// StarKingdoms.IO, a browser game about drifting through space
//     Copyright (C) 2023 ghostly_zsh, TerraMaster85, core
//
//     This program is free software: you can redistribute it and/or modify
//     it under the terms of the GNU Affero General Public License as published by
//     the Free Software Foundation, either version 3 of the License, or
//     (at your option) any later version.
//
//     This program is distributed in the hope that it will be useful,
//     but WITHOUT ANY WARRANTY; without even the implied warranty of
//     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//     GNU Affero General Public License for more details.
//
//     You should have received a copy of the GNU Affero General Public License
//     along with this program.  If not, see <https://www.gnu.org/licenses/>.
use std::net::Ipv4Addr;

use crate::mathutil::rot2d;
use bevy::math::{vec2, vec3};
use bevy::utils::tracing;
use bevy::{ecs::event::ManualEventReader, prelude::*};
use bevy_rapier2d::prelude::*;
use bevy_twite::{twite::frame::MessageType, ServerEvent, TwiteServerConfig, TwiteServerPlugin};
use component::*;
use packet::*;
use rand::Rng;

pub mod component;
pub mod macros;
pub mod mathutil;
pub mod packet;

const SCALE: f32 = 10.0;
const EARTH_SIZE: f32 = 1000.0;
const GRAVITY: f32 = 0.02;
const PART_HALF_SIZE: f32 = 25.0;
const THRUSTER_FORCE: f32 = 0.08;

fn main() {
    let subscriber = tracing_subscriber::FmtSubscriber::new();
    tracing::subscriber::set_global_default(subscriber).unwrap();
    info!(
        "StarKingdoms server v{} starting up",
        env!("CARGO_PKG_VERSION")
    );

    App::new()
        .insert_resource(TwiteServerConfig {
            addr: Ipv4Addr::new(0, 0, 0, 0),
            port: 3000,
        })
        .add_plugins(MinimalPlugins)
        .insert_resource(RapierConfiguration {
            gravity: Vect { x: 0.0, y: 0.0 },
            ..Default::default()
        })
        .add_plugins(RapierPhysicsPlugin::<NoUserData>::pixels_per_meter(SCALE))
        .add_plugins(TwiteServerPlugin)
        .add_systems(Startup, setup_integration_parameters)
        .add_systems(Startup, spawn_planets)
        .add_systems(Startup, module_spawn)
        .add_systems(Update, on_message)
        .add_systems(Update, on_close)
        .add_systems(FixedUpdate, on_position_change)
        .add_systems(FixedUpdate, gravity_update)
        .add_systems(FixedUpdate, player_input_update)
        //.insert_resource(Time::<Fixed>::from_seconds(1.0/20.0))
        .run();

    info!("Goodbye!");
}

fn setup_integration_parameters(mut context: ResMut<RapierContext>) {
    context.integration_parameters.dt = 1.0 / 60.0;
    context.integration_parameters.joint_erp = 0.2;
    context.integration_parameters.erp = 0.5;
    context.integration_parameters.max_stabilization_iterations = 16;
}
fn spawn_planets(mut commands: Commands) {
    info!("Spawning planets");
    let earth_pos = Transform::from_xyz(0.0, 0.0, 0.0);
    commands
        .spawn(PlanetBundle {
            planet_type: PlanetType::Earth,
            transform: TransformBundle::from(earth_pos),
        })
        .insert(Collider::ball(EARTH_SIZE / SCALE))
        .insert(AdditionalMassProperties::Mass(10000.0))
        .insert(ReadMassProperties::default())
        .insert(RigidBody::Fixed);
}
fn module_spawn(mut commands: Commands) {
    commands
        .spawn(PartBundle {
            part_type: PartType::Cargo,
            transform: TransformBundle::from(Transform::from_xyz(1100. / SCALE, 0., 0.)),
        })
        //.insert(Collider::cuboid(18.75 / SCALE, 23.4375 / SCALE))
        .insert(RigidBody::Dynamic)
        .with_children(|children| {
            children
                .spawn(Collider::cuboid(18.75 / SCALE, 23.4375 / SCALE))
                .insert(TransformBundle::from(Transform::from_xyz(
                    0.,
                    1.5625 / SCALE,
                    0.,
                )));
        })
        .insert(ExternalForce::default())
        .insert(ExternalImpulse::default())
        .insert(Velocity::default())
        .insert(ReadMassProperties::default());
}

