// src/modes/handlers/mode_manager.rs
use crate::state::state::AppState;
use crate::modes::handlers::event::EventHandler;

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum AppMode {
    General,   // For intro and admin screens
    ReadOnly,  // Canvas read-only mode
    Edit,      // Canvas edit mode
    Command,   // Command mode overlay
}

pub struct ModeManager;

impl ModeManager {
    // Determine current mode based on app state
    pub fn derive_mode(app_state: &AppState, event_handler: &EventHandler) -> AppMode {
        if event_handler.command_mode {
            return AppMode::Command;
        }

        if app_state.ui.show_login {  // NEW: Check auth visibility
            if event_handler.is_edit_mode {
                AppMode::Edit
            } else {
                AppMode::ReadOnly
            }
        } else if app_state.ui.show_form {
            if event_handler.is_edit_mode {
                AppMode::Edit
            } else {
                AppMode::ReadOnly
            }
        } else {
            AppMode::General
        }
    }

    // Mode transition rules
    pub fn can_enter_command_mode(current_mode: AppMode) -> bool {
        !matches!(current_mode, AppMode::Edit)  // Can't enter from Edit mode
    }
    
    pub fn can_enter_edit_mode(current_mode: AppMode) -> bool {
        matches!(current_mode, AppMode::ReadOnly)  // Only from ReadOnly
    }
    
    pub fn can_enter_read_only_mode(current_mode: AppMode) -> bool {
        matches!(current_mode, AppMode::Edit | AppMode::Command)
    }
}