diff --git a/access_control.py b/access_control.py
index ad4d95a..50ba8b1 100644
--- a/access_control.py
+++ b/access_control.py
@@ -1,40 +1,45 @@
 import json
 from datetime import datetime, timezone
 
-ACCESS_FILE = "./data/access.json"
+class AccessControl:
+    _ACCESS_FILE = "./data/access.json"
 
-def load_access():
-    try:
-        with open(ACCESS_FILE, "r") as f:
-            return json.load(f)
-    except FileNotFoundError:
-        return {}
+    def __init__(self):
+        self._access = self._load_access()
 
-def save_access(data):
-    with open(ACCESS_FILE, "w") as f:
-        json.dump(data, f)
+    def _load_access(self) -> dict:
+        try:
+            with open(self._ACCESS_FILE, "r") as f:
+                return json.load(f)
+        except FileNotFoundError:
+            return {}
+    
+    def _save_access(self):
+        with open(self._ACCESS_FILE, "w") as f:
+            json.dump(self._access, f)
 
-def get_grantor(user_id, gate):
-    access = load_access().get(str(user_id), {})
-    entry = access.get(gate) or access.get("all")
-    return entry.get("grantor", "")
+    def get_grantor(self, user_id: str, gate: str) -> str:
+        access = self._access.get(user_id, {})
+        entry = access.get(gate) or access.get("all")
+        return entry.get("grantor", "")
 
-def can_open_gate(user_id, gate):
-    access = load_access().get(str(user_id), {})
-    entry = access.get(gate) or access.get("all")
-    if not entry or entry["type"] != "timed":
+    def can_open_gate(self, user_id: str, gate: str) -> bool:
+        access = self._access.get(user_id, {})
+        entry = access.get(gate) or access.get("all")
+        if not entry or entry["type"] != "timed":
+            return False
+        if datetime.now(timezone.utc) < datetime.fromisoformat(entry["expires_at"].replace("Z", "+00:00")):
+            return True
         return False
-    if datetime.now(timezone.utc) < datetime.fromisoformat(entry["expires_at"].replace("Z", "+00:00")):
-        return True
-    return False
 
-def grant_access(user_id, gate, expires_at, grantor_id):
-    access = load_access()
-    user_access = access.get(str(user_id), {})
-    user_access[gate] = {
-        "type": "timed",
-        "expires_at": expires_at,
-        "grantor": grantor_id
-    }
-    access[str(user_id)] = user_access
-    save_access(access)
+    def grant_access(self, user_id: str, gate: str, expires_at: str, grantor_id: str):
+        user_access = self._access.get(user_id, {})
+        user_access[gate] = {
+            "type": "timed",
+            "granted_at": datetime.now(timezone.utc).isoformat(),
+            "expires_at": expires_at,
+            "grantor": grantor_id,
+            "last_used_at": None
+        }
+        self._access[user_id] = user_access
+        self._save_access()
diff --git a/avconnect.py b/avconnect.py
index efa35e8..d2e7963 100644
--- a/avconnect.py
+++ b/avconnect.py
@@ -1,42 +1,46 @@
 import requests
 import pprint
-
-BASE_URL = "https://www.avconnect.it"
+from fake_useragent import UserAgent
+from commons import Credential
 
 class AVConnectAPI:
-    def __init__(self, username: str, password: str):
-        self.username = username
-        self.password = password
-        self.session = requests.Session()
-        self.authenticated = False
+    _BASE_URL = "https://www.avconnect.it"
 
-    def authenticate(self) -> bool:
-        login_url = f"{BASE_URL}/loginone.php"
+    def __init__(self, credentials: Credential):
+        self._ua = UserAgent(browsers=["Chrome Mobile"], os=["Android"], platforms=["mobile"]).random
+        self._username = credentials.username
+        self._password = credentials.password
+        self._session = requests.Session()
+        self._authenticated = False
+
+    def _authenticate(self) -> bool:
+        login_url = f"{self._BASE_URL}/loginone.php"
         headers = {
             "Content-Type": "application/x-www-form-urlencoded"
         }
-        payload = f"userid={self.username}&password={self.password}&entra=Login"
-        response = self.session.post(login_url, data=payload, headers=headers)
+        payload = f"userid={self._username}&password={self._password}&entra=Login"
+        response = self._session.post(login_url, data=payload, headers=headers)
 