fn on_message(
    mut commands: Commands,
    planet_query: Query<(Entity, &PlanetType, &Transform)>,
    mut part_query: Query<(Entity, &PartType, &mut Transform, &mut Velocity), (Without<PlanetType>, Without<Player>, Without<Attach>)>,
    mut attached_query: Query<(Entity, &PartType, &mut Transform, &Attach), (Without<PlanetType>, Without<Player>)>,
    mut player_query: Query<(Entity, &mut Player, &Transform, &Velocity, &mut Attach), Without<PlanetType>>,
    mut packet_recv: Local<ManualEventReader<ServerEvent>>,
    mut packet_event_send: ResMut<Events<ServerEvent>>,
) {
    let mut event_queue = Vec::new();
    for ev in packet_recv.read(&packet_event_send) {
        if let ServerEvent::Recv(addr, MessageType::Text, data) = ev {
            let data = String::from_utf8_lossy(&data);
            let packet: Packet = err_or_cont!(serde_json::from_str(&data));

            match packet {
                Packet::ClientLogin { username, .. } => {
                    let angle: f32 = {
                        let mut rng = rand::thread_rng();
                        rng.gen::<f32>() * std::f32::consts::PI * 2.
                    };
                    let mut transform = Transform::from_xyz(
                        angle.cos() * 1100.0 / SCALE,
                        angle.sin() * 1100.0 / SCALE,
                        0.0,
                    );
                    transform.rotate_z(angle);
                    let entity_id = commands
                        .spawn(PlayerBundle {
                            part: PartBundle {
                                part_type: PartType::Hearty,
                                transform: TransformBundle::from(transform),
                            },
                            player: Player {
                                addr: *addr,
                                username: username.to_string(),
                                input: component::Input::default(),
                                selected: None,
                            },
                            attach: Attach {
                                associated_player: None,
                                children: [None, None, None, None],
                            },
                        })
                        .insert(Collider::cuboid(
                            PART_HALF_SIZE / SCALE,
                            PART_HALF_SIZE / SCALE,
                        ))
                        .insert(AdditionalMassProperties::MassProperties(MassProperties {
                            local_center_of_mass: vec2(0.0, 0.0),
                            mass: 0.0001,
                            principal_inertia: 0.005,
                        }))
                        .insert(ExternalImpulse {
                            impulse: Vec2::ZERO,
                            torque_impulse: 0.0,
                        })
                        .insert(ExternalForce::default())
                        .insert(ReadMassProperties::default())
                        .insert(Velocity::default())
                        .insert(RigidBody::Dynamic).id();
                    let id = entity_id.index();

                    // tell this player the planets
                    let mut planets = Vec::new();
                    for (entity, planet_type, transform) in planet_query.iter() {
                        let translation = transform.translation;
                        planets.push((
                            entity.index(),
                            Planet {
                                planet_type: *planet_type,
                                transform: proto_transform!(Transform::from_translation(
                                    translation * SCALE
                                )),
                                radius: match *planet_type {
                                    PlanetType::Earth => EARTH_SIZE,
                                },
                            },
                        ));
                    }
                    let packet = Packet::PlanetPositions { planets };
                    let buf = serde_json::to_vec(&packet).unwrap();
                    event_queue.push(ServerEvent::Send(*addr, MessageType::Text, buf));

                    // tell the player already existing users
                    let mut players = Vec::new();
                    for (entity, player, _, _, _) in &player_query {
                        players.push((entity.index(), player.username.clone()));
                    }
                    let packet = Packet::PlayerList { players };
                    let buf = serde_json::to_vec(&packet).unwrap();
                    event_queue.push(ServerEvent::Send(*addr, MessageType::Text, buf));

