use std::{time::Duration, sync::Arc, f64::consts::PI};
use log::{debug, warn};
use nalgebra::{vector, point};
use rand::Rng;
use rapier2d_f64::prelude::{PhysicsPipeline, ColliderBuilder, RigidBodyBuilder, MassProperties};
use async_std::sync::RwLock;
use async_std::task::sleep;
use starkingdoms_protocol::{player::Player, planet::PlanetType, module::ModuleType};
use crate::{manager::{ClientHandlerMessage, ClientManager, PhysicsData, Module}, SCALE, planet::{Planets, Planet}, entity::{get_entity_id, Entity}};
use crate::entity::EntityHandler;
use crate::orbit::constants::{GAME_ORBITS_ENABLED, MOON_APOAPSIS, MOON_ORBIT_TIME, MOON_PERIAPSIS};
use crate::orbit::orbit::{calculate_point_on_orbit, calculate_world_position_of_orbit};

pub const ROTATIONAL_FORCE: f64 = 100.0;
pub const LATERAL_FORCE: f64 = 100.0;
pub const MODULE_SPAWN: f64 = 3000.0;
pub const MODULE_MAX: u32 = 10;

pub async fn timer_main(mgr: ClientManager, physics_data_orig: Arc<RwLock<PhysicsData>>, entities: Arc<RwLock<EntityHandler>>) {
    let mut pipeline = PhysicsPipeline::new();

    let mut time = 0.0;
    let mut module_timer = 0.0;
    let _planet_ids;

    {
        let mut data_handle = physics_data_orig.write().await;

        let mut rigid_body_set = data_handle.rigid_body_set.clone();
        let mut collider_set = data_handle.collider_set.clone();

        _planet_ids = Planets::create_planets(&mut rigid_body_set, &mut collider_set, &mut entities.write().await.entities).await;

        data_handle.rigid_body_set = rigid_body_set;
        data_handle.collider_set = collider_set;
    }

    loop {
        sleep(Duration::from_millis(5)).await;
        time += 5.0 / 1000.0; // 5ms, time is in seconds
        module_timer += 5.0 / 1000.0;

        let mut physics_data = physics_data_orig.write().await;

        // update orbits (but dont, actually, yet)
        // DO NOT SIMPLIFY EXPRESSION
        // IT MAY ALWAYS BE TRUE
        // THATS FINE
        if GAME_ORBITS_ENABLED {
            let planets = entities.write().await;

            // update earth (nothing changes, yet)
            let earth = planets.get_planet(PlanetType::Earth).unwrap();
            let new_earth_position = vector![earth.position.0, earth.position.1];

            // update moon
            let moon: &mut Planet = &mut planets.get_planet(PlanetType::Moon).unwrap();
            let new_moon_position = calculate_world_position_of_orbit(calculate_point_on_orbit(MOON_PERIAPSIS, MOON_APOAPSIS, time / MOON_ORBIT_TIME), new_earth_position);
            let moon_body = physics_data.rigid_body_set.get_mut(moon.body_handle).unwrap();
            moon_body.set_next_kinematic_position(new_moon_position.into());
            moon.position = (moon_body.translation()[0] / SCALE, moon_body.translation()[1] / SCALE);
        }

        physics_data.tick(&mut pipeline);

        let mut protocol_players = vec![];

        {
            if module_timer > 1.0 && entities.read().await.get_module_count() < MODULE_MAX {
                debug!("module spawn");
                module_timer = 0.;

                let mut rigid_body_set = physics_data.rigid_body_set.clone();
                let mut collider_set = physics_data.collider_set.clone();

                let module_collider = ColliderBuilder::cuboid(18.75 / SCALE, 23.4375 / SCALE)
                    .translation(vector![0.0, 1.5625 / SCALE])
                    .mass_properties(MassProperties::new(point![0.0, 0.0], 120.0, 122500.0))
                    .build();
                let angle: f64 = {
                    let mut rng = rand::thread_rng();
                    rng.gen::<f64>() * PI * 2.
                };
                let module_body = RigidBodyBuilder::dynamic()
                    .translation(vector![angle.cos() * 2050. / SCALE, angle.sin() * 2050.0/SCALE])
                    .build();
                let module_handler = rigid_body_set.insert(module_body);
                collider_set.insert_with_parent(module_collider, module_handler, &mut rigid_body_set);

                physics_data.rigid_body_set = rigid_body_set;
                physics_data.collider_set = collider_set;

                let module = Module {
                    handle: module_handler,
                    module_type: ModuleType::Cargo,
                };
                entities.write().await.entities.insert(get_entity_id(), Entity::Module(module));
            }
            for module in entities.read().await.get_modules().iter() {
                let module_handle = module.handle;
                let module_body = physics_data.rigid_body_set.get_mut(module_handle).unwrap();
                module_body.reset_forces(true);
                module_body.reset_torques(true);
                let planets = entities.read().await;
                let grav_force = planets.gravity((module_body.translation().x, module_body.translation().y), module_body.mass());
                module_body.apply_impulse(vector![grav_force.0, grav_force.1], true);
            }
        }

