .clicked .connect (self ._open_github_link )
-        self .instagram_button .clicked .connect (self ._open_instagram_link )
-        self .Discord_button .clicked .connect (self ._open_Discord_link )
-        self .github_button .setToolTip (self ._tr ("help_guide_github_tooltip","Visit project's GitHub page (Opens in browser)"))
-        self .instagram_button .setToolTip (self ._tr ("help_guide_instagram_tooltip","Visit our Instagram page (Opens in browser)"))
-        self .Discord_button .setToolTip (self ._tr ("help_guide_discord_tooltip","Visit our Discord community (Opens in browser)"))
+        footer_layout.addStretch(1)
 
+        self.finish_button = QPushButton(self._tr("tour_dialog_finish_button", "Finish"))
+        self.finish_button.clicked.connect(self.accept)
+        footer_layout.addWidget(self.finish_button)
 
-        social_layout =QHBoxLayout ()
-        social_layout .setSpacing (10 )
-        social_layout .addWidget (self .github_button )
-        social_layout .addWidget (self .instagram_button )
-        social_layout .addWidget (self .Discord_button )
-
-        while buttons_layout .count ():
-            item =buttons_layout .takeAt (0 )
-            if item .widget ():
-                item .widget ().setParent (None )
-            elif item .layout ():
-                pass 
-        buttons_layout .addLayout (social_layout )
-        buttons_layout .addStretch (1 )
-        buttons_layout .addWidget (self .back_button )
-        buttons_layout .addWidget (self .next_button )
-        main_layout .addLayout (buttons_layout )
-        self ._update_button_states ()
-
-    def _next_step_action (self ):
-        if self .current_step <len (self .tour_steps_widgets )-1 :
-            self .current_step +=1 
-            self .stacked_widget .setCurrentIndex (self .current_step )
-        else :
-            self .accept ()
-        self ._update_button_states ()
-
-    def _previous_step (self ):
-        if self .current_step >0 :
-            self .current_step -=1 
-            self .stacked_widget .setCurrentIndex (self .current_step )
-        self ._update_button_states ()
-
-    def _update_button_states (self ):
-        if self .current_step ==len (self .tour_steps_widgets )-1 :
-            self .next_button .setText (self ._tr ("tour_dialog_finish_button","Finish"))
-        else :
-            self .next_button .setText (self ._tr ("tour_dialog_next_button","Next"))
-        self .back_button .setEnabled (self .current_step >0 )
-
-    def _open_github_link (self ):
-        QDesktopServices .openUrl (QUrl ("https://github.com/Yuvi9587"))
-
-    def _open_instagram_link (self ):
-        QDesktopServices .openUrl (QUrl ("https://www.instagram.com/uvi.arts/"))
-
-    def _open_Discord_link (self ):
-        QDesktopServices .openUrl (QUrl ("https://discord.gg/BqP64XTdJN"))
+        main_layout.addLayout(footer_layout)

src/ui/main_window.py

@@ -4288,13 +4288,13 @@ class DownloaderApp (QWidget ):
             self.log_signal.emit("    Cancelling active External Link download thread...")
             self.external_link_download_thread.cancel()
 
-    def _get_domain_for_service (self ,service_name :str )->str :
+    def _get_domain_for_service(self, service_name: str) -> str:
         """Determines the base domain for a given service."""
-        if not isinstance (service_name ,str ):
-            return "kemono.cr"
-        service_lower =service_name .lower ()
-        coomer_primary_services ={'onlyfans','fansly','manyvids','candfans','gumroad','patreon','subscribestar','dlsite','discord','fantia','boosty','pixiv','fanbox'}
-        if service_lower in coomer_primary_services and service_lower not in ['patreon','discord','fantia','boosty','pixiv','fanbox']:
+        if not isinstance(service_name, str):
+            return "kemono.cr"  # Default fallback
+        service_lower = service_name.lower()
+        coomer_primary_services = {'onlyfans', 'fansly', 'manyvids', 'candfans', 'gumroad', 'subscribestar', 'dlsite'}
+        if service_lower in coomer_primary_services:
             return "coomer.st"
         return "kemono.cr"
 