                    // tell other players that a player has spawned in
                    let packet = Packet::SpawnPlayer {
                        id,
                        username: username.to_string(),
                    };
                    let buf = serde_json::to_vec(&packet).unwrap();
                    event_queue.push(ServerEvent::Broadcast(MessageType::Text, buf));
                    let packet = Packet::Message {
                        message_type: packet::MessageType::Server,
                        actor: "SERVER".to_string(),
                        content: format!("{} has joined the server!", username),
                    };
                    let buf = serde_json::to_vec(&packet).unwrap();
                    event_queue.push(ServerEvent::Broadcast(MessageType::Text, buf));

                    // tell the player where parts are
                    let mut parts = Vec::new();
                    for (entity, part_type, transform, _) in &part_query {
                        parts.push((
                            entity.index(),
                            Part {
                                part_type: *part_type,
                                transform: proto_transform!(Transform::from_translation(
                                    transform.translation * SCALE
                                )),
                            },
                        ));
                    }
                    for (entity, part_type, transform, _) in &attached_query {
                        parts.push((
                            entity.index(),
                            Part {
                                part_type: *part_type,
                                transform: proto_transform!(Transform::from_translation(
                                    transform.translation * SCALE
                                )),
                            },
                        ));
                    }
                    parts.push((
                        id,
                        Part {
                            part_type: PartType::Hearty,
                            transform: proto_transform!(Transform::from_translation(
                                transform.translation * SCALE
                            )
                            .with_rotation(transform.rotation)),
                        },
                    ));
                    let packet = Packet::PartPositions { parts };
                    let buf = serde_json::to_vec(&packet).unwrap();
                    event_queue.push(ServerEvent::Send(*addr, MessageType::Text, buf));

                    // and send the welcome message :)
                    let packet = Packet::Message {
                        message_type: packet::MessageType::Server,
                        actor: "SERVER".to_string(),
                        content: "Welcome to StarKingdoms.IO! Have fun!".to_string(),
                    };
                    let buf = serde_json::to_vec(&packet).unwrap();
                    event_queue.push(ServerEvent::Send(*addr, MessageType::Text, buf));
                }
                Packet::SendMessage { target, content } => {
                    // find our player
                    let mut player = None;
                    for (_, q_player, _, _, _) in &player_query {
                        if q_player.addr == *addr {
                            player = Some(q_player);
                        }
                    }
                    let player = player.unwrap();
                    if let Some(target_username) = target {
                        let mut target_player = None;
                        for (_, q_player, _, _, _) in &player_query {
                            if q_player.username == target_username {
                                target_player = Some(q_player);
                            }
                        }
                        let target_player = target_player.unwrap();
                        let packet = Packet::Message {
                            message_type: packet::MessageType::Direct,
                            actor: player.username.clone(),
                            content,
                        };
                        let buf = serde_json::to_vec(&packet).unwrap();
                        event_queue.push(ServerEvent::Send(
                            target_player.addr,
                            MessageType::Text,
                            buf.clone(),
                        ));
                        event_queue.push(ServerEvent::Send(*addr, MessageType::Text, buf));
                    } else {
                        // send to general chat
                        let packet = Packet::Message {
                            message_type: packet::MessageType::Chat,
                            actor: player.username.clone(),
                            content,
                        };
                        let buf = serde_json::to_vec(&packet).unwrap();
                        event_queue.push(ServerEvent::Broadcast(MessageType::Text, buf));
                    }
                }
                Packet::PlayerInput {
                    up,
                    down,
                    left,
                    right,
                } => {
                    for (_, mut q_player, _, _, _) in &mut player_query {
                        if q_player.addr == *addr {
                            q_player.input.up = up;
                            q_player.input.down = down;
                            q_player.input.left = left;
                            q_player.input.right = right;
                        }
                    }
                }
                Packet::PlayerMouseInput { x, y, released, button: _ } => {
                    for (entity, mut q_player, transform, velocity, mut attach) in &mut player_query {
                        if q_player.addr == *addr {
                            if released {
                                let select = if let Some(s) = q_player.selected { s } else {
                                    break;
                                };
                                q_player.selected = None;
                                let mut module = part_query.get_mut(select).unwrap();
                                // attach module
                                let p_pos = transform.translation;
                                let (rel_x, rel_y) = (
                                    p_pos.x - x / SCALE,
                                    p_pos.y - y / SCALE,
                                );
                                let angle = transform.rotation.to_euler(EulerRot::ZYX).0;
                                let (rel_x, rel_y) = (
                                    rel_x * (-angle).cos() - rel_y * (-angle).sin(),
                                    rel_x * (-angle).sin() + rel_y * (-angle).cos(),
                                );

