"""
Settings Registry - Central definition of all application settings.

This file defines ALL configurable settings in the application with:
- Storage location (database in /config, localStorage, env)
- Scope (global or user-specific)
- Default values
- Data types
- Descriptions

IMPORTANT: Any new setting MUST be added here first.
"""

from enum import Enum
from dataclasses import dataclass, field
from typing import Any, Optional


class SettingScope(Enum):
    """Defines who the setting applies to."""
    GLOBAL = "global"           # Same for all users, admin-controlled
    USER_SPECIFIC = "user"      # Each user can have different value
    SYSTEM = "system"           # Infrastructure/env settings, not in DB


class SettingStorage(Enum):
    """Defines where the setting is stored."""
    DATABASE = "database"       # Stored in /config/config.db (settings table)
    LOCAL_STORAGE = "localStorage"  # Browser localStorage (frontend only)
    ENV = "env"                 # Environment variable (.env file)
    MEMORY = "memory"           # Runtime only, not persisted


class SettingType(Enum):
    """Data type of the setting value."""
    BOOLEAN = "boolean"
    STRING = "string"
    INTEGER = "integer"
    JSON = "json"
    LIST = "list"


@dataclass
class SettingDefinition:
    """Definition of a single setting."""
    key: str
    type: SettingType
    scope: SettingScope
    storage: SettingStorage
    default: Any
    description: str
    category: str
    admin_only: bool = True          # Only admins can modify (for DB settings)
    sync_to_frontend: bool = True    # Should be synced to frontend
    choices: Optional[list] = None   # Valid values if restricted


# =============================================================================
# SETTINGS REGISTRY
# =============================================================================

SETTINGS_REGISTRY: dict[str, SettingDefinition] = {}


def register_setting(setting: SettingDefinition) -> SettingDefinition:
    """Register a setting in the registry."""
    SETTINGS_REGISTRY[setting.key] = setting
    return setting


# =============================================================================
# THEME SETTINGS (Global, Database)
# =============================================================================

register_setting(SettingDefinition(
    key="theme_accent_color",
    type=SettingType.STRING,
    scope=SettingScope.GLOBAL,
    storage=SettingStorage.DATABASE,
    default="auto",
    description="Accent color for UI elements",
    category="theme",
    choices=["auto", "blue", "purple", "green", "orange", "pink", "red", "teal", "amber", "indigo", "cyan", "rose"]
))

register_setting(SettingDefinition(
    key="theme_border_radius",
    type=SettingType.STRING,
    scope=SettingScope.GLOBAL,
    storage=SettingStorage.DATABASE,
    default="large",
    description="Border radius style for UI components",
    category="theme",
    choices=["small", "medium", "large"]
))

register_setting(SettingDefinition(
    key="theme_sidebar_style",
    type=SettingType.STRING,
    scope=SettingScope.GLOBAL,
    storage=SettingStorage.DATABASE,
    default="default",
    description="Visual style of the sidebar",
    category="theme",
    choices=["default", "dark", "light"]
))

register_setting(SettingDefinition(
    key="theme_density",
    type=SettingType.STRING,
    scope=SettingScope.GLOBAL,
    storage=SettingStorage.DATABASE,
    default="compact",
    description="UI density/spacing",
    category="theme",
    choices=["compact", "comfortable", "spacious"]
))

register_setting(SettingDefinition(
    key="theme_font_family",
    type=SettingType.STRING,
    scope=SettingScope.GLOBAL,
    storage=SettingStorage.DATABASE,
    default="sans",
    description="Font family for the application",
    category="theme",
    choices=["sans", "inter", "roboto"]
))

register_setting(SettingDefinition(
    key="theme_color_palette",
    type=SettingType.STRING,
    scope=SettingScope.GLOBAL,
    storage=SettingStorage.DATABASE,
    default="monochrome",
    description="Color palette preset",
    category="theme",
    choices=["default", "monochrome", "monochromeBlue", "sepia", "nord", "dracula", "solarized", "github", "ocean", "forest", "midnight", "sunset"]
))

