use std::error::Error;

use crate::core::app::context::ApplicationContext;

use super::Scene;

pub struct SceneManager {
    scenes: Vec<Box<dyn Scene>>,
    current_scene_index: Option<usize>,
}

impl SceneManager {
    pub fn new() -> Self {
        Self {
            scenes: Vec::new(),
            current_scene_index: None,
        }
    }

    pub fn load_scene(&mut self, scene: Box<dyn Scene>) {
        self.scenes.push(scene);
        self.current_scene_index = Some(self.scenes.len() - 1);
    }

    pub fn replace_current_scene(&mut self, scene: Box<dyn Scene>) {
        if let Some(index) = self.current_scene_index {
            if index < self.scenes.len() {
                self.scenes[index].unload();
                self.scenes[index] = scene;
            }
        } else {
            self.load_scene(scene);
        }
    }

    pub fn current_scene(&self) -> Option<&Box<dyn Scene>> {
        if let Some(index) = self.current_scene_index {
            self.scenes.get(index)
        } else {
            None
        }
    }

    pub fn current_scene_mut(&mut self) -> Option<&mut Box<dyn Scene>> {
        if let Some(index) = self.current_scene_index {
            self.scenes.get_mut(index)
        } else {
            None
        }
    }

    pub fn load_scene_if_not_loaded(
        &mut self,
        app_context: &mut ApplicationContext,
    ) -> Result<(), Box<dyn Error>> {
        if let Some(scene) = self.current_scene_mut() {
            if !scene.loaded() {
                scene.load(app_context)?;
            }
        } else {
            log::warn!("No scene found in SceneManager!");
        }
        Ok(())
    }
}