-        if response.ok and "PHPSESSID" in self.session.cookies:
-            self.authenticated = True
+        if response.ok and "PHPSESSID" in self._session.cookies:
+            self._authenticated = True
             return True
         return False
 
-    def exec_gate_macro(self, id_macro) -> requests.Response:
-        if not self.authenticated and not self.authenticate():
+    def exec_gate_macro(self, id_macro) -> bool:
+        if not self._authenticated and not self._authenticate():
             raise Exception("Authentication failed.")
         
-        exec_url = f"{BASE_URL}/exemacrocom.php"
+        exec_url = f"{self._BASE_URL}/exemacrocom.php"
         headers = {
+            "User-Agent": self._ua,
             "Content-Type": "application/x-www-form-urlencoded; charset=UTF-8"
         }
         payload = f"idmacrocom={id_macro}&nome=16"
 
-        response = self.session.prepare_request(requests.Request("POST", exec_url, data=payload, headers=headers))
+        response = self._session.prepare_request(requests.Request("POST", exec_url, data=payload, headers=headers))
         pprint.pprint(response.headers)
         return True
-        #response = self.session.post(exec_url, data=payload, headers=headers)
+        #response = self._session.post(exec_url, data=payload, headers=headers)
         #if response.ok:
         #    return True
         #return False
\ No newline at end of file
diff --git a/bot.py b/bot.py
index 91254c2..b363762 100644
--- a/bot.py
+++ b/bot.py
@@ -1,38 +1,42 @@
 from telegram import Update
 from telegram.ext import Application, CommandHandler, MessageHandler, ContextTypes
-from config import get_bot_token, get_commands
-from access_control import can_open_gate, grant_access, get_grantor
-from gates import get_name, open_gate
-from users import get_role, set_credentials, get_credentials, get_grantor_credentials, get_admins, update_user, get_fullname, get_username
+from config import BotConfig
+from gates import Gates
+from users import Users, Credential, Role
 
-BOT_NAME = "lagomareGateKeeperBot"
+BOT_USERNAME = "lagomareGateKeeperBot"
+bot_config = BotConfig(BOT_USERNAME)
+gates = Gates()
+users = Users()
 
 async def post_init(application: Application) -> None:
-    bot_commands = get_commands(BOT_NAME)
+    bot_commands = bot_config.commands
     await application.bot.set_my_commands(bot_commands)
-    await application.bot.set_my_name("Lagomare GateKeeper Bot")
-    await application.bot.set_my_description("This bot is used to open Lagomare gates by members. You can also request timed access if you are a guest.")
-    await application.bot.set_my_short_description("Open Lagomare gates or request guest access")
+    await application.bot.set_my_name(bot_config.name)
+    await application.bot.set_my_description(bot_config.description)
+    await application.bot.set_my_short_description(bot_config.short_description)
 
 async def updateuser(update: Update, context: ContextTypes.DEFAULT_TYPE):
     user_id = str(update.effective_user.id)
     username = update.effective_user.username
     fullname = update.effective_user.full_name
-    update_user(user_id, username, fullname)
+    users.update_user(user_id, username, fullname)
 
 async def start(update: Update, context: ContextTypes.DEFAULT_TYPE):
-    await update.message.reply_text("Welcome to GatekeeperBot! Use `/setcredentials` to configure your access.")
+    await update.message.reply_text("Welcome to GatekeeperBot! Use `/setcredentials` to configure your access")
 