                                if 15./SCALE < rel_y && rel_y < 30./SCALE && -20./SCALE < rel_x && rel_x < 20./SCALE {
                                    module.2.translation = vec3(p_pos.x + 53./SCALE*angle.sin(), p_pos.y - 53./SCALE*angle.cos(), 0.);
                                    module.2.rotation = Quat::from_euler(EulerRot::ZYX, angle, 0., 0.);
                                    module.3.linvel = velocity.linvel;
                                    let joint = FixedJointBuilder::new().local_anchor1(vec2(0. / SCALE, -53. / SCALE));
                                    let mut module_entity = commands.entity(module.0);
                                    module_entity.insert(ImpulseJoint::new(entity, joint));
                                    attach.children[2] = Some(module.0);
                                    break;
                                } else if -30./SCALE < rel_y && rel_y < -15./SCALE && -20./SCALE < rel_x && rel_x < 20./SCALE {
                                    module.2.translation = vec3(p_pos.x - 53./SCALE*angle.sin(), p_pos.y + 53./SCALE*angle.cos(), 0.);
                                    module.2.rotation = Quat::from_euler(EulerRot::ZYX, angle + std::f32::consts::PI, 0., 0.);
                                    module.3.linvel = velocity.linvel;
                                    let joint = FixedJointBuilder::new().local_anchor1(vec2(0. / SCALE, 53. / SCALE));
                                    let mut module_entity = commands.entity(module.0);
                                    module_entity.insert(ImpulseJoint::new(entity, joint));
                                    attach.children[0] = Some(module.0);
                                    break;
                                } else if -30./SCALE < rel_x && rel_x < -15./SCALE && -20./SCALE < rel_y && rel_y < 20./SCALE {
                                    module.2.translation = vec3(p_pos.x + 53./SCALE*angle.cos(), p_pos.y + 53./SCALE*angle.sin(), 0.);
                                    module.2.rotation = Quat::from_euler(EulerRot::ZYX, angle + (std::f32::consts::PI/2.), 0., 0.);
                                    module.3.linvel = velocity.linvel;
                                    let joint = FixedJointBuilder::new()
                                        .local_anchor1(vec2(53. / SCALE, 0. / SCALE))
                                        .local_basis2(std::f32::consts::PI/2.);
                                    let mut module_entity = commands.entity(module.0);
                                    module_entity.insert(ImpulseJoint::new(entity, joint));
                                    attach.children[1] = Some(module.0);
                                    break;
                                } else if 15./SCALE < rel_x && rel_x < 30./SCALE && -20./SCALE < rel_y && rel_y < 20./SCALE {
                                    module.2.translation = vec3(p_pos.x - 53./SCALE*angle.cos(), p_pos.y - 53./SCALE*angle.sin(), 0.);
                                    module.2.rotation = Quat::from_euler(EulerRot::ZYX, angle - (std::f32::consts::PI/2.), 0., 0.);
                                    module.3.linvel = velocity.linvel;
                                    let joint = FixedJointBuilder::new()
                                        .local_anchor1(vec2(-53. / SCALE, 0. / SCALE))
                                        .local_basis2(-std::f32::consts::PI/2.);
                                    let mut module_entity = commands.entity(module.0);
                                    module_entity.insert(ImpulseJoint::new(entity, joint));
                                    attach.children[1] = Some(module.0);
                                    break;
                                }
                                module.2.translation = vec3(x / SCALE, y / SCALE, 0.);
                                break;
                            }
                            for (entity, part_type, transform, _) in &part_query {
                                let pos = transform.translation;
                                let rel_x = pos.x - x / SCALE;
                                let rel_y = pos.y - y / SCALE;
                                let angle = -transform.rotation.z;
                                let x = rel_x*angle.cos() - rel_y*angle.sin();
                                let y = rel_x*angle.sin() + rel_y*angle.cos();
                                let mut bound = [-25. / SCALE, 25. / SCALE, -25. / SCALE, 25. / SCALE]; // left, right, top, bottom
                                if let PartType::Cargo = part_type {
                                    bound = [-18.75 / SCALE, 18.75 / SCALE, -25. / SCALE, 21.875 / SCALE];
                                }