register_setting(SettingDefinition(
    key="theme_custom_colors",
    type=SettingType.JSON,
    scope=SettingScope.GLOBAL,
    storage=SettingStorage.DATABASE,
    default="{}",
    description="Custom color overrides as JSON",
    category="theme"
))

register_setting(SettingDefinition(
    key="theme_dark_mode_location",
    type=SettingType.STRING,
    scope=SettingScope.GLOBAL,
    storage=SettingStorage.DATABASE,
    default="sidebar",
    description="Where to show dark mode toggle",
    category="theme",
    choices=["sidebar", "user_menu"]
))

register_setting(SettingDefinition(
    key="theme_language_location",
    type=SettingType.STRING,
    scope=SettingScope.GLOBAL,
    storage=SettingStorage.DATABASE,
    default="sidebar",
    description="Where to show language toggle",
    category="theme",
    choices=["sidebar", "user_menu"]
))

register_setting(SettingDefinition(
    key="theme_show_dark_mode_toggle",
    type=SettingType.BOOLEAN,
    scope=SettingScope.GLOBAL,
    storage=SettingStorage.DATABASE,
    default=True,
    description="Show/hide dark mode toggle globally",
    category="theme"
))

register_setting(SettingDefinition(
    key="theme_show_language_toggle",
    type=SettingType.BOOLEAN,
    scope=SettingScope.GLOBAL,
    storage=SettingStorage.DATABASE,
    default=False,
    description="Show/hide language toggle globally",
    category="theme"
))

register_setting(SettingDefinition(
    key="theme_show_dark_mode_login",
    type=SettingType.BOOLEAN,
    scope=SettingScope.GLOBAL,
    storage=SettingStorage.DATABASE,
    default=True,
    description="Show dark mode toggle on login page",
    category="theme"
))

register_setting(SettingDefinition(
    key="theme_show_language_login",
    type=SettingType.BOOLEAN,
    scope=SettingScope.GLOBAL,
    storage=SettingStorage.DATABASE,
    default=False,
    description="Show language toggle on login page",
    category="theme"
))

register_setting(SettingDefinition(
    key="theme_tab_bar_position",
    type=SettingType.STRING,
    scope=SettingScope.GLOBAL,
    storage=SettingStorage.DATABASE,
    default="top",
    description="Position of the tab bar (top, bottom, or responsive)",
    category="theme",
    choices=["top", "bottom", "responsive"]
))


# =============================================================================
# MODULE/FEATURE SETTINGS (Global, Database)
# =============================================================================

register_setting(SettingDefinition(
    key="module_feature1_admin_enabled",
    type=SettingType.BOOLEAN,
    scope=SettingScope.GLOBAL,
    storage=SettingStorage.DATABASE,
    default=True,
    description="Enable Feature 1 module for admin users",
    category="modules"
))

register_setting(SettingDefinition(
    key="module_feature1_user_enabled",
    type=SettingType.BOOLEAN,
    scope=SettingScope.GLOBAL,
    storage=SettingStorage.DATABASE,
    default=True,
    description="Enable Feature 1 module for regular users",
    category="modules"
))

register_setting(SettingDefinition(
    key="module_feature2_admin_enabled",
    type=SettingType.BOOLEAN,
    scope=SettingScope.GLOBAL,
    storage=SettingStorage.DATABASE,
    default=True,
    description="Enable Feature 2 module for admin users",
    category="modules"
))

register_setting(SettingDefinition(
    key="module_feature2_user_enabled",
    type=SettingType.BOOLEAN,
    scope=SettingScope.GLOBAL,
    storage=SettingStorage.DATABASE,
    default=True,
    description="Enable Feature 2 module for regular users",
    category="modules"
))

register_setting(SettingDefinition(
    key="module_feature3_admin_enabled",
    type=SettingType.BOOLEAN,
    scope=SettingScope.GLOBAL,
    storage=SettingStorage.DATABASE,
    default=True,
    description="Enable Feature 3 module for admin users",
    category="modules"
))