 async def setcredentials(update: Update, context: ContextTypes.DEFAULT_TYPE):
     user_id = str(update.effective_user.id)
     args = context.args
     if len(args) != 2:
         return await update.message.reply_text("Usage: `/setcredentials <username> <password>`")
-    role = get_role(user_id)
+    role = users.get_role(user_id)
     if role not in ("admin", "member"):
-        return await update.message.reply_text("Only members or admins can set credentials.")
-    set_credentials(user_id, args[0], args[1])
-    await update.message.reply_text("Credentials saved.")
+        return await update.message.reply_text("Only members or admins can set credentials")
+    if users.set_credentials(user_id, Credential(args[0], args[1])):
+        await update.message.reply_text("Credentials saved")
+    else:
+        await update.message.reply_text("Error saving credentials")
 
 async def opengate(update: Update, context: ContextTypes.DEFAULT_TYPE):
     user_id = str(update.effective_user.id)
@@ -40,55 +44,57 @@ async def opengate(update: Update, context: ContextTypes.DEFAULT_TYPE):
     if not args:
         return await update.message.reply_text("Usage: `/opengate <gate>`")
     gate = args[0]
-    role = get_role(user_id)
-    if role in ("admin", "member"):
-        creds = get_credentials(user_id)
+    gate_name = gates.get_name(gate)
+    role = users.get_role(user_id)
+    if role in (Role.ADMIN, Role.MEMBER):
+        creds = users.get_credentials(user_id)
         if not creds:
-            return await update.message.reply_text("Please set your credentials with `/setcredentials` first.")
-    elif role == "guest" and can_open_gate(user_id, gate):
-        creds = get_grantor_credentials(user_id, gate)
+            return await update.message.reply_text("Please set your credentials with `/setcredentials` first")
+    elif role == Role.GUEST and users.can_open_gate(user_id, gate):
+        grantor = users.get_grantor(user_id, gate)
+        creds = users.get_credentials(grantor)
+        if not grantor:
+            return await update.message.reply_text("No valid grantor available.")
         if not creds:
             return await update.message.reply_text("No valid grantor credentials available.")
-        grantor = get_grantor(user_id, gate)
-        if grantor:
-            try:
-                await context.bot.send_message(chat_id=grantor, text=f"Guest {user_id} opened {get_name(gate)}")
-            except Exception as e:
-                print(f"Failed to notify {grantor} that guest {user_id} opened {get_name(gate)}: {e}")
+        #TODO: update guest last_used_at
+        try:
+            await context.bot.send_message(chat_id=grantor, text=f"Guest {user_id} opened {gate_name}")
+        except Exception as e:
+            print(f"Failed to notify {grantor} that guest {user_id} opened {gate_name}: {e}")
     else:
         return await update.message.reply_text("Access denied.")
 
-    if open_gate(gate, creds):
-        return await update.message.reply_text(f"Gate {get_name(gate)} opened!")
-    await update.message.reply_text(f"ERROR: Cannot open gate {get_name(gate)}")
+    if gates.open_gate(gate, creds):
+        return await update.message.reply_text(f"Gate {gate_name} opened!")
+    await update.message.reply_text(f"ERROR: Cannot open gate {gate_name}")
 
 async def requestaccess(update: Update, context: ContextTypes.DEFAULT_TYPE):
     user_id = str(update.effective_user.id)
-    role = get_role(user_id)
+    role = users.get_role(user_id)
     if role not in ("guest"):
         return await update.message.reply_text("Only guests can request access.")
     if not context.args:
-        return await update.message.reply_text("Usage: `/requestaccess <gate>`")
-    gate = context.args[0]
-    requester = get_fullname(user_id) or get_username(user_id)
-    text = (f"Access request: {requester} ({user_id}) requests access to *{gate}*.\nUse `/approve {user_id} {gate} 60` to grant access.")
+        return await update.message.reply_text("Usage: `/requestaccess`", parse_mode="Markdown")
+    requester = users.get_fullname(user_id) or users.get_username(user_id)
+    text = (f"Access request: {requester} ({user_id}) requests access.\nUse `/approve {user_id} <gate|all> YYYY-MM-DDTHH:MM:SSZ` to grant access.")
     await update.message.reply_text("Your request has been submitted.")
-    admins = get_admins()
+    admins = users.get_admins()
     for admin_id in admins:
         try:
             await context.bot.send_message(chat_id=admin_id, text=text, parse_mode="Markdown")
         except Exception as e:
-            print(f"Failed to notify {admin_id} that guest {user_id} requested access for {gate}: {e}")
+            print(f"Failed to notify {admin_id} that guest {user_id} requested access: {e}")
 