                                if bound[0] < x && x < bound[1] {
                                    if bound[2] < y && y < bound[3] {
                                        q_player.selected = Some(entity);
                                        break;
                                    }
                                }
                            }
                        }
                    }
                }
                _ => continue,
            }
        }
    }
    for event in event_queue {
        packet_event_send.send(event);
    }
}

fn on_close(
    player_query: Query<(Entity, &Player, &Attach)>,
    attached_query: Query<&Attach, With<PartType>>,
    part_query: Query<&PartType>,
    mut commands: Commands,
    mut packet_recv: Local<ManualEventReader<ServerEvent>>,
    mut packet_send: ResMut<Events<ServerEvent>>,
) {
    let mut packets = Vec::new();
    for packet in packet_recv.read(&packet_send) {
        if let ServerEvent::Close(addr) = packet {
            for (entity, player, attach) in &player_query {
                if player.addr == *addr {
                    despawn_module_tree(&mut commands, attach, &attached_query, &part_query);
                    commands.entity(entity).despawn_recursive();

                    let packet = Packet::PlayerLeave { id: entity.index() };
                    let buf = serde_json::to_vec(&packet).unwrap();
                    for (in_entity, player, _) in &player_query {
                        if entity != in_entity {
                            packets.push(ServerEvent::Send(
                                player.addr,
                                MessageType::Text,
                                buf.clone(),
                            ));
                        }
                    }
                }
            }
        }
    }
    for packet in packets {
        packet_send.send(packet);
    }
}

fn despawn_module_tree(
    commands: &mut Commands,
    attach: &Attach,
    attached_query: &Query<&Attach, With<PartType>>,
    part_query: &Query<&PartType>,
) {
    for child in attach.children {
        if let Some(child) = child {
            commands.entity(child).despawn_recursive();
            let attach = match attached_query.get(child) {
                Ok(s) => s,
                Err(_) => {
                    match part_query.get(child) {
                        Ok(_) => {
                            continue;
                        }
                        Err(e) => panic!("{}", e)
                    }
                }
            };
            despawn_module_tree(commands, attach, attached_query, part_query);
        }
    }
}

fn on_position_change(
    mut commands: Commands,
    part_query: Query<(Entity, &PartType, &Transform), Changed<Transform>>,
    planet_query: Query<(Entity, &PlanetType, &Transform), Changed<Transform>>,
    mut packet_send: EventWriter<ServerEvent>,
) {
    let mut updated_parts = Vec::new();
    for (entity, part_type, transform) in part_query.iter() {
        let id = commands.entity(entity).id().index();
        updated_parts.push((
            id,
            Part {
                part_type: *part_type,
                transform: proto_transform!(Transform::from_translation(
                    transform.translation * SCALE
                )
                .with_rotation(transform.rotation)),
            },
        ));
    }

    if !updated_parts.is_empty() {
        let packet = Packet::PartPositions {
            parts: updated_parts,
        };
        let buf = serde_json::to_vec(&packet).unwrap();

        packet_send.send(ServerEvent::Broadcast(MessageType::Text, buf));
    }

    let mut planets = Vec::new();
    for (entity, planet_type, transform) in planet_query.iter() {
        let id = commands.entity(entity).id().index();
        planets.push((
            id,
            Planet {
                planet_type: *planet_type,
                transform: proto_transform!(Transform::from_translation(
                    transform.translation * SCALE
                )),
                radius: match *planet_type {
                    PlanetType::Earth => EARTH_SIZE,
                },
            },
        ));
    }

    if !planets.is_empty() {
        let packet = Packet::PlanetPositions { planets };
        let buf = serde_json::to_vec(&packet).unwrap();

