Allow configuration of wifi credentials + hostname via settings.json

What it says on the tin.

• Replaces the hardcoded camp wifi credentials with ssid + psk read from settings.json. Also allows configuration of the badge network hostname.
• Adds barebones code for string type 'tunables'/settings. (Read only, can only be set via settings.json at the moment)
• Declaratively define hierarchical settings (sub-)menu structure
  • Only WiFi settings have their own submenu for now

Known issues: Display of string settings values in the settings screen is a bit glitchy. Not quite sure why, but I also haven't spent much time debugging it since this is just a barebones implementation for the functionality and the display issue is purely cosmetic and doesn't affect the core features of this patch.

python_payload/st3m/settings.py

@@ -11,8 +11,8 @@ request.
 import json
 
 from st3m import InputState, Responder, logging
-from st3m.goose import ABCBase, abstractmethod, Any, Dict, List, Optional, Callable
-from st3m.ui.menu import MenuController, MenuItem, MenuItemBack
+from st3m.goose import ABCBase, abstractmethod, Any, Dict, List, Tuple, Optional, Callable, Union, TYPE_CHECKING
+from st3m.ui.menu import MenuController, MenuItem, MenuItemBack, MenuItemForeground
 from st3m.ui.elements.menus import SimpleMenu
 from st3m.ui.view import ViewManager
 from st3m.utils import lerp, ease_out_cubic, reduce
@@ -337,7 +337,9 @@ onoff_wifi = OnOffTunable("Enable WiFi", "system.wifi.enabled", False)
 str_wifi_ssid = StringTunable("WiFi SSID", "system.wifi.ssid", "Camp2023-open")
 str_wifi_psk = StringTunable("WiFi Password", "system.wifi.psk", None)
 str_hostname = StringTunable("Hostname", "system.hostname", "flow3r")
-all_settings: List[UnaryTunable] = [
+
+# List of all settings to be loaded/saved
+load_save_settings: List[UnaryTunable] = [
     onoff_show_tray,
     onoff_button_swap,
     onoff_debug,
@@ -348,6 +350,27 @@ all_settings: List[UnaryTunable] = [
     str_hostname,
 ]
 
+if TYPE_CHECKING:
+    MenuStructureEntry = Union[UnaryTunable, Tuple[str, List['MenuStructureEntry']]]
+    MenuStructure = List[MenuStructureEntry]
+
+# WiFi submenu
+wifi_settings: MenuStructure = [
+    onoff_wifi,
+    str_wifi_ssid,
+    str_wifi_psk,
+    str_hostname,
+]
+
+# Main settings menu
+settings_menu_structure: MenuStructure = [
+    onoff_show_tray,
+    onoff_button_swap,
+    onoff_debug,
+    onoff_debug_touch,
+    ("Wifi", wifi_settings)
+]
+
 
 def load_all() -> None:
     """
@@ -362,7 +385,7 @@ def load_all() -> None:
         return
 
     log.info("Loaded settings from flash")
-    for setting in all_settings:
+    for setting in load_save_settings:
         setting.load(data)
 
 
@@ -383,7 +406,7 @@ def save_all() -> None:
     Save all settings to flash.
     """
     res: Dict[str, Any] = {}
-    for setting in all_settings:
+    for setting in load_save_settings:
         res = _update(res, setting.save())
     try:
         with open("/flash/settings.json", "w") as f:
@@ -395,12 +418,22 @@ def save_all() -> None:
     log.info("Saved settings to flash")
 
 
-def build_menu() -> SimpleMenu:
+def build_menu_recursive(items: MenuStructure) -> SimpleMenu:
     """
-    Return a SimpleMenu for all settings.
+    Recursively build a menu for the given setting structure.
     """
     mib: MenuItem = SettingsMenuItemBack()
     positions: List[MenuItem] = [
         mib,
-    ] + [SettingsMenuItem(t) for t in all_settings]
+    ] + [
+        SettingsMenuItem(t) if isinstance(t, UnaryTunable) else MenuItemForeground(t[0], build_menu_recursive(t[1])) for t in items
+    ]
+
     return SettingsMenu(positions)
+
+
+def build_menu() -> SimpleMenu:
+    """
+    Return a SettingsMenu for all settings.
+    """
+    return build_menu_recursive(settings_menu_structure)