 async def approve(update: Update, context: ContextTypes.DEFAULT_TYPE):
     approver_id = str(update.effective_user.id)
-    if get_role(approver_id) != "admin":
+    if users.get_role(approver_id) != "admin":
         return await update.message.reply_text("Only admins can approve access.")
     try:
         user_id = context.args[0]
         gate = context.args[1]
         expires_at = context.args[2]
-        grant_access(user_id, gate, expires_at, grantor_id=approver_id)
+        users.grant_access(user_id, gate, expires_at, grantor_id=approver_id)
         await update.message.reply_text(f"Access to {gate} granted to user {user_id}.")
         try:
             await context.bot.send_message(chat_id=user_id, text=f"Access granted to gate {gate} up to {expires_at}")
@@ -98,7 +104,7 @@ async def approve(update: Update, context: ContextTypes.DEFAULT_TYPE):
         await update.message.reply_text("Usage: `/approve <user_id> <gate|all> <expires_at:YYYY-MM-DDTHH:MM:SSZ>`")
 
 def main():
-    app = Application.builder().token(get_bot_token(BOT_NAME)).post_init(post_init).build()
+    app = Application.builder().token(bot_config.token).post_init(post_init).build()
     app.add_handler(MessageHandler(None, updateuser), group=1)
     app.add_handler(CommandHandler("start", start))
     app.add_handler(CommandHandler("setcredentials", setcredentials))
diff --git a/commons.py b/commons.py
new file mode 100644
index 0000000..094dbc2
--- /dev/null
+++ b/commons.py
@@ -0,0 +1,32 @@
+from enum import Enum
+
+class Status(Enum):
+    ENABLED = 1
+    DISABLED = 0
+
+class Credential:
+    def __init__(self, username: str, password: str):
+        self._username: str = username
+        self._password: str = password
+    
+    def __dict__(self):
+        return {
+            "username": self._username,
+            "password": self._password
+        }
+    
+    @property
+    def username(self) -> str:
+        return self._username
+    
+    @username.setter
+    def username(self, username: str):
+        self._username = username
+    
+    @property
+    def password(self) -> str:
+        return self._password
+    
+    @password.setter
+    def password(self, password: str):
+        self._password = password
\ No newline at end of file
diff --git a/config.py b/config.py
index 425d111..a5dac82 100644
--- a/config.py
+++ b/config.py
@@ -1,21 +1,50 @@
 import json
 from telegram import BotCommand
 
-ACCESS_FILE = "./data/config.json"
+class BotConfig:
 
-def load_config():
-    try:
-        with open(ACCESS_FILE, "r") as f:
-            return json.load(f)
-    except FileNotFoundError:
-        return {}
+    def __init__(self, bot_username: str, json_path: str = "./data/config.json"):
+        self._json_path: str = json_path
+        self._bot_username: str = bot_username
+        self._token: str = ""
+        self._name: str = ""
+        self._description: str = ""
+        self._short_description: str = ""
+        self._commands: list[BotCommand] = []
 
-def get_bot_token(bot_name):
-    config = load_config().get(str(bot_name), {})
-    return config.get("token", "")
+        self._load_config()
+        
+    def _load_config(self):
+        try:
+            with open(self._json_path, "r") as f:
+                config = json.load(f).get(self._bot_username, {})
+                self._token = config.get("token", "")
+                self._name = config.get("name", "")
+                self._description = config.get("description", "")
+                self._short_description = config.get("short_description", "")
+                self._commands = [
+                    BotCommand(command, description)
+                    for command, description in config.get("commands", {}).items()
+                ]
+        except Exception:
+            return {}
 