        packet_send.send(ServerEvent::Broadcast(MessageType::Text, buf));
    }
}

fn player_input_update(
    mut player_and_body_query: Query<(Entity, &mut Player, &mut ExternalForce, &Transform)>,
) {
    for (_, player, mut forces, transform) in &mut player_and_body_query {
        forces.torque = 0.0;
        forces.force = Vec2::ZERO;
        if !(player.input.up || player.input.down || player.input.right || player.input.left) {
            continue;
        }

        let mut fmul_bottom_left_thruster: f32 = 0.0;
        let mut fmul_bottom_right_thruster: f32 = 0.0;
        let mut fmul_top_left_thruster: f32 = 0.0;
        let mut fmul_top_right_thruster: f32 = 0.0;
        if player.input.up {
            fmul_bottom_left_thruster += 1.0;
            fmul_bottom_right_thruster += 1.0;
        }
        if player.input.down {
            fmul_top_left_thruster -= 1.0;
            fmul_top_right_thruster -= 1.0;
        }
        if player.input.left {
            fmul_top_left_thruster += 1.0;
            fmul_bottom_right_thruster -= 1.0;
        }
        if player.input.right {
            fmul_top_right_thruster += 1.0;
            fmul_bottom_left_thruster -= 1.0;
        }
        fmul_top_left_thruster = fmul_top_left_thruster.clamp(-1.0, 1.0);
        fmul_top_right_thruster = fmul_top_right_thruster.clamp(-1.0, 1.0);
        fmul_bottom_left_thruster = fmul_bottom_left_thruster.clamp(-1.0, 1.0);
        fmul_bottom_right_thruster = fmul_bottom_right_thruster.clamp(-1.0, 1.0);
        if player.input.up {
            fmul_bottom_left_thruster -= 60.0;
            fmul_bottom_right_thruster -= 60.0;
        }
        if player.input.down {
            fmul_top_left_thruster += 60.0;
            fmul_top_right_thruster += 60.0;
        }

        let rot = transform.rotation.to_euler(EulerRot::ZYX).0;

        let thrusters = [
            (fmul_bottom_left_thruster, -PART_HALF_SIZE, -PART_HALF_SIZE),
            (fmul_bottom_right_thruster, PART_HALF_SIZE, -PART_HALF_SIZE),
            (fmul_top_left_thruster, -PART_HALF_SIZE, PART_HALF_SIZE),
            (fmul_top_right_thruster, PART_HALF_SIZE, PART_HALF_SIZE),
        ];

        for (force_multiplier, x_offset, y_offset) in thrusters {
            if force_multiplier != 0.0 {
                let thruster_pos_uncast = vec2(x_offset / SCALE, y_offset / SCALE);
                let thruster_pos_cast =
                    rot2d(thruster_pos_uncast, rot) + transform.translation.xy();
                let thruster_force = force_multiplier * THRUSTER_FORCE;
                let thruster_vec = vec2(
                    -thruster_force / SCALE * rot.sin(),
                    thruster_force / SCALE * rot.cos(),
                );
                let thruster_force = ExternalForce::at_point(
                    thruster_vec,
                    thruster_pos_cast,
                    transform.translation.xy(),
                );
                forces.force += thruster_force.force;
                forces.torque += thruster_force.torque;
            }
        }
    }
}

fn gravity_update(
    mut part_query: Query<(&Transform, &ReadMassProperties, &mut ExternalImpulse), With<PartType>>,
    planet_query: Query<(&Transform, &ReadMassProperties), With<PlanetType>>,
) {
    for (part_transform, part_mp, mut impulses) in &mut part_query {
        impulses.impulse = Vec2::ZERO;
        let part_mp = part_mp.get();
        let part_mass = part_mp.mass;
        let part_translate = part_transform.translation;
        for (planet_transform, planet_mp) in &planet_query {
            let planet_mp = planet_mp.get();
            let planet_mass = planet_mp.mass;
            let planet_translate = planet_transform.translation;
            let distance = planet_translate.distance(part_translate);
            let force = GRAVITY * ((part_mass * planet_mass) / (distance * distance));
            let direction = (planet_translate - part_translate).normalize() * force;
            impulses.impulse += direction.xy();
        }
    }
}