@@ -5343,42 +5343,54 @@ class DownloaderApp (QWidget ):
 
         target_domain_preference_for_fetch =None 
 
-        if cookies_config ['use_cookie']:
-            self .log_signal .emit ("Favorite Posts: 'Use Cookie' is checked. Determining target domain...")
-            kemono_cookies =prepare_cookies_for_request (
-            cookies_config ['use_cookie'],
-            cookies_config ['cookie_text'],
-            cookies_config ['selected_cookie_file'],
-            cookies_config ['app_base_dir'],
-            lambda msg :self .log_signal .emit (f"[FavPosts Cookie Check - Kemono] {msg }"),
-            target_domain ="kemono.su"
+        if cookies_config['use_cookie']:
+            self.log_signal.emit("Favorite Posts: 'Use Cookie' is checked. Determining target domain...")
+            
+            # --- Kemono Check with Fallback ---
+            kemono_cookies = prepare_cookies_for_request(
+                cookies_config['use_cookie'], cookies_config['cookie_text'], cookies_config['selected_cookie_file'],
+                cookies_config['app_base_dir'], lambda msg: self.log_signal.emit(f"[FavPosts Cookie Check] {msg}"),
+                target_domain="kemono.cr"
             )
-            coomer_cookies =prepare_cookies_for_request (
-            cookies_config ['use_cookie'],
-            cookies_config ['cookie_text'],
-            cookies_config ['selected_cookie_file'],
-            cookies_config ['app_base_dir'],
-            lambda msg :self .log_signal .emit (f"[FavPosts Cookie Check - Coomer] {msg }"),
-            target_domain ="coomer.su"
+            if not kemono_cookies:
+                self.log_signal.emit("  ↳ No cookies for kemono.cr, trying fallback kemono.su...")
+                kemono_cookies = prepare_cookies_for_request(
+                    cookies_config['use_cookie'], cookies_config['cookie_text'], cookies_config['selected_cookie_file'],
+                    cookies_config['app_base_dir'], lambda msg: self.log_signal.emit(f"[FavPosts Cookie Check] {msg}"),
+                    target_domain="kemono.su"
+                )
+
+            # --- Coomer Check with Fallback ---
+            coomer_cookies = prepare_cookies_for_request(
+                cookies_config['use_cookie'], cookies_config['cookie_text'], cookies_config['selected_cookie_file'],
+                cookies_config['app_base_dir'], lambda msg: self.log_signal.emit(f"[FavPosts Cookie Check] {msg}"),
+                target_domain="coomer.st"
             )
+            if not coomer_cookies:
+                self.log_signal.emit("  ↳ No cookies for coomer.st, trying fallback coomer.su...")
+                coomer_cookies = prepare_cookies_for_request(
+                    cookies_config['use_cookie'], cookies_config['cookie_text'], cookies_config['selected_cookie_file'],
+                    cookies_config['app_base_dir'], lambda msg: self.log_signal.emit(f"[FavPosts Cookie Check] {msg}"),
+                    target_domain="coomer.su"
+                )
 
-            kemono_ok =bool (kemono_cookies )
-            coomer_ok =bool (coomer_cookies )
+            kemono_ok = bool(kemono_cookies)
+            coomer_ok = bool(coomer_cookies)
 
-            if kemono_ok and not coomer_ok :
-                target_domain_preference_for_fetch ="kemono.su"
-                self .log_signal .emit ("  ↳ Only Kemono.su cookies loaded. Will fetch favorites from Kemono.su only.")
-            elif coomer_ok and not kemono_ok :
-                target_domain_preference_for_fetch ="coomer.su"
-                self .log_signal .emit ("  ↳ Only Coomer.su cookies loaded. Will fetch favorites from Coomer.su only.")
-            elif kemono_ok and coomer_ok :
-                target_domain_preference_for_fetch =None 
-                self .log_signal .emit ("  ↳ Cookies for both Kemono.su and Coomer.su loaded. Will attempt to fetch from both.")
-            else :
-                self .log_signal .emit ("  ↳ No valid cookies loaded for Kemono.su or Coomer.su.")
-                cookie_help_dialog =CookieHelpDialog (self ,self )
-                cookie_help_dialog .exec_ ()
-                return 
+            if kemono_ok and not coomer_ok:
+                target_domain_preference_for_fetch = "kemono.cr"
+                self.log_signal.emit("  ↳ Only Kemono cookies loaded. Will fetch favorites from Kemono.cr only.")
+            elif coomer_ok and not kemono_ok:
+                target_domain_preference_for_fetch = "coomer.st"
+                self.log_signal.emit("  ↳ Only Coomer cookies loaded. Will fetch favorites from Coomer.st only.")
+            elif kemono_ok and coomer_ok:
+                target_domain_preference_for_fetch = None
+                self.log_signal.emit("  ↳ Cookies for both Kemono and Coomer loaded. Will attempt to fetch from both.")
+            else:
+                self.log_signal.emit("  ↳ No valid cookies loaded for Kemono.cr or Coomer.st.")
+                cookie_help_dialog = CookieHelpDialog(self, self)
+                cookie_help_dialog.exec_()
+                return
         else :
             self .log_signal .emit ("Favorite Posts: 'Use Cookie' is NOT checked. Cookies are required.")
             cookie_help_dialog =CookieHelpDialog (self ,self )