-def get_commands(bot_name):
-    config = load_config().get(str(bot_name), {})
-    commands = config.get("commands", {})
-    bot_commands = []
-    return [BotCommand(command, description) for command, description in commands.items()]
\ No newline at end of file
+    @property
+    def token(self) -> str:
+        return self._token
+    
+    @property
+    def name(self) -> str:
+        return self._name
+    
+    @property
+    def description(self) -> str:
+        return self._description
+    
+    @property
+    def short_description(self) -> str:
+        return self._short_description
+    
+    @property
+    def commands(self) -> list[BotCommand]:
+        return self._commands
\ No newline at end of file
diff --git a/gates.py b/gates.py
index 5b18783..9cd1592 100644
--- a/gates.py
+++ b/gates.py
@@ -1,27 +1,54 @@
 import json
 from avconnect import AVConnectAPI
+from commons import Status, Credential
 
-GATE_FILE = "./data/gates.json"
+class _Gate:
+    def __init__(self, id: str, name: str, status: int | Status = Status.ENABLED):
+        self._id: str = id
+        self._name: str = name
+        self._status: Status = status if isinstance(status, Status) else Status(status)
+    
+    @property
+    def id(self) -> str:
+        return self._id
+    
+    @property
+    def name(self) -> str:
+        return self._name
+    
+    @property
+    def status(self) -> Status:
+        return self._status
+    
+    @status.setter
+    def status(self, status: int | Status):
+        self._status = status if isinstance(status, Status) else Status(status)
 
-def load_gates():
-    try:
-        with open(GATE_FILE, "r") as f:
-            return json.load(f)
-    except FileNotFoundError:
-        return {}
+class Gates:
 
-def get_name(gate):
-    return load_gates().get(str(gate), {}).get("name", "")
+    def __init__(self, json_path: str = "./data/gates.json"):
+        self._json_path: str = json_path
+        self._gates: dict[str, _Gate] = self._load_gates()
 
-def open_gate(gate, credentials):
-    gate_info = load_gates().get(str(gate), {})
-    if not gate_info:
-        return False
-    gate_id = gate_info["id"]
+    def _load_gates(self):
+        try:
+            with open(self._json_path, "r") as file:
+                gates_data = json.load(file)
+                return {gate: _Gate(data["id"], data["name"]) for gate, data in gates_data.items()}
+        except Exception:
+            return {}
 
-    try:
-        api = AVConnectAPI(credentials["username"], credentials["password"])
-        return api.exec_gate_macro(gate_id)
-    except Exception as e:
-        print(f"Failed to open gate {gate}: {e}")
-        return False
+    def get_name(self, gate: str) -> str:
+        return self._gates.get(gate, {}).name
+
+    def open_gate(self, gate: str, credentials: Credential) -> bool:
+        if gate not in self._gates.keys():
+            return False
+        if self._gates[gate].status == Status.DISABLED:
+            return False
+        try:
+            api = AVConnectAPI(credentials)
+            return api.exec_gate_macro(self._gates[gate].id)
+        except Exception as e:
+            print(f"Failed to open gate {gate}: {e}")
+            return False
diff --git a/requirements.txt b/requirements.txt
index 5050803..6379964 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1 +1,2 @@
-python-telegram-bot==20.7
\ No newline at end of file
+python-telegram-bot==20.7
+fake-useragent==2.2.0
\ No newline at end of file
diff --git a/users.py b/users.py
index dddcf5d..7e7e187 100644
--- a/users.py
+++ b/users.py
@@ -1,65 +1,213 @@
 import json
+from enum import Enum
+from datetime import datetime, timezone
+from commons import Status, Credential
 
-USER_FILE = "./data/users.json"
+class Role(Enum):
+    ADMIN = "admin"
+    MEMBER = "member"
+    GUEST = "guest"
 
