use anyhow::Result;
use cgmath::{ortho, vec2, vec3, vec4, Deg, InnerSpace, Matrix4, Rad, Vector2, Vector3};
use rfactor_sm_reader::*;
use vulkan_rs::prelude::*;

use std::{sync::Arc, time::Instant};

use super::rendering::PositionOnlyVertex;
use crate::write_log;

fn convert_vec(v: rF2Vec3) -> Vector3<f32> {
    vec3(v.x as f32, v.y as f32, v.z as f32)
}

pub trait RenderObject {
    fn descriptor(&self) -> &Arc<DescriptorSet>;
    fn buffer(&self) -> &Arc<Buffer<PositionOnlyVertex>>;
}

pub struct DataConfig {
    pub radar_scale: f32,
    pub radar_car_distance: f32,
    pub safe_color: Vector3<f32>,
    pub danger_color: Vector3<f32>,
}

pub struct RFactorData {
    // config
    config: DataConfig,

    // rf2 memory mapped data
    telemetry_reader: TelemetryReader,
    scoring_reader: ScoringReader,

    // radar objects
    background: RadarObject,
    player_car: RadarObject,
    cars: Vec<RadarObject>,

    // buffer car objects, to prevent recreating them every update
    car_handles: Vec<RadarObject>,

    // game info
    player_id: Option<i32>,

    // math objects
    radar_center: Vector2<f32>,
    ortho: Matrix4<f32>,
    _window_width: u32,
    _window_height: u32,
    radar_extent: f32,
    car_width: f32,
    car_height: f32,

    start_time: Instant,

    device: Arc<Device>,
    descriptor_layout: Arc<DescriptorSetLayout>,
}

impl RFactorData {
    pub fn new(
        config: DataConfig,
        device: Arc<Device>,
        descriptor_layout: &Arc<DescriptorSetLayout>,
        width: u32,
        height: u32,
    ) -> Result<Self> {
        write_log!(" =================== create RFactorData ===================");

        let radar_extent = width as f32 * 0.075 * config.radar_scale;
        let car_height = radar_extent * 0.15;
        let car_width = car_height / 2.5;
        let radar_center = vec2(
            width as f32 / 2.0,
            height as f32 / 2.0 - height as f32 * 0.25,
        );

        let flip_y = matrix4_from_diagonal(vec3(1.0, -1.0, 1.0));
        let ortho = flip_y * ortho(0.0, width as f32, 0.0, height as f32, -1.0, 1.0);
        let start_time = Instant::now();

        Ok(Self {
            config,

            telemetry_reader: TelemetryReader::new(start_time.elapsed().as_secs_f32())?,
            scoring_reader: ScoringReader::new(start_time.elapsed().as_secs_f32())?,

            background: RadarObject::new(
                device.clone(),
                descriptor_layout,
                PositionOnlyVertex::from_2d_corners(
                    ortho * Matrix4::from_translation(radar_center.extend(0.0)),
                    [
                        vec2(-radar_extent, -radar_extent),
                        vec2(-radar_extent, radar_extent),
                        vec2(radar_extent, radar_extent),
                        vec2(radar_extent, -radar_extent),
                    ],
                ),
                [0.5, 0.5, 0.5, 0.5],
            )?,
            player_car: RadarObject::new(
                device.clone(),
                descriptor_layout,
                PositionOnlyVertex::from_2d_corners(
                    ortho * Matrix4::from_translation(radar_center.extend(0.0)),
                    [
                        vec2(-car_width, -car_height),
                        vec2(-car_width, car_height),
                        vec2(car_width, car_height),
                        vec2(car_width, -car_height),
                    ],
                ),
                [0.0, 0.9, 0.0, 0.9],
            )?,
            cars: Vec::new(),
            car_handles: Vec::new(),

            player_id: None,

            radar_center,
            ortho,
            _window_width: width,
            _window_height: height,
            radar_extent,
            car_width,
            car_height,

            start_time,

            device,
            descriptor_layout: descriptor_layout.clone(),
        })
    }

    fn create_car_object(&self, offset: Vector2<f32>, color: [f32; 4]) -> Result<RadarObject> {
        write_log!(" =================== create car object ===================");