register_setting(SettingDefinition(
    key="module_feature3_user_enabled",
    type=SettingType.BOOLEAN,
    scope=SettingScope.GLOBAL,
    storage=SettingStorage.DATABASE,
    default=True,
    description="Enable Feature 3 module for regular users",
    category="modules"
))

register_setting(SettingDefinition(
    key="modules_order",
    type=SettingType.LIST,
    scope=SettingScope.GLOBAL,
    storage=SettingStorage.DATABASE,
    default=["feature1", "feature2", "feature3"],
    description="Order of feature modules in sidebar",
    category="modules"
))


# =============================================================================
# AUTHENTICATION & SECURITY SETTINGS (Global, Database)
# =============================================================================

register_setting(SettingDefinition(
    key="registration_enabled",
    type=SettingType.BOOLEAN,
    scope=SettingScope.GLOBAL,
    storage=SettingStorage.DATABASE,
    default=True,
    description="Allow new user registration",
    category="auth"
))

register_setting(SettingDefinition(
    key="user_mode_enabled",
    type=SettingType.BOOLEAN,
    scope=SettingScope.GLOBAL,
    storage=SettingStorage.DATABASE,
    default=False,
    description="Enable admin/user view mode switching",
    category="auth"
))

# Password policy settings
register_setting(SettingDefinition(
    key="password_min_length",
    type=SettingType.INTEGER,
    scope=SettingScope.GLOBAL,
    storage=SettingStorage.DATABASE,
    default=8,
    description="Minimum password length",
    category="security"
))

register_setting(SettingDefinition(
    key="password_require_uppercase",
    type=SettingType.BOOLEAN,
    scope=SettingScope.GLOBAL,
    storage=SettingStorage.DATABASE,
    default=True,
    description="Require uppercase letters in passwords",
    category="security"
))

register_setting(SettingDefinition(
    key="password_require_lowercase",
    type=SettingType.BOOLEAN,
    scope=SettingScope.GLOBAL,
    storage=SettingStorage.DATABASE,
    default=True,
    description="Require lowercase letters in passwords",
    category="security"
))

register_setting(SettingDefinition(
    key="password_require_digit",
    type=SettingType.BOOLEAN,
    scope=SettingScope.GLOBAL,
    storage=SettingStorage.DATABASE,
    default=True,
    description="Require digits in passwords",
    category="security"
))

register_setting(SettingDefinition(
    key="password_require_special",
    type=SettingType.BOOLEAN,
    scope=SettingScope.GLOBAL,
    storage=SettingStorage.DATABASE,
    default=False,
    description="Require special characters in passwords",
    category="security"
))


# =============================================================================
# UI/LAYOUT SETTINGS (Global, Database)
# =============================================================================

register_setting(SettingDefinition(
    key="sidebar_mode",
    type=SettingType.STRING,
    scope=SettingScope.GLOBAL,
    storage=SettingStorage.DATABASE,
    default="toggle",
    description="Sidebar behavior mode",
    category="ui",
    choices=["collapsed", "expanded", "toggle", "dynamic"]
))

register_setting(SettingDefinition(
    key="show_logo",
    type=SettingType.BOOLEAN,
    scope=SettingScope.GLOBAL,
    storage=SettingStorage.DATABASE,
    default=True,
    description="Show logo in sidebar instead of text",
    category="ui"
))