-def load_users():
-    try:
-        with open(USER_FILE, "r") as f:
-            return json.load(f)
-    except FileNotFoundError:
-        return {}
-
-def save_users(data):
-    with open(USER_FILE, "w") as f:
-        json.dump(data, f)
-
-def update_user(user_id, username, fullname):
-    has_changes = False
-    users = load_users()
-    user = users.get(str(user_id), {})
+class _Grant:
+    def __init__(self, grantor: str, expires_at: datetime, granted_at: datetime = datetime.now(), last_used_at: datetime = None, status: int | Status = Status.ENABLED):
+        self._grantor: str = grantor
+        self._granted_at: datetime = granted_at
+        self._expires_at = expires_at
+        self._last_used_at = last_used_at
+        self._status: Status = status
     
-    if user.get("username", "") != username:
-        has_changes = True
-        user["username"] = username
-    if user.get("fullname", "") != fullname:
-        has_changes = True
-        user["fullname"] = fullname
-    if not user.get("role"):
-        has_changes = True
-        user["role"] = "guest"
+    def __dict__(self):
+        return {
+            "grantor": self._grantor,
+            "granted_at": self._granted_at.isoformat(),
+            "expires_at": self._expires_at.isoformat(),
+            "last_used_at": self._last_used_at.isoformat() if self._last_used_at else None,
+            "status": self._status.value
+        }
+
+    @property
+    def grantor(self) -> str:
+        return self._grantor
     
-    if has_changes:
-        users[str(user_id)] = user
-        save_users(users)
+    @grantor.setter
+    def grantor(self, grantor: str):
+        self._grantor = grantor
+    
+    @property
+    def granted_at(self) -> datetime:
+        return self._granted_at
+    
+    @property
+    def expires_at(self) -> datetime:
+        return self._expires_at
+    
+    @property
+    def last_used_at(self) -> datetime:
+        return self._last_used_at
+    
+    @property
+    def status(self) -> Status:
+        return self._status
+
+class _User:
+    def __init__(self, id: str, username: str, fullname: str, role: str | Role = Role.GUEST, credentials: dict = None, grants: dict = None, status: int | Status = Status.ENABLED):
+        self._id: str = id
+        self._username: str = username
+        self._fullname: str = fullname
+        self._role: Role = role if isinstance(role, Role) else Role(role)
+        self._credentials: Credential = Credential(**credentials)
+        self._grants: dict[str, _Grant] = {gate: _Grant(**grant) for gate, grant in grants.items()} if grants else {}
+        self._status: Status = status if isinstance(status, Status) else Status(status)
+    
+    def __dict__(self):
+        return {
+            "id": self._id,
+            "username": self._username,
+            "fullname": self._fullname,
+            "role": self._role.value,
+            "credentials": self._credentials.__dict__(),
+            "grants": {gate: grant.__dict__() for gate, grant in self._grants.items()},
+            "status": self._status.value
+        }
+    
+    @property
+    def id(self) -> str:
+        return self._id
+    
+    @property
+    def username(self) -> str:
+        return self._username
+    
+    @username.setter
+    def username(self, username: str):
+        self._username = username
+    
+    @property
+    def fullname(self) -> str:
+        return self._fullname
+    
+    @fullname.setter
+    def fullname(self, fullname: str):
+        self._fullname = fullname
+
+    @property
+    def role(self) -> Role:
+        return self._role
+    
+    @role.setter
+    def role(self, role: str | Role):
+        self._role = role if isinstance(role, Role) else Role(role)
+    
+    @property
+    def credentials(self) -> Credential:
+        return self._credentials
+    
+    @credentials.setter
+    def credentials(self, credentials: Credential):
+        self._credentials = credentials
+    
+    @property
+    def grants(self) -> dict[str, _Grant]:
+        return self._grants
+
+    @property
+    def status(self) -> Status:
+        return self._status
+    
+    @status.setter
+    def status(self, status: int | Status):
+        self._status = status if isinstance(status, Status) else Status(status)
+    
+    def grant(self, gate: str, grant: _Grant):
+        self._grants[gate] = grant
+    
+    def revoke(self, gate: str):
+        self._grants.pop(gate, None) 
 
