MAJOR: Restructured backend Flask application moved all non-routes into utils, renamed routes to not prefix get, created middleware.py to replace utils.py within blueprints

web_server/utils/utils.py

@@ -0,0 +1,75 @@
+from database.database import Database
+from typing import Optional, List
+from re import match
+
+def get_all_categories() -> Optional[List[dict]]:
+    """
+    Returns all possible streaming categories
+    """
+    with Database() as db:
+        all_categories = db.fetchall("SELECT * FROM categories")
+    
+    return all_categories
+
+def get_all_tags() -> Optional[List[dict]]:
+    """
+    Returns all possible streaming tags
+    """
+    with Database() as db:
+        all_tags = db.fetchall("SELECT * FROM tags")
+    
+    return all_tags
+
+def get_most_popular_category() -> Optional[List[dict]]:
+    """
+    Returns the most popular category based on live stream viewers
+    """
+    with Database() as db:
+        category = db.fetchone("""
+            SELECT categories.category_id, categories.category_name
+            FROM streams
+            JOIN categories ON streams.category_id = categories.category_id
+            WHERE streams.isLive = 1
+            GROUP BY categories.category_name
+            ORDER BY SUM(streams.num_viewers) DESC
+            LIMIT 1;
+        """)
+    
+    return category
+
+def sanitize(user_input: str, input_type="username") -> str:
+    """
+    Sanitizes user input based on the specified input type.
+    
+    `input_type`: The type of input to sanitize (e.g., 'username', 'email', 'password').
+    """
+    # Strip leading and trailing whitespace
+    sanitised_input = user_input.strip()
+
+    # Define allowed patterns and length constraints for each type
+    rules = {
+        "username": {
+            "pattern": r"^[a-zA-Z0-9_]+$",  # Alphanumeric + underscores
+            "min_length": 3,
+            "max_length": 50,
+        },
+        "email": {
+            "pattern": r"^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$",  # Standard email regex
+            "min_length": 5,
+            "max_length": 128,
+        },
+        "password": {
+            "pattern": r"^[\S]+$",  # Non-whitespace characters only
+            "min_length": 8,
+            "max_length": 256,
+        },
+    }
+
+    # Get the validation rules for the specified type
+    r = rules.get(input_type)
+    if not r or \
+    not (r["min_length"] <= len(sanitised_input) <= r["max_length"]) or \
+    not match(r["pattern"], sanitised_input):
+        raise ValueError("Unaccepted character or length in input")
+
+    return sanitised_input