refactor: modify backend for better understand

backend/utils.py

@@ -3,50 +3,62 @@ import random
 import uuid
 import time
 import math
+import re
 
-ValidUsername = set(map(lambda x:chr(x), range(48, 58, 1))) | set(map(lambda x:chr(x), range(65, 91, 1))) | set(map(lambda x:chr(x), range(97, 123, 1)))
-ValidPassword = set(map(lambda x:chr(x), range(33, 127, 1)))
+USERNAME_PATTERN: re.Pattern = re.compile("^[0-9A-Za-z]+$")
+PASSWORD_PATTERN: re.Pattern = re.compile("^[!-~]+$")
 
-def IsValidUsername(strl):
-    return (len(set(strl) - ValidUsername) == 0)
 
-def IsValidPassword(strl):
-    return (len(set(strl) - ValidPassword) == 0)
+def IsValidUsername(strl: str) -> bool:
+    return USERNAME_PATTERN.match(strl) is not None
 
-def ComputePasswordHash(password):
+
+def IsValidPassword(strl: str) -> bool:
+    return PASSWORD_PATTERN.match(strl) is not None
+
+
+def ComputePasswordHash(password: str) -> str:
     s = hashlib.sha256()
-    s.update(password.encode('utf-8'))
+    s.update(password.encode("utf-8"))
     return s.hexdigest()
 
-def GenerateUUID():
+
+def GenerateUUID() -> str:
     return str(uuid.uuid1())
 
-def GenerateToken(username):
+
+def GenerateToken(username: str) -> str:
     s = hashlib.sha256()
-    s.update(username.encode('utf-8'))
-    s.update(GenerateUUID().encode('utf-8'))
+    s.update(username.encode("utf-8"))
+    s.update(GenerateUUID().encode("utf-8"))
     return s.hexdigest()
 
-def GenerateSalt():
+
+def GenerateSalt() -> int:
     return random.randint(0, 6172748)
 
-def ComputePasswordHashWithSalt(passwordHashed, salt):
+
+def ComputePasswordHashWithSalt(passwordHashed: str, salt: int) -> str:
     s = hashlib.sha256()
-    s.update((passwordHashed + str(salt)).encode('utf-8'))
+    s.update((passwordHashed + str(salt)).encode("utf-8"))
     return s.hexdigest()
 
-def GetCurrentTimestamp():
+
+def GetCurrentTimestamp() -> int:
     return int(time.time())
 
-def GetTokenExpireOn():
-    return GetCurrentTimestamp() + 60 * 60 * 24 * 2 # add 2 day from now
 
-def Str2Bool(strl):
-    return strl.lower() == 'true'
+def GetTokenExpireOn() -> int:
+    return GetCurrentTimestamp() + 60 * 60 * 24 * 2  # add 2 day from now
 
-def GCD(a, b):
+
+def Str2Bool(strl: str) -> bool:
+    return strl.lower() == "true"
+
+
+def GCD(a: int, b: int) -> int:
     return math.gcd(a, b)
 
-def LCM(a, b):
-    return int(a * b / GCD(a, b))
-        
+
+def LCM(a: int, b: int) -> int:
+    return (a * b) // GCD(a, b)