 
-def get_role(user_id):
-    return load_users().get(str(user_id), {}).get("role", "guest")
+class Users:
+    def __init__(self, json_path: str = "./data/users.json"):
+        self._json_path: str = json_path
+        self._users = self._load_users()
 
-def get_username(user_id):
-    return load_users().get(str(user_id), {}).get("username", None)
+    def _load_users(self) -> dict[str, _User]:
+        try:
+            with open(self._json_path, "r") as f:
+                return {uid: _User(**info) for uid, info in json.load(f)}
+        except Exception:
+            return {}
 
-def get_fullname(user_id):
-    return load_users().get(str(user_id), {}).get("fullname", None)
-
-def set_credentials(user_id, username, password):
-    users = load_users()
-    user = users.get(str(user_id), {})
-    user["credentials"] = {"username": username, "password": password}
-    users[str(user_id)] = user
-    save_users(users)
-
-def get_credentials(user_id):
-    return load_users().get(str(user_id), {}).get("credentials")
-
-def get_grantor_credentials(user_id, gate):
-    from access_control import load_access
-    access = load_access().get(str(user_id), {})
-    entry = access.get(gate) or access.get("all")
-    if not entry:
+    def _save_users(self) -> None:
+        with open(self._json_path, "w") as f:
+            json.dump({uid: user.__dict__ for uid, user in self._users.items()}, f, default=str)
+    
+    def update_user(self, id: str, username: str, fullname: str) -> bool:
+        if id in self._users.keys():
+            self._users[id].username = username
+            self._users[id].fullname = fullname
+        else:
+            self._users[id] = _User(id, username, fullname)
+        self._save_users()
+        return True
+    
+    def get_username(self, id: str) -> str:
+        if id in self._users.keys():
+            return self._users[id].username
         return None
-    grantor_id = entry.get("grantor")
-    return get_credentials(grantor_id)
+    
+    def get_fullname(self, id: str) -> str:
+        if id in self._users.keys():
+            return self._users[id].fullname
+        return None
+    
+    def get_status(self, id: str) -> Status:
+        if id in self._users.keys():
+            return self._users[id].status
+        return Status.DISABLED
+    
+    def get_role(self, id: str) -> Role:
+        if id in self._users.keys():
+            return self._users[id].role
+        return Role.GUEST
 
-def get_admins():
-    return [uid for uid, u in load_users().items() if u.get("role") == "admin"]
+    def get_credentials(self, id: str) -> Credential:
+        if id in self._users.keys():
+            return self._users[id].credentials
+        return None
+    
+    def set_credentials(self, id: str, credentials: Credential) -> bool:
+        if id in self._users.keys():
+            self._users[id].credentials = credentials
+            return True
+        return False
+    
+    def can_open_gate(self, id: str, gate: str) -> bool:
+        if id in self._users.keys():
+            if gate in self._users[id].grants.keys():
+                if self._users[id].grants[gate].status == Status.ENABLED:
+                    if self._users[id].grants[gate].expires_at > datetime.now(timezone.utc):
+                        return True
+        return False
+    
+    def get_grantor(self, id: str, gate: str) -> str:
+        if id in self._users.keys():
+            if gate in self._users[id].grants.keys():
+                return self._users[id].grants[gate].grantor
+        return None
+
+    def get_admins(self) -> list[str]:
+        return [uid for uid, user in self._users.items() if user.role == Role.ADMIN]
+    
+    def grant_access(self, id: str, gate: str, expires_at: datetime, grantor_id: str) -> bool:
+        if id in self._users.keys():
+            self._users[id].grant(gate, _Grant(grantor_id, expires_at))
+            self._save_users()
+            return True
+        return False
+    
+    def revoke_access(self, id: str, gate: str) -> bool:
+        if id in self._users.keys():
+            self._users[id].revoke(gate)
+            self._save_users()
+            return True
+        return False