use bevy::prelude::*;
use crate::{settings, camera};

pub struct EffectsPlugin;

impl Plugin for EffectsPlugin {
    fn build(&self, app: &mut App) {
        app.add_systems(Startup, setup);
        app.add_systems(Startup, spawn_effects.after(setup).after(camera::setup_camera));
        app.add_systems(Update, spawn_effects);
        app.add_systems(Update, update_fadeblack);
        app.add_event::<SpawnEffectEvent>();
    }
}

#[derive(Clone)]
pub enum Effects {
    FadeIn,
}

#[derive(Component)] pub struct FadeBlack;
#[derive(Component)]
pub struct Effect {
    pub class: Effects,
    pub duration: f64,
    pub start_time: f64,
}
#[derive(Event)]
pub struct SpawnEffectEvent {
    pub class: Effects,
    pub duration: f64,
}

pub fn setup(
    settings: Res<settings::Settings>,
    mut ew_effect: EventWriter<SpawnEffectEvent>,
) {
    if !settings.dev_mode {
        ew_effect.send(SpawnEffectEvent { class: Effects::FadeIn, duration: 4.0 });
    }
}

pub fn spawn_effects(
    mut commands: Commands,
    mut er_effect: EventReader<SpawnEffectEvent>,
    time: Res<Time>,
) {
    let now = time.elapsed_seconds_f64();
    for effect in er_effect.read() {
        match effect.class {
            Effects::FadeIn => {
                commands.spawn((
                    Effect {
                        class: effect.class.clone(),
                        duration: effect.duration,
                        start_time: now,
                    },
                    FadeBlack,
                    NodeBundle {
                        style: Style {
                            width: Val::Vw(100.0),
                            height: Val::Vh(100.0),
                            position_type: PositionType::Absolute,
                            top: Val::Px(0.0),
                            left: Val::Px(0.0),
                            ..default()
                        },
                        background_color: Color::rgba(0.0, 0.0, 0.0, 1.0).into(),
                        ..default()
                    },
                ));
            },
            //_ => {},
        }
    }
}

pub fn update_fadeblack(
    mut commands: Commands,
    mut q_effect: Query<(Entity, &Effect, &mut BackgroundColor), With<FadeBlack>>,
    time: Res<Time>,
) {
    for (entity, effect, mut bgcolor) in &mut q_effect {
        let now = time.elapsed_seconds_f64();
        if effect.start_time + effect.duration < now {
            commands.entity(entity).despawn();
            continue;
        }
        let alpha = (1.3 - 1.3 * (now - effect.start_time) / effect.duration).clamp(0.0, 1.0);
        bgcolor.0 = Color::rgba(0.0, 0.0, 0.0, alpha as f32);
    }
}