        RadarObject::new(
            self.device.clone(),
            &self.descriptor_layout,
            Self::create_car_vertices(
                self.ortho
                    * Matrix4::from_translation(self.radar_center.extend(0.0))
                    * Matrix4::from_translation(offset.extend(0.0)),
                self.car_width,
                self.car_height,
            ),
            color,
        )
    }

    fn create_car_vertices(
        mvp: Matrix4<f32>,
        car_width: f32,
        car_height: f32,
    ) -> [PositionOnlyVertex; 6] {
        PositionOnlyVertex::from_2d_corners(
            mvp,
            [
                vec2(-car_width, -car_height),
                vec2(-car_width, car_height),
                vec2(car_width, car_height),
                vec2(car_width, -car_height),
            ],
        )
    }

    fn now(&self) -> f32 {
        self.start_time.elapsed().as_secs_f32()
    }

    pub fn update(&mut self) -> Result<()> {
        write_log!(" =================== update RFactorData ===================");

        // get scoring info
        if let Some((scoring_info, vehicle_scorings)) =
            self.scoring_reader.vehicle_scoring(self.now())
        {
            write_log!(format!(
                "new scoring info: vehicles: {}",
                scoring_info.mNumVehicles
            ));

            // check for player id
            if scoring_info.mNumVehicles == 0 {
                self.player_id = None;
            } else if self.player_id.is_none() {
                for vehicle_scoring in vehicle_scorings.iter() {
                    if vehicle_scoring.mIsPlayer != 0 {
                        write_log!(format!("player found: {}", vehicle_scoring.mID));
                        self.player_id = Some(vehicle_scoring.mID);
                        break;
                    }
                }
            }
        }

        // if player id is set (a map is loaded), check telemetry data
        if let Some(player_id) = &self.player_id {
            write_log!("before telemetry update");
            if let Some(telemetries) = self.telemetry_reader.query_telemetry(self.now()) {
                write_log!("new telemetry update");

                // make sure there are enough cars in buffer
                if self.car_handles.len() < telemetries.len() {
                    let size_diff = telemetries.len() - self.car_handles.len();

                    for _ in 0..size_diff {
                        self.car_handles
                            .push(self.create_car_object(vec2(0.0, 0.0), [0.0, 0.0, 0.0, 0.0])?);
                    }
                }

                let mut player_position = CarPosition::default();
                let mut other_positions = Vec::new();

                for telemetry in telemetries {
                    let car = CarPosition::new(
                        convert_vec(telemetry.position),
                        [
                            convert_vec(telemetry.orientation[0]),
                            convert_vec(telemetry.orientation[1]),
                            convert_vec(telemetry.orientation[2]),
                        ],
                    );

                    if telemetry.id == *player_id {
                        player_position = car
                    } else {
                        other_positions.push(car);
                    }
                }

                // update radar objects
                self.cars.clear();
                let mut buffer_car_index = 0;

                for other_position in other_positions {
                    let diff = player_position.position - other_position.position;
                    let distance = diff.magnitude();

                    // check if car is close enough to the players car
                    if distance < self.config.radar_car_distance {
                        let offset =
                            diff.xz() * (self.radar_extent / self.config.radar_car_distance);

                        let buffered_car = self.car_handles[buffer_car_index].clone();
                        buffer_car_index += 1;
                        buffered_car.update(
                            self.ortho,
                            offset,
                            player_position.rotation,
                            other_position.rotation,
                            self.radar_center,
                            self.car_width,
                            self.car_height,
                            [0.9, 0.9, 0.0, 0.9],
                        )?;

                        self.cars.push(buffered_car);
                    }
                }
            }
        }