        {
            for (player_id, player) in entities.read().await.get_players().iter() {
                let player_handle = player.handle;
                let player_body = physics_data.rigid_body_set.get_mut(player_handle).unwrap();
                player_body.reset_forces(true);
                player_body.reset_torques(true);
                let planets = entities.read().await;
                let grav_force = planets.gravity((player_body.translation().x, player_body.translation().y), player_body.mass());
                player_body.apply_impulse(vector![grav_force.0, grav_force.1], true);

                let mut left_top_thruster: f64 = 0.0;
                let mut right_top_thruster: f64 = 0.0;
                let mut left_bottom_thruster: f64 = 0.0;
                let mut right_bottom_thruster: f64 = 0.0;

                if player.input.right {
                    left_top_thruster -= 1.0;
                    right_bottom_thruster += 1.0;
                }
                if player.input.left {
                    right_top_thruster -= 1.0;
                    left_bottom_thruster += 1.0;
                }

                if player.input.up {
                    left_bottom_thruster -= 1.0;
                    right_bottom_thruster -= 1.0;
                }
                if player.input.down {
                    left_top_thruster += 1.0;
                    right_top_thruster += 1.0;
                }
                left_top_thruster = LATERAL_FORCE * left_top_thruster.clamp(-1.0, 1.0);
                right_top_thruster = LATERAL_FORCE * right_top_thruster.clamp(-1.0, 1.0);
                left_bottom_thruster = LATERAL_FORCE * left_bottom_thruster.clamp(-1.0, 1.0);
                right_bottom_thruster = LATERAL_FORCE * right_bottom_thruster.clamp(-1.0, 1.0);

                let rotation = player_body.rotation().clone().angle();
                let left_top_thruster = vector![
                    -left_top_thruster * rotation.sin(),
                    left_top_thruster * rotation.cos()
                ];
                let right_top_thruster = vector![
                    -right_top_thruster * rotation.sin(),
                    right_top_thruster * rotation.cos()
                ];
                let left_bottom_thruster = vector![
                    -left_bottom_thruster * rotation.sin(),
                    left_bottom_thruster * rotation.cos()
                ];
                let right_bottom_thruster = vector![
                    -right_bottom_thruster * rotation.sin(),
                    right_bottom_thruster * rotation.cos()
                ];
                let scale = SCALE;
                let top_left_point = point![
                    -25. / scale * rotation.cos() +25. / scale * rotation.sin(), 
                    -25. / scale * rotation.sin() -25. / scale * rotation.cos()
                ] + player_body.translation();
                let top_right_point = point![
                     25. / scale * rotation.cos() +25. / scale * rotation.sin(), 
                     25. / scale * rotation.sin() -25. / scale * rotation.cos()
                ] + player_body.translation();
                let bottom_left_point = point![
                    -25. / scale * rotation.cos() -25. / scale * rotation.sin(), 
                    -25. / scale * rotation.sin() +25. / scale * rotation.cos()
                ] + player_body.translation();
                let bottom_right_point = point![
                     25. / scale * rotation.cos() -25. / scale * rotation.sin(), 
                     25. / scale * rotation.sin() +25. / scale * rotation.cos()
                ] + player_body.translation();

                player_body.add_force_at_point(
                    left_top_thruster,
                    top_left_point, true);
                player_body.add_force_at_point(
                    right_top_thruster,
                    top_right_point, true);
                player_body.add_force_at_point(
                    left_bottom_thruster,
                    bottom_left_point, true);
                player_body.add_force_at_point(
                    right_bottom_thruster,
                    bottom_right_point, true);


                let translation = player_body.translation();

                let username;
                {
                    let usernames = mgr.usernames.read().await;
                    username = usernames.get(player_id).unwrap().clone();
                }

                // TODO: Figure out how to adjust codegen to use f64
                protocol_players.push(Player {
                    rotation: rotation as f32,
                    x: (translation.x * SCALE) as f32,
                    y: (translation.y * SCALE) as f32,
                    username,
                    special_fields: Default::default(),
                });
            }
        }

        let mut to_remove = vec![];

        let mut mgr_w = mgr.handlers.write().await;
        let mgr_r = mgr_w.clone();

        for (addr, client_thread) in mgr_r.iter() {
            match client_thread.tx.send(ClientHandlerMessage::Tick).await {
                Ok(_) => {
                    match client_thread.tx.send(ClientHandlerMessage::PlayersUpdate {players: protocol_players.clone()}).await {
                        Ok(_) => (),
                        Err(e) => {
                            warn!("unable to send position packet: {}", e);
                        }
                    };
                    let modules = entities.read().await.get_modules();
                    let protocol_modules: Vec<starkingdoms_protocol::module::Module> = modules.iter()
                        .map(|module| {
                            let body = physics_data.rigid_body_set.get(module.handle).unwrap();
                            return starkingdoms_protocol::module::Module {
                                module_type: module.module_type.into(),
                                rotation: body.rotation().angle() as f32,
                                x: (body.translation().x * SCALE) as f32,
                                y: (body.translation().y * SCALE) as f32,
                                special_fields: Default::default(),
                            };
                        }).collect();
                    match client_thread.tx.send(ClientHandlerMessage::ModulesUpdate { modules: protocol_modules.clone() }).await {
                        Ok(_) => (),
                        Err(e) => {
                            warn!("unable to send module position packet: {}", e);
                        }
                    };

                    let world = entities.read().await;
                    let planet_data = world.to_protocol();
                    match client_thread.tx.send(planet_data).await {
                        Ok(_) => (),
                        Err(e) => {
                            warn!("unable to send earth packet: {}", e);
                        }
                    };
                }
                Err(e) => {
                    warn!("unable to update a client thread: {}", e);
                    to_remove.push(addr);
                }
            }
        }

        for pending_removal in to_remove {
            mgr_w.remove(pending_removal);
        }
    }
}