# =============================================================================
# USER-SPECIFIC SETTINGS (Frontend localStorage)
# These settings are managed by the frontend per-browser/user-session.
# If you need cross-device persistence, implement a per-user DB table + API.
# =============================================================================

register_setting(SettingDefinition(
    key="user_theme_mode",
    type=SettingType.STRING,
    scope=SettingScope.USER_SPECIFIC,
    storage=SettingStorage.LOCAL_STORAGE,
    default="system",
    description="User's preferred theme mode (light/dark/system)",
    category="user_preferences",
    admin_only=False,
    choices=["light", "dark", "system"]
))

register_setting(SettingDefinition(
    key="user_language",
    type=SettingType.STRING,
    scope=SettingScope.USER_SPECIFIC,
    storage=SettingStorage.LOCAL_STORAGE,
    default="en",
    description="User's preferred language",
    category="user_preferences",
    admin_only=False,
    choices=["en", "it"]
))

register_setting(SettingDefinition(
    key="user_sidebar_collapsed",
    type=SettingType.BOOLEAN,
    scope=SettingScope.USER_SPECIFIC,
    storage=SettingStorage.LOCAL_STORAGE,
    default=False,
    description="User's sidebar collapsed state preference",
    category="user_preferences",
    admin_only=False
))

register_setting(SettingDefinition(
    key="user_view_mode",
    type=SettingType.STRING,
    scope=SettingScope.USER_SPECIFIC,
    storage=SettingStorage.LOCAL_STORAGE,
    default="admin",
    description="User's current view mode (admin/user)",
    category="user_preferences",
    admin_only=False,
    choices=["admin", "user"]
))


# =============================================================================
# SYSTEM/ENVIRONMENT SETTINGS (Infrastructure, .env file)
# These are NOT stored in the database
# =============================================================================

register_setting(SettingDefinition(
    key="SECRET_KEY",
    type=SettingType.STRING,
    scope=SettingScope.SYSTEM,
    storage=SettingStorage.ENV,
    default=None,  # Required, no default
    description="Secret key for JWT token signing",
    category="security",
    sync_to_frontend=False
))

register_setting(SettingDefinition(
    key="DATABASE_URL",
    type=SettingType.STRING,
    scope=SettingScope.SYSTEM,
    storage=SettingStorage.ENV,
    default="sqlite:////config/config.db",
    description="Database connection URL",
    category="infrastructure",
    sync_to_frontend=False
))

register_setting(SettingDefinition(
    key="ALGORITHM",
    type=SettingType.STRING,
    scope=SettingScope.SYSTEM,
    storage=SettingStorage.ENV,
    default="HS256",
    description="JWT signing algorithm",
    category="security",
    sync_to_frontend=False
))

register_setting(SettingDefinition(
    key="ACCESS_TOKEN_EXPIRE_MINUTES",
    type=SettingType.INTEGER,
    scope=SettingScope.SYSTEM,
    storage=SettingStorage.ENV,
    default=1440,
    description="JWT token expiration time in minutes",
    category="security",
    sync_to_frontend=False
))

register_setting(SettingDefinition(
    key="ALLOWED_HOSTS",
    type=SettingType.LIST,
    scope=SettingScope.SYSTEM,
    storage=SettingStorage.ENV,
    default=[],
    description="Additional allowed CORS origins",
    category="security",
    sync_to_frontend=False
))

register_setting(SettingDefinition(
    key="LOG_LEVEL",
    type=SettingType.STRING,
    scope=SettingScope.SYSTEM,
    storage=SettingStorage.ENV,
    default="info",
    description="Application logging level",
    category="infrastructure",
    choices=["debug", "info", "warning", "error", "critical"],
    sync_to_frontend=False
))

register_setting(SettingDefinition(
    key="DEBUG",
    type=SettingType.BOOLEAN,
    scope=SettingScope.SYSTEM,
    storage=SettingStorage.ENV,
    default=False,
    description="Enable debug mode",
    category="infrastructure",
    sync_to_frontend=False
))


# =============================================================================
# FRONTEND-ONLY SETTINGS (localStorage, not in database)
# These are managed entirely by the frontend
# =============================================================================

register_setting(SettingDefinition(
    key="token",
    type=SettingType.STRING,
    scope=SettingScope.USER_SPECIFIC,
    storage=SettingStorage.LOCAL_STORAGE,
    default=None,
    description="JWT authentication token",
    category="auth",
    sync_to_frontend=False  # Managed by frontend only
))


