feat(download screen):implement download capabilities

fastanime/Utility/utils.py

@@ -1,7 +1,7 @@
 import os
 import shutil
 from datetime import datetime
-
+import re
 # TODO: make it use color_text instead of fixed vals
 # from .kivy_markup_helper import color_text
 
@@ -34,3 +34,62 @@ def move_file(source_path, dest_path):
         return (1, path)
     except Exception as e:
         return (0, e)
+
+
+def sanitize_filename(filename: str):
+    """
+    Sanitize a string to be safe for use as a file name.
+
+    :param filename: The original filename string.
+    :return: A sanitized filename string.
+    """
+    # List of characters not allowed in filenames on various operating systems
+    invalid_chars = r'[<>:"/\\|?*\0]'
+    reserved_names = {
+        "CON",
+        "PRN",
+        "AUX",
+        "NUL",
+        "COM1",
+        "COM2",
+        "COM3",
+        "COM4",
+        "COM5",
+        "COM6",
+        "COM7",
+        "COM8",
+        "COM9",
+        "LPT1",
+        "LPT2",
+        "LPT3",
+        "LPT4",
+        "LPT5",
+        "LPT6",
+        "LPT7",
+        "LPT8",
+        "LPT9",
+    }
+
+    # Replace invalid characters with an underscore
+    sanitized = re.sub(invalid_chars, "_", filename)
+
+    # Remove leading and trailing whitespace
+    sanitized = sanitized.strip()
+
+    # Check for reserved filenames
+    name, ext = os.path.splitext(sanitized)
+    if name.upper() in reserved_names:
+        name += "_file"
+        sanitized = name + ext
+
+    # Ensure the filename is not empty
+    if not sanitized:
+        sanitized = "default_filename"
+
+    return sanitized
+
+
+# Example usage
+unsafe_filename = "CON:example?file*name.txt"
+safe_filename = sanitize_filename(unsafe_filename)
+print(safe_filename)  # Output: 'CON_example_file_name.txt'