use bevy::{
    asset::RenderAssetUsages,
    prelude::*,
    render::mesh::{Indices, PrimitiveTopology},
};
use icarus::TerritoryType::TerritoryTypeSheet;
use kawari::config::get_config;
use physis::{
    common::{Language, Platform},
    layer::{LayerEntryData, LayerGroup, ModelCollisionType, Transformation},
    lvb::Lvb,
    pcb::{Pcb, ResourceNode},
    resource::{Resource, SqPackResource},
};
use recastnavigation_sys::rcAllocPolyMesh;

#[derive(Resource)]
struct ZoneToLoad(u16);

fn main() {
    tracing_subscriber::fmt::init();

    let args: Vec<String> = std::env::args().collect();
    let zone_id: u16 = args[1].parse().unwrap();

    App::new()
        .add_plugins(DefaultPlugins)
        .add_systems(Startup, setup)
        .insert_resource(ZoneToLoad(zone_id))
        .run();
}

/// Walk each node, add it's collision model to the scene.
fn walk_node(
    node: &ResourceNode,
    commands: &mut Commands,
    meshes: &mut ResMut<Assets<Mesh>>,
    materials: &mut ResMut<Assets<StandardMaterial>>,
    transform: &Transformation,
    //tile_input_builder: &mut TileInputBuilder,
) {
    if !node.vertices.is_empty() {
        let mut mesh = Mesh::new(
            PrimitiveTopology::TriangleList,
            RenderAssetUsages::RENDER_WORLD,
        );

        let mut positions = Vec::new();
        for vec in &node.vertices {
            positions.push(vec.clone());
        }

        mesh.insert_attribute(Mesh::ATTRIBUTE_POSITION, positions.clone());

        let mut indices = Vec::new();
        for polygon in &node.polygons {
            let mut vec: Vec<u32> = Vec::from(&polygon.vertex_indices)
                .iter()
                .map(|x| *x as u32)
                .collect();
            assert!(vec.len() == 3);
            indices.append(&mut vec);
        }

        mesh.insert_indices(Indices::U32(indices.clone()));

        // insert into 3d scene
        commands.spawn((
            Mesh3d(meshes.add(mesh)),
            MeshMaterial3d(materials.add(Color::srgb(
                fastrand::f32(),
                fastrand::f32(),
                fastrand::f32(),
            ))),
            Transform {
                translation: Vec3::from_array(transform.translation),
                rotation: Quat::from_euler(
                    EulerRot::XYZ,
                    transform.rotation[0],
                    transform.rotation[1],
                    transform.rotation[2],
                ),
                scale: Vec3::from_array(transform.scale),
            },
        ));

        // insert into navmesh builder
        //let tile_vertices: Vec<DtVector> = positions.iter().map(|vec| DtVector::new(vec[0], vec[1], vec[2])).collect();
        //let tile_indices: Vec<i32> = indices.iter().map(|x| *x as i32).collect();

        //tile_input_builder.append(&tile_vertices, &tile_indices, 0);
    }

    for child in &node.children {
        walk_node(&child, commands, meshes, materials, transform);
    }
}

/// Setup 3D scene.
fn setup(
    mut commands: Commands,
    mut meshes: ResMut<Assets<Mesh>>,
    mut materials: ResMut<Assets<StandardMaterial>>,
    zone_id: Res<ZoneToLoad>,
) {
    let zone_id = zone_id.0;
    let config = get_config();

    tracing::info!("Generating navmesh for zone {zone_id}!");

    let mut sqpack_resource =
        SqPackResource::from_existing(Platform::Win32, &config.filesystem.game_path);
    let sheet = TerritoryTypeSheet::read_from(&mut sqpack_resource, Language::None).unwrap();
    let Some(row) = sheet.get_row(zone_id as u32) else {
        tracing::error!("Invalid zone id {zone_id}!");
        return;
    };

    // e.g. ffxiv/fst_f1/fld/f1f3/level/f1f3
    let bg_path = row.Bg().into_string().unwrap();

    let path = format!("bg/{}.lvb", &bg_path);
    let lvb_file = sqpack_resource.read(&path).unwrap();
    let lvb = Lvb::from_existing(&lvb_file).unwrap();

    unsafe {
        let poly_mesh = rcAllocPolyMesh();
    }

    for path in &lvb.scns[0].header.path_layer_group_resources {
        if path.contains("bg.lgb") {
            tracing::info!("Processing {path}...");

            let lgb_file = sqpack_resource.read(path).unwrap();
            let lgb = LayerGroup::from_existing(&lgb_file);
            let Some(lgb) = lgb else {
                tracing::error!(
                    "Failed to parse {path}, this is most likely a bug in Physis and should be reported somewhere!"
                );
                return;
            };

            // TODO: i think we know which layer is specifically used for navmesh gen, better check that LVB
            for chunk in &lgb.chunks {
                for layer in &chunk.layers {
                    for object in &layer.objects {
                        if let LayerEntryData::BG(bg) = &object.data {
                            if !bg.collision_asset_path.value.is_empty() {
                                tracing::info!("Considering {} for navimesh", object.instance_id);
                                tracing::info!("- Loading {}", bg.collision_asset_path.value);

                                // NOTE: assert is here to find out the unknown
                                assert!(bg.collision_type == ModelCollisionType::Replace);

                                let pcb_file = sqpack_resource
                                    .read(&bg.collision_asset_path.value)
                                    .unwrap();
                                let pcb = Pcb::from_existing(&pcb_file).unwrap();

                                walk_node(
                                    &pcb.root_node,
                                    &mut commands,
                                    &mut meshes,
                                    &mut materials,
                                    &object.transform,
                                    //&mut tile_input_builder,
                                );
                            }
                        }
                    }
                }
            }
        }
    }

    // camera
    commands.spawn((
        Camera3d::default(),
        Transform::from_xyz(15.0, 15.0, 15.0).looking_at(Vec3::ZERO, Vec3::Y),
    ));
}