use crate::plugins::environment::systems::voxels::debug::{draw_grid, visualize_octree_system};
use crate::plugins::environment::systems::voxels::lod::update_chunk_lods;
use crate::plugins::environment::systems::voxels::meshing_gpu::{
    GpuMeshingWorker, queue_gpu_meshing,
};
use bevy_app_compute::prelude::{AppComputePlugin, AppComputeWorkerPlugin};
use crate::plugins::environment::systems::voxels::queue_systems::process_chunk_queue;
use crate::plugins::environment::systems::voxels::visibility_gpu::{
    enqueue_visible_chunks_gpu, GpuVisibilityWorker,
};
use crate::plugins::environment::systems::voxels::render_chunks::rebuild_dirty_chunks;
use crate::plugins::environment::systems::voxels::structure::{
    ChunkBudget, ChunkCullingCfg, ChunkQueue, MeshBufferPool, PrevCameraChunk, SparseVoxelOctree,
    SpawnedChunks,
};
use bevy::app::{App, Plugin, Startup};
use bevy::prelude::*;

pub struct EnvironmentPlugin;
impl Plugin for EnvironmentPlugin {
    fn build(&self, app: &mut App) {
        app.add_systems(
            Startup,
            (
                crate::plugins::environment::systems::camera_system::setup,
                crate::plugins::environment::systems::environment_system::setup
                    .after(crate::plugins::environment::systems::camera_system::setup),
                crate::plugins::environment::systems::voxel_system::setup,
            ),
        );
        app.add_plugins(AppComputePlugin);
        app.add_plugins(AppComputeWorkerPlugin::<GpuMeshingWorker>::default());
        app.add_plugins(AppComputeWorkerPlugin::<GpuVisibilityWorker>::default());

        let view_distance_chunks = 100;
        app.insert_resource(ChunkCullingCfg {
            view_distance_chunks,
        });
        app.insert_resource(ChunkBudget { per_frame: 20 });
        app.init_resource::<PrevCameraChunk>();
        app.add_systems(Update, log_mesh_count);
        app
            // ------------------------------------------------------------------------
            // resources
            // ------------------------------------------------------------------------
            .init_resource::<ChunkQueue>()
            .init_resource::<SpawnedChunks>()
            .init_resource::<MeshBufferPool>()
            // ------------------------------------------------------------------------
            // frame update
            // ------------------------------------------------------------------------
            .add_systems(
                Update,
                (
                    /* ---------- culling & streaming ---------- */
                    enqueue_visible_chunks_gpu,
                    process_chunk_queue.after(enqueue_visible_chunks_gpu),
                    update_chunk_lods.after(process_chunk_queue),
                    rebuild_dirty_chunks.after(process_chunk_queue), // 4.  (re)mesh dirty chunks
                    queue_gpu_meshing.after(rebuild_dirty_chunks),
                    /* ---------- optional debug drawing ------- */
                    visualize_octree_system
                        .run_if(should_visualize_octree)
                        .after(rebuild_dirty_chunks),
                    draw_grid
                        .run_if(should_draw_grid)
                        .after(visualize_octree_system),
                )
                    .chain(), // make the whole tuple execute in this exact order
            );
    }
}

fn log_mesh_count(meshes: Res<Assets<Mesh>>, time: Res<Time>) {
    if time.delta_secs_f64() as i32 % 5 == 0 {
        info!("meshes: {}", meshes.len());
    }
}

fn should_visualize_octree(octree_query: Query<&SparseVoxelOctree>) -> bool {
    let Ok(octree) = octree_query.get_single() else {
        return false;
    };
    octree.show_wireframe
}

fn should_draw_grid(octree_query: Query<&SparseVoxelOctree>) -> bool {
    let Ok(octree) = octree_query.get_single() else {
        return false;
    };
    octree.show_world_grid
}