        Ok(())
    }

    pub fn objects(&self) -> Vec<&dyn RenderObject> {
        write_log!(" =================== get objects of RFactorData ===================");

        let mut objects: Vec<&dyn RenderObject> = Vec::new();

        // only draw radar when player is loaded into a map
        if let Some(_player_id) = &self.player_id {
            // only draw radar when any car is near enough
            if !self.cars.is_empty() {
                objects.push(&self.background);

                for other_player_cars in &self.cars {
                    objects.push(other_player_cars);
                }

                objects.push(&self.player_car);
            }
        }

        objects
    }
}

#[derive(Clone)]
struct RadarObject {
    descriptor_set: Arc<DescriptorSet>,

    // uniform buffer
    color_buffer: Arc<Buffer<f32>>,

    // vertex buffer
    position_buffer: Arc<Buffer<PositionOnlyVertex>>,
}

impl RadarObject {
    fn new(
        device: Arc<Device>,
        descriptor_layout: &Arc<DescriptorSetLayout>,
        positions: [PositionOnlyVertex; 6],
        color: [f32; 4],
    ) -> Result<Self> {
        let color_buffer = Buffer::builder()
            .set_usage(VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT)
            .set_memory_usage(MemoryUsage::CpuOnly)
            .set_data(&color)
            .build(device.clone())?;

        let position_buffer = Buffer::builder()
            .set_usage(VK_BUFFER_USAGE_VERTEX_BUFFER_BIT)
            .set_memory_usage(MemoryUsage::CpuOnly)
            .set_data(&positions)
            .build(device.clone())?;

        let descriptor_pool = DescriptorPool::builder()
            .set_layout(descriptor_layout.clone())
            .build(device.clone())?;

        let descriptor_set = descriptor_pool.prepare_set().allocate()?;
        descriptor_set.update(&[DescriptorWrite::uniform_buffers(0, &[&color_buffer])])?;

        Ok(Self {
            descriptor_set,
            color_buffer,
            position_buffer,
        })
    }

    pub fn update(
        &self,

        ortho: Matrix4<f32>,
        offset: Vector2<f32>,
        player_rotation: impl Into<Deg<f32>>,
        rotation: impl Into<Deg<f32>>,
        radar_center: Vector2<f32>,
        car_width: f32,
        car_height: f32,
        color: [f32; 4],
    ) -> Result<()> {
        self.position_buffer
            .fill(&RFactorData::create_car_vertices(
                ortho
                    * Matrix4::from_translation(radar_center.extend(0.0))
                    * Matrix4::from_angle_z(-player_rotation.into())
                    * Matrix4::from_translation(offset.extend(0.0))
                    * Matrix4::from_angle_z(rotation.into()),
                car_width,
                car_height,
            ))?;
        self.color_buffer.fill(&color)
    }
}

impl RenderObject for RadarObject {
    fn descriptor(&self) -> &Arc<DescriptorSet> {
        &self.descriptor_set
    }

    fn buffer(&self) -> &Arc<Buffer<PositionOnlyVertex>> {
        &self.position_buffer
    }
}

struct CarPosition {
    pub position: Vector3<f32>,
    pub rotation: Rad<f32>,
}

impl CarPosition {
    fn new(position: Vector3<f32>, orientation: [Vector3<f32>; 3]) -> Self {
        Self {
            position,
            rotation: Rad(orientation[2].x.atan2(orientation[2].z)),
        }
    }
}

impl Default for CarPosition {
    fn default() -> Self {
        Self {
            position: vec3(0.0, 0.0, 0.0),
            rotation: Rad(0.0),
        }
    }
}

const fn matrix4_from_diagonal(diagonal: Vector3<f32>) -> Matrix4<f32> {
    Matrix4::from_cols(
        vec4(diagonal.x, 0.0, 0.0, 0.0),
        vec4(0.0, diagonal.y, 0.0, 0.0),
        vec4(0.0, 0.0, diagonal.z, 0.0),
        vec4(0.0, 0.0, 0.0, 1.0),
    )
}