# =============================================================================
# HELPER FUNCTIONS
# =============================================================================

def get_settings_by_category(category: str) -> list[SettingDefinition]:
    """Get all settings in a specific category."""
    return [s for s in SETTINGS_REGISTRY.values() if s.category == category]


def get_settings_by_scope(scope: SettingScope) -> list[SettingDefinition]:
    """Get all settings with a specific scope."""
    return [s for s in SETTINGS_REGISTRY.values() if s.scope == scope]


def get_settings_by_storage(storage: SettingStorage) -> list[SettingDefinition]:
    """Get all settings stored in a specific location."""
    return [s for s in SETTINGS_REGISTRY.values() if s.storage == storage]


def get_database_settings() -> list[SettingDefinition]:
    """Get all settings that should be stored in the database."""
    return get_settings_by_storage(SettingStorage.DATABASE)


def get_global_settings() -> list[SettingDefinition]:
    """Get all global (non user-specific) settings."""
    return get_settings_by_scope(SettingScope.GLOBAL)


def get_user_specific_settings() -> list[SettingDefinition]:
    """Get all user-specific settings."""
    return get_settings_by_scope(SettingScope.USER_SPECIFIC)


def get_default_value(key: str) -> Any:
    """Get the default value for a setting."""
    if key in SETTINGS_REGISTRY:
        return SETTINGS_REGISTRY[key].default
    return None


def get_all_defaults() -> dict[str, Any]:
    """Get all default values as a dictionary."""
    return {key: setting.default for key, setting in SETTINGS_REGISTRY.items()}


def get_database_defaults() -> dict[str, Any]:
    """Get default values for all database-stored settings."""
    return {
        setting.key: setting.default
        for setting in get_database_settings()
    }


def validate_setting_value(key: str, value: Any) -> bool:
    """Validate a setting value against its definition."""
    if key not in SETTINGS_REGISTRY:
        return False

    setting = SETTINGS_REGISTRY[key]

    # Check type
    if setting.type == SettingType.BOOLEAN:
        if not isinstance(value, bool) and value not in ['true', 'false', 'True', 'False']:
            return False
    elif setting.type == SettingType.INTEGER:
        if not isinstance(value, int):
            try:
                int(value)
            except (ValueError, TypeError):
                return False
    elif setting.type == SettingType.STRING:
        if not isinstance(value, str):
            return False

    # Check choices if defined
    if setting.choices and value not in setting.choices:
        # For booleans converted to strings
        if setting.type == SettingType.BOOLEAN:
            return True
        return False

    return True


# =============================================================================
# CATEGORY KEYS (for API endpoints)
# =============================================================================

THEME_KEYS = [s.key for s in get_settings_by_category("theme")]
MODULE_KEYS = [s.key for s in get_settings_by_category("modules")]
AUTH_KEYS = [s.key for s in get_settings_by_category("auth")]
UI_KEYS = [s.key for s in get_settings_by_category("ui")]
USER_PREFERENCE_KEYS = [s.key for s in get_settings_by_category("user_preferences")]


# =============================================================================
# PRINT SUMMARY (for debugging)
# =============================================================================

if __name__ == "__main__":
    print("\n=== SETTINGS REGISTRY SUMMARY ===\n")

    print(f"Total settings: {len(SETTINGS_REGISTRY)}")
    print(f"  - Database settings: {len(get_database_settings())}")
    print(f"  - Global settings: {len(get_global_settings())}")
    print(f"  - User-specific settings: {len(get_user_specific_settings())}")

    print("\n--- By Category ---")
    categories = set(s.category for s in SETTINGS_REGISTRY.values())
    for cat in sorted(categories):
        settings = get_settings_by_category(cat)
        print(f"  {cat}: {len(settings)} settings")

    print("\n--- Database Settings (stored in /config/config.db) ---")
    for setting in get_database_settings():
        scope_label = "GLOBAL" if setting.scope == SettingScope.GLOBAL else "USER"
        print(f"  [{scope_label}] {setting.key}: {setting.type.value